2016/03/28 by Fabio Pacucci, Andrea Ferrara, Andrea Grazian +6
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Black hole (networking) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gamma-ray bursts and supernovae #Physics #Redshift #Solar mass #Star formation #Stellar mass #Universe #astro-ph.CO #astro-ph.GA #astro-ph.HE
paper · pdf · doi:10.1093/mnras/stw725
Accepted for publication in MNRAS. First published online March 28, 2016 (8 pages)
openalex publication_date 2016/03/28 · arxiv created 2016/04/04 · arxiv updated 2016/04/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The first black hole seeds, formed when the Universe was younger than ∼500 Myr, are recognized to play an important role for the growth of early (z ∼ 7) supermassive black holes. While progresses have been made in understanding their formation and growth, their observational signatures remain largely unexplored. As a result, no detection of such sources has been confirmed so far. Supported by numerical simulations, we present a novel photometric method to identify black hole seed candidates in deep multiwavelength surveys. We predict that these highly obscured sources are characterized by a steep spectrum in the infrared (1.6-4.5 μm), i.e. by very red colours. The method selects the only two objects with a robust X-ray detection found in the CANDELS/GOODS-S survey with a photometric redshift z ≳ 6. Fitting their infrared spectra only with a stellar component would require unrealistic star formation rates (≳2000 M⊙ yr−1). To date, the selected objects represent the most promising black hole seed candidates, possibly formed via the direct collapse black hole scenario, with predicted mass >105 M⊙. While this result is based on the best photometric observations of high-z sources available to date, additional progress is expected from spectroscopic and deeper X-ray data. Upcoming observatories, like the JWST, will greatly expand the scope of this work.