A UV flux constraint on the formation of direct collapse black holes

Latif, Muhammad; Bovino, S.; Borm, C. Van; Schleicher, Dominik R. G.; Spaans, Marco

doi:10.1093/mnras/stu1230

Cited by 92 publications

(90 citation statements)

References 75 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, any theoretical model that attempts to explore the abundance of such sites is extremely sensitive to the choice of Jcrit. For example, an order of magnitude increase in Jcrit can reduce the DCBH number density at z = 6 by three orders of magnitude (Dijkstra et al 2008;Latif et al 2014;Dijkstra et al 2014). This emphasizes the need to understand and calculate the value of Jcrit produced by galaxies composed of Pop II stars in the early Universe.…”

Section: Conclusion and Discussionmentioning

confidence: 99%

See 1 more Smart Citation

New constraints on direct collapse black hole formation in the early Universe

Agarwal

Smith

Glover

et al. 2016

Mon. Not. R. Astron. Soc.

107

View full text Add to dashboard Cite

Direct collapse black holes (DCBH) have been proposed as a solution to the challenge of assembling supermassive black holes by z > 6 to explain the bright quasars observed at this epoch. The formation of a DCBH seed with M BH ∼ 10 4−5 M ⊙ requires a pristine atomiccooling halo to be illuminated by an external radiation field that is sufficiently strong to entirely suppress H 2 cooling in the halo. Many previous studies have attempted to constrain the critical specific intensity that is likely required to suppress H 2 cooling, denoted as J crit . However, these studies have typically assumed that the incident external radiation field can be modeled with a black-body spectrum. Under this assumption, it is possible to derive a unique value for J crit that depends only on the temperature of the black-body. In this study we consider a more realistic spectral energy distribution (SED) for the external source of radiation that depends entirely on its star formation history and age. The rate of destruction of the species responsible for suppressing molecular hydrogen cooling depends on the detailed shape of the SED. Therefore the value of J crit is tied to the shape of the incident SED of the neighbouring galaxy. We fit a parametric form to the rates of destruction of H 2 and H − that permit direct collapse. Owing to this, we find that J crit is not a fixed threshold but can lie anywhere in the range J crit ∼ 0.5-10 3 , depending on the details of the source stellar population.

show abstract

Section: Conclusion and Discussionmentioning

confidence: 99%

“…Latif et al (2014) and SG15a have shown that omitting this process introduces a factor of two our chemical model, using the rate given in Martin et al (1996).…”

Section: Appendix A: Chemical Networkmentioning

confidence: 99%

New constraints on direct collapse black hole formation in the early Universe

Agarwal

Smith

Glover

et al. 2016

Mon. Not. R. Astron. Soc.

107

View full text Add to dashboard Cite

show abstract

“…Such a black hole mass is in the range of masses associated to direct collapse of warm gas inside atomic cooling haloes at high redshift (e.g. Oh & Haiman 2002;Lodato & Natarajan 2006;Begelman et al 2006Begelman et al , 2008Agarwal et al 2012;Latif et al 2013Latif et al , 2014Choi et al 2015). We did not allow more BH formation after the formation of the first one.…”

Section: Sink Particles and Black Hole Accretionmentioning

confidence: 99%

“…If there is no molecular hydrogen to avoid fragmentation (e.g. Agarwal et al 2012;Latif et al 2013Latif et al , 2014 and there is an efficient outward AM transport (Choi et al 2015) such a scenario could favor the formation of a BH seed of ∼ 10 4 −10 6 [M ], e.g. Begelman et al (2008).…”

Section: Introductionmentioning

confidence: 99%

Multiscale mass transport inz ∼6 galactic discs: fuelling black holes

Prieto

Escala

2016

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

By using AMR cosmological hydrodynamic N-body zoom-in simulations, with the RAMSES code, we studied the mass transport processes onto galactic nuclei from high redshift up to z ∼ 6. Due to the large dynamical range of the simulations we were able to study the mass accretion process on scales from ∼ 50[kpc] to ∼ few 1 [pc]. We studied the BH growth on to the galactic center in relation with the mass transport processes associated to both the Reynolds stress and the gravitational stress on the disc. Such methodology allowed us to identify the main mass transport process as a function of the scales of the problem. We found that in simulations that include radiative cooling and SNe feedback, the SMBH grows at the Eddington limit for some periods of time presenting f EDD ≈ 0.5 throughout its evolution. The α parameter is dominated by the Reynolds term, α R , with α R 1. The gravitational part of the α parameter, α G , has an increasing trend toward the galactic center at higher redshifts, with values α G ∼ 1 at radii < ∼ few 10 1 [pc] contributing to the BH fueling. In terms of torques, we also found that gravity has an increasing contribution toward the galactic center at earlier epochs with a mixed contribution above ∼ 100 [pc]. This complementary work between pressure gradients and gravitational potential gradients allows an efficient mass transport on the disc with average mass accretion rates of the order ∼ few 1[M /yr]. These level of SMBH accretion rates found in our cosmological simulations are needed in all models of SMBH growth that attempt to explain the formation of redshift 6 − 7 quasars.

show abstract

“…In three-dimensional (3D) simulations, the self-shielding depends on the direction as well, due to a spatial variation of the gas density and its temperature. This direction dependence can cause a substantial difference in the estimate of J crit , between 3D and 1D simulations (e.g., Shang et al 2010;Latif et al 2014a). Moreover, existence of the X-rays could increase the hydrogen ionization fraction and the free electron fraction, which promotes the H − and H 2 formation via the electron-catalysed reactions.…”

Section: Introductionmentioning

confidence: 99%

Direct collapse to supermassive black hole seeds: the critical conditions for suppression of H2 cooling

Luo

Shlosman

Nagamine

et al. 2020

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Observations of high-redshift quasars imply the presence of supermassive black holes (SMBHs) already at z ∼ 7.5. An appealing and promising pathway to their formation is the direct collapse scenario of a primordial gas in atomic-cooling haloes at z ∼ 10 − 20, when the H 2 formation is inhibited by a strong background radiation field, whose intensity exceeds a critical value, J crit . To estimate J crit , idealized spectra have been assumed, with a fixed ratio of H 2 photo-dissociation rate k H 2 to the H − photodetachment rate k H − . This assumption, however, could be too narrow in scope as the nature of the background radiation field is not known precisely. In this work we show that the critical condition for suppressing the H 2 cooling in the collapsing gas could be described in a more general way by a combination of k H 2 and k H − parameters, without any additional assumptions about the shape of the underlying radiation spectrum. By performing a series of cosmological zoom-in simulations with an encompassing set of k H 2 and k H − , we examine the gas flow by following evolution of basic parameters of the accretion flow. We test under what conditions the gas evolution is dominated by H 2 and/or atomic cooling. We confirm the existence of a critical curve in the k H 2 − k H − plane, and provide an analytical fit to it. This curve depends on the conditions in the direct collapse, and reveals domains where the atomic cooling dominates over the molecular cooling. Furthermore, we have considered the effect of H 2 self-shielding on the critical curve, by adopting three methods for the effective column density approximation in H 2 . We find that the estimate of the characteristic length-scale for shielding can be improved by using λ Jeans25 , which is 0.25 times that of the local Jeans length.

show abstract

A UV flux constraint on the formation of direct collapse black holes

Cited by 92 publications

References 75 publications

New constraints on direct collapse black hole formation in the early Universe

New constraints on direct collapse black hole formation in the early Universe

Multiscale mass transport inz ∼6 galactic discs: fuelling black holes

Direct collapse to supermassive black hole seeds: the critical conditions for suppression of H2 cooling

Contact Info

Product

Resources

About