The Supermassive Black Hole at the Galactic Center

Abstract

The inner few parsecs at the Galactic Center have come under intense scrutiny in recent years, in part due to the exciting broad-band observations of this region, but also because of the growing interest from theorists motivated to study the physics of black hole accretion, magnetized gas dynamics and unusual star formation. The Galactic Center is now known to contain arguably the most compelling supermassive black hole candidate, weighing in at a little over 2.6 million suns. Its interaction with the nearby environment, comprised of clusters of evolved and young stars, a molecular dusty ring, ionized gas streamers, diffuse hot gas, and a hypernova remnant, is providing a wealth of accretion phenomenology and high-energy processes for detailed modeling. In this review, we summarize the latest observational results, and focus on the physical interpretation of the most intriguing object in this region---the compact radio source Sgr A*, thought to be the radiative manifestation of the supermassive black hole.

Annual Review of Astronomy & Astrophysics, Vol. 39 (2001), in press, 48 pages, 20 figures (partially in reduced quality), also available at http://www.mpifr-bonn.mpg.de/staff/hfalcke/publications.html#gcreview

Cited by in corpus (281)

• Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies
• Measuring Distance and Properties of the Milky Way's Central Supermassive Black Hole with Stellar Orbits
• The Galactic Center Massive Black Hole and Nuclear Star Cluster
• A fundamental plane of black hole activity
• Supermassive Black Holes in Galactic Nuclei: Past, Present and Future Research
• Chandra X-ray Spectroscopic Imaging of Sgr A* and the Central Parsec of the Galaxy
• A Scheme to Unify Low-Power Accreting Black Holes - Jet-Dominated Accretion Flows and the Radio/X-Ray Correlation
• Nonthermal Electrons in Radiatively Inefficient Accretion Flow Models of Sagittarius A*
• Near-infrared flares from accreting gas around the supermassive black hole at the Galactic Centre
• Foundations of Black Hole Accretion Disk Theory
• Calculating black hole shadows: Review of analytical studies
• Rapid X-ray flaring from the direction of the supermassive black hole at the Galactic Centre
• Going with the flow: can the base of jets subsume the role of compact accretion disk coronae?
• The Stellar Cusp Around the Supermassive Black Hole in the Galactic Center
• What Drives the Growth of Black Holes?
• Very high energy gamma rays from the direction of Sagittarius A*
• Stellar dynamics in the central arcsecond of our galaxy
• Radiative Models of Sgr A* from GRMHD Simulations
• Unified Rotation Curve of the Galaxy -- Decomposition into de Vaucouleurs Bulge, Disk, Dark Halo, and the 9-kpc Rotation Dip --
• Stellar Processes Near the Massive Black Hole in the Galactic Center
• The Dynamical Structure of Nonradiative Black Hole Accretion Flows
• Variable Infrared Emission from the Supermassive Black Hole at the Center of the Milky Way
• A Jet-ADAF model for Sgr A*
• Interferometric Detection of Linear Polarization from Sagittarius A* at 230 GHz
• The structure of the nuclear stellar cluster of the Milky Way
• A size of ~1 AU for the radio source Sgr A* at the centre of the Milky Way
• Optical properties of black hole in the presence of plasma: shadow
• Could supermassive black holes be quintessential primordial black holes?
• An X-ray, IR, and Submillimeter Flare of Sagittarius A*
• Black Hole Parameter Estimation from Its Shadow
• XMM-Newton observation of the brightest X-ray flare detected so far from SgrA*
• Strong gravitational lensing by braneworld black holes
• Coronal outflow dominated accretion discs: a new possibility for low luminosity black holes?
• Two Dimensional Adiabatic Flows onto a Black Hole: I. Fluid Accretion
• Detection of the Intrinsic Size of Sagittarius A* through Closure Amplitude Imaging (includes Online Supporting Material)
• Evidence for X-ray synchrotron emission from simultaneous mid-IR to X-ray observations of a strong Sgr A* flare
• Polarimetry of near-infrared flares from Sagittarius A*
• A Chandra/HETGS Census of X-ray Variability From Sgr A* During 2012
• On The Nature of the Variable Infrared Emission from Sgr A*
• Discovery of a superluminal Fe K echo at the Galactic Center: The glorious past of Sgr A* preserved by molecular clouds
• First Simultaneous NIR/X-ray Detection of a Flare from SgrA*
• Accretion of low angular momentum material onto black holes: 2D magnetohydrodynamical case
• Flaring Activity of Sgr A* at 43 and 22 GHz: Evidence for Expanding Hot Plasma
• Analytic Kerr black hole lensing for equatorial observers in the strong deflection limit
• Constraints on a charge in the Reissner--Nordström metric for the black hole at the Galactic Center
• BlackHoleCam: fundamental physics of the Galactic center
• Chandra-HETGS Observations of the Brightest Flare Seen from Sgr A*
• A Multi-Wavelength Study of Sgr A*: The Role of Near-IR Flares in Production of X-ray, Soft $\gamma$-ray and Sub-millimeter Emission
• The central parsecs of M87: jet emission and an elusive accretion disc
• Hard X-ray view of the past activity of Sgr A* in a natural Compton mirror
• A near-IR variability study of the Galactic black hole: a red noise source with no detected periodicity
• Probing the Spacetime Around Sgr A* with Radio Pulsars
• Strong deflection limit of black hole gravitational lensing with arbitrary source distances
• X-ray flares reveal mass and angular momentum of the Galactic Center black hole
• Radiatively Inefficient Accretion: Breezes, Winds and Hyperaccretion
• High energy gamma rays from the massive black hole in the Galactic Center
• X-ray hiccups from SgrA* observed by XMM-Newton. The second brightest flare and three moderate flares caught in half a day
• Sgr A* and General Relativity
• 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
• Towards the event horizon -- the supermassive black hole in the Galactic Center
• The Milky Way's Supermassive Black Hole: How good a case is it? A Challenge for Astrophysics & Philosophy of Science
• Wild at Heart:-The Particle Astrophysics of the Galactic Centre
• A polarised infrared flare from Sagittarius A* and the signatures of orbiting plasma hotspots
• A strongly magnetized pulsar within grasp of the Milky Way's supermassive black hole
• Multi-wavelength signals of dark matter annihilations at the Galactic center
• A New X-Ray Flare from the Galactic Nucleus Detected with the XMM-Newton Photon Imaging Cameras
• Simultaneous Chandra, CSO and VLA Observations of Sgr A*: The Nature of Flaring Activity
• Mirages around Kerr black holes and retro-gravitational lenses
• Variability Timescale and Spectral Index of Sgr A* in the Near Infrared: Approximate Bayesian Computation Analysis of the Variability of the Closest Supermassive Black Hole
• Echoes of multiple outbursts of Sagittarius A* revealed by Chandra
• Simultaneous Multi-Wavelength Observations of Sgr A* during 2007 April 1-11
• Millimeter light curves of Sagittarius A* observed during the 2017 Event Horizon Telescope campaign
• Direct Measurements of Black Hole Charge with Future Astrometrical Missions
• The Spectrum and Variability of Circular Polarization in Sagittarius A* from 1.4 to 15 GHz
• How to hide large scale outflows: size constraints on the jets of Sgr A*
• Polarimetric Imaging of the Massive Black Hole at the Galactic Center
• An Accretion-Induced X-ray Flare in Sgr A*
• G359.95-0.04: Pulsar Candidate Near Sgr A*
• Circular Polarization of Radio Emission from Relativistic Jets
• Simulations of the Origin and Fate of the Galactic Center Cloud G2
• Tilted black hole accretion disc models of Sagittarius A*: time-variable millimetre to near-infrared emission
• On the origin of black hole X-ray emission in quiescence: Chandra observations of XTE J1550-564 and H 1743-322
• Electron Acceleration around the Supermassive Black Hole at the Galactic Center
• Pre-Merger Localization of Gravitational-Wave Standard Sirens With LISA: Triggered Search for an Electromagnetic Counterpart
• General relativistic magnetohydrodynamical $\kappa$-jet models for Sgr A*
• Intra-day Variability of Sagittarius A* at 3 Millimeters
• Dynamics of a Massive Black Hole at the Center of a Dense Stellar System
• Variable Linear Polarization from Sagittarius A*: Evidence for a Hot Turbulent Accretion Flow
• The Disruption of Stellar Clusters Containing Massive Black Holes near the Galactic Center
• The Rotation Measure and 3.5mm Polarization of Sgr A*
• On the Nature of Angular Momentum Transport in Nonradiative Accretion Flows
• GRMHD simulations of accretion onto Sgr A*: How important are radiative losses?
• Detection of intrinsic source structure at ~3 Schwarzschild radii with Millimeter-VLBI observations of SAGITTARIUS A*
• Circular polarization from stochastic synchrotron sources
• A Possible Rossby Wave Instability Origin for the Flares in Sagittarius A*
• Sgr A* flares: tidal disruption of asteroids and planets?
• NGC4258: a jet-dominated low-luminosity AGN?
• The Black Hole Mass of NGC 4151: Comparison of Reverberation Mapping and Stellar Dynamical Measurements
• Covariant Magnetoionic Theory I: Ray Propagation
• Evidence for quiescent synchrotron emission in the black hole X-ray transient Swift J1357.2-0933
• The AGASA/SUGAR Anisotropies and TeV Gamma Rays from the Galactic Center: A Possible Signature of Extremely High-energy Neutrons
• The mean infrared emission of SagittariusA*
• Traces of past activity in the Galactic Centre
• The Submillimeter Polarization of Sgr A*
• Black Hole Shadow Image and Visibility Analysis of Sagittarius A*
• Diffuse X-Rays from the Inner 3 Parsecs of the Galaxy
• TeV Emission from the Galactic Center Black-Hole Plerion
• Galactic Center Research: Manifestations of the Central Black Hole
• Jet-lag in Sgr A*: What size and timing measurements tell us about the central black hole in the Milky Way
• A Black Hole in the Galactic Center Complex IRS 13E?
• The Atlas3D project -- XXXI. Nuclear radio emission in nearby early-type galaxies
• A Persistent High-Energy Flux from the Heart of the Milky Way : Integral's view of the Galactic Center
• X-ray Diagnostics of Giant Molecular Clouds in the Galactic Center Region and Past Activity of Sgr A*
• First proper motions of thin dust filaments at the Galactic Center
• Multi-wavelength astronomical searches for primordial black holes
• Repeated X-ray Flaring Activity in Sagittarius A*
• Evidence for A Parsec-scale Jet from The Galactic Center Black Hole: Interaction with Local Gas
• X-ray flares from Sgr A*: star-disk interactions?
• Hot Accretion With Conduction: Spontaneous Thermal Outflows
• Synchrotron Radiation From Radiatively Inefficient Accretion Flow Simulations: Applications to Sgr A*
• Identifying Decaying Supermassive Black Hole Binaries from their Variable Electromagnetic Emission
• Cosmic Ray Production of Lithium-6 by Structure Formation Shocks in the Early Milky Way: A Fossil Record of Dissipative Processes during Galaxy Formation
• Obscuring Active Galactic Nuclei with Nuclear Starburst Disks
• Detection of a High Brightness Temperature Radio Core in the AGN-Driven Molecular Outflow Candidate NGC 1266
• Limits on the Short Term Variability of Sagittarius A* in the Near-Infrared
• Does the Milky Way Produce a Nuclear Galactic Wind?
• Stochastic Acceleration in the Galactic Center HESS Source
• Formation of a galaxy with a central black hole in the Lemaitre-Tolman model
• The X-ray flaring properties of Sgr A* during six years of monitoring with Swift
• Simultaneous Multi-Wavelength Observations of Sgr A*
• Constraints on tidal charge of the supermassive black hole at the Galactic Center with trajectories of bright stars
• The Galactic Center Weather Forecast
• The X-ray-faint Emission of the Supermassive Nuclear Black Hole of IC1459
• A Radio Census of Nuclear Activity in Nearby Galaxies
• General relativistic MHD simulations of non-thermal flaring in Sagittarius A*
• The Intrinsic Two-Dimensional Size of Sagittarius A*
• MHD Simulations of Accretion onto Sgr A*: Quiescent Fluctuations, Outbursts, and Quasi-Periodicity
• A new infrared color criterion for the selection of 0<z<7 AGN: application to deep fields and implications for JWST surveys
• Imaging an Event Horizon: Mitigation of Source Variability of Sagittarius A*
• Detection of the "Active" Nucleus of M32
• Constraints on a tidal charge of the supermassive black hole in M87* with the EHT observations in April 2017
• Direct Feeding of the Black Hole at the Galactic Center with Radial Gas Streams from Close-In Stellar Winds
• Modeling mm- to X-ray flare emission from SgrA*
• New Constraints on the Nature of Radio Emission in Sagittarius A*
• Gravitational Lensing of stars in the central arcsecond of our Galaxy
• Weighing the cusp at the Galactic Centre
• The Murmur of The Hidden Monster: Chandra's Decadal View of The Super-massive Black Hole in M31
• NUclei of GAlaxies: V. Radio emission in 7 NUGA sources
• Gamma-Rays and the Far-Infrared-Radio Continuum Correlation Reveal a Powerful Galactic Centre Wind
• Detection of hard X-ray emission from the Galactic nuclear region with INTEGRAL
• The pattern of accretion flow onto Sgr A*
• A Radio Transient 0.1 pc from Sagittarius A*
• The extreme luminosity states of Sagittarius A*
• Self-consistent spectra from radiative GRMHD simulations of accretion onto Sgr A*
• Diffuse Gamma-ray Emission from the Galactic Center - A Multiple Energy Injection Model
• Spectral and Imaging properties of Sgr A* from High-Resolution 3D GRMHD Simulations with Radiative Cooling
• A Multiwavelength View of a Mass Outflow from the Galactic Center
• Detection of Circular Polarization in M81*
• General Relativistic Flux Modulations from Disk Instabilities in Sagittarius A*
• Compact radio cores: from the first black holes to the last
• Non-thermal Processes in Black-Hole-Jet Magnetospheres
• A Comprehensive Bayesian Discrimination of the Simple Stellar Population Model, Star Formation History and Dust Attenuation Law in the Spectral Energy Distribution Modeling of Galaxies
• The Dynamics of the Magnetoviscous Instability
• A Detection of Sgr A* in the far infrared
• Testing RIAF model for Sgr A* using the size measurements
• Exploring plasma evolution during Sagittarius A* flares
• Imprints of dark matter on gravitational ringing of supermassive black holes
• The Activity of the Neighbours of Seyfert Galaxies
• Unveiling the nature of SgrA* with the geodesic motion of S-stars
• Sgr A* in context: daily flares as a probe of the fundamental X-ray emission process in accreting black holes
• The X-ray Ridge Surrounding Sgr A* at the Galactic Center
• An Inverse Compton Scattering Origin of X-ray Flares from Sgr A*
• Growing Massive Black Holes in a Local Group Environment: the Central Supermassive, Slowly Sinking, and Ejected Populations
• Radio Recombination Lines toward the Galactic Center Lobe
• The role of feedback in accretion on Low Luminosity AGN: Sgr A* case study
• A Systematic Chandra study of Sgr A${}^{\star }$: I. X-ray flare detection
• The Variability of Polarized Radiation from Sgr A*
• From Multiwavelength to Mass Scaling: Accretion and Ejection in Microquasars and AGN
• Continuum emission in NGC1068 and NGC3147: Indications for a turnover in the core spectra
• Constraints on Yukawa gravity parameters from observations of bright stars
• The Galactic Center as a laboratory for theories of gravity and dark matter
• The energetics, evolution, and stellar depletion of Li6 in the early Galaxy
• The black hole at the Galactic Center: observations and models
• Fundamental galaxy parameters for radio-loud AGN and the black hole - radio power connection
• Diffuse X-rays from the Arches and Quintuplet clusters
• A Possible Link Between the Galactic Center HESS Source and Sgr A*
• Close stars and an inactive accretion disk in Sgr A*: Eclipses and flares
• On angular momentum transport in convection-dominated accretion flows
• Probing spacetime noncommutative constant via charged astrophysical black hole lensing
• Covariant Kinetic Theory with an Application to the Coma Cluster
• Rapid Intrinsic Variability of Sgr A* at Radio Wavelengths
• The impact of non-thermal electrons on event horizon scale images and spectra of Sgr A*
• Highest Energy Cosmic Rays and results from the HiRes Experiment
• The Observed Galactic Annihilation Line. Possible Signature of the Cluster for Accreting Small Mass Black Holes
• A Jet Model for the Broadband Spectrum of the Seyfert-1 Galaxy NGC 4051
• Modelling the thermal X-ray emission around the Galactic Centre from colliding Wolf-Rayet winds
• The Sgr B2 X-ray Echo of the Galactic Center Supernova Explosion that Produced Sgr A East
• Sgr A* at low radio frequencies: GMRT observations
• Study of the Gamma-ray Spectrum from the Galactic Center in view of Multi-TeV Dark Matter Candidates
• Flux-limited strong gravitational lensing and dark energy
• A Deep Chandra View of A Candidate Parsec-Scale Jet from the Galactic Center Super-massive Black Hole
• The Galactic Center stellar cluster: The central arcsecond
• On the origin of kinematic distribution of the sub-parsec young stars in the Galactic center
• Sub-mm Jet Properties of the X-Ray Binary Swift J1745$-$26
• Horizon-Penetrating Transonic Accretion Disks around Rotating Black Holes
• Strong lensing and shadow of Ayon-Beato-Garcia (ABG) nonsingular black hole
• Using infrared/X-ray flare statistics to probe the emission regions near the event horizon of Sgr A*
• Gravitational lensing and shadow by a Schwarzschild-like black hole in metric-affine bumblebee gravity
• Colliding Winds in and around the Stellar Group IRS 13E at the Galactic Center
• High Resolution Radio Astronomy Using Very Long Baseline Interferometry
• A "coronal-mass-ejection'' model for flares in Sagittarius A*
• Bright stars and an inactive disk in Sgr A* and other dormant galaxy centers. I. The optically thick disk
• The millimetre variability of M81* -- Multi-epoch dual frequency mm-observations of the nucleus of M81
• Kinetic axi-symmetric gravitational equilibria in collisionless accretion disc plasmas
• Flares and variability from Sagittarius A*: five nights of simultaneous multi-wavelength observations
• Linearly and Circularly Polarized Emission in Sagittarius A*
• No asymmetric outflows from Sagittarius A* during the pericenter passage of the gas cloud G2
• Consistency of the Infrared Variability of Sgr A* over 22 years
• Capture of a Red Giant by the Black Hole Sagittarius A* as a Possible Origin for the TeV Gamma Rays from the Galactic Center
• Imaging black holes: past, present and future
• The absence of a thin disc in M81
• Dynamics of Hot Accretion Flow with Thermal Conduction
• Soft gamma-ray constraints on a bright flare from the Galactic Center supermassive black hole
• Hybrid model of GeV-TeV gamma ray emission from Galactic Center
• Detection of Sagittarius A* at 330 MHz with the Very Large Array
• Fractal Holography: a geometric re-interpretation of cosmological large scale structure
• Study of relativistic accretion flow around KTN black hole with shocks
• Radio Linear and Circular Polarization from M81*
• Analytical and numerical studies of central galactic outflows powered by tidal disruption events -- a model for the Fermi bubbles?
• Synchrotron Blob Model of Infrared and X-ray Flares from Sagittarius A${}^{\ast }$
• The fate of supernova remnants near quiescent supermassive black holes
• The Galactic Centre Source IRS 13E: a Post-LBV Wolf-Rayet Colliding Wind Binary?
• Supernovae without host galaxy? - Hypervelocity stars in foreign galaxies
• Constraining Radiatively Inefficient Accretion Flows with Polarization
• Is Thermal Expansion Driving the Initial Gas Ejection in NGC 6251?
• Dusty plasma in active galactic nuclei
• Accretion models of Sgr A*
• A single HII region model of the strong interstellar scattering towards Sgr A*
• Monitoring the Galactic Centre with Australia Telescope Compact Array
• The Discovery of Sgr A*
• Coordinated multi-wavelength observations of Sgr A*
• Role of galactic bars in the formation of spiral arms: A study through orbital and escape dynamics -- I
• Gravitational waves from a dust disk around a Schwarzschild black hole
• Galactic black hole immersed in a dark halo with its surrounding thin accretion disk
• The Physics of E x B-Drifting Jets
• High-resolution observations of SDSS J080800.99+483807.7 in the optical and radio domains. A possible example of jet-triggered star formation
• Resolving the Nuclear Radio Emission from M32 with Very Large Array
• Detection of a 20 minute time lag observed from Sgr A* between 8 and 10 GHz with the VLA
• Flare emission from Sagittarius A*
• Transrelativistic Synchrotron Emissivity, Cross-Section, and Polarization
• Atomic X-ray Spectroscopy of Accreting Black Holes
• Very Large Array multi-band monitoring observations of M 31*
• Sculpting the Stellar Cusp in the Galactic Center
• High-resolution Millimeter-VLBI Imaging of Sgr A*
• Long-Term Radio Modulation in Sagittarius A* from Spin-Induced Disk Precession
• Effects of wind on radiation spectra from magnetized accretion disks
• Gravitational lensing signature of matter distribution around Schwarzschild black hole
• Gravitationally Focused Dark Matter Around Compact Stars
• Self-similar solutions of viscous and resistive ADAFs with thermal conduction
• Time Lag in Intra-Day Variability of Sgr A* between the Light Curves at 90 and 102GHz
• The contribution of young core-collapse supernova remnants to the X-ray emission near quiescent supermassive black holes
• The frozen (inactive) disk in Sgr A: freezing the accretion of the hot gas too?
• Ultra high energy cosmic ray sources & experimental results
• A cool disk in the Galactic Center?
• Sgr A* as probe of the theory of supermassive compact objects without event horizon
• Viewing angle effects in quasar application to cosmology
• Hydrodynamical wind on magnetized Accretion Flows with Convection
• The Jet in the Galactic Center: An Ideal Laboratory for Magnetohydrodynamics and General Relativity
• Radio Variability of the Sagittarius ${\mathrm{A}}^{\ast }$ due to an Orbiting Star
• Shadowing of the Nascent Jet in NGC 4261 by a Line-Emitting Supersonic Accretion Disk
• High Energy Activity of the Super-Massive Black Hole at the Galactic Center
• A Relativistic Disk in Sagittarius A*
• Juergen Ehlers - and the Fate of the Black-Hole Spacetimes
• Microlensing in phase space I: Continuous propagation of variability moments
• A New X-Ray Flare from the Galactic Nucleus Detected with the XMM-Newton
• SgrA* emission at 7mm: variability and periodicity
• The Core-shift of Sagittarius A* as a Discriminant between Disk and Jet Emission Models with millimeter-VLBI
• Linear and Circular Polarization Properties of Jets
• HOLESOM: Constraining the Properties of Slowly-Accreting Massive Black Holes with Self-Organizing Maps
• High Energy Emission from the Galactic Center
• Variability of Sagittarius A* at 3 GHz on minute-scale with MeerKAT