Evidence for the Preferential Disruption of Moderately Massive Stars by Supermassive Black Holes

Abstract Tidal disruption events (TDEs) provide a unique opportunity to probe the stellar populations around supermassive black holes (SMBHs). By combining light-curve modeling with spectral line information and knowledge about the stellar populations in the host galaxies, we are able to constrain the properties of the disrupted star for three TDEs. The TDEs in our sample have UV spectra, and measurements of the UV N iii to C iii line ratios enabled estimates of the nitrogen-to-carbon abundance ratios for these events. We show that the measured nitrogen line widths are consistent with originating from the disrupted stellar material dispersed by the central SMBH. We find that these nitrogen-to-carbon abundance ratios necessitate the disruption of moderately massive stars (≳1–2 M ⊙). We determine that these moderately massive disruptions are overrepresented by a factor of ≳102 when compared to the overall stellar population of the post-starburst galaxy hosts. This implies that SMBHs are preferentially disrupting higher mass stars, possibly due to ongoing top-heavy star formation in nuclear star clusters or to dynamical mechanisms that preferentially transport higher mass stars to their tidal radii.

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Supermassive Black Holes

The First Galaxies in the Universe ◽

10.23943/princeton/9780691144917.003.0007 ◽

2013 ◽

Author(s):

Abraham Loeb ◽

Steven R. Furlanetto

Keyword(s):

Black Holes ◽

Black Hole ◽

Massive Stars ◽

Galactic Nuclei ◽

Stellar Mass ◽

Supermassive Black Holes ◽

Material Object ◽

Formation Mechanisms ◽

Host Galaxies ◽

Bright Source

This chapter analyzes formation mechanisms for supermassive black holes, their observable characteristics, and their interactions with their host galaxies and the wider Universe. A black hole is the end product of the complete gravitational collapse of a material object, such as a massive star. It is surrounded by a horizon from which even light cannot escape. Astrophysical black holes appear in two flavors: stellar-mass black holes that form when massive stars die, and the monstrous supermassive black holes that sit at the center of galaxies, reaching masses of up to ten billion Suns. The latter type is observed as active galactic nuclei (AGN), and the chapter introduces the quasar—a point-like (“quasi-stellar”) bright source at the center of a galaxy which serves as the most powerful type of AGN—in discussing the observable nature of supermassive black holes.

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Host Galaxies of Obscured Quasars: Infant Starbursts Caught in Action

Proceedings of the International Astronomical Union ◽

10.1017/s174392131000579x ◽

2009 ◽

Vol 5 (S267) ◽

pp. 118-118

Author(s):

Xin Liu ◽

Nadia L. Zakamska ◽

Jenny E. Greene ◽

Michael A. Strauss ◽

Julian H. Krolik

Keyword(s):

Black Holes ◽

Pilot Study ◽

Stellar Populations ◽

Supermassive Black Holes ◽

Substantial Contribution ◽

Host Galaxy ◽

Host Galaxies ◽

Massive Galaxies

Supermassive black holes (SMBHs) in the centers of massive galaxies are thought to predominantly grow in brief Eddington-rate quasar phases accompanied by starbursts, but on-going starbursts in luminous quasars are difficult to observe. Buried under the natural coronagraph, obscured quasars offer a unique window for direct, robust host-galaxy spectroscopy otherwise virtually inaccessible for luminous quasars. Our pilot study at z ~ 0.5 (Liu et al. 2009) revealed a substantial contribution from very young stellar populations with ages less than ~ 100 Myr in all of the observed host galaxy spectra. More dramatically, in three out of the nine SDSS quasars observed, we have witnessed strong infant starbursts with ages of ~ 5 Myr, clocked by the telltale Wolf–Rayet emission features.

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The energetic role of massive stars in the AGN phenomenon

Symposium - International Astronomical Union ◽

10.1017/s0074180900206608 ◽

1999 ◽

Vol 193 ◽

pp. 703-715

Author(s):

Timothy M. Heckman

Keyword(s):

Black Holes ◽

Massive Stars ◽

Uv Light ◽

Radiant Energy ◽

Supermassive Black Holes ◽

High Mass ◽

Continuum Emission ◽

Hot Stars

I review the evidence for a possible connection between AGN and starbursts and assess the energetic role of massive stars in the AGN phenomenon. My particular focus is on UV spectroscopy, since this is the energetically dominant spectral regime for the hot high-mass stars that power starbursts, and contains a wealth of spectral features for diagnosing the presence of such stars. I also review the non-stellar sources of UV line and continuum emission in AGN, including scattered or reprocessed light from the ‘central engine’. Spectroscopy directly shows that hot stars provide most of the UV light in about half of the brightest type 2 Seyfert nuclei and UV-bright LINERS. The population of hot stars in these AGN is typically heavily extinct and reddened by dust with A(1600Å) ≃ 2–4 mag. The implied intrinsic UV luminosities of the starburst range from 108 to 109 L⊙ in the LINERS to 1010 to 1011 L⊙ in the type 2 Seyferts. Massive stars play an energetically significant role in many AGN, but the causal or evolution connection between starbursts and AGN is unclear. I also consider the energetics of massive stars and accreting supermassive black holes from a global, cosmic perspective. Recent inventories in the local universe of the cumulative effect of nuclear burning (metal production) and of AGN-fueling (compact dark objects in galactic nuclei) imply that accretion onto supermassive black holes may have produced as much radiant energy as massive stars over the history of the universe.

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Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). VIII. A less biased view of the early co-evolution of black holes and host galaxies

Publications of the Astronomical Society of Japan ◽

10.1093/pasj/psz096 ◽

2019 ◽

Vol 71 (6) ◽

Cited By ~ 10

Author(s):

Takuma Izumi ◽

Masafusa Onoue ◽

Yoshiki Matsuoka ◽

Tohru Nagao ◽

Michael A Strauss ◽

...

Keyword(s):

Black Holes ◽

Far Infrared ◽

Supermassive Black Holes ◽

Host Galaxies ◽

Star Forming ◽

Wide Range ◽

The Galaxy ◽

Order Of Magnitude ◽

Local Relation ◽

Almost All

Abstract We present ALMA [C ii] line and far-infrared (FIR) continuum observations of three $z \gt 6$ low-luminosity quasars ($M_{\rm 1450} \gt -25$ mag) discovered by our Subaru Hyper Suprime-Cam (HSC) survey. The [C ii] line was detected in all three targets with luminosities of $(2.4\mbox{--}9.5) \times 10^8\, L_{\odot }$, about one order of magnitude smaller than optically luminous ($M_{\rm 1450} \lesssim -25$ mag) quasars. The FIR continuum luminosities range from $\lt 9 \times 10^{10}\, L_{\odot }$ (3 $\sigma$ limit) to ${\sim } 2 \times 10^{12}\, L_{\odot }$, indicating a wide range in star formation rates in these galaxies. Most of the HSC quasars studied thus far show [C ii]/ FIR luminosity ratios similar to local star-forming galaxies. Using the [C ii]-based dynamical mass ($M_{\rm dyn}$) as a surrogate for bulge stellar mass ($M_{\rm\, bulge}$), we find that a significant fraction of low-luminosity quasars are located on or even below the local $M_{\rm\, BH}$–$M_{\rm\, bulge}$ relation, particularly at the massive end of the galaxy mass distribution. In contrast, previous studies of optically luminous quasars have found that black holes are overmassive relative to the local relation. Given the low luminosities of our targets, we are exploring the nature of the early co-evolution of supermassive black holes and their hosts in a less biased way. Almost all of the quasars presented in this work are growing their black hole mass at a much higher pace at $z \sim 6$ than the parallel growth model, in which supermassive black holes and their hosts grow simultaneously to match the local $M_{\rm\, BH}$–$M_{\rm\, bulge}$ relation at all redshifts. As the low-luminosity quasars appear to realize the local co-evolutionary relation even at $z \sim 6$, they should have experienced vigorous starbursts prior to the currently observed quasar phase to catch up with the relation.

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Coevolution of supermassive black holes and their host galaxies

10.1063/1.3009487 ◽

2008 ◽

Author(s):

J. K. Kotilainen ◽

R. Decarli ◽

R. Falomo ◽

M. Labita ◽

R. Scarpa ◽

...

Keyword(s):

Black Holes ◽

Supermassive Black Holes ◽

Host Galaxies

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Supermassive black holes: Coevolution (or not) of black holes and host galaxies

Proceedings of the International Astronomical Union ◽

10.1017/s174392131300495x ◽

2012 ◽

Vol 8 (S295) ◽

pp. 241-256

Author(s):

John Kormendy

Keyword(s):

Black Holes ◽

Galaxy Formation ◽

Globular Clusters ◽

Hubble Space Telescope ◽

Supermassive Black Holes ◽

Host Galaxy ◽

Late Time ◽

Host Galaxies ◽

Energy Feedback ◽

Negative Effect

AbstractSupermassive black holes (BHs) have been found in 75 galaxies by observing spatially resolved dynamics. The Hubble Space Telescope (HST) revolutionized BH work 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 masses M• and the velocity dispersions σ of stars in the host galaxy bulge components at radii where the stars mostly feel each other and not the BH. Together with correlations between M• and bulge luminosity, with the ‘missing light’ that defines galaxy cores, and with numbers of globular clusters, this has led to the conclusion that BHs and bulges coevolve by regulating each other's growth. This simple picture with one set of correlations for all galaxies dominated BH work in the past decade.New results are now replacing the above, simple story with a richer and more plausible picture in which BHs correlate differently with different kinds of galaxy components. BHs with masses of 105—106M⊙ live in some bulgeless galaxies. So classical (merger-built) bulges are not necessary equipment for BH formation. On the other hand, while they live in galaxy disks, BHs do not correlate with galaxy disks or with disk-grown pseudobulges. They also have no special correlation with dark matter halos beyond the fact that halo gravity controls galaxy formation. This leads to the suggestion that there are two modes of BH feeding, (1) local, secular and episodic feeding of small BHs in largely bulgeless galaxies that involves too little energy feedback to drive BH–host-galaxy coevolution and (2) global feeding in major galaxy mergers that rapidly grows giant BHs in short-duration events whose energy feedback does affect galaxy formation. After these quasar-like phases, maintenance-mode BH feedback into hot, X-ray-emitting gas continues to have a primarily negative effect in preventing late-time star formation when cold gas or gas-rich galaxies get accreted. Finally, the highest-mass galaxies inherit coevolution effects from smaller galaxies; the tightness of their BH correlations is caused mainly by averaging during dissipationless major mergers.

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A FUNDAMENTAL EQUATION FOR SUPERMASSIVE BLACK HOLES

International Journal of Modern Physics D ◽

10.1142/s0218271811020330 ◽

2011 ◽

Vol 20 (12) ◽

pp. 2305-2315 ◽

Cited By ~ 7

Author(s):

ANTONIO FEOLI ◽

LUIGI MANCINI

Keyword(s):

Black Holes ◽

Angular Momentum ◽

Scaling Laws ◽

Velocity Dispersion ◽

Fundamental Equation ◽

Supermassive Black Holes ◽

Host Galaxies ◽

Starting Point ◽

Interstellar Material ◽

Energy And Momentum

We developed a theoretical model that is able to give a common origin to the correlations between the mass M• of supermassive black holes and the mass, velocity dispersion, kinetic energy and momentum parameter of the corresponding host galaxies. Our model is essentially based on the transformation of the angular momentum of the interstellar material, which falls into the black hole, into the angular momentum of the radiation emitted in this process. In this framework, we predict the existence of a relation of the form M• ∝ R e σ3, which is confirmed by the experimental data and can be the starting point to understand the other popular scaling laws too.

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Correlations between supermassive black holes and hot gas atmospheres in IllustrisTNG and X-ray observations

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3880 ◽

2020 ◽

Vol 501 (2) ◽

pp. 2210-2230

Author(s):

Nhut Truong ◽

Annalisa Pillepich ◽

Norbert Werner

Keyword(s):

Black Holes ◽

Supermassive Black Holes ◽

High Mass ◽

Mass Relation ◽

Host Galaxies ◽

X Ray ◽

Hierarchical Assembly ◽

Hot Gas ◽

The Masses

ABSTRACT Recent X-ray observations have revealed remarkable correlations between the masses of central supermassive black holes (SMBHs) and the X-ray properties of the hot atmospheres permeating their host galaxies, thereby indicating the crucial role of the atmospheric gas in tracing SMBH growth in the high-mass regime. We examine this topic theoretically using the IllustrisTNG cosmological simulations and provide insights to the nature of this SMBH – gaseous halo connection. By carrying out a mock X-ray analysis for a mass-selected sample of TNG100 simulated galaxies at $z$ = 0, we inspect the relationship between the masses of SMBHs and the hot gas temperatures and luminosities at various spatial and halo scales – from galactic (∼Re) to group/cluster scales (∼R500c). We find strong SMBH-X-ray correlations mostly in quenched galaxies and find that the correlations become stronger and tighter at larger radii. Critically, the X-ray temperature (kBTX) at large radii (r ≳ 5Re) traces the SMBH mass with a remarkably small scatter (∼0.2 dex). The relations emerging from IllustrisTNG are broadly consistent with those obtained from recent X-ray observations. Overall, our analysis suggests that, within the framework of IllustrisTNG, the present-time MBH–kBTX correlations at the high-mass end (MBH ≳ 108M⊙) are fundamentally a reflection of the SMBH mass–halo mass relation, which at such high masses is set by the hierarchical assembly of structures. The exact form, locus, and scatter of those scaling relations are, however, sensitive to feedback processes such as those driven by star formation and SMBH activity.

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