The black hole mass–stellar velocity dispersion correlation: bulges versus pseudo-bulges |
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| Authors: | Jian Hu |
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| Institution: | Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Straße 1, D-85741 Garching bei München, Germany |
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| Abstract: | We investigate the correlation between the supermassive black holes (SMBHs) mass ( M bh) and the stellar velocity dispersion (σ*) in two types of host galaxies: the early-type bulges (disc galaxies with classical bulges or elliptical galaxies) and pseudo-bulges. In the form log ( M bh/M⊙) =α+β log (σ*/200 km s−1) , the best-fitting results for the 39 early-type bulges are the slope β= 4.06 ± 0.28 and the normalization α= 8.28 ± 0.05 ; the best-fitting results for the nine pseudo-bulges are β= 4.5 ± 1.3 and α= 7.50 ± 0.18 . Both relations have intrinsic scatter in log M bh of ≲0.27 dex. The M bh–σ* relation for pseudo-bulges is different from the relation in the early-type bulges over the 3σ significance level. The contrasting relations indicate the formation and growth histories of SMBHs depend on their host type. The discrepancy between the slope of the M bh–σ* relations using different definition of velocity dispersion vanishes in our sample, a uniform slope will constrain the coevolution theories of the SMBHs and their host galaxies more effectively. We also find the slope for the 'core' elliptical galaxies at the high-mass range of the relation appears steeper (β≃ 5–6) , which may be the imprint of their origin of dissipationless mergers. |
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| Keywords: | black hole physics galaxies: bulges galaxies: formation galaxies: fundamental parameters galaxies: nuclei |
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