2002/05/13 by Takashi Hosokawa, T. Hosokawa · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1086/341546
published as Astrophys.J. 576 (2002) 75-80 · 18 pages, including 6 postscript figures, accepted for publication on ApJ
arxiv created 2002/05/13 · openalex publication_date 2002/09/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
Using the theoretical models of quasar (QSO) formation, we can reproduce optical QSO luminosity functions (LFs) at high redshifts ( z ≥ 2.2). Two different models can reproduce LFs successfully, though the lifetime of the QSOs, t Q , and the relation between the black hole mass and the host halo mass are different for each model; t Q ~ 10 6 yr in one model and t Q ≥ 10 7 yr in the other model. Here we propose a method to break this degeneracy. We calculate the mass function of supermassive black holes (SMBHs) at z = 2.5 and compare the results with the current mass function obtained by Salucci et al. (1999). In the shorter lifetime model, the mass function at z = 2.5 exceeds that of z = 0.0 by 1 order of magnitude, in which case it should be ruled out. We conclude that the lifetime is at least t Q ≥ 10 7 yr. Next, we examine the difference of the formation epoch of SMBHs existing at z = 3.0 for each model, under the model assumptions. We simply discuss the difference of the formation epoch as another possible model discriminator.