Sugimura, K.K.SugimuraCoppola, C. M.C. M.CoppolaOmukai, K.K.OmukaiGALLI, DanieleDanieleGALLIPalla, F.F.Palla2020-09-092020-09-0920170037-8720http://hdl.handle.net/20.500.12386/27232The remnant black holes (BHs) of supermassive stars formed at z > 10 are promising candidates of the seeds for supermassive BHs. They are thought to form in pristine atomic cooling halos in which H_2 cooling is totally suppressed by strong external radiation. Here, we obtain the critical FUV specific intensity J21(cr) (in units of 10-21 erg s-1 Hz-1 sr-1 cm-2) required for supermassive star formation, with non-local thermodynamic equilibrium (non-LTE) primordial-gas chemistry. We consider the non-LTE chemistry with the vibrationally resolved H_2+ kinetics, as well as realistic radiation spectra of galaxies. We find that while the effect of non-LTE H_2+ chemistry is important for soft radiation sources, it is negligible and J21(cr) ∼ 1000 for the hard spectra of young and metal-poor galaxies, considered as typical radiation sources in the early Universe.STAMPAenArticlehttp://sait.oat.ts.astro.it/MmSAI/88/PDF/860.pdfhttp://sait.oat.ts.astro.it/MSAIt880417/index.html2017MmSAI..88..860SFIS/05 - ASTRONOMIA E ASTROFISICA