Supermassive black holes (BHs) have been found in 85 galaxies by dynamical modeling of spatially resolved kinematics. The Hubble Space Telescope revolutionized BH research by advancing the subject from its proof-of-concept phase into quantitative studies of BH demographics. Most influential was the discovery of a tight correlation between BH mass and the velocity dispersion σ of the bulge component of the host galaxy. Together with similar correlations with bulge luminosity and mass, this led to the widespread belief that BHs and bulges coevolve by regulating each other's growth. Conclusions based on one set of correlations from in brightest cluster ellipticals to in the smallest galaxies dominated BH work for more than a decade. New results are now replacing this simple story with a richer and more plausible picture in which BHs correlate differently with different galaxy components. A reasonable aim is to use this progress to refine our understanding of BH-galaxy coevolution. BHs with masses of 105−106M...

https://www.annualreviews.org/doi/suppl/10.1146/annurev-astro-082708-101811/suppl_file/aa51_kormendy_supmat.pdf

Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies

We review progress over the past decade in observations of large-scale star formation, with a focus on the interface between extragalactic and Galactic studies. Methods of measuring gas contents and star-formation rates are discussed, and updated prescriptions for calculating star-formation rates are provided. We review relations between star formation and gas on scales ranging from entire galaxies to individual molecular clouds.

Star Formation in the Milky Way and Nearby Galaxies

This is the Supplemental Material to Kormendy and Ho 2013, ARAA, 51, 511 (arXiv:1304.7762). Section S1 summarizes indirect methods that are used to estimate black hole (BH) masses for galaxies with active nuclei (AGNs). Section S2 lists the observational criteria that are used to classify classical and pseudo bulges. The (pseudo)bulge classifications used in the main paper are not based on physical interpretation; rather, they are based on these observational criteria. Section S3 supplements the BH database in Section 5 of the main paper and Section S4 here. It discusses corrections to galaxy and BH parameters, most importantly to 2MASS K-band apparent magnitudes. It presents evidence that corrections are needed because 2MASS misses light at large radii when the images of galaxies subtend large angles on the sky or have shallow outer brightness gradients. Section S4 reproduces essentially verbatim the first part of Section 5 in the main paper, the BH database. It includes the list of BH and host-galaxy properties (Tables 2 and 3). Its most important purpose is to provide all of the notes on individual objects.

Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies: Supplemental Material

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. We present the current evidence, 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 1e6 Msun, beyond any reasonable doubt. We report what is known about the structure and evolution of the dense nuclear star cluster surrounding this black hole, including the astounding fact that stars have been forming in the vicinity of Sgr A* recently, apparently with a top-heavy stellar mass function. We discuss a dense concentration of fainter stars centered in the immediate vicinity of the massive black hole, 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'. We also summarize what is known about the emission properties of the accreting gas onto Sgr A* and how this emission is beginning to delineate the physical properties in the hot accretion zone around the event horizon.

The galactic center massive black hole and nuclear star cluster

Our Galaxy, the Milky Way, is a benchmark for understanding disk galaxies. It is the only galaxy whose formation history can be studied using the full distribution of stars from faint dwarfs to supergiants. The oldest components provide us with unique insight into how galaxies form and evolve over billions of years. The Galaxy is a luminous (L⋆) barred spiral with a central box/peanut bulge, a dominant disk, and a diffuse stellar halo. Based on global properties, it falls in the sparsely populated “green valley” region of the galaxy color-magnitude diagram. Here we review the key integrated, structural and kinematic parameters of the Galaxy, and point to uncertainties as well as directions for future progress. Galactic studies will continue to play a fundamental role far into the future because there are measurements that can only be made in the near field and much of contemporary astrophysics depends on such observations.

The Galaxy in Context: Structural, Kinematic, and Integrated Properties

We analyse IRAS and COBE DIRBE data at wavelengths between 2.2 and 240 of the central 500 pc of the Galaxy and derive the large-scale distribution of stars and interstellar matter in the Nuclear Bulge. Models of the Galactic Disk and Bulge are developed in order to correctly decompose the total surface brightness maps of the inner Galaxy and to apply proper extinction corrections. The Nuclear Bulge appears as a distinct, massive disk-like complex of stars and molecular clouds which is, on a large scale, symmetric with respect to the Galactic Centre. It is distinguished from the Galactic Bulge by its flat disk-like morphology, very high density of stars and molecular gas, and ongoing star formation. The Nuclear Bulge consists of an R^(-2) Nuclear Stellar Cluster at the centre, a large Nuclear Stellar Disk with radius 230 ± 20 pc and scale height 45 ± 5 pc, and the Nuclear Molecular Disk of same size. The total stellar mass and luminosity of the Nuclear Bulge are 1.4 ± 0.6 x 10^9 and 2.5 ± 1 x 10^9, respectively. About 70% of the luminosity is due to optical and UV radiation from young massive Main-Sequence stars which are most abundant in the Nuclear Stellar Cluster. For the first time, we derive a photometric mass distribution for the central 500 pc of the Galaxy which is fully consistent with the kinematic mass distribution. We find that the often cited R^(-2) distribution holds only for the central ~30 pc and that at larger radii the mass distribution is dominated by the Nuclear Stellar Disk which has a flatter density profile. The total interstellar hydrogen mass in the Nuclear Bulge is M_H = 2 ± 0.3 x 10^7, distributed in a warm inner disk with R = 110 ± 20 pc and a massive, cold outer torus which contains more than 80% of this mass. Interstellar matter in the Nuclear Bulge is very clumpy with ~90% of the mass contained in dense and massive molecular clouds with a volume filling factor of only a few per cent. This extreme clumpiness, probably caused by the tidal stability limit in the gravitational potential of the Nuclear Bulge, enables the strong interstellar radiation field to penetrate the entire Nuclear Bulge and explains the relatively low average extinction towards the Galactic Centre. In addition, we find 3 x 10^7 of cold and dense material outside the Nuclear Bulge at positive longitudes and 1 x 10^7 at negative longitudes. This material is not heated by the stars in the Nuclear Bulge and gives rise to the observed asymmetry in the distribution of interstellar matter in the Central Molecular Zone.

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The Nuclear Bulge of the Galaxy. III. Large-Scale Physical Characteristics of Stars and Interstellar Matter

We present first results from a submillimetre continuum survey of the Galactic Centre `Central Molecular Zone' (CMZ), made with SCUBA on the James Clerk Maxwell Telescope. SCUBA's scan-map mode has allowed us to make extremely wide-field maps of thermal dust emission with unprecedented speed and sensitivity. We also discuss some issues related to the elimination of artefacts in scan-map data. Our simultaneous 850/450 micron maps have a total size of approximately 2.8 x 0.5 degrees (400 x 75 pc) elongated along the galactic plane. They cover the Sgr A region-including Sgr A*, the circumnuclear disc, and the +20 km/s and +50 km/s clouds; the area around the Pistol; Sgr B2-the brightest feature on the map; and at their Galactic Western and Eastern edges the Sgr C and Sgr D regions. There are many striking features such as filaments and shell-like structures, as well as point sources such as Sgr A* itself. The total mass in the Central Molecular Zone is greater than that revealed in previous optically-thin molecular line maps by a factor of ~3, and new details are revealed on scales down to 0.33 pc across this 400 pc wide region.

A deep submillimetre survey of the Galactic Centre

First radio astronomical estimate of the temperature of Pluto

We present submm images of Sgr A* and its surroundings obtained at 800, 600 and 450 $\mu$m with the JCMT and derive flux densities of Sgr A* at all three wave- lengths. Combined with upper limits by Gezari and associates at MIR wavelengths a time averaged radio spectrum is obtained which increases $\propto \nu^{1/3}$, attains a maximum at $\nu_max \ga 600 GHz$ and must decrease rapidly at fre- quencies $\ga 10^4$GHz. This spectrum allows for about $3 M}_\odot$ of 50K dust and associated hydrogen in the telescope beam. While variations on time-scales of a few months are now well established for the frequency range $\nu \la 100 GHz$, our investigation of variability at higher frequencies still yields only marginal results. The Circum-Nuclear Disk (CND) extends over the central 12 pc. At the galactocentric radius $R \sim 1 pc$ dust and hydrogen column densities drop to low values and form the Central Cavity. Our submm images show that the bottom of this cavity is rather flat. Variations in the dust emission are just consistent with the detection of a `Tongue' of $\sim 200 M_\odot$ of atomic hydrogen reported by Jackson et al. (1993) to be located between the Northern and the Eastern Arm of the Minispiral. We present a revised submm/IR spectrum of the central $30\arcsec$ (R$\la 0.6 pc$) with flux densities corrected for an interstellar extinction of $A_v \sim 31 mag$. This spectrum attains its maximum at $\lambda \sim 20 \mu m$ and comes from dust with temperatures $\sim 170 - 400 K$ which is associated with the Eastern Arm and the East-West Bar. The in- tegrated luminosity is $\sim 5 10^6 L_\odot$ to which emission at $\lambda \la 30 \mu m$ contributes $\sim 80\%$. Heating of this dust is not provided by a central source but rather by a cluster of hot ($T eff \sim 3 - 3.5 10^4 K$) and luminous stars which could include the He{\sc i}/H{\sc i}-stars detected by

Peter G. Mezger

Papers

The Nuclear Bulge of the Galaxy. III. Large-Scale Physical Characteristics of Stars and Interstellar Matter

A deep submillimetre survey of the Galactic Centre

First radio astronomical estimate of the temperature of Pluto

Anatomy of the Sagittarius A complex: IV. Sgr A* and the Central Cavity revisi- ted

Anatomy of the sagittarius a complex. 4. Sgr a* and the central cavity revisi- ted