Basu, Shantanu and Das, Arpan (2019) The Mass Function of Supermassive Black Holes in the Direct-collapse Scenario. The Astrophysical Journal, 879 (1). L3. ISSN 2041-8213
Basu_2019_ApJL_879_L3.pdf - Published Version
Download (395kB)
Abstract
One of the ideas that explains the existence of supermassive black holes (SMBHs) that are in place by z ∼ 7 is that there was an earlier phase of very rapid accretion onto direct-collapse black holes (DCBHs) that started their lives with masses ∼104–5 ${M}_{\odot }$. Working in this scenario, we show that the mass function of SMBHs after such a limited time period, with growing formation rate paired with super-Eddington accretion, can be described as a broken power law with two characteristic features. There is a power law at intermediate masses whose index is the dimensionless ratio α ≡ λ/γ, where λ is the growth rate of the number of DCBHs during their formation era, and γ is the growth rate of DCBH masses by super-Eddington accretion during the DCBH growth era. A second feature is a break in the power-law profile at high masses, above which the mass function declines rapidly. The location of the break is related to the dimensionless number β = γ T, where T is the duration of the period of DCBH growth. If the SMBHs continue to grow at later times at an Eddington-limited accretion rate, then the observed quasar luminosity function can be directly related to the tapered power-law function derived in this Letter.
Item Type: | Article |
---|---|
Subjects: | Pacific Library > Physics and Astronomy |
Depositing User: | Unnamed user with email support@pacificlibrary.org |
Date Deposited: | 02 Jun 2023 04:28 |
Last Modified: | 07 Jun 2024 11:12 |
URI: | http://editor.classicopenlibrary.com/id/eprint/1460 |