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

Journal Article · Sun Jan 01 00:00:00 EST 2012 · Advances in Astronomy

DOI:https://doi.org/10.1155/2012/946368· OSTI ID:1209641

Erwin, Peter ^[1]; Gadotti, Dimitri Alexei ^[2]

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1. Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstraβe, 85748 Garching, Germany, Universitäts-Sternwarte München, Scheinerstraβe 1, 81679 München, Germany
2. European Southern Observatory, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago 19, Chile

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 the bulge component of galaxies, the masses of NSCs correlate much better with the total galaxy stellar mass. In addition, the mass ratio $M_{\text{NSC}}/M_{\star ,\hspace{0.17em}\text{tot}}$ for NSCs in spirals (at least those with Hubble types Sc and later) is typically an order of magnitude smaller than the mass ratio $M_{\text{BH}}/M_{\star ,\hspace{0.17em}\text{bul}}$ of 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.

• Sponsoring Organization: USDOE
• OSTI ID: 1209641
• Journal Information: Advances in Astronomy, Journal Name: Advances in Astronomy Vol. 2012; ISSN 1687-7969
• Publisher: Hindawi Publishing Corporation
• Country of Publication: Country unknown/Code not available
• Language: English