Optimal neighbourhood to nurture giants: a fundamental link between star forming galaxies and direct collapse black holes
Abstract
Massive 104-5\ M black hole seeds resulting from the direct collapse of pristine gas require a metal-free atomic cooling halo with extremely low H2 fraction, allowing the gas to cool isothermally in the presence of atomic hydrogen. In order to achieve this chemo-thermodynamical state, the gas needs to be irradiated by both: Lyman-Werner (LW) photons in the energy range 11.2-13.6 eV capable of photodissociating H2, and 0.76 eV photons capable of photodetaching H-. Employing cosmological simulations capable of creating the first galaxies in high resolution, we explore if there exists a subset that favours DCBH formation in their vicinity. We find a fundamental relation between the maximum distance at which a galaxy can cause DCBH formation and its star formation rate (SFR), which automatically folds in the chemo-thermodynamical effects of both H2 photo-dissociation and H- photo-detachment. This is in contrast to the scatter in the LW flux parameter seen at the maximum distance. It shows up to a 3 order of magnitude scatter, which can be interpreted as a scatter in `Jcrit'. Thus, computing the rates and/or the LW flux from a galaxy is no longer necessary to identify neighbouring sites of DCBH formation, as our relation allows one to distinguish regions where DCBH formation could be triggered in the vicinity of a galaxy of a given SFR.
Turn this paper into a lesson
ArcXiv compiles a structured reading guide from this paper's metadata: plain-English importance, contributions, prerequisite concepts, which sections to read first, flashcards, and a quiz. Grounded in the abstract, never invented.