{"date_published":"2010-02-02T00:00:00Z","intvolume":"       402","title":"Supermassive black hole formation by direct collapse: keeping protogalactic gas H2 free in dark matter haloes with virial temperatures T_vir > rsim10^4 K ","status":"public","year":"2010","user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","issue":"2","type":"journal_article","abstract":[{"text":"In the absence of H_2 molecules, the primordial gas in early dark matter halos with virial temperatures just above T_vir >~ 10^4 K cools by collisional excitation of atomic H. Although it cools efficiently, this gas remains relatively hot, at a temperature near T ~ 8000 K, and consequently might be able to avoid fragmentation and collapse directly into a supermassive black hole (SMBH). In order for H_2--formation and cooling to be strongly suppressed, the gas must be irradiated by a sufficiently intense ultraviolet (UV) flux. We performed a suite of three--dimensional hydrodynamical adaptive mesh refinement (AMR) simulations of gas collapse in three different protogalactic halos with T_vir >~ 10^4 K, irradiated by a UV flux with various intensities and spectra. We determined the critical specific intensity, Jcrit, required to suppress H_2 cooling in each of the three halos. For a hard spectrum representative of metal--free stars, we find (in units of 10^{-21} erg s^{-1} Hz^{-1} sr^{-1} cm^{-2}) 10^4<Jcrit<10^5, while for a softer spectrum, which is characteristic of a normal stellar population, and for which H^{-} --dissociation is important, we find 30<Jcrit<300. These values are a factor of 3--10 lower than previous estimates. We attribute the difference to the higher, more accurate H_2 collisional dissociation rate we adopted. The reduction in Jcrit exponentially increases the number of rare halos exposed to super--critical radiation. When H_2 cooling is suppressed, gas collapse starts with a delay, but it ultimately proceeds more rapidly. The infall velocity is near the increased sound speed, and an object as massive as M ~ 10^5 solar mass may form at the center of these halos, compared to the M ~ 10^2 solar mass stars forming when H_2--cooling is efficient.","lang":"eng"}],"main_file_link":[{"open_access":"1","url":"https://doi.org/10.1111/j.1365-2966.2009.15960.x"}],"extern":"1","author":[{"full_name":"Shang, Cien","first_name":"Cien","last_name":"Shang"},{"last_name":"Bryan","full_name":"Bryan, Greg L.","first_name":"Greg L."},{"id":"7c006e8c-cc0d-11ee-8322-cb904ef76f36","first_name":"Zoltán","full_name":"Haiman, Zoltán","last_name":"Haiman"}],"_id":"17648","publication_status":"published","volume":402,"month":"02","article_processing_charge":"No","doi":"10.1111/j.1365-2966.2009.15960.x","date_updated":"2024-09-24T12:49:06Z","oa":1,"date_created":"2024-09-06T07:26:50Z","oa_version":"Published Version","quality_controlled":"1","publication":"Monthly Notices of the Royal Astronomical Society","article_type":"original","citation":{"ieee":"C. Shang, G. L. Bryan, and Z. Haiman, “Supermassive black hole formation by direct collapse: keeping protogalactic gas H2 free in dark matter haloes with virial temperatures T_vir &#62; rsim10^4 K ,” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 402, no. 2. Oxford University Press, pp. 1249–1262, 2010.","ista":"Shang C, Bryan GL, Haiman Z. 2010. Supermassive black hole formation by direct collapse: keeping protogalactic gas H2 free in dark matter haloes with virial temperatures T_vir &#62; rsim10^4 K . Monthly Notices of the Royal Astronomical Society. 402(2), 1249–1262.","chicago":"Shang, Cien, Greg L. Bryan, and Zoltán Haiman. “Supermassive Black Hole Formation by Direct Collapse: Keeping Protogalactic Gas H2 Free in Dark Matter Haloes with Virial Temperatures T_vir &#62; Rsim10^4 K .” <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press, 2010. <a href=\"https://doi.org/10.1111/j.1365-2966.2009.15960.x\">https://doi.org/10.1111/j.1365-2966.2009.15960.x</a>.","mla":"Shang, Cien, et al. “Supermassive Black Hole Formation by Direct Collapse: Keeping Protogalactic Gas H2 Free in Dark Matter Haloes with Virial Temperatures T_vir &#62; Rsim10^4 K .” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 402, no. 2, Oxford University Press, 2010, pp. 1249–62, doi:<a href=\"https://doi.org/10.1111/j.1365-2966.2009.15960.x\">10.1111/j.1365-2966.2009.15960.x</a>.","ama":"Shang C, Bryan GL, Haiman Z. Supermassive black hole formation by direct collapse: keeping protogalactic gas H2 free in dark matter haloes with virial temperatures T_vir &#62; rsim10^4 K . <i>Monthly Notices of the Royal Astronomical Society</i>. 2010;402(2):1249-1262. doi:<a href=\"https://doi.org/10.1111/j.1365-2966.2009.15960.x\">10.1111/j.1365-2966.2009.15960.x</a>","apa":"Shang, C., Bryan, G. L., &#38; Haiman, Z. (2010). Supermassive black hole formation by direct collapse: keeping protogalactic gas H2 free in dark matter haloes with virial temperatures T_vir &#62; rsim10^4 K . <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press. <a href=\"https://doi.org/10.1111/j.1365-2966.2009.15960.x\">https://doi.org/10.1111/j.1365-2966.2009.15960.x</a>","short":"C. Shang, G.L. Bryan, Z. Haiman, Monthly Notices of the Royal Astronomical Society 402 (2010) 1249–1262."},"day":"02","scopus_import":"1","page":"1249-1262","language":[{"iso":"eng"}],"publisher":"Oxford University Press","publication_identifier":{"issn":["0035-8711","1365-2966"]}}