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The growth of brightest cluster galaxies and intracluster light over the past 10 billion years.
- Source :
- Monthly Notices of the Royal Astronomical Society; 01/21/2020, Vol. 491 Issue 3, p3751-3759, 9p
- Publication Year :
- 2020
-
Abstract
- We constrain the evolution of the brightest cluster galaxy plus intracluster light (BCG + ICL) using an ensemble of 42 galaxy groups and clusters that span redshifts of z  = 0.05−1.75 and masses of M<subscript>500, c </subscript>= 2 × 10<superscript>13</superscript>−10<superscript>15</superscript> M<subscript>⊙</subscript>. Specifically, we measure the relationship between the BCG + ICL stellar mass M<subscript>⋆</subscript> and M<subscript>500, c </subscript> at projected radii 10 < r < 100 kpc for three different epochs. At intermediate redshift (|$\bar{z}=0.40$|), where we have the best data, we find M<subscript>⋆</subscript> ∝ M<subscript>500, c </subscript><superscript>0.48 ± 0.06</superscript>. Fixing the exponent of this power law for all redshifts, we constrain the normalization of this relation to be 2.08 ± 0.21 times higher at |$\bar{z}=0.40$| than at high redshift (|$\bar{z}=1.55$|). We find no change in the relation from intermediate to low redshift (|$\bar{z}=0.10$|). In other words, for fixed M<subscript>500, c </subscript>, M<subscript>⋆</subscript> at 10 < r < 100 kpc increases from |$\bar{z}=1.55$| to |$\bar{z}=0.40$| and not significantly thereafter. Theoretical models predict that the physical mass growth of the cluster from z  = 1.5 to z  = 0 within r<subscript>500, c </subscript> is 1.4×, excluding evolution due to definition of r<subscript>500, c </subscript>. We find that M<subscript>⋆</subscript> within the central 100 kpc increases by ∼3.8× over the same period. Thus, the growth of M<subscript>⋆</subscript> in this central region is more than a factor of 2 greater than the physical mass growth of the cluster as a whole. Furthermore, the concentration of the BCG + ICL stellar mass, defined by the ratio of stellar mass within 10 kpc to the total stellar mass within 100 kpc, decreases with increasing M<subscript>500, c </subscript> at all z. We interpret this result as evidence for inside–out growth of the BCG + ICL over the past 10 Gyr, with stellar mass assembly occurring at larger radii at later times. [ABSTRACT FROM AUTHOR]
- Subjects :
- STELLAR mass
GALAXY clusters
REDSHIFT
GALACTIC evolution
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Subjects
Details
- Language :
- English
- ISSN :
- 00358711
- Volume :
- 491
- Issue :
- 3
- Database :
- Complementary Index
- Journal :
- Monthly Notices of the Royal Astronomical Society
- Publication Type :
- Academic Journal
- Accession number :
- 140823390
- Full Text :
- https://doi.org/10.1093/mnras/stz3236