TY - JOUR
T1 - Is the dark-matter halo spin a predictor of galaxy spin and size?
AU - Jiang, Fangzhou
AU - Dekel, Avishai
AU - Kneller, Omer
AU - Lapiner, Sharon
AU - Ceverino, Daniel
AU - Primack, Joel R.
AU - Faber, Sandra M.
AU - Macciò, Andrea V.
AU - Dutton, Aaron A.
AU - Genel, Shy
AU - Somerville, Rachel S.
N1 - Funding Information:
We acknowledge stimulating discussions with Frank van den Bosch, Andreas Burkert, and Reinhard Genzel. We are thankful to the referee who provided insightful comments and helped to make the paper more well rounded, and the Scientific Editor who provided constructive comments. This work was partly supported by the grants ISF124/12, I-CORE Program of thePBC/ISF1829/12, BSF 2014-273, PICS 2015-18, and NSF AST-1405962. FJ is partly supported by the Planning and Budgeting Committee (PBC) fellowship of the Council for Higher Education in Israel. JP is support by the grant HST-AR-14578.001-A. The VELA simulations were performed at the National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory, and at NASA Advanced Supercomputing (NAS) at NASA Ames Research Center. DC is supported by the ERC Advanced Grant, STARLIGHT: Formation of the First Stars (project number 339177). The NIHAO simulations were performed on the High Performance Computing resources at New York University Abu Dhabi on the THEO cluster of the Max-Planck-Institut f?r Astronomie and on the HYDRA clusters at the Rechenzentrum in Garching.
Funding Information:
We acknowledge stimulating discussions with Frank van den Bosch, Andreas Burkert, and Reinhard Genzel. We are thankful to the referee who provided insightful comments and helped to make the paper more well rounded, and the Scientific Editor who provided constructive comments. This work was partly supported by the grants ISF124/12, I-CORE Program of thePBC/ISF1829/12, BSF 2014-273, PICS 2015-18, and NSF AST-1405962. FJ is partly supported by the Planning and Budgeting Committee (PBC) fellowship of the Council for Higher Education in Israel. JP is support by the grant HST-AR-14578.001-A. The VELA simulations were performed at the National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory, and at NASA Advanced Supercomputing (NAS) at NASA Ames Research Center. DC is supported by the ERC Advanced Grant, STARLIGHT: Formation of the First Stars (project number 339177). The NIHAO simulations were performed on the High Performance Computing resources at New York University Abu Dhabi on the THEO cluster of the Max-Planck-Institut für Astronomie and on the HYDRA clusters at the Rechenzentrum in Garching.
Publisher Copyright:
© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society
PY - 2019/10/1
Y1 - 2019/10/1
N2 - The similarity between the distributions of spins for galaxies (λgal) and for dark-matter haloes (λhalo), indicated both by simulations and observations, is naively interpreted as a one-to-one correlation between the spins of a galaxy and its host halo. This is used to predict galaxy sizes in semi-analytic models via Re = fjλhaloRvir, where Re is the half-mass radius of the galaxy, fj is the angular momentum retention factor, and Rvir is the halo radius. Using two suites of zoom-in cosmological simulations, we find that λgal and the λhalo of its host halo are in fact barely correlated, especially at z ≥ 1, in line with previous indications. Since the spins of baryons and dark matter are correlated at accretion into Rvir, the null correlation in the end reflects an anticorrelation between fj and λhalo, which can arise from mergers and a 'wet compaction' phase that many high-redshift galaxies undergo. It may also reflect that unrepresentative small fractions of baryons are tapped to the galaxies. The galaxy spin is better correlated with the spin of the inner halo, but this largely reflects the effect of the baryons on the halo. While λhalo is not a useful predictor for Re, our simulations reproduce a general relation of the form of Re = ARvir, in agreement with observational estimates. We find that the relation becomes tighter with A = 0.02(c/10)−0.7, where c is the halo concentration, which in turn introduces a dependence on mass and redshift.
AB - The similarity between the distributions of spins for galaxies (λgal) and for dark-matter haloes (λhalo), indicated both by simulations and observations, is naively interpreted as a one-to-one correlation between the spins of a galaxy and its host halo. This is used to predict galaxy sizes in semi-analytic models via Re = fjλhaloRvir, where Re is the half-mass radius of the galaxy, fj is the angular momentum retention factor, and Rvir is the halo radius. Using two suites of zoom-in cosmological simulations, we find that λgal and the λhalo of its host halo are in fact barely correlated, especially at z ≥ 1, in line with previous indications. Since the spins of baryons and dark matter are correlated at accretion into Rvir, the null correlation in the end reflects an anticorrelation between fj and λhalo, which can arise from mergers and a 'wet compaction' phase that many high-redshift galaxies undergo. It may also reflect that unrepresentative small fractions of baryons are tapped to the galaxies. The galaxy spin is better correlated with the spin of the inner halo, but this largely reflects the effect of the baryons on the halo. While λhalo is not a useful predictor for Re, our simulations reproduce a general relation of the form of Re = ARvir, in agreement with observational estimates. We find that the relation becomes tighter with A = 0.02(c/10)−0.7, where c is the halo concentration, which in turn introduces a dependence on mass and redshift.
KW - Dark matter
KW - Galaxies: evolution
KW - Galaxies: formation
KW - Galaxies: haloes
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U2 - 10.1093/mnras/stz1952
DO - 10.1093/mnras/stz1952
M3 - Article
AN - SCOPUS:85075142217
VL - 488
SP - 4801
EP - 4815
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 4
ER -