Galaxy Formation from the Primordial Black Holes

¹ Department of Physics, Ochanomizu University, 2-1-1 Otsuka, Bunkyo,, Tokyo 112-8610, Japan.

^a e-mail: hiro@phys.ocha.ac.jp

Published online: 5 December 2017

Abstract

Supermassive black hole (SMBH) of size M_BH = 10^6-10M_⊙ is common in the Universe and it defines the center of the galaxy. A galaxy and the SMBH are generally thought to have co-evolved. However, the SMBH cannot evolve so fast as commonly observed even at redshift z > 6. Therefore, we explore a natural hypothesis that the SMBH has been already formed mature at z ⪆ 10 before stars and galaxies. The SMBH forms energetic jets and out-flows which trigger massive star formation in the ambient gas. They eventually construct globular clusters and classical bulge as well as the body of elliptical galaxies. We propose simple models which implement these processes. We point out that the globular clusters and classical bulges have a common origin but are in different phases. The same is true for the elliptical and spiral galaxies. Physics behind these phase division is the runaway star formation process with strong feedback to SMBH. This is similar to the forest-fire model that displays self-organized criticality.