scholarly journals Do Nuclear Star Clusters and Supermassive Black Holes Follow the Same Host-Galaxy Correlations?

2010 ◽  
Author(s):  
Peter Erwin ◽  
Dimitri Gadotti ◽  
Victor P. Debattista ◽  
C. C. Popescu
Keyword(s):  
Black Holes ◽  
Star Clusters ◽  
Supermassive Black Holes ◽  
Host Galaxy

scholarly journals Do Nuclear Star Clusters and Supermassive Black Holes Follow the Same Host-Galaxy Correlations?

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Peter Erwin ◽  
Dimitri Alexei Gadotti
Keyword(s):  
Black Holes ◽  
Star Clusters ◽  
Careful Analysis ◽  
Stellar Mass ◽  
Supermassive Black Holes ◽  
Host Galaxy ◽  
Mass Ratio ◽  
Host Galaxies ◽  
Order Of Magnitude ◽  
The Masses

Studies have suggested that there is a strong correlation between the masses of nuclear star clusters (NSCs) and their host galaxies, a correlation which is said to be an extension of the well-known correlations between supermassive black holes (SMBHs) and their host galaxies. But careful analysis of disk galaxies—including 2D bulge/disk/bar decompositions—shows that while SMBHs correlate with the stellar mass of thebulgecomponent of galaxies, the masses of NSCs correlate much better with thetotalgalaxy stellar mass. In addition, the mass ratioMNSC/M⋆, totfor NSCs in spirals (at least those with Hubble types Sc and later) is typically an order of magnitude smaller than the mass ratioMBH/M⋆, bulof SMBHs. The absence of a universal “central massive object” correlation argues against common formation and growth mechanisms for both SMBHs and NSCs. We also discuss evidence for a break in the NSC-host galaxy correlation, galaxies with Hubble types earlier than Sbc appear to host systematically more massive NSCs than do types Sc and later.

scholarly journals Compact nuclear objects and properties of their parent galaxies

2013 ◽  
Vol 9 (S304) ◽  
pp. 379-382
Author(s):  
Anatoly V. Zasov ◽  
Anatoly M. Cherepashchuk
Keyword(s):  
Black Holes ◽  
Total Mass ◽  
Color Index ◽  
Star Clusters ◽  
Supermassive Black Holes ◽  
Host Galaxy ◽  
Maximal Velocity ◽  
Interstellar Gas ◽  
Active Growth ◽  
Nuclear Clusters

AbstractWe consider the relationship between the masses of the compact nuclear objects in the centers of disky galaxies – supermassive black holes (SMBHs) or nuclear star clusters (NCs) – and such parameters as the maximal velocity of rotation Vmax, obtained from the rotation curves, indicative dynamical mass M25, and the color index (B−V) of their parent galaxies. It was found that the mass of nuclear clusters Mnc correlates more closely with the velocity of rotation and total mass of galaxies than the mass of supermassive black holes Mbh. The dependence of masses of the central objects on the color index is bimodal: galaxies of the red group (red-sequence), which have (B−V) > 0.6−0.7, differ from bluer galaxies, by higher values of Mbh for similar host-galaxy parameters. In contrast, in the diagrams for nuclear clusters the “blue” and “red” galaxies form unified sequences. It agrees with scenarios in which most red-group galaxies form as a result of loss of interstellar gas in a stage of high nuclear activity in galaxies whose central black-hole masses are high, exceeding 106 − 107M⊙ (depending on the total mass of the galaxy). The active growth of nuclear star clusters possibly begun after the violent AGN activity.

scholarly journals Nuclear star clusters

2009 ◽  
Vol 5 (S266) ◽  
pp. 58-63 ◽  
Author(s):  
Torsten Böker
Keyword(s):  
Black Holes ◽  
Structural Properties ◽  
Galaxy Evolution ◽  
Globular Clusters ◽  
Star Clusters ◽  
Supermassive Black Holes ◽  
Subsequent Growth ◽  
Local Universe ◽  
Fundamental Plane ◽  
Evolutionary Connection

AbstractThe centers of most galaxies in the local Universe are occupied by compact, barely resolved sources. Based on their structural properties, position in the Fundamental Plane, and integrated spectra, these sources clearly have a stellar origin. They are therefore called ‘nuclear star clusters’ (NCs) or ‘stellar nuclei’. NCs are found in galaxies of all Hubble types, suggesting that their formation is intricately linked to galaxy evolution. Here, I review some recent studies of NCs, describe ideas for their formation and subsequent growth, and touch on their possible evolutionary connection with both supermassive black holes and globular clusters.

scholarly journals The fates of merging supermassive black holes and a proposal for a new class of X-ray sources

2020 ◽  
Vol 498 (3) ◽  
pp. 3807-3816
Author(s):  
Charles Zivancev ◽  
Jeremiah Ostriker ◽  
Andreas H W Küpper
Keyword(s):  
Black Holes ◽  
Structure Formation ◽  
Hierarchical Structure ◽  
Dynamical Evolution ◽  
Supermassive Black Holes ◽  
Host Galaxy ◽  
X Ray ◽  
Massive Galaxies ◽  
New Class ◽  
Low Mass

ABSTRACT We perform N-body simulations on some of the most massive galaxies extracted from a cosmological simulation of hierarchical structure formation with total masses in the range 1012 M⊙ < Mtot < 3 × 1013 M⊙ from 4 ≥ z ≥ 0. After galactic mergers, we track the dynamical evolution of the infalling black holes (BHs) around their host’s central BHs (CBHs). From 11 different simulations, we find that, of the 86 infalling BHs with masses >104 M⊙, 36 merge with their host’s CBH, 13 are ejected from their host galaxy, and 37 are still orbiting at z = 0. Across all galaxies, 33 BHs are kicked to a higher orbit after close interactions with the CBH binary or multiple, after which only one of them merged with their hosts. These orbiting BHs should be detectable by their anomalous (not low-mass X-ray binary) spectra. The X-ray luminosities of the orbiting massive BHs at z = 0 are in the range $10^{28}-10^{43}\, \mathrm{erg}~\mathrm{s}^{-1}$, with a currently undetectable median value of $10^{33}\, \mathrm{erg}~\mathrm{s}^{-1}$. However, the most luminous ∼5 per cent should be detectable by existing X-ray facilities.

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