Free to Read
Access by Xinjiang University

The Galactic Center massive black hole and nuclear star cluster

Reinhard Genzel^*, Frank Eisenhauer, and Stefan Gillessen

Max-Planck Institut für Extraterrestrische Physik, 85748 Garching, Germany

^*Also at Department of Physics, University of California, Berkeley, CA 94720.

Rev. Mod. Phys. 82, 3121 – Published 20 December, 2010

DOI: https://doi.org/10.1103/RevModPhys.82.3121

Abstract

The Galactic Center is an excellent laboratory for studying phenomena and physical processes that may be occurring in many other galactic nuclei. The center of our Milky Way is by far the closest galactic nucleus, and observations with exquisite resolution and sensitivity cover 18 orders of magnitude in energy of electromagnetic radiation. Theoretical simulations have become increasingly more powerful in explaining these measurements. This review summarizes the recent progress in observational and theoretical work on the central parsec, with a strong emphasis on the current empirical evidence for a central massive black hole and on the processes in the surrounding dense nuclear star cluster. Current evidence is presented, from the analysis of the orbits of more than two dozen stars and from the measurements of the size and motion of the central compact radio source, Sgr $A *$ , that this radio source must be a massive black hole of about $4.4 \times 10^{6} M_{☉}$ , beyond any reasonable doubt. What is known about the structure and evolution of the dense nuclear star cluster surrounding this black hole is reported, including the astounding fact that stars have been forming in the vicinity of Sgr $A *$ recently, apparently with a top-heavy stellar-mass function. A dense concentration of fainter stars centered in the immediate vicinity of the massive black hole are discussed, three of which have orbital peri-bothroi of less than one light day. This “S-star cluster” appears to consist mainly of young early-type stars, in contrast to the predicted properties of an equilibrium “stellar cusp” around a black hole. This constitutes a remarkable and presently not fully understood “paradox of youth.” What is known about the emission properties of the accreting gas onto Sgr $A *$ is also summarized and how this emission is beginning to delineate the physical properties in the hot accretion zone around the event horizon.

Article Text

References (565)

Abadi, M. G., et al., 2009, “An alternative origin for hypervelocity stars,” Astrophys. J. Lett. 691, L63.
Abramowicz, M. A., et al., 2002, “No observational proof of the black-hole event-horizon,” Astron. Astrophys. 396, L31.
Acero, F., et al., 2009, “Localizing the VHE gamma-ray source at the galactic centre,” Mon. Not. R. Astron. Soc.402, 1915.
Afflerbach, A., et al., 1997, “Galactic abundance gradients from infrared fine-structure lines in compact H II regions,” Astrophys. J. 478, 190.
Agol, E., 2000, “Sagittarius $A *$ polarization: No advection-dominated accretion flow, low accretion rate, and nonthermal synchrotron emission,” Astrophys. J. 538, L121.
Aharonian, F., and A. Neronov, 2005, “High-energy gamma rays from the massive black hole in the galactic center,” Astrophys. J. 619, 306.
Aharonian, F., et al., 2004, “Very high energy gamma rays from the direction of Sagittarius $A *$ ,” Astron. Astrophys. 425, L13.
Aharonian, F., et al., 2008, “Simultaneous HESS and Chandra observations of Sagittarius Astar during an x-ray flare,” Astron. Astrophys. 492, L25.
Aitken, D. K., et al., 1991, “Polarimetric imaging of the galactic center at $12.4 microns$ —The detailed magnetic field structure in the northern arm and the east-west bar,” Astrophys. J. 380, 419.
Aitken, D. K., et al., 2000, “Detection of polarized millimeter and submillimeter emission from Sagittarius $A *$ ,” Astrophys. J. 534, L173.
Albert, J., et al., 2006, “Observation of gamma rays from the galactic center with the MAGIC telescope,” Astrophys. J. 638, L101.
Alexander, R. D., et al., 2008a, “Self-gravitating fragmentation of eccentric accretion disks,” Astrophys. J. 674, 927.
Alexander, R. D., et al., 2008b, “Binary formation and mass function variations in fragmenting discs with short cooling times,” Mon. Not. R. Astron. Soc. 389, 1655.
Alexander, T., 1999, “The distribution of stars near the supermassive black hole in the galactic center,” Astrophys. J. 527, 835.
Alexander, T., 2005, “Stellar processes near the massive black hole in the galactic center,” Phys. Rep. 419, 65.
Alexander, T., 2007, “Stellar relaxation processes near the galactic massive black hole,” e-print arXiv:0708.0688.
Alexander, T., 2010, “Key questions about galactic center dynamics,” e-print arXiv:1007.4991.
Alexander, T., and C. Hopman, 2009, “Strong mass segregation around a massive black hole,” Astrophys. J. 697, 1861.
Alexander, T., and M. Livio, 2004, “Orbital capture of stars by a massive black hole via exchanges with compact remnants,” Astrophys. J. Lett. 606, L21.
Allen, D. A., and M. Burton, 1994, “The population I core of the Galaxy,” Proc. Astron. Soc. Aust. 11, 191.
Allen, D. A., and R. H. Sanders, 1986, “Is the galactic centre black hole a dwarf?,” Nature (London) 319, 191.
Allen, D. A., et al., 1990, “The source of luminosity at the galactic centre,” Mon. Not. R. Astron. Soc. 244, 706.
Aloisio, R., et al., 2004, “Neutralino annihilation at the galactic centre revisited,” J. Cosmol. Astropart. Phys. 2004, 007.
Amin, M. A., and T. Wizansky, 2008, “Relativistic dark matter at the galactic center,” Phys. Rev. D 77, 123510.
Angelil, R., and P. Saha, 2010, “Relativistic redshift effects and the galactic-center stars,” Astrophys. J. 711, 157.
Aschenbach, B., et al., 2004, “X-ray flares reveal mass and angular momentum of the galactic center black hole,” Astron. Astrophys. 417, 71.
Asplund, M., et al., 2005, The Solar Chemical Composition: Cosmic Abundances as Records of Stellar Evolution and Nucleosynthesis in Honor of David L. Lambert (ASP, San Francisco), Vol. 336, pp. 25.
Atoyan, A., and C. D. Dermer, 2004, “TeV emission from the galactic center black hole plerion,” Astrophys. J. Lett. 617, L123.
Baade, W., 1951, Galaxies—Present Day Problems (Observatory of Michigan), Vol. 10.
Babusiaux, C., and G. Gilmore, 2005, “The structure of the galactic bar,” Mon. Not. R. Astron. Soc. 358, 1309.
Backer, D. C., and R. A. Sramek, 1999, “Proper motion of the compact, nonthermal radio source in the galactic center, Sagittarius $A *$ ,” Astrophys. J. 524, 805.
Baganoff, F. K., 2003, “Multiwavelength monitoring of Sgr $A *$ during Chandra observations of multiple x-ray flares,” Bull. Am. Astron. Soc. 7, 606.
Baganoff, F. K., et al., 2001, “Rapid x-ray flaring from the direction of the supermassive black hole at the galactic centre,” Nature (London) 413, 45.
Baganoff, F. K., et al., 2003, “Chandra x-ray spectroscopic imaging of Sagittarius $A *$ and the central parsec of the Galaxy,” Astrophys. J. 591, 891.
Bahcall, J. N., and S. Tremaine, 1981, “Methods for determining the masses of spherical systems. I—Test particles around a point mass,” Astrophys. J. 244, 805.
Bahcall, J. N., and R. A. Wolf, 1976, “Star distribution around a massive black hole in a globular cluster,” Astrophys. J. 209, 214.
Bahcall, J. N., and R. A. Wolf, 1977, “The star distribution around a massive black hole in a globular cluster. II. Unequal star masses,” Astrophys. J. 216, 883.
Bailey, V. C., and M. B. Davies, 1999, “Red giant collisions in the galactic centre,” Mon. Not. R. Astron. Soc. 308, 257.
Balick, B., and R. L. Brown, 1974, “Intense sub-arcsecond structure in the galactic center,” Astrophys. J. 194, 265.
Ball, G. H., et al., 2001, “Spectral models of convection-dominated accretion flows,” Astrophys. J. 552, 221.
Bar-Or, B., et al., 2010, unpublished.
Bartko, H., 2010, private communication.
Bartko, H., et al., 2009, “Evidence for warped disks of young stars in the galactic center,” Astrophys. J. 697, 1741.
Bartko, H., et al., 2010, “An extremely top-heavy initial mass function in the galactic center stellar disks,” Astrophys. J. 708, 834.
Baumgardt, H., et al., 2006, “Ejection of hypervelocity stars from the galactic centre by intermediate-mass black holes,” Mon. Not. R. Astron. Soc. 372, 174.
Becklin, E. E., and G. Neugebauer, 1968, “Infrared observations of the galactic center,” Astrophys. J. 151, 145.
Becklin, E. E., and G. Neugebauer, 1975, “High-resolution maps of the galactic center at 2.2 and $10 microns$ ,” Astrophys. J. Lett. 200, L71.
Becklin, E. E., et al., 1978, “Infrared observations of the galactic center. I—Nature of the compact sources,” Astrophys. J. 219, 121.
Becklin, E. E., et al., 1982, “Far-infrared observations of Sagittarius A—The luminosity and dust density in the central parsec of the Galaxy,” Astrophys. J. 258, 135.
Belanger, G., et al., 2004, “Detection of hard x-ray emission from the galactic nuclear region with integral,” Astrophys. J. Lett. 601, L163.
Belanger, G., et al., 2005, “Repeated x-ray flaring activity in Sagittarius $A *$ ,” Astrophys. J. 635, 1095.
Belanger, G., et al., 2006, “Periodic modulations in an x-ray flare from Sagittarius $A *$ ,” J. Phys.: Conf. Ser. 54, 420.
Beloborodov, A. M., and Y. Levin, 2004, “Orbital roulette: A new method of gravity estimation from observed motions,” Astrophys. J. 613, 224.
Beloborodov, A. M., et al., 2006, “Clockwise stellar disk and the dark mass in the galactic center,” Astrophys. J. 648, 405.
Bender, R., et al., 2005, “HST STIS spectroscopy of the triple nucleus of M31: Two nested disks in Keplerian rotation around a supermassive black hole,” Astrophys. J. 631, 280.
Bergström, L., 2000, “Non-baryonic dark matter: Observational evidence and detection methods,” Rep. Prog. Phys. 63, 793.
Berukoff, S. J., and B. M. S. Hansen, 2006, “Cluster core dynamics in the galactic center,” Astrophys. J. 650, 901.
Bica, E., et al., 2006, “Globular cluster system and Milky Way properties revisited,” Astron. Astrophys. 450, 105.
Binney, J., 2009, “The bulge-disc connection in the Milky Way,” The Galaxy Disk in Cosmological Context, Proceedings of the International Astronomical Union, edited by J. Andersen , IAU Symposium Vol. 254 (Cambridge University Press, Cambridge), p. 145.
Binney, J., and S. Tremaine, 2008, Galactic Dynamics, 2nd ed. (Princeton University Press, Princeton).
Blanco, V. M., 1985, “The distance to the galactic center,” Bull. Am. Astron. Soc. 17, 562.
Blandford, R. D., and M. C. Begelman, 1999, “On the fate of gas accreting at a low rate on to a black hole,” Mon. Not. R. Astron. Soc. 303, L1.
Blitz, L., et al., 1993, “The centre of the Milky Way,” Nature (London) 361, 417.
Blum, R. D., et al., 1995, “A comparison of near-infrared spectra of the galactic center compact He I emission-line sources and early-type mass-losing stars,” Astrophys. J. 441, 603.
Blum, R. D., et al., 1996, “JHKL photometry and the K-band luminosity function at the galactic center,” Astrophys. J. 470, 864.
Blum, R. D., et al., 2003, “Really cool stars and the star formation history at the galactic center,” Astrophys. J. 597, 323.
Boehm, C., et al., 2004, “MeV dark matter: Has it been detected?,” Phys. Rev. Lett. 92, 101301.
Bonnell, I. A., and W. K. M. Rice, 2008, “Star formation around supermassive black holes,” Science 321, 1060.
Bower, G. C., et al., 1999a, “The linear polarization of Sagittarius $A *$ . II. VLA and BIMA polarimetry at 22, 43, and $86 GHz$ ,” Astrophys. J. 527, 851.
Bower, G. C., et al., 1999b, “The linear polarization of Sagittarius $A *$ . I. VLA spectropolarimetry at 4.8 and $8.4 GHZ$ ,” Astrophys. J. 521, 582.
Bower, G. C., et al., 1999c, “Detection of circular polarization in the galactic center black hole candidate Sagittarius $A *$ ,” Astrophys. J. Lett. 523, L29.
Bower, G. C., et al., 2004, “Detection of the intrinsic size of Sagittarius $A *$ through closure amplitude imaging,” Science 304, 704.
Bower, G. C., et al., 2006, “The intrinsic size of Sagittarius $A *$ from $0.35 to 6 cm$ ,” Astrophys. J. Lett. 648, L127.
Broderick, A. E., and A. Loeb, 2006, “Imaging optically-thin hotspots near the black hole horizon of Sgr $A *$ at radio and near-infrared wavelengths,” Mon. Not. R. Astron. Soc. 367, 905.
Broderick, A. E., and R. Narayan, 2006, “On the nature of the compact dark mass at the galactic center,” Astrophys. J. Lett. 638, L21.
Broderick, A. E., et al., 2009a, “The event horizon of Sagittarius $A *$ ,” Astrophys. J. 701, 1357.
Broderick, A. E., et al., 2009b, “Estimating the parameters of Sagittarius $A *$ ’s accretion flow via millimeter VLBI,” Astrophys. J. 697, 45.
Brown, R. L., and K. Y. Lo, 1982, “Variability of the compact radio source at the galactic center,” Astrophys. J. 253, 108.
Brown, W. R., 2008, “Hypervelocity stars and the galactic center,” e-print arXiv:0811.0571.
Brown, W. R., et al., 2005, “Discovery of an unbound hypervelocity star in the Milky Way halo,” Astrophys. J. Lett. 622, L33.
Brown, W. R., et al., 2006a, “Hypervelocity stars. I. The spectroscopic survey,” Astrophys. J. 647, 303.
Brown, W. R., et al., 2006b, “A successful targeted search for hypervelocity stars,” Astrophys. J. Lett. 640, L35.
Brown, W. R., et al., 2009a, “The anisotropic spatial distribution of hypervelocity stars,” Astrophys. J. Lett. 690, L69.
Brown, W. R., et al., 2009b, “MMT hypervelocity star survey,” Astrophys. J. 690, 1639.
Brown, W. R., et al., 2010, “A galactic origin for HE 0437-5439, the hypervelocity star near the Large Magellanic Cloud,” Astrophys. J. Lett. 719, L23.
Buchholz, R. M., et al., 2009, “Composition of the galactic center star cluster. Population analysis from adaptive optics narrow band spectral energy distributions,” Astron. Astrophys. 499, 483.
Burton, M., and D. A. Allen, 1992, “Imaging the hot molecular gas at the centre of the Galaxy,” Proc. Astron. Soc. Aust. 10, 55.
Carney, B. W., et al., 1995, “The distance to the galactic center obtained by infrared photometry of RR Lyrae variables,” Astron. J. 110, 1674.
Carr, J. S., et al., 2000, “The first stellar abundance measurements in the galactic center: The M Supergiant IRS 7,” Astrophys. J. 530, 307.
Catchpole, R. M., et al., 1990, “The distribution of stars within two degrees of the galactic centre,” Mon. Not. R. Astron. Soc. 247, 479.
Cesarini, A., et al., 2004, “The galactic center as a dark matter gamma-ray source,” Astropart. Phys. 21, 267.
Chabrier, G., 2001, “The galactic disk mass budget. I. Stellar mass function and density,” Astrophys. J. 554, 1274.
Chakrabarty, D., and P. Saha, 2001, “A nonparametric estimate of the mass of the central black hole in the Galaxy,” Astron. J. 122, 232.
Chan, C.-k., et al., 2009, “MHD simulations of accretion onto Sgr $A *$ : Quiescent fluctuations, outbursts, and quasiperiodicity,” Astrophys. J. 701, 521.
Chang, P., 2009, “The effectiveness of the Kozai mechanism in the galactic centre,” Mon. Not. R. Astron. Soc. 393, 224.
Chapline, G., 2005, “Dark energy stars,” in Proceedings of the 22nd Texas Symposium on Relativistic Astrophysics at Stanford, edited by P. Chen, E. Bloom, G. Madejski, and V. Patrosian (Stanford University, Stanford, CA), p. 101.
Chatterjee, P., et al., 2002, “Dynamics of a massive black hole at the center of a dense stellar system,” Astrophys. J. 572, 371.
Christopher, M. H., et al., 2005, “HCN and $H C O + observations$ of the galactic circumnuclear disk,” Astrophys. J. 622, 346.
Clenet, Y., et al., 2004, “Detection of the Sgr $A *$ activity at 3.8 and $4.8 μ m$ with NACO,” Astron. Astrophys. 424, L21.
Cohn, H., and R. M. Kulsrud, 1978, “The stellar distribution around a black hole—Numerical integration of the Fokker-Planck equation,” Astrophys. J. 226, 1087.
Coker, R. F., and F. Melia, 1997, “Hydrodynamical accretion onto Sagittarius $A *$ from distributed point sources,” Astrophys. J. Lett. 488, L149.
Coker, R. F., et al., 2002, “The galactic centre source IRS 13E: A post-LBV Wolf-Rayet colliding wind binary?,” Astron. Astrophys. 383, 568.
Collin, S., and J.-M. Hure, 1999, “Influence of the metallicity and of the irradiation on the structure of accretion disks around massive black holes,” Astron. Astrophys. 341, 385.
Collin, S., and J.-P. Zahn, 1999, “Star formation and evolution in accretion disks around massive black holes,” Astron. Astrophys. 344, 433.
Cotera, A., et al., 1999, “Mid-infrared imaging of the central parsec with Keck,” in The Central Parsecs of the Galaxy, edited by H. Falcke , ASP Conf. Ser. Vol. 186 (ASP, San Francisco), p. 240.
Crawford, M. K., et al., 1985, “Mass distribution in the galactic centre,” Nature (London) 315, 467.
Cuadra, J., et al., 2008a, “Variable accretion and emission from the stellar winds in the galactic centre,” Mon. Not. R. Astron. Soc. 383, 458.
Cuadra, J., et al., 2008b, “Stellar dynamical evidence against a cold disc origin for stars in the galactic centre,” Mon. Not. R. Astron. Soc. 388, L64.
Cunha, K., et al., 2007, “Chemical abundances of luminous cool stars in the galactic center from high-resolution infrared spectroscopy,” Astrophys. J. 669, 1011.
Dale, J. E., et al., 2009, “Red giant stellar collisions in the galactic centre,” Mon. Not. R. Astron. Soc. 393, 1016.
Dambis, A. K., 2009, “The kinematics and zero-point of the $\log P$ -⟨MK⟩ relation for galactic RR Lyrae variables via statistical parallax,” Mon. Not. R. Astron. Soc. 396, 553.
Davidson, J. A., et al., 1992, “The luminosity of the galactic center,” Astrophys. J. 387, 189.
Davies, B., et al., 2009, “The chemical abundances in the galactic center from the atmospheres of red supergiants,” Astrophys. J. 694, 46.
Davies, M. B., and A. King, 2005, “The stars of the galactic center,” Astrophys. J. Lett. 624, L25.
Davies, M. B., et al. 2010a, “The impact of stellar collisions in the galactic center,” e-print arXiv:1002.0338.
Davies, R. I., et al., 2010b, “Science and adaptive optics requirements of MICADO, the E-ELT adaptive optics imaging camera,” Proceedings of the 1st AO4ELT Conference—Adaptative Optics for Extremely Large Telescopes (unpublished), p. 1002.
Delplancke, F., 2008, “The PRIMA facility phase-referenced imaging and micro-arcsecond astrometry,” New Astron. Rev. 52, 199.
Dent, W. R. F., et al., 1993, “Sub-millimeter continuum emission from the galactic center region,” Astrophys. J. 410, 650.
de Vaucouleurs, G., 1983, “The galaxy as fundamental calibrator of the extragalactic distance scale. I—The basic scale factors of the galaxy and two kinematic tests of the long and short distance scales,” Astrophys. J. 268, 451.
Dexter, J., et al., 2009, “Millimeter flares and VLBI visibilities from relativistic simulations of magnetized accretion onto the galactic center black hole,” Astrophys. J. Lett. 703, L142.
Dexter, J., et al., 2010, “The submillimeter bump in Sgr $A *$ from relativistic MHD simulations,” Astrophys. J. 717, 1092.
Do, T., et al., 2009a, “High angular resolution integral-field spectroscopy of the Galaxy’s nuclear cluster: A missing stellar cusp?,” Astrophys. J. 703, 1323.
Do, T., et al., 2009b, “A Near-infrared variability study of the galactic black hole: A red noise source with NO detected periodicity,” Astrophys. J. 691, 1021.
Dodds-Eden, K., et al., 2009, “Evidence for x-ray synchrotron emission from simultaneous mid-infrared to x-ray observations of a strong Sgr $A *$ flare,” Astrophys. J. 698, 676.
Dodds-Eden, K., et al., 2010a, “The two states of Sgr $A *$ in the near-infrared: Bright episodic flares on top of low-level continuous variability,” e-print arXiv:1008.1984.
Dodds-Eden, K., et al., 2010b, “Time dependent models of flares from Sagittarius $A *$ ,” e-print arXiv:1005.0389.
Doeleman, S. S., et al., 2001, “Structure of Sagittarius $A *$ at $86 GHZ$ using VLBI closure quantities,” Astron. J. 121, 2610.
Doeleman, S. S., et al., 2008, “Event-horizon-scale structure in the supermassive black hole candidate at the galactic centre,” Nature (London) 455, 78.
Dorband, E. N., et al., 2003, “Systolic and hyper-systolic algorithms for the gravitational N-body problem, with an application to Brownian motion,” J. Comput. Phys. 185, 484.
Draine, B. T., 1989, “Interstellar extinction in the infrared,” Eur. Space Agency, [Spec. Publ.] ESA SP 290, 93.
Draine, B. T., 2003, “Interstellar dust grains,” Annu. Rev. Astron. Astrophys. 41, 241.
Dray, L. M., et al., 2006, “Young stars in the galactic centre: A potential intermediate-mass star origin,” Mon. Not. R. Astron. Soc. 372, 31.
Eckart, A., and R. Genzel, 1996, “Observations of stellar proper motions near the galactic centre,” Nature (London) 383, 415.
Eckart, A., and R. Genzel, 1997, “Stellar proper motions in the central $0.1 pc$ of the Galaxy,” Mon. Not. R. Astron. Soc. 284, 576.
Eckart, A., et al., 1993, “Near-infrared $0.15 arcsec$ resolution imaging of the galactic center,” Astrophys. J. Lett. 407, L77.
Eckart, A., et al., 2002, “Stellar orbits near Sagittarius $A *$ ,” Mon. Not. R. Astron. Soc. 331, 917.
Eckart, A., et al., 2004, “First simultaneous NIR/x-ray detection of a flare from Sgr $A *$ ,” Astron. Astrophys. 427, 1.
Eckart, A., et al., 2005, The Black Hole at the Center of the Milky Way (Imperial College Press, London).
Eckart, A., et al., 2006a, “The flare activity of Sagittarius $A *$ . New coordinated mm to x-ray observations,” Astron. Astrophys. 450, 535.
Eckart, A., et al., 2006b, “Polarimetry of near-infrared flares from Sagittarius $A *$ ,” Astron. Astrophys. 455, 1.
Eckart, A., et al., 2008a, “Simultaneous NIR/sub-mm observation of flare emission from Sagittarius $A *$ ,” Astron. Astrophys. 492, 337.
Eckart, A., et al., 2008b, “Polarized NIR and x-ray flares from Sagittarius $A *$ ,” Astron. Astrophys. 479, 625.
Eisenhauer, F., et al., 2003, “A geometric determination of the distance to the galactic center,” Astrophys. J. Lett. 597, L121.
Eisenhauer, F., et al., 2005, “SINFONI in the galactic center: Young stars and infrared flares in the central light-month,” Astrophys. J. 628, 246.
Eisenhauer, F., et al., 2008, “Gravity: Getting to the event horizon of Sgr $A *$ ,” in Optical and Infrared Interferometry, edited by M. Schöller, W. C. Danchi, and F. Delplancke (SPIE, Bellingham, WA), Vol. 7013, p. 69.
Ekers, R. D., et al., 1983, “The radio structure of SGR A,” Astron. Astrophys. 122, 143.
Espinoza, P., et al., 2009, “The massive star initial mass function of the Arches cluster,” Astron. Astrophys. 501, 563.
Falcke, H., 1999, “Radio variablilty of Sgr $A *$ at centimeter wavelengths,” in The Central Parsecs of the Galaxy, edited by H. Falcke, A. Cotera, W. J. Duschl, F. Melia, and M. J. Rieke (ASP, San Francisco), p. 113.
Falcke, H., and S. Markoff, 2000, “The jet model for Sgr $A *$ : Radio and x-ray spectrum,” Astron. Astrophys. 362, 113.
Falcke, H., et al., 1998, “The simultaneous spectrum of Sagittarius $A *$ from $20 centimeters to 1 millimeter$ and the nature of the millimeter excess,” Astrophys. J. 499, 731.
Falcke, H., et al., 2000, “Viewing the shadow of the black hole at the galactic center,” Astrophys. J. Lett. 528, L13.
Falcke, H., et al., 2004, “A scheme to unify low-power accreting black holes. Jet-dominated accretion flows and the radio/x-ray correlation,” Astron. Astrophys. 414, 895.
Feast, M., 1967, “The radial velocities of distant Cepheids and galactic models,” Mon. Not. R. Astron. Soc. 136, 141.
Fernley, J. A., et al., 1987, “The absolute magnitude of RR Lyraes and the distance to the galactic centre,” Mon. Not. R. Astron. Soc. 226, 927.
Ferrarese, L., and D. Merritt, 2000, “A fundamental relation between supermassive black holes and their host Galaxies,” Astrophys. J. 539, L9.
Figer, D. F., 2008, “Young massive clusters,” in Massive Stars as Cosmic Engines, Proceedings of the International Astronomical Union, IAU Symposium Vol. 250 (Cambridge University Press, Cambridge), p. 247.
Figer, D. F., et al., 1999, “Hubble space telescope/NICMOS observations of massive stellar clusters near the galactic center,” Astrophys. J. 525, 750.
Figer, D. F., et al., 2004, “An extended star formation history for the galactic center from Hubble space telescope NICMOS observations,” Astrophys. J. 601, 319.
Fish, V. L., and S. S. Doeleman, 2010, “Observing a black hole event horizon: (Sub)millimeter VLBI of Sgr $A *$ ,” in Relativity in Fundamental Astronomy: Dynamics, Reference Frames, and Data Analysis, Proceedings of the International Astronomical Union, IAU Symposium Vol. 261 (Cambridge University Press, Cambridge), p. 271.
Forrest, W. J., et al., 1987, “Brackett alpha images of the galactic center,” AIP Conf. Proc. 155, 153.
Fragile, P. C., and G. J. Mathews, 2000, “Reconstruction of stellar orbits close to Sagittarius $A *$ : Possibilities for testing general relativity,” Astrophys. J. 542, 328.
Freitag, M., et al., 2006, “Stellar remnants in galactic nuclei: Mass segregation,” Astrophys. J. 649, 91.
Fritz, T., et al., 2010a, “What is limiting near-infrared astrometry in the galactic centre?,” Mon. Not. R. Astron. Soc. 401, 1177.
Fritz, T., et al., 2010b, “GC-IRS 13E—An association of three puzzling early-type stars,” Astrophys. J. 721, 395.
Fryer, C. L., et al., 2006, “The Sgr B2 x-ray echo of the galactic center supernova explosion that produced Sgr A east,” Astrophys. J. 638, 786.
Fuji, M., et al., 2009, “Trojan stars in the galactic center,” Astrophys. J. 695, 1421.
Fuji, M., et al., 2010, “The origin of S-stars and a young stellar disk: Distribution of debris stars of a sinking star cluster,” Astrophys. J. Lett. 716, L80.
Gammie, C. F., 2001, “Nonlinear outcome of gravitational instability in cooling, gaseous disks,” Astrophys. J. 553, 174.
Gatley, I., et al., 1986, “The spatial distribution and velocity field of the molecular hydrogen line emission from the centre of the Galaxy,” Mon. Not. R. Astron. Soc. 222, 299.
Geballe, T. R., et al., 2004, “A bow shock of heated dust surrounding galactic center source IRS 8,” Astrophys. J. 602, 770.
Geballe, T. R., et al., 2006, “The K-band spectrum of the hot star in IRS 8: An outsider in the galactic center?,” Astrophys. J. 652, 370.
Gebhardt, K., et al., 2000, “A relationship between nuclear black hole mass and Galaxy velocity dispersion,” Astrophys. J. Lett. 539, L13.
Genzel, R., 2007, “The power of new experimental techniques in astronomy: Zooming in on the black hole in the center of the Milky Way,” Highlights Astron. 14, 63.
Genzel, R., and A. Eckart, 1999, “The galactic center black hole,” “The Central Parsecs of the Galaxy,” ASP Conference Series (unpublished), Vol. 186, p. 3.
Genzel, R., and C. H. Townes, 1987, “Physical conditions, dynamics, and mass distribution in the center of the Galaxy,” Annu. Rev. Astron. Astrophys. 25, 377.
Genzel, R., et al., 1981, “Proper motions and distances of H2O maser sources. II—W51 MAIN,” Astrophys. J. 247, 1039.
Genzel, R., et al., 1985, “The neutral-gas disk around the galactic center,” Astrophys. J. 297, 766.
Genzel, R., et al., 1994, “The nucleus of our Galaxy,” Rep. Prog. Phys. 57, 417.
Genzel, R., et al., 1996, “The dark mass concentration in the central parsec of the Milky Way,” Astrophys. J. 472, 153.
Genzel, R., et al., 1997, “On the nature of the dark mass in the centre of the Milky Way,” Mon. Not. R. Astron. Soc. 291, 219.
Genzel, R., et al., 2000, “Stellar dynamics in the galactic centre: Proper motions and anisotropy,” Mon. Not. R. Astron. Soc. 317, 348.
Genzel, R., et al., 2003a, “The stellar cusp around the supermassive black hole in the galactic center,” Astrophys. J. 594, 812.
Genzel, R., et al., 2003b, “Near-infrared flares from accreting gas around the supermassive black hole at the galactic centre,” Nature (London) 425, 934.
Gerhard, O., 2001, “The galactic center HE I stars: Remains of a dissolved young cluster?,” Astrophys. J. Lett. 546, L39.
Gezari, D., 1996, “Mid-infrared emission amid luminous sources in the central parsec,” in The Galactic Center, edited by R. Gredel, ASP Conf. Ser. Vol 102 (Astronomical Society of the Pacific, San Francisco), p. 491.
Gezari, D., 1999, “Sgr $A *$ in the mid-infrared reference frame: The relationship between the radio and infrared sources in the central parsec,” in The Central Parsecs of the Galaxy, edited by H. Falcke , ASP Conf. Ser. Vol 186 (Astronomical Society of the Pacific, San Francisco), p. 234.
Ghez, A. M., et al., 1998, “High proper-motion stars in the vicinity of Sagittarius $A *$ : Evidence for a supermassive black hole at the center of our Galaxy,” Astrophys. J. 509, 678.
Ghez, A. M., et al., 2000, “The accelerations of stars orbiting the Milky Way’s central black hole,” Nature (London) 407, 349.
Ghez, A. M., et al., 2003, “The first measurement of spectral lines in a short-period star bound to the Galaxy’s central black hole: A paradox of youth,” Astrophys. J. Lett. 586, L127.
Ghez, A. M., et al., 2004, “Variable infrared emission from the supermassive black hole at the center of the Milky Way,” Astrophys. J. Lett. 601, L159.
Ghez, A. M., et al., 2005a, “The first laser guide star adaptive optics observations of the galactic center: Sgr $A *$ ’s infrared color and the extended red emission in its vicinity,” Astrophys. J. 635, 1087.
Ghez, A. M., et al., 2005b, “Stellar orbits around the galactic center black hole,” Astrophys. J. 620, 744.
Ghez, A. M., et al., 2008, “Measuring distance and properties of the Milky Way’s central supermassive black hole with stellar orbits,” Astrophys. J. 689, 1044.
Gillessen, S., et al., 2006, “Variations in the spectral slope of Sagittarius $A *$ during a near-infrared flare,” Astrophys. J. Lett. 640, L163.
Gillessen, S., et al., 2008, “IAUS: $15 years$ of high precision astrometry in the galactic center,” in A Giant Step: From Milli- to Micro-Arcsecond Astrometry, Proceedings of the International Astronomical Union, IAU Symposium Vol. 248 (Cambridge University Press, Cambridge), p. 466.
Gillessen, S., et al., 2009a, “The orbit of the star S2 around Sgr $A *$ from very large telescope and Keck data,” Astrophys. J. Lett. 707, L114.
Gillessen, S., et al., 2009b, “Monitoring stellar orbits around the massive black hole in the galactic center,” Astrophys. J. 692, 1075.
Gillessen, S., et al., 2010, “Gravity: A four-telescope beam combiner instrument for the VLTI,” Proc. SPIE 7734, 77340Y-20.
Ginsburg, I., and A. Loeb, 2006, “The fate of former companions to hypervelocity stars originating at the galactic centre,” Mon. Not. R. Astron. Soc. 368, 221.
Giveon, U., et al., 2002, “The excitation and metallicity of galactic H II regions from infrared space observatory SWS observations of mid-infrared fine-structure lines,” Astrophys. J. 566, 880.
Glass, I. S., and M. W. Feast, 1982, “Infrared photometry of Mira variables in the Baade windows and the distance to the galactic centre,” Mon. Not. R. Astron. Soc. 198, 199.
Gnedin, O. Y., and J. R. Primack, 2004, “Dark matter profile in the galactic center,” Phys. Rev. Lett. 93, 061302.
Goldwurm, A., 2010, “An overview of the high-energy emission from the galactic center,” e-print arXiv:1007.4174.
Goldwurm, A., et al., 2003, “A new x-ray flare from the galactic nucleus detected with the XMM-Newton photon imaging cameras,” Astrophys. J. 584, 751.
Gondolo, P., 2000, “Either neutralino dark matter or cuspy dark halos,” Phys. Lett. B 494, 181.
Gondolo, P., and J. Silk, 1999, “Dark matter annihilation at the galactic center,” Phys. Rev. Lett. 83, 1719.
Goobar, A., et al. 2006, “The neutrino mass bound from WMAP $3 year$ data, the baryon acoustic peak, the SNLS supernovae and the Lyman- $α$ forest,” J. Cosmol. Astropart. Phys. 06, 019.
Goodman, J., 2003, “Self-gravity and quasi-stellar object discs,” Mon. Not. R. Astron. Soc. 339, 937.
Gould, A., and A. C. Quillen, 2003, “Sagittarius $A *$ companion S0-2: A probe of very high mass star formation,” Astrophys. J. 592, 935.
Graham, A. W., 2008a, “Fundamental planes and the barless Mbh- $σ$ relation for supermassive black holes,” Astrophys. J. 680, 143.
Graham, A. W., 2008b, “Populating the Galaxy velocity dispersion—Supermassive black hole mass diagram: A catalogue of (Mbh, $σ$ ) values,” Publ. - Astron. Soc. Aust. 25, 167.
Graham, A. W., and L. R. Spitler, 2009, “Quantifying the coexistence of massive black holes and dense nuclear star clusters,” Mon. Not. R. Astron. Soc. 397, 2148.
Groenewegen, M. A. T., and J. A. D. L. Blommaert, 2005, “Mira variables in the OGLE bulge fields,” Astron. Astrophys. 443, 143.
Groenewegen, M. A. T., et al., 2008, “The distance to the galactic centre based on population II Cepheids and RR Lyrae stars,” Astron. Astrophys. 481, 441.
Gualandris, A., and D. Merritt, 2009, “Perturbations of Intermediate-mass black holes on stellar orbits in the galactic center,” Astrophys. J. 705, 361.
Gualandris, A., et al., 2005, “Three-body encounters in the galactic centre: The origin of the hypervelocity star SDSS $J 090745.0 + 024507$ ,” Mon. Not. R. Astron. Soc. 363, 223.
Gültekin, K., et al., 2009, “The M- $σ$ and M-L relations in galactic bulges, and determinations of their intrinsic scatter,” Astrophys. J. 698, 198.
Gürkan, M. A., and F. A. Rasio, 2005, “The disruption of stellar clusters containing massive black holes near the galactic center,” Astrophys. J. 628, 236.
Gürkan, M. A., et al., 2004, “Formation of massive black holes in dense star clusters. I. Mass segregation and core collapse,” Astrophys. J. 604, 632.
Güsten, R., and D. Downes, 1980, “Formaldehyde in the galactic center region—Interpretation,” Astron. Astrophys. 87, 6.
Güsten, R., et al., 1987, “Aperture synthesis observations of the circumnuclear ring in the galactic center,” Astrophys. J. 318, 124.
Gwinn, C. R., et al., 1992, “Distance and kinematics of the W49N H2O maser outflow,” Astrophys. J. 393, 149.
Hall, J., and P. Gondolo, 2006, “Stellar orbit constraints on neutralino annihilation at the galactic center,” Phys. Rev. D 74, 063511.
Haller, J. W., et al., 1996, “Stellar kinematics and the black hole in the galactic center,” Astrophys. J. 456, 194.
Hamaus, N., et al., 2009, “Prospects for testing the nature of Sgr $A *$ ’s near-infrared flares on the basis of current very large telescope and future very large telescope interferometer observations,” Astrophys. J. 692, 902.
Hansen, B. M. S., and M. Milosavljevic, 2003, “The need for a second black hole at the galactic center,” Astrophys. J. Lett. 593, L77.
Haubois, X., et al., 2010, unpublished.
Hawley, J. F., and S. A. Balbus, 2002, “The dynamical structure of nonradiative black hole accretion flows,” Astrophys. J. 573, 738.
Heber, U., et al., 2008, “The B-type giant HD 271791 in the galactic halo. Linking run-away stars to hyper-velocity stars,” Astron. Astrophys. 483, L21.
Herbst, T. M., et al., 1993, “Infrared imaging spectroscopy of the galactic center—Distribution and motions of the ionized gas,” Astron. J. 105, 956.
Herrnstein, R. M., et al., 2004, “The variability of Sagittarius $A *$ at centimeter wavelengths,” Astron. J. 127, 3399.
Hildebrand, R. H., et al., 1993, “Polarization of the thermal emission from the dust ring at the center of the Galaxy,” Astrophys. J. 417, 565.
Hills, J. G., 1988, “Hyper-velocity and tidal stars from binaries disrupted by a massive galactic black hole,” Nature (London) 331, 687.
Hills, J. G., 1991, “Computer simulations of encounters between massive black holes and binaries,” Astron. J. 102, 704.
Ho, L. C., 2008, “Nuclear activity in nearby galaxies,” Annu. Rev. Astron. Astrophys. 46, 475.
Hobbs, A., and S. Nayakshin, 2009, “Simulations of the formation of stellar discs in the galactic centre via cloud-cloud collisions,” Mon. Not. R. Astron. Soc. 394, 191.
Honma, M., and Y. Sofue, 1996, “Mass of the Galaxy inferred from outer rotation curve,” Publ. Astron. Soc. Jpn. 48, L103.
Hooper, D., et al., 2004, “Have atmospheric Cerenkov telescopes observed dark matter?,” J. Cosmol. Astropart. Phys. 09, 002.
Hopman, C., 2009, “Binary dynamics near a massive black hole,” Astrophys. J. 700, 1933.
Hopman, C., and T. Alexander, 2006a, “The effect of mass segregation on gravitational wave sources near massive black holes,” Astrophys. J. Lett. 645, L133.
Hopman, C., and T. Alexander, 2006b, “Resonant relaxation near a massive black hole: The stellar distribution and gravitational wave sources,” Astrophys. J. 645, 1152.
Horns, D., 2005, “TeV $γ$ -radiation from dark matter annihilation in the galactic center,” Phys. Lett. B 607, 225.
Hornstein, S. D., et al., 2002, “Limits on the short-term variability of Sagittarius $A *$ in the near-infrared,” Astrophys. J. Lett. 577, L9.
Hornstein, S. D., et al., 2007, “A constant spectral index for Sagittarius $A *$ during infrared/x-ray intensity variations,” Astrophys. J. 667, 900.
Hu, J., 2008, “The black hole mass-stellar velocity dispersion correlation: Bulges versus pseudo-bulges,” Mon. Not. R. Astron. Soc. 386, 2242.
Huang, L., et al., 2009, “Testing the accretion flow with plasma wave heating mechanism for Sagittarius $A *$ by the $1.3 mm$ VLBI measurements,” Astrophys. J. 706, 960.
Huterer, D., et al., 1995, “Distances to nearby galaxies, combining fragmentary data using four different methods,” Astron. J. 110, 2705.
Ivanov, V. D., et al., 2005, “Discovery of new Milky Way star cluster candidates in the 2MASS point source catalog. IV. Follow-up observations of cluster candidates in the galactic plane,” Astron. Astrophys. 435, 107.
Jackson, J. M., et al., 1993, “Neutral gas in the central $2 parsecs$ of the Galaxy,” Astrophys. J. 402, 173.
Joy, A. H., 1939, “Rotation effects, interstellar absorption, and certain dynamical constants of the Galaxy determined from Cepheid variables,” Astrophys. J. 89, 356.
Kenyon, S. J., et al., 2008, “Hypervelocity stars: From the galactic center to the halo,” Astrophys. J. 680, 312.
Kerr, F. J., and D. Lynden-Bell, 1986, “Review of galactic constants,” Mon. Not. R. Astron. Soc. 221, 1023.
Kim, S. S., and M. Morris, 2003, “Dynamical friction on star clusters near the galactic center,” Astrophys. J. 597, 312.
Kim, S. S., et al., 2004, “Dynamical friction on galactic center star clusters with an intermediate-mass black hole,” Astrophys. J. Lett. 607, L123.
Kim, S. S., et al., 2006, “The Arches cluster mass function,” Astrophys. J. Lett. 653, L113.
Knödlseder, J., et al., 2003, “Early SPI/INTEGRAL constraints on the morphology of the $511 keV$ line emission in the 4th galactic quadrant,” Astron. Astrophys. 411, L457.
Kobulnicky, H. A., and C. L. Fryer, 2007, “A new look at the binary characteristics of massive stars,” Astrophys. J. 670, 747.
Kocsis, B., and S. Tremaine, 2010, “Resonant relaxation and the warp of the stellar disc in the galactic centre,” e-print arXiv:1006.0001.
Kolykhalov, P. I., and R. A. Sunyaev, 1980, “The outer parts of the accretion disks around supermassive black holes in galaxy nuclei and quasars,” Sov. Astron. Lett. 6, 357.
Koposov, S. E., et al., 2010, “Constraining the Milky Way potential with a 6-D phase-space map of the GD-1 stellar stream,” Astrophys. J. 712, 260.
Kormendy, J., 2004, “The stellar-dynamical search for supermassive black holes in galactic nuclei,” in Coevolution of Black Holes and Galaxies (Cambridge University Press, Cambridge), Vol. 1, p. 1.
Kormendy, J., and D. Richstone, 1995, “Inward bound—The search for supermassive black holes in galactic nuclei,” Annu. Rev. Astron. Astrophys. 33, 581.
Kosack, K., et al., 2004, “TeV gamma-ray observations of the galactic center,” Astrophys. J. Lett. 608, L97.
Koyama, K., et al., 1996, “ASCA view of our galactic center: Remains of past activities in x-rays?,” Publ. Astron. Soc. Jpn. 48, 249.
Koyama, K., et al., 2003, “The ASCA and Chandra observations of the galactic center,” Chin. J. Astron. Astrophys. 3, 297.
Koyama, K., et al., 2009, “Spatial distribution of the galactic center diffuse x-rays and the spectra of the Brightest $6.4 keV$ clumps,” Publ. Astron. Soc. Jpn. 61, 255.
Kozai, Y., 1962, “Secular perturbations of asteroids with high inclination and eccentricity,” Astron. J. 67, 591.
Krabbe, A., et al., 1991, “A cluster of He I emission-line stars in the galactic center,” Astrophys. J. Lett. 382, L19.
Krabbe, A., et al., 1995, “The nuclear cluster of the Milky Way: Star formation and velocity dispersion in the central $0.5 parsec$ ,” Astrophys. J. Lett. 447, L95.
Krabbe, A., et al., 2006, “Diffraction-limited imaging spectroscopy of the Sagittarius $A *$ region using OSIRIS, a new Keck instrument,” Astrophys. J. Lett. 642, L145.
Kraniotis, G. V., 2007, “Periapsis and gravitomagnetic precessions of stellar orbits in Kerr and Kerr de Sitter black hole spacetimes,” Class. Quantum Grav. 24, 1775.
Krichbaum, T. P., et al., 1993, “First 43-GHZ VLBI detection of the compact source Sagittarius- $A *$ in the galactic center,” Astron. Astrophys. 274, L37.
Krichbaum, T. P., et al., 1998, “VLBI observations of the galactic center source Sgr $A *$ at $86 GHz$ and $215 GHz$ ,” Astron. Astrophys. 335, L106.
Kroupa, P., 2002, “The initial mass function of stars: Evidence for uniformity in variable systems,” Science 295, 82.
Krumholz, M. R., and C. F. McKee, 2005, “A general theory of turbulence-regulated star formation, from spirals to ultraluminous infrared galaxies,” Astrophys. J. 630, 250.
Kunneriath, D., et al., 2008, “Coordinated mm/sub-mm observations of Sagittarius $A *$ in May 2007,” J. Phys.: Conf. Ser. 131, 1.
Lacy, J. H., et al., 1980, “Observations of the motion and distribution of the ionized gas in the central parsec of the Galaxy. II,” Astrophys. J. 241, 132.
Lacy, J. H., et al., 1982, “The nature of the central parsec of the Galaxy,” Astrophys. J. 262, 120.
Lacy, J. H., et al., 1991, “Galactic center gas dynamics—A one-armed spiral in a Keplerian disk,” Astrophys. J. Lett. 380, L71.
Larson, R. B., 2006, “Understanding the stellar initial mass function,” in Proceedings of the XI IAU Regional Latin American Meeting of Astronomy (Serie de Conferencias), edited by L. Infante and M. Rubio (Revista Mexicana de Astronomia y Astrofisica), Vol. 26, p. 55.
Latvakoski, H. M., et al., 1999, “Kuiper widefield infrared camera far-infrared imaging of the galactic center: The circumnuclear disk revealed,” Astrophys. J. 511, 761.
Launhardt, R., et al., 2002, “The nuclear bulge of the Galaxy. III. Large-scale physical characteristics of stars and interstellar matter,” Astron. Astrophys. 384, 112.
Lee, H. M., 1987, “Dynamical effects of successive mergers on the evolution of spherical stellar systems,” Astrophys. J. 319, 801.
Leonard, P. J. T., and D. Merritt, 1989, “The mass of the open star cluster M35 as derived from proper motions,” Astrophys. J. 339, 195.
Lester, D. F., et al., 1987, “Far-infrared measurements of $N ∕ O$ in H II regions—Evidence for enhanced CN process nucleosynthesis in the inner Galaxy,” Astrophys. J. 320, 573.
Levin, Y., 2006, “Ejection of high-velocity stars from the galactic center by an inspiraling intermediate-mass black hole,” Astrophys. J. 653, 1203.
Levin, Y., 2007, “Starbursts near supermassive black holes: Young stars in the galactic centre, and gravitational waves in LISA band,” Mon. Not. R. Astron. Soc. 374, 515.
Levin, Y., and A. M. Beloborodov, 2003, “Stellar disk in the galactic center: A remnant of a dense accretion disk?,” Astrophys. J. Lett. 590, L33.
Li, J., et al., 2009, “The variability of Sagittarius $A *$ at $3 millimeter$ ,” Astrophys. J. 700, 417.
Libonate, S., et al., 1995, “Near-infrared spectra of compact stellar wind sources at the galactic center,” Astrophys. J. 439, 202.
Lin, D. N. C., and J. E. Pringle, 1987, “A viscosity prescription for a self-gravitating accretion disc,” Mon. Not. R. Astron. Soc. 225, 607.
Lindqvist, M., et al., 1992, “OH/IR stars close to the galactic centre. II—Their spatial and kinematic properties and the mass distribution within 5–100 PC from the galactic centre,” Astron. Astrophys. 259, 118.
Lissauer, J. J., 1987, “Timescales for planetary accretion and the structure of the protoplanetary disk,” Icarus 69, 249.
Liszt, H. S., 2003, “The velocity field of ionized gas near Sgr $A *$ ,” Astron. Astrophys. 408, 1009.
Liszt, H. S., et al., 1983, “VLA synthesis of H I absorption toward SGR A,” Astron. Astrophys. 126, 341.
Lo, K. Y., and M. J. Claussen, 1983, “High-resolution observations of ionized gas in central $3 parsecs$ of the Galaxy—Possible evidence for infall,” Nature (London) 306, 647.
Lo, K. Y., et al., 1985, “On the size of the galactic centre compact radio source diameter less than $20 AU$ ,” Nature (London) 315, 124.
Löckmann, U., and H. Baumgardt, 2009, “On the number of young stellar discs in the galactic centre,” Mon. Not. R. Astron. Soc. 394, 1841.
Löckmann, U., et al., 2009, “Influence of a stellar cusp on the dynamics of young stellar discs and the origin of the S-stars in the galactic centre,” Mon. Not. R. Astron. Soc. 398, 429.
Löckmann, U., et al., 2010, “Constraining the initial mass function of stars in the galactic centre,” Mon. Not. R. Astron. Soc. 402, 519.
Loeb, A., and E. Waxman, 2007, “Properties of the radio-emitting gas around Sgr $A *$ ,” J. Cosmol. Astropart. Phys. 03, 011.
Lu, J. R., et al., 2006, “Galactic center youth: Orbits and origins of the young stars in the central parsec,” J. Phys.: Conf. Ser. 54, 279.
Lu, J. R., et al., 2009, “A disk of young stars at the galactic center as determined by individual stellar orbits,” Astrophys. J. 690, 1463.
Lu, Y., Q. Yu, and D. N. C. Lin, 2007, “Hypervelocity binary stars: Smoking gun of massive binary black holes,” Astrophys. J. Lett. 666, L89.
Lutz, D., 1999, “ISO observations of the galactic centre,” in The Universe as Seen by ISO, edited by P. Cox and M. F. Kessler, Vol. 427, p. 623.
Lutz, D., et al., 1996, “SWS observations of the galactic center,” Astron. Astrophys. 315, L269.
Lynden-Bell, D., 1969, “Galactic nuclei as collapsed old quasars,” Nature (London) 223, 690.
Lynden-Bell, D., and M. J. Rees, 1971, “On quasars, dust and the galactic centre,” Mon. Not. R. Astron. Soc. 152, 461.
Macquart, J.-P., and G. C. Bower, 2006, “Understanding the radio variability of Sagittarius $A *$ ,” Astrophys. J. 641, 302.
Macquart, J.-P., et al., 2006, “The rotation measure and $3.5 millimeter$ polarization of Sagittarius $A *$ ,” Astrophys. J. Lett. 646, L111.
Madigan, A.-M., et al., 2009, “A new secular instability of eccentric stellar disks around supermassive black holes, with application to the galactic center,” Astrophys. J. Lett. 697, L44.
Maeda, Y., et al., 2002, “A Chandra study of Sagittarius A east: A supernova remnant regulating the activity of our galactic center?,” Astrophys. J. 570, 671.
Maeder, A., and G. Meynet, 2000, “The evolution of rotating stars,” Annu. Rev. Astron. Astrophys. 38, 143.
Maillard, J. P., et al., 2004, “The nature of the galactic center source IRS 13 revealed by high spatial resolution in the infrared,” Astron. Astrophys. 423, 155.
Majaess, D. J., 2010, “Concerning the distance to the center of the Milky Way and its structure,” Acta Astron. 60, 55.
Maloney, P. R., et al., 1992, “Heating of H II regions with application to the galactic center,” Astrophys. J. 401, 559.
Maness, H., et al., 2007, “Evidence for a long-standing top-heavy initial mass function in the central parsec of the Galaxy,” Astrophys. J. 669, 1024.
Maoz, E., 1998, “Dynamical constraints on alternatives to supermassive black holes in galactic nuclei,” Astrophys. J. Lett. 494, L181.
Mapelli, M., et al., 2008, “In situ formation of the massive stars around Sgr $A *$ ,” e-print arXiv:0805.0185.
Markoff, S., et al., 2001, “The nature of the $10 kilosecond$ x-ray flare in Sgr $A *$ ,” Astron. Astrophys. 379, L13.
Marrone, D. P., et al., 2006, “Interferometric measurements of variable $340 GHz$ linear polarization in Sagittarius $A *$ ,” Astrophys. J. 640, 308.
Marrone, D. P., et al., 2007, “An unambiguous detection of faraday rotation in Sagittarius $A *$ ,” Astrophys. J. Lett. 654, L57.
Marrone, D. P., et al., 2008, “An x-ray, infrared, and submillimeter flare of Sagittarius $A *$ ,” Astrophys. J. 682, 373.
Martins, F., 2010, private communication.
Martins, F., et al., 2006, “GCIRS 16SW: A massive eclipsing binary in the galactic center,” Astrophys. J. Lett. 649, L103.
Martins, F., et al., 2007, “Stellar and wind properties of massive stars in the central parsec of the Galaxy,” Astron. Astrophys. 468, 233.
Martins, F., et al., 2008a, “The most massive stars in the Arches cluster,” Astron. Astrophys. 478, 219.
Martins, F., et al., 2008b, “On the nature of the fast-moving star S2 in the galactic center,” Astrophys. J. Lett. 672, L119.
Matsunaga, N., et al., 2009, “A near-infrared survey of Miras and the distance to the galactic centre,” Mon. Not. R. Astron. Soc. 399, 1709.
Mauerhan, J. C., et al., 2005, “Intraday variability of Sagittarius $A *$ at $3 millimeters$ ,” Astrophys. J. Lett. 623, L25.
Mazur, P. O., and E. Mottola, 2001, “Gravitational condensate stars: An alternative to black holes,” e-print arXiv:gr-qc/0109035.
McGinn, M. T., et al., 1989, “Stellar kinematics in the galactic center,” Astrophys. J. 338, 824.
McKee, C. F., and E. C. Ostriker, 2007, “Theory of star formation,” Annu. Rev. Astron. Astrophys. 45, 565.
Melia, F., 1992, “An accreting black hole model for Sagittarius A,” Astrophys. J. Lett. 387, L25.
Melia, F., 2003, The Black Hole at the Center of our Galaxy (Princeton University Press, Princeton).
Melia, F., and H. Falcke, 2001, “The supermassive black hole at the galactic center,” Annu. Rev. Astron. Astrophys. 39, 309.
Menten, K. M., et al., 1997, “The position of SGR A star: Accurate alignment of the radio and infrared reference frames at the galactic center,” Astrophys. J. Lett. 475, L111.
Merloni, A., et al., 2003, “A fundamental plane of black hole activity,” Mon. Not. R. Astron. Soc. 345, 1057.
Merritt, D., 2006, “Dynamics of galaxy cores and supermassive black holes,” Rep. Prog. Phys. 69, 2513.
Merritt, D., 2010 “The distribution of stars and stellar remnants at the galactic center,” Astrophys. J. 718, 739.
Merritt, D., et al., 2002, “Dark matter spikes and annihilation radiation from the galactic center,” Phys. Rev. Lett. 88, 191301.
Merritt, D., et al., 2007, “Brownian motion of black holes in dense nuclei,” Astron. J. 133, 553.
Merritt, D., et al., 2009, “Explaining the orbits of the galactic center S-stars,” Astrophys. J. Lett. 693, L35.
Merritt, D., et al., 2010, “Testing properties of the galactic center black hole using stellar orbits,” Phys. Rev. D 81, 062002.
Metzger, M. R., et al., 1998, “The shape and scale of galactic rotation from Cepheid kinematics,” Astron. J. 115, 635.
Meyer, L., et al., 2006, “K-band polarimetry of an Sgr $A *$ flare with a clear sub-flare structure,” Astron. Astrophys. 458, L25.
Meyer, L., et al., 2007, “On the orientation of the Sagittarius $A *$ system,” Astron. Astrophys. 473, 707.
Meyer, L., et al., 2008, “A $600 minute$ near-infrared light curve of Sagittarius $A *$ ,” Astrophys. J. Lett. 688, L17.
Mezger, P. G., and J. E. Wink, 1986, “Dynamics of the ionized gas within $2 pc$ of the galactic center. I—First results of a radio recombination line survey,” Astron. Astrophys. 157, 252.
Mezger, P. G., et al., 1989, “Continuum observations of SGR A at mm/submm wavelengths,” Astron. Astrophys. 209, 337.
Mezger, P. G., et al., 1996, “The galactic center: A laboratory for AGN?,” Astron. Astrophys. Rev. 7, 289.
Mikkola, S., and D. Merritt, 2008, “Implementing few-body algorithmic regularization with post-Newtonian terms,” Astron. J. 135, 2398.
Milosavljevic, M., and A. Loeb, 2004, “The link between warm molecular disks in maser nuclei and star formation near the black hole at the galactic center,” Astrophys. J. Lett. 604, L45.
Milosavljevic, M., and D. Merritt, 2001, “Formation of galactic nuclei,” Astrophys. J. 563, 34.
Miralda-Escude, J., and A. Gould, 2000, “A cluster of black holes at the galactic center,” Astrophys. J. 545, 847.
Miyazaki, A., et al., 2004, “Intraday variation of Sagittarius $A *$ at short millimeter wavelengths,” Astrophys. J. Lett. 611, L97.
Miyoshi, M., et al., 1995, “Evidence for a black hole from high rotation velocities in a sub-parsec region of NGC4258,” Nature (London) 373, 127.
Montero-Castano, M. M., et al., 2009, “Gas infall toward Sgr $A *$ from the clumpy circumnuclear disk,” Astrophys. J. 695, 1477.
Morris, M., 1993, “Massive star formation near the galactic center and the fate of the stellar remnants,” Astrophys. J. 408, 496.
Morris, M., and E. Serabyn, 1996, “The galactic center environment,” Annu. Rev. Astron. Astrophys. 34, 645.
Morris, M., and F. Yusef-Zadeh, 1987, “Radio emission from Sgr A and its extended halo,” AIP Conf. Proc. 155, 127.
Mościbrodzka, M., et al., 2009, “Radiative models of Sgr $A *$ from GRMHD simulations,” Astrophys. J. 706, 497.
Moskalenko, I. V., and L. L. Wai, 2007, “Dark matter burners,” Astrophys. J. Lett. 659, L29.
Mouawad, N., et al., 2005, “Weighing the cusp at the galactic centre,” Astron. Nachr. 326, 83.
Muno, M. P., et al., 2004, “Diffuse x-ray emission in a deep Chandra image of the galactic center,” Astrophys. J. 613, 326.
Muno, M. P., et al., 2005, “An overabundance of transient x-ray binaries within $1 parsec$ of the galactic center,” Astrophys. J. Lett. 622, L113.
Muno, M. P., et al., 2007, “Discovery of variable iron fluorescence from reflection nebulae in the galactic center,” Astrophys. J. Lett. 656, L69.
Muno, M. P., et al., 2008, “A catalog of diffuse x-ray-emitting features within $20 pc$ of Sagittarius $A *$ : Twenty pulsar wind nebulae?,” Astrophys. J. 673, 251.
Muno, M. P., et al., 2009, “A catalog of x-ray point sources from two megaseconds of Chandra observations of the galactic center,” Astrophys. J., Suppl. Ser. 181, 110.
Munyaneza, F., et al., 1998, “Sagittarius $A *$ : A supermassive black hole or a spatially extended object?,” Astrophys. J. Lett. 509, L105.
Murphy, B. W., et al., 1991, “Dynamical and luminosity evolution of active galactic nuclei—Models with a mass spectrum,” Astrophys. J. 370, 60.
Muzic, K., et al., 2008, “IRS 13N: A new comoving group of sources at the galactic center,” Astron. Astrophys. 482, 173.
Najarro, F., et al., 1994, “The nature of the brightest galactic center HeI emission line star,” Astron. Astrophys. 285, 573.
Najarro, F., et al., 1997, “Quantitative spectroscopy of the HeI cluster in the galactic center,” Astron. Astrophys. 325, 700.
Najarro, F., et al., 2004, “Metallicity in the galactic center: The Arches cluster,” Astrophys. J. Lett. 611, L105.
Najarro, F., et al., 2009, “Metallicity in the galactic center: The Quintuplet cluster,” Astrophys. J. 691, 1816.
Narayan, R., and I. Yi, 1995, “Advection-dominated accretion: Underfed black holes and neutron stars,” Astrophys. J. 452, 710.
Narayan, R., et al., 1995, “Explaining the spectrum of Sagittarius $A *$ with a model of an accreting black hole,” Nature (London) 374, 623.
Narayan, R., et al., 1997, “Advection-dominated accretion and black hole event horizons,” Astrophys. J. Lett. 478, L79.
Narayan, R., et al., 1998, “Advection-dominated accretion model of Sagittarius $A *$ : Evidence for a black hole at the galactic center,” Astrophys. J. 492, 554.
Narayan, R., et al., 2002, “The magnetohydrodynamics of convection-dominated accretion flows,” Astrophys. J. 577, 295.
Navarro, J. F., et al., 1997, “A universal density profile from hierarchical clustering,” Astrophys. J. 490, 493.
Nayakshin, S., 2005a, “Warped accretion discs and the unification of active galactic nuclei,” Mon. Not. R. Astron. Soc. 359, 545.
Nayakshin, S., 2005b, “Using close stars as probes of hot accretion flow in Sgr $A *$ ,” Astron. Astrophys. 429, L33.
Nayakshin, S., and J. Cuadra, 2005, “A self-gravitating accretion disk in Sgr $A *$ a few million years ago: Is Sgr $A *$ a failed quasar?,” Astron. Astrophys. 437, 437.
Nayakshin, S., and R. A. Sunyaev, 2005, “The ‘missing’ young stellar objects in the central parsec of the Galaxy: Evidence for star formation in a massive accretion disc and a top-heavy initial mass function,” Mon. Not. R. Astron. Soc. 364, L23.
Nayakshin, S., et al., 2006, “Weighing the young stellar discs around Sgr $A *$ ,” Mon. Not. R. Astron. Soc. 366, 1410.
Nayakshin, S., et al., 2007, “Simulations of star formation in a gaseous disc around Sgr $A *$ —A failed active galactic nucleus,” Mon. Not. R. Astron. Soc. 379, 21.
Nikiforov, I., 2004, “The distance to the center of the Galaxy: The current state-of-the-art in measuring R0,” in Proceedings of the Conference on Order and Chaos in Stellar and Planetary Systems, edited by G. G. Byrd (Astronomical Society of the Pacific, San Francisco), Vol. 316, p. 199.
Nishiyama, S., et al., 2006, “The distance to the galactic center derived from infrared photometry of bulge red clump stars,” Astrophys. J. 647, 1093.
Nishiyama, S., et al., 2009a, “Near-infrared polarimetry of flares from Sgr $A *$ with Subaru/CIAO,” Astrophys. J. Lett. 702, L56.
Nishiyama, S., et al., 2009b, “Interstellar extinction law toward the galactic center III: J, H, KS bands in the 2MASS and the MKO systems, and 3.6, 4.5, 5.8, $8.0 μ m$ in the Spitzer/IRAC system,” Astrophys. J. 696, 1407.
Noble, S. C., et al., 2007, “Simulating the emission and outflows from accretion discs,” Class. Quantum Grav. 24, S259.
O’Leary, R. M., and A. Loeb, 2008, “Production of hypervelocity stars through encounters with stellar-mass black holes in the galactic centre,” Mon. Not. R. Astron. Soc. 383, 86.
Olling, R. P., and M. R. Merrifield, 2001, “Luminous and dark matter in the Milky Way,” Mon. Not. R. Astron. Soc. 326, 164.
Oort, J. H., 1977, “The galactic center,” Annu. Rev. Astron. Astrophys. 15, 295.
Öpik, E., 1924, “Statistical studies of double stars: On the distribution of relative luminosities and distances of double stars in the Harvard revised photometry north of declination $- 30 °$ ,” Publ. Obs. Astron. Univ. Tartu 25, 1.
Ott, T., et al., 1999, “Variable and embedded stars in the galactic center,” Astrophys. J. 523, 248.
Özel, F., et al., 2000, “Hybrid thermal-nonthermal synchrotron emission from hot accretion flows,” Astrophys. J. 541, 234.
Paczynski, B., 1978, “A model of selfgravitating accretion disk,” Acta Astron. 28, 91.
Paczynski, B., and K. Z. Stanek, 1998, “Galactocentric distance with the optical gravitational lensing experiment and HIPPARCOS red clump stars,” Astrophys. J. Lett. 494, L219.
Paumard, T., et al., 2001, “New results on the helium stars in the galactic center using BEAR spectro-imagery,” Astron. Astrophys. 366, 466.
Paumard, T., et al., 2003, “New results on the galactic center helium stars,” Astron. Nachr. 324, 303.
Paumard, T., et al., 2004, “Kinematic and structural analysis of the minispiral in the galactic center from BEAR spectro-imagery,” Astron. Astrophys. 426, 81.
Paumard, T., et al., 2006, “The two young star disks in the central parsec of the galaxy: Properties, dynamics, and formation,” Astrophys. J. 643, 1011.
Perets, H. B., 2009, “Dynamical and evolutionary constraints on the nature and origin of hypervelocity stars,” Astrophys. J., 690, 795.
Perets, H. B., and A. Gualandris, 2010, “Dynamical constraints on the origin of the young B-stars in the galactic center,” Astrophys. J. 719, 220.
Perets, H. B., et al., 2007, “Massive perturber-driven interactions between stars and a massive black hole,” Astrophys. J. 656, 709.
Perets, H. B., et al., 2008a, “Getting a kick out of the stellar disk(s) in the galactic center,” in IAUS: Dynamical Evolution of Dense Stellar Systems, Proceedings of the International Astronomical Union, IAU Symposium Vol. 246 (Cambridge University Press, Cambridge), p. 275.
Perets, H. B., et al., 2008b, “Dynamical evolution of the young stars in the galactic center,” Mem. Soc. Astron. Ital. 79, 1100.
Perets, H. B., et al., 2009, “Dynamical evolution of the young stars in the galactic center: N-body simulations of the S-stars,” Astrophys. J. 702, 884.
Perger, M., et al., 2008, “Compact mid-IR sources east of galactic center source IRS 5,” Astron. Astrophys. 478, 127.
Phinney, E. S., 1989, “Manifestations of a massive black hole in the galactic center,” in The Center of the Galaxy, Proceedings of the 136th Symposium of the IAU (Kluwer Academic, Dordrecht), Vol. 136, p. 543.
Pfuhl, O., 2010, private communication.
Pfuhl, O., et al., 2010, unpublished.
Ponti, G., et al., 2010, “Discovery of a superluminal Fe K echo at the galactic center: The glorious past of Sgr $A *$ preserved by molecular clouds,” Astrophys. J. 714, 732.
Porquet, D., et al., 2003, “XMM-Newton observation of the brightest x-ray flare detected so far from Sgr $A *$ ,” Astron. Astrophys. 407, L17.
Porquet, D., et al., 2008, “X-ray hiccups from Sagittarius $A *$ observed by XMM-Newton. The second brightest flare and three moderate flares caught in half a day,” Astron. Astrophys. 488, 549.
Portegies Zwart, S. F., and S. L. W. McMillan, 2002, “The runaway growth of intermediate-mass black holes in dense star clusters,” Astrophys. J. 576, 899.
Portegies Zwart, S. F., et al., 2003, “The origin of IRS 16: Dynamically driven in-spiral of a dense star cluster to the galactic center?,” Astrophys. J. 593, 352.
Portegies Zwart, ., et al., 2006, “The Ecology of star clusters and intermediate-mass black holes in the galactic bulge,” Astrophys. J. 641, 319.
Pott, J. U., et al. 2008, “Astrometry with the Keck-interferometer: The ASTRA project and its science,” New Astron. Rev. 53, 363.
Pradel, N., et al., 2006, “Astrometric accuracy of phase-referenced observations with the VLBA and EVN,” Astron. Astrophys. 452, 1099.
Predehl, P., et al., 2003, “XMM-Newton observation of the galactic centre—Evidence against the x-ray reflection nebulae model?,” Astron. Nachr. 324, 73.
Preto, M., and P. Amaro-Seoane, 2010, “On strong mass segregation around a massive black hole: Implications for lower-frequency gravitational-wave astrophysics,” Astrophys. J. Lett. 708, L42.
Quataert, E., 2002, “A thermal bremsstrahlung model for the quiescent x-ray emission from Sagittarius $A *$ ,” Astrophys. J. 575, 855.
Quataert, E., 2003, “Radiatively inefficient accretion flow models of Sgr $A *$ ,” Astron. Nachr. 324, 435.
Quataert, E., 2004, “A dynamical model for hot gas in the galactic center,” Astrophys. J. 613, 322.
Quataert, E., and A. Gruzinov, 2000, “Convection-dominated accretion flows,” Astrophys. J. 539, 809.
Quinlan, G. D., et al., 1995, “Models of galaxies with central black holes: Adiabatic growth in spherical galaxies,” Astrophys. J. 440, 554.
Rafelski, M., et al., 2007, “Photometric stellar variability in the galactic center,” Astrophys. J. 659, 1241.
Ramirez, S. V., et al., 2000, “Stellar iron abundances at the galactic center,” Astrophys. J. 537, 205.
Rauch, K. P., and S. Tremaine, 1996, “Resonant relaxation in stellar systems,” New Astron. 1, 149.
Rees, M. J., 1982, “The compact source at the galactic center. in The galactic center,” Proceedings of the Workshop on the Galactic Center (AIP, New York), Vol. 83, p. 166.
Rees, M. J., 1984, “Black hole models for active galactic nuclei,” Annu. Rev. Astron. Astrophys. 22, 471.
Regis, M., and P. Ullio, 2008, “Multiwavelength signals of dark matter annihilations at the galactic center,” Phys. Rev. D 78, 043505.
Reid, M. J., 1989, “The distance to the galactic center: R0 (review),” Proceedings of the Workshop on the Galactic Center (AIP, New York), Vol. 183, p. 37.
Reid, M. J., 1993, “The distance to the center of the Galaxy,” Annu. Rev. Astron. Astrophys. 31, 345.
Reid, M. J., 2009, “Is there a supermassive black hole at the center of the Milky Way?,” Int. J. Mod. Phys. D 18, 889.
Reid, M. J., and A. Brunthaler, 2004, “The proper motion of Sagittarius $A *$ . II. The mass of Sagittarius $A *$ ,” Astrophys. J. 616, 872.
Reid, M. J., et al., 1988, “The distance to the center of the Galaxy— $H_{2} O$ maser proper motions in Sagittarius B2(N),” Astrophys. J. 330, 809.
Reid, M. J., et al., 2003, “The position of Sagittarius $A *$ . II. Accurate positions and proper motions of stellar SiO masers near the galactic center,” Astrophys. J. 587, 208.
Reid, M. J., et al., 2007, “The position of Sagittarius $A *$ . III. Motion of the stellar cusp,” Astrophys. J. 659, 378.
Reid, M. J., et al., 2009a, “Trigonometric parallaxes of massive star-forming regions. VI. Galactic structure, fundamental parameters, and noncircular motions,” Astrophys. J. 700, 137.
Reid, M. J., et al., 2009b, “A trigonometric parallax of Sgr B2,” Astrophys. J. 705, 1548.
Revnivtsev, M., et al., 2006, “Map of the Galaxy in the $6.7 − keV$ emission line,” Mon. Not. R. Astron. Soc. 373, L11.
Revnivtsev, M., et al., 2009, “Discrete sources as the origin of the galactic x-ray ridge emission,” Nature (London) 458, 1142.
Revnivtsev, M. G., et al., 2004, “Hard x-ray view of the past activity of Sgr $A *$ in a natural Compton mirror,” Astron. Astrophys. 425, L49.
Rieke, G. H., and M. J. Lebofsky, 1982, “Comparison of galactic center with other galaxies. In The Galactic Center,” Proceedings of the Workshop 83, 194.
Rieke, G. H., and M. J. Lebofsky, 1985, “The interstellar extinction law from 1 to 13 microns,” Astrophys. J. 288, 618.
Rieke, G. H., and M. J. Rieke, 1988, “Stellar velocities and the mass distribution in the galactic center,” Astrophys. J. Lett. 330, L33.
Rieke, G. H., et al., 1989, “Origin of the excitation of the galactic center,” Astrophys. J. 336, 752.
Rieke, M. J., 1999, “NICMOS search for the tip of the main sequence,” The Central Parsecs of the Galaxy, edited by H. Falcke, A. Cotera, W. J. Dunschl, F. Melia, and M. J. Rieke, ASP Conf. Ser. Vol. 186 (ASP, San Francisco), p. 32.
Roberts, D. A., and W. M. Goss, 1993, “Multiconfiguration VLA H92-alpha observations of Sagittarius A west at $1 arcsecond$ resolution,” Astrophys. J., Suppl. Ser. 86, 133.
Roberts, D. A., et al., 1996, “Kinematics of the ionized gas in Sagittarius A west: Mass estimates of the inner $0.13 parsecs$ of the Galaxy,” Astrophys. J. 459, 627.
Rogers, A. E. E., et al., 1994, “Small-scale structure and position of Sagittarius $A (*)$ from VLBI at $3 millimeter$ wavelength,” Astrophys. J. Lett. 434, L59.
Rosenthal, D., et al., 2000, “ISO-SWS observations of OMC-1: H̱2 and fine structure lines,” Astron. Astrophys. 356, 705.
Rubilar, G. F., and A. Eckart, 2001, “Periastron shifts of stellar orbits near the galactic center,” Astron. Astrophys. 374, 95.
Rybicki, M., et al., 1974, “From galactic disk models,” Bull. Am. Astron. Soc. 6, 453.
Sabha, N., et al., 2010, “The extreme luminosity states of Sagittarius $A *$ ,” Astron. Astrophys. 512, A2.
Sakano, M., et al., 2004, “XMM-Newton observations of Sagittarius A east,” Mon. Not. R. Astron. Soc. 350, 129.
Salati, P., and J. Silk, 1989, “A stellar probe of dark matter annihilation in galactic nuclei,” Astrophys. J. 338, 24.
Salim, S., and A. Gould, 1999, “Sagittarius $A *$ ‘visual binaries’: A direct measurement of the galactocentric distance,” Astrophys. J. 523, 633.
Salpeter, E. E., 1955, “The luminosity function and stellar evolution,” Astrophys. J. 121, 161.
Sanders, R. H., 1998, “The circumnuclear material in the galactic centre—A clue to the accretion process,” Mon. Not. R. Astron. Soc. 294, 35.
Sari, R., et al., 2010, “Hypervelocity stars and the restricted parabolic three-body problem,” Astrophys. J. 708, 605.
Sault, R. J., and J.-P. Macquart, 1999, “Confirmation and analysis of circular polarization from Sagittarius $A *$ ,” Astrophys. J. Lett. 526, L85.
Schmidt, M., 1963, “3C 273: A Star-like object with large red-shift,” Nature (London) 197, 1040.
Schneps, M. H., et al., 1981, “Proper motions and distances of H2O maser sources. III—W51NORTH,” Astrophys. J. 249, 124.
Schödel, R., 2010, “The Milky Way nuclear star cluster in context,” e-print arXiv:1001.4238.
Schödel, R., et al., 2002, “A star in a $15.2 -year$ orbit around the supermassive black hole at the centre of the Milky Way,” Nature (London) 419, 694.
Schödel, R., et al., 2003, “The galactic center stellar cluster: The central arcsecond,” Astron. Nachr. 324, 535.
Schödel, R., et al., 2005, “A black hole in the galactic center complex IRS 13E?,” Astrophys. J. Lett. 625, L111.
Schödel, R., et al., 2007a, “The structure of the nuclear stellar cluster of the Milky Way,” Astron. Astrophys. 469, 125.
Schödel, R., et al., 2007b, “The possibility of detecting Sagittarius $A *$ at $8.6 μ m$ from sensitive imaging of the galactic center,” Astron. Astrophys. 462, L1.
Schödel, R., et al., 2009, “The nuclear star cluster of the Milky Way: Proper motions and mass,” Astron. Astrophys. 502, 91.
Schödel, R., et al., 2010, “Peering through the veil: Near-infrared photometry and extinction for the galactic nuclear star cluster. Accurate near infrared H, Ks, and $L^{'}$ photometry and the near-infrared extinction-law toward the central parsec of the Galaxy,” Astron. Astrophys. 511, 18.
Schwarz, U. J., et al., 1989, “The distribution and kinematics of the ionized gas in the galactic centre region,” Astron. Astrophys. 215, 33.
Scott, P., et al., 2009, “Dark stars at the galactic centre—The main sequence,” Mon. Not. R. Astron. Soc. 394, 82.
Scoville, N. Z., et al., 2003, “Hubble space telescope $P α$ and $1.9 micron$ imaging of Sagittarius A west,” Astrophys. J. 594, 294.
Sellgren, K., et al., 1990, “Velocity dispersion and the stellar population in the central $1.2 parsecs$ of the Galaxy,” Astrophys. J. 359, 112.
Serabyn, E., and J. H. Lacy, 1985, “Forbidden NE II observations of the galactic center—Evidence for a massive block hole,” Astrophys. J. 293, 445.
Serabyn, E., and M. Morris, 1996, “Sustained star formation in the central stellar cluster of the Milky Way,” Nature (London) 382, 602.
Serabyn, E., et al., 1986, “CO 1–0 and CS 2–1 observations of the neutral disk around the galactic center,” Astron. Astrophys. 169, 85.
Serabyn, E., et al., 1988, “High-resolution forbidden NE II observations of the ionized filaments in the galactic center,” Astrophys. J. 326, 171.
Serabyn, E., et al., 1991, “A gaseous tail ablated from the supergiant IRS 7 near the galactic center,” Astrophys. J. 378, 557.
Serabyn, E., et al., 1997, “High frequency measurements of the spectrum of Sgr $A *$ ,” Astrophys. J. Lett. 490, L77.
Sharma, P., et al., 2007a, “Faraday rotation in global accretion disk simulations: Implications for Sgr $A *$ ,” Astrophys. J. 671, 1696.
Sharma, P., et al., 2007b, “Electron heating in hot accretion flows,” Astrophys. J. 667, 714.
Shaver, P. A., et al., 1983, “The galactic abundance gradient,” Mon. Not. R. Astron. Soc. 204, 53.
Shen, Z.-Q., et al., 2005, “A size of $\sim 1 AU$ for the radio source Sgr $A *$ at the centre of the Milky Way,” Nature (London) 438, 62.
Shields, J. C., and G. J. Ferland, 1994, “Nebular properties and the ionizing radiation field in the galactic center,” Astrophys. J. 430, 236.
Shlosman, I., and M. C. Begelman, 1989, “Evolution of self-gravitating accretion disks in active galactic nuclei,” Astrophys. J. 341, 685.
Simpson, J. P., et al., 1995, “Far-infrared lines from H II regions: Abundance variations in the galaxy,” Astrophys. J. 444, 721.
Smith, M. C., et al., 2007, “The RAVE survey: Constraining the local galactic escape speed,” Mon. Not. R. Astron. Soc. 379, 755.
Spitzer, L., and M. Schwarzschild, 1951, “The possible influence of interstellar clouds on stellar velocities,” Astrophys. J. 114, 385.
Stark, A. A., et al., 1991, “On the fate of galactic centre molecular clouds,” Mon. Not. R. Astron. Soc. 248, 14P.
Stolte, A., et al., 2005, “The Arches cluster: Evidence for a truncated mass function?,” Astrophys. J. Lett. 628, L113.
Subr, L., et al., 2009, “The warped young stellar disc in the galactic centre,” Astron. Astrophys. 496, 695.
Sunyaev, R. A., et al., 1993, “The center of the Galaxy in the recent past—A view from GRANAT,” Astrophys. J. 407, 606.
Surdin, V. G., 1999, “Distance to the galactic centre,” Astron. Astrophys. Trans. 18, 367.
Tamblyn, P., and G. H. Rieke, 1993, “IRS 16—The galaxy’s central wimp?,” Astrophys. J. 414, 573.
Tamblyn, P., et al., 1996, “The peculiar population of hot stars at the galactic center,” Astrophys. J. 456, 206.
Tanner, A., et al., 2002, “Spatially resolved observations of the galactic center source IRS 21,” Astrophys. J. 575, 860.
Tanner, A., et al., 2005, “Stellar bow shocks in the northern arm of the galactic center: More members and kinematics of the massive star population,” Astrophys. J. 624, 742.
Tanner, A., et al., 2006, “High spectral resolution observations of the massive stars in the galactic center,” Astrophys. J. 641, 891.
Telesco, C. M., et al., 1996, “ $10 - 30 micron$ maps of the central $5 parsecs$ of the galaxy: Heating of the cavity and neutral gas disk,” Astrophys. J. 456, 541.
Thornley, M. D., et al., 2000, “Massive star formation and evolution in starburst galaxies: Mid-infrared spectroscopy with the ISO short wavelength spectrometer,” Astrophys. J. 539, 641.
Toomre, A., 1964, “On the gravitational stability of a disk of stars,” Astrophys. J. 139, 1217.
Torres, D. F., et al., 2000, “Supermassive boson star at the galactic center?,” Phys. Rev. D 62, 104012.
Trap, G., et al., 2010, private communication.
Tremaine, S., et al., 2002, “The slope of the black hole mass versus velocity dispersion correlation,” Astrophys. J. 574, 740.
Trippe, S., et al., 2007, “A polarized infrared flare from Sagittarius $A *$ and the signatures of orbiting plasma hotspots,” Mon. Not. R. Astron. Soc. 375, 764.
Trippe, S., et al., 2008, “Kinematics of the old stellar population at the galactic centre,” Astron. Astrophys. 492, 419.
Tsuchiya, K., et al., 2004, “Detection of sub-TeV gamma rays from the galactic center direction by CANGAROO-II,” Astrophys. J. Lett. 606, L115.
Vachaspati, T., et al., 2007, “Observation of incipient black holes and the information loss problem,” Phys. Rev. D 76, 024005.
Valinia, A., et al., 2000, “On the origin of the iron K line in the spectrum of the galactic x-ray background,” Astrophys. J. 543, 733.
van de Hulst, H. C., et al., 1954, “The spiral structure of the outer part of the galactic system derived from the hydrogen emission at $21 cm$ wavelength,” Bull. Astron. Inst. Neth. 12, 117.
van den Bergh, S., and E. Herbst, 1974, “Photometry of stars in the nuclear bulge of the Galaxy through a low absorption window at $1 = 0 d$ , $b = - 8 d$ ,” Astron. J. 79, 603.
van Eldik, C., 2008, “Very high energy gamma-ray observations of the galactic centre region,” AIP Conf. Proc. 1085, 146.
Vanhollebeke, E., et al., 2009, “Stellar populations in the galactic bulge. Modelling the galactic bulge with TRILEGAL,” Astron. Astrophys. 498, 95.
Vasiliev, E., and M. Zelnikov, 2008, “Dark matter dynamics in the galactic center,” Phys. Rev. D 78, 083506.
Viehmann, T., et al., 2006, “Dusty sources at the galactic center the N- and Q-band views with VISIR,” Astrophys. J. 642, 861.
Viollier, R. D., et al., 1993, “Supermassive neutrino stars and galactic nuclei,” Phys. Lett. B 306, 79.
Vollmer, B., and W. J. Duschl, 2000, “The minispiral in the galactic center revisited,” New Astron. 4, 581.
Vollmer, B., and W. J. Duschl, 2002, “The dynamics of the circumnuclear disk and its environment in the galactic centre,” Astron. Astrophys. 388, 128.
Von Linden, S., et al., 1993, “Molecular clouds as tracers of the dynamics in the central region of the galaxy,” Astron. Astrophys. 269, 169.
Wang, Q. D., 2006, “Chandra observations of the galactic center: High energy processes at arcsecond resolution,” J. Phys.: Conf. Ser. 54, 115.
Wardle, M., and F. Yusef-Zadeh, 2008, “On the formation of compact stellar disks around Sagittarius $A *$ ,” Astrophys. J. Lett. 683, L37.
Weinberg, N. N., et al., 2005, “Stellar dynamics at the galactic center with an extremely large telescope,” Astrophys. J. 622, 878.
Weingartner, J. C., and B. T. Draine, 2001, “Dust grain-size distributions and extinction in the Milky Way, Large Magellanic Cloud, and Small Magellanic Cloud,” Astrophys. J. 548, 296.
Will, C. M., 2008, “Testing the general relativistic “no-hair” theorems using the galactic center black hole Sagittarius $A *$ ,” Astrophys. J. Lett. 674, L25.
Wollman, E. R., et al., 1977, “NE II $12.8 micron$ emission from the galactic center. II,” Astrophys. J. Lett. 218, L103.
Wright, M. C. H., et al., 1989, “Hat creek ${HCO}^{\land} {+}$ and HCN observations of SGR a,” The Center of the Galaxy: Proceedings of the 136th Symposium of the IAU (Kluwer Academic, Dordrecht), Vol. 136, p. 407.
Xu, Y.-D., et al., 2006, “Thermal x-ray iron line emission from the galactic center black hole Sagittarius $A *$ ,” Astrophys. J. 640, 319.
Young, P., 1980, “Numerical models of star clusters with a central black hole. I—Adiabatic models,” Astrophys. J. 242, 1232.
Yu, Q., and S. Tremaine, 2003, “Ejection of hypervelocity stars by the (binary) black hole in the galactic center,” Astrophys. J. 599, 1129.
Yu, Q., et al., 2007, “On the origin of the kinematic distribution of the subparsec young stars in the galactic center,” Astrophys. J. 666, 919.
Yuan, F., 2010, “Accretion and ejection in Sgr $A *$ ,” e-print arXiv:1002.3012.
Yuan, F., et al., 2002, “A Jet-ADAF model for Sgr $A *$ ,” Astron. Astrophys. 383, 854.
Yuan, F., et al., 2003, “Nonthermal electrons in radiatively inefficient accretion flow models of Sagittarius $A *$ ,” Astrophys. J. 598, 301.
Yuan, F., et al., 2004, “On the nature of the variable infrared emission from Sagittarius $A *$ ,” Astrophys. J. 606, 894.
Yuan, F., et al., 2006, “Testing the radiatively inefficient accretion flow model for Sagittarius $A *$ using the size measurements,” Astrophys. J. Lett. 642, L45.
Yuasa, T., et al., 2008, “Suzaku detection of extended/diffuse hard x-ray emission from the galactic center,” Publ. Astron. Soc. Jpn. 60, 207.
Yusef-Zadeh, F., and F. Melia, 1992, “The bow shock structure of IRS 7—Wind-wind collision near the galactic center,” Astrophys. J. Lett. 385, L41.
Yusef-Zadeh, F., et al., 1986, “Nonthermal radio emission from the galactic center arc,” Astrophys. J. 310, 689.
Yusef-Zadeh, F., et al., 1998, “Proper motions of ionized gas at the galactic center: Evidence for unbound orbiting gas,” Astrophys. J. Lett. 499, L159.
Yusef-Zadeh, F., et al., 2001, “High spectral and spatial resolution observations of shocked molecular hydrogen at the galactic center,” Astrophys. J. 560, 749.
Yusef-Zadeh, F., et al., 2006a, “Flaring activity of Sagittarius $A *$ at 43 and $22 GHz$ : Evidence for expanding hot plasma,” Astrophys. J. 650, 189.
Yusef-Zadeh, F., et al., 2006b, “A multiwavelength study of Sgr $A *$ : The role of near-IR flares in production of x-ray, soft gamma-ray, and submillimeter emission,” Astrophys. J. 644, 198.
Yusef-Zadeh, F., et al., 2008a, “Simultaneous Chandra, CSO, and VLA observations of Sgr $A *$ : The nature of flaring activity,” Astrophys. J. 682, 361.
Yusef-Zadeh, F., et al., 2008b, “Massive star formation in the molecular ring orbiting the black hole at the galactic center,” Astrophys. J. Lett. 683, L147.
Yusef-Zadeh, F., et al., 2009, “Simultaneous multi-wavelength observations of Sgr $A *$ during 2007 April 1–11,” Astrophys. J. 706, 348.
Yusef-Zadeh, F, et al., 2010, private communication.
Zakharov, A. F., et al., 2007, “Apoastron shift constraints on dark matter distribution at the galactic center,” Phys. Rev. D 76, 062001.
Zamaninasab, M., et al., 2010, “Near infrared flares of Sagittarius $A *$ : Importance of near infrared polarimetry,” Astron. Astrophys. 510, 3.
Zelnikov, M. I., and E. A. Vasiliev, 2005, “The influence of dark matter halo onto evolution of supermassive black hole,” Int. J. Mod. Phys. A 20, 4217.
Zhao, J.-H., and W. M. Goss, 1998, “Radio continuum structure of IRS 13 and proper motions of compact HII components at the galactic center,” Astrophys. J. Lett. 499, L163.
Zhao, J.-H., et al., 1992, “A transient radio source near the center of the Milky Way Galaxy,” Science 255, 1538.
Zhao, J.-H., et al., 2001, “Radio variability of Sagittarius $A *$ —A $106 day$ cycle,” Astrophys. J. Lett. 547, L29.
Zhao, H., et al., 2002, “Feeding black holes at galactic centres by capture from isothermal cusps,” New Astron. 7, 385.
Zhao, J.-H., et al., 2003, “Variability of Sagittarius $A *$ : Flares at $1 millimeter$ ,” Astrophys. J. Lett. 586, L29.
Zhao, J.-H., et al., 2009, “Dynamics of ionized gas at the galactic center: Very large array observations of the three-dimensional velocity field and location of the ionized streams in Sagittarius A west,” Astrophys. J. 699, 186.
Zucker, S., et al., 2006, “Probing post-Newtonian physics near the galactic black hole with stellar redshift measurements,” Astrophys. J. Lett. 639, L21.
Zylka, R., et al., 1995, “Anatomy of the Sagittarius A complex. 4: Sgr $A *$ and the central cavity revisited,” Astron. Astrophys. 297, 83.

Reviews of Modern Physics

Export citation

Export citation

The Galactic Center massive black hole and nuclear star cluster

Abstract

Article Text

References (565)

Outline

Information

Filter

Filter

Article Lookup

Enter a citation