Metallicity evolution of direct collapse black hole hosts

• Verfasst von: Agarwal, Bhaskar [VerfasserIn]
• Verfasst von: Pellegrini, Eric William [VerfasserIn]
• Verfasst von: Klessen, Ralf S. [VerfasserIn]
• Titel: Metallicity evolution of direct collapse black hole hosts
• Titelzusatz: CR7 as a case study
• Verf.angabe: Bhaskar Agarwal, Jarrett L. Johnson, Sadegh Khochfar, Eric Pellegrini, Claes-Erik Rydberg, Ralf S. Klessen and Pascal Oesch
• E-Jahr: 2017
• Jahr: 2017 March 30
• Umfang: 6 S.
• Fussnoten: Gesehen am 14.12.2018
• Titel Quelle: Enthalten in: Royal Astronomical SocietyMonthly notices of the Royal Astronomical Society
• Ort Quelle: Oxford : Oxford Univ. Press, 1827
• Jahr Quelle: 2017
• Band/Heft Quelle: 469(2017), 1, Seite 231-236
• ISSN Quelle: 1365-2966
• DOI: doi:10.1093/mnras/stx794
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 157211150X

Abstract

In this study, we focus on the z ∼ 6.6 Lyman α CR7 consisting of clump A, which is host to a potential direct collapse black hole (DCBH), and two metal-enriched star-forming clumps B and C. In contrast to claims that signatures of metals rule out the existence of DCBHs, we show that metal pollution of A from star-forming clumps B and C is inevitable, and that A can form a DCBH well before its metallicity exceeds the critical threshold of $$10^{-5}\text{--}10^{-6}\ \rm Z_{{\odot }}$$. Assuming that metal mixing happens instantaneously, we derive the metallicity of A based on the star formation history of B and C. We find that treating a final accreting BH of 106-107 M⊙ in A for nebular emission already pushes its H160 − [3.6] and [3.6] − [4.5] colours into the 3σ limit of observations. Hence, we show that the presence of metals in DCBH hosts is inevitable, and that it is the coevolution of the Lyman-Werner radiation field and metals originating from neighbouring galaxies that governs DCBH formation in neighbouring initially pristine atomic cooling haloes.