J/A+A/666/A97 Early- and late-forming galaxy cluster pair samples (Lin+, 2022)
A pair of early- and late-forming galaxy cluster samples:
a novel way of studying halo assembly bias assisted by a constrained simulation.
Lin Y.-T., Miyatake H., Guo H., Chiang Y.-K., Chen K.-F., Lan T.-W.,
Chang Y.-Y.
<Astron. Astrophys. 666, A97 (2022)>
=2022A&A...666A..97L 2022A&A...666A..97L (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Redshifts
Keywords: large-scale structure of Universe - cosmology: observations -
galaxies: clusters
Abstract:
The halo assembly bias, a phenomenon referring to dependencies of the
large-scale bias of a dark matter halo other than its mass, is a
fundamental property of the standard cosmological model. First
discovered in 2005 from the Millennium Run simulation, it has been
proven very difficult to be detected observationally, with only a few
convincing claims of detection so far. The main obstacle lies in
finding an accurate proxy of the halo formation time. In this study,
by utilizing a constrained simulation that can faithfully reproduce
the observed structures larger than 2Mpc in the local universe, for a
sample of 634 massive clusters at z≤0.12, we found their counterpart
halos in the simulation and used the mass growth history of the
matched halos to estimate the formation time of the observed clusters.
This allowed us to construct a pair of early- and late-forming
clusters, with a similar mass as measured via weak gravitational
lensing, and large-scale biases differing at the ∼3σ level,
suggestive of the signature of assembly bias, which is further
corroborated by the properties of cluster galaxies, including the
brightest cluster galaxy and the spatial distribution and number of
member galaxies. Our study paves a way to further detect assembly bias
based on cluster samples constructed purely on observed quantities.
Description:
Using a novel approach of combining a constrained simulation of the
local universe Elucid with a sample of galaxy clusters from SDSS, we
have constructed a pair of early- and late-forming cluster samples.
The formation time indicator z20 of the clusters is derived from their
counterpart massive halos found in Elucid.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 52 138 Early-forming clusters of the z20ex,Mz set
table2.dat 52 121 Late-forming clusters of the z20ex,Mz set
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Byte-by-byte Description of file: table1.dat table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID Cluster identification number
5- 13 F9.6 Msun logM200 log cluster mass (in M☉/h)
15- 24 F10.6 deg RAdeg Right ascension (J2000)
26- 34 F9.6 deg DEdeg Declination (J2000)
36- 43 F8.6 --- z Cluster redshift
45- 52 F8.6 --- z20 Formation redshift
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Acknowledgements:
Yen-Ting Lin, ytl(at)asiaa.sinica.edu.tw
(End) Patricia Vannier [CDS] 03-Aug-2022