scholarly journals NIHAO – XXII. Introducing black hole formation, accretion, and feedback into the NIHAO simulation suite

2019 ◽  
Vol 487 (4) ◽  
pp. 5476-5489 ◽  
Author(s):  
Marvin Blank ◽  
Andrea V Macciò ◽  
Aaron A Dutton ◽  
Aura Obreja

ABSTRACT We introduce algorithms for black hole physics, i.e. black hole formation, accretion, and feedback, into the Numerical Investigation of a Hundred Astrophysical Objects (NIHAO) project of galaxy simulations. This enables us to study high mass, elliptical galaxies, where feedback from the central black hole is generally thought to have a significant effect on their evolution. We furthermore extend the NIHAO suite by 45 simulations that encompass z = 0 halo masses from 1 × 1012 to $4 \times 10^{13}\, \mathrm{M}_{\odot }$, and resimulate five galaxies from the original NIHAO sample with black hole physics, which have z = 0 halo masses from 8 × 1011 to $3 \times 10^{12}\, \mathrm{M}_{\odot }$. Now NIHAO contains 144 different galaxies and thus has the largest sample of zoom-in simulations of galaxies, spanning z = 0 halo masses from 9 × 108 to $4 \times 10^{13}\, \mathrm{M}_{\odot }$. In this paper we focus on testing the algorithms and calibrating their free parameters against the stellar mass versus halo mass relation and the black hole mass versus stellar mass relation. We also investigate the scatter of these relations, which we find is a decreasing function with time and thus in agreement with observations. For our fiducial choice of parameters we successfully quench star formation in objects above a z = 0 halo mass of $10^{12}\, \mathrm{M}_{\odot }$, thus transforming them into red and dead galaxies.

2020 ◽  
Vol 894 (1) ◽  
pp. 4 ◽  
Author(s):  
André da Silva Schneider ◽  
Evan O’Connor ◽  
Elvira Granqvist ◽  
Aurore Betranhandy ◽  
Sean M. Couch

2018 ◽  
Vol 857 (1) ◽  
pp. 13 ◽  
Author(s):  
Kuo-Chuan Pan ◽  
Matthias Liebendörfer ◽  
Sean M. Couch ◽  
Friedrich-Karl Thielemann

Author(s):  
S. J. Smartt

AbstractOver the last 15 years, the supernova community has endeavoured to directly identify progenitor stars for core-collapse supernovae discovered in nearby galaxies. These precursors are often visible as resolved stars in high-resolution images from space-and ground-based telescopes. The discovery rate of progenitor stars is limited by the local supernova rate and the availability and depth of archive images of galaxies, with 18 detections of precursor objects and 27 upper limits. This review compiles these results (from 1999 to 2013) in a distance-limited sample and discusses the implications of the findings. The vast majority of the detections of progenitor stars are of type II-P, II-L, or IIb with one type Ib progenitor system detected and many more upper limits for progenitors of Ibc supernovae (14 in all). The data for these 45 supernovae progenitors illustrate a remarkable deficit of high-luminosity stars above an apparent limit of logL/L⊙ ≃ 5.1 dex. For a typical Salpeter initial mass function, one would expect to have found 13 high-luminosity and high-mass progenitors by now. There is, possibly, only one object in this time- and volume-limited sample that is unambiguously high-mass (the progenitor of SN2009ip) although the nature of that supernovae is still debated. The possible biases due to the influence of circumstellar dust, the luminosity analysis, and sample selection methods are reviewed. It does not appear likely that these can explain the missing high-mass progenitor stars. This review concludes that the community’s work to date shows that the observed populations of supernovae in the local Universe are not, on the whole, produced by high-mass (M ≳ 18 M⊙) stars. Theoretical explosions of model stars also predict that black hole formation and failed supernovae tend to occur above an initial mass of M ≃ 18 M⊙. The models also suggest there is no simple single mass division for neutron star or black-hole formation and that there are islands of explodability for stars in the 8–120 M⊙ range.The observational constraints are quite consistent with the bulk of stars above M ≳ 18 M⊙ collapsing to form black holes with no visible supernovae.


2020 ◽  
Vol 15 (S359) ◽  
pp. 238-242
Author(s):  
Mar Mezcua

AbstractDetecting the seed black holes from which quasars formed is extremely challenging; however, those seeds that did not grow into supermassive should be found as intermediate-mass black holes (IMBHs) of 100 – 105 M⊙ in local dwarf galaxies. The use of deep multiwavelength surveys has revealed that a population of actively accreting IMBHs (low-mass AGN) exists in dwarf galaxies at least out to z ˜3. The black hole occupation fraction of these galaxies suggests that the early Universe seed black holes formed from direct collapse of gas, which is reinforced by the possible flattening of the black hole-galaxy scaling relations at the low-mass end. This scenario is however challenged by the finding that AGN feedback can have a strong impact on dwarf galaxies, which implies that low-mass AGN in dwarf galaxies might not be the untouched relics of the early seed black holes. This has important implications for seed black hole formation models.


2015 ◽  
Vol 2015 (7) ◽  
Author(s):  
Sinya Aoki ◽  
Masanori Hanada ◽  
Norihiro Iizuka

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