2014/05/31 by Jarrett L. Johnson, Daniel J. Whalen, Bhaskar Agarwal +3 · 1 citation
Physics and Astronomy · #Adaptive optics and wavefront sensing #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Dark Ages #Galaxies: Formation, Evolution, Phenomena #Galaxy #Halo #Ionizing radiation #Irradiation #Nuclear physics #Physics #Radiation #Redshift #Reionization #Star formation #Supermassive black hole #astro-ph.CO #astro-ph.GA
paper · pdf · doi:10.1093/mnras/stu1676
9 pages, 8 figures; published in MNRAS; Figure 1 slightly degraded to reduce size; acknowledgement added
openalex publication_date 2014/09/30 · arxiv created 2015/10/14 · arxiv updated 2015/10/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Direct collapse black holes (DCBHs) formed from the collapse of atomically cooled primordial gas in the early Universe are strong candidates for the seeds of supermassive BHs. DCBHs are thought to form in atomic cooling haloes in the presence of a strong molecule-dissociating, Lyman–Werner (LW) radiation field. Given that star-forming galaxies are likely to be the source of the LW radiation in this scenario, ionizing radiation from these galaxies may accompany the LW radiation. We present cosmological simulations resolving the collapse of primordial gas into an atomic cooling halo, including the effects of both LW and ionizing radiation. We find that in cases where the gas is not self-shielded from the ionizing radiation, the collapse can be delayed by ∼25 Myr. When the ionized gas does collapse, the free electrons that are present catalyse H2 formation. In turn, H2 cooling becomes efficient in the centre of the halo, and DCBH formation is prevented. We emphasize, however, that in many cases the gas collapsing into atomic cooling haloes at high redshift is self-shielding to ionizing radiation. Therefore, it is only in a fraction of such haloes in which DCBH formation is prevented due to reionization.