THE EVOLUTION OF BLACK HOLE SCALING RELATIONS IN GALAXY MERGERS

Journal Article · Sun Dec 20 04:00:00 EST 2009 · Astrophysical Journal (Online)

DOI:https://doi.org/10.1088/0004-637X/707/2/L184· OSTI ID:21392547

Johansson, Peter H; Burkert, Andreas; Naab, Thorsten ^[1]

---

1. Universitaets-Sternwarte Muenchen, Scheinerstr. 1, D-81679 Muenchen (Germany)

We study the evolution of black holes (BHs) on the M{sub BH}-sigma and M{sub BH}-M{sub bulge} planes as a function of time in disk galaxies undergoing mergers. We begin the simulations with the progenitor BH masses being initially below (DELTAlog M{sub BH,i} approx -2), on (DELTAlog M{sub BH,i} approx 0), and above (DELTAlog M{sub BH,i} approx 0.5) the observed local relations. The final relations are rapidly established after the final coalescence of the galaxies and their BHs. Progenitors with low initial gas fractions (f{sub gas} = 0.2) starting below the relations evolve onto the relations (DELTAlog M{sub BH,f} approx -0.18), progenitors on the relations stay there (DELTAlog M{sub BH,f} approx 0), and finally progenitors above the relations evolve toward the relations, but still remain above them (DELTAlog M{sub BH,f} approx 0.35). Mergers in which the progenitors have high initial gas fractions (f{sub gas} = 0.8) evolve above the relations in all cases (DELTAlog M{sub BH,f} approx 0.5). We find that the initial gas fraction is the prime source of scatter in the observed relations, dominating over the scatter arising from the evolutionary stage of the merger remnants. The fact that BHs starting above the relations do not evolve onto the relations indicates that our simulations rule out the scenario in which overmassive BHs evolve onto the relations through gas-rich mergers. By implication our simulations thus disfavor the picture in which supermassive BHs develop significantly before their parent bulges.

• OSTI ID: 21392547
• Journal Information: Astrophysical Journal (Online), Journal Name: Astrophysical Journal (Online) Journal Issue: 2 Vol. 707; ISSN 1538-4357
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BLACK HOLES
COALESCENCE
EVOLUTION
GALACTIC EVOLUTION
GALAXIES
INTERACTIONS
MASS
SIMULATION
TIME DEPENDENCE