The Halo Boundary of Galaxy Clusters in the SDSS

Eric Baxter, Chihway Chang, Bhuvnesh Jain, Susmita Adhikari, Neal Dalal, Andrey Kravtsov, Surhud More, Eduardo Rozo, Eli Rykoff, Ravi K. Sheth

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Analytical models and simulations predict a rapid decline in the halo density profile associated with the transition from the "infalling" regime outside the halo to the "collapsed" regime within the halo. Using data from SDSS, we explore evidence for such a feature in the density profiles of galaxy clusters using several different approaches. We first estimate the steepening of the outer galaxy density profile around clusters, finding evidence for truncation of the halo profile. Next, we measure the galaxy density profile around clusters using two sets of galaxies selected on color. We find evidence of an abrupt change in galaxy colors that coincides with the location of the steepening of the density profile. Since galaxies that have completed orbits within the cluster are more likely to be quenched of star formation and thus appear redder, this abrupt change in galaxy color can be associated with the transition from single-stream to multi-stream regimes. We also use a standard model comparison approach to measure evidence for a "splashback"-like feature, but find that this approach is very sensitive to modeling assumptions. Finally, we perform measurements using an independent cluster catalog to test for potential systematic errors associated with cluster selection. We identify several avenues for future work: improved understanding of the small-scale galaxy profile, lensing measurements, identification of proxies for the halo accretion rate, and other tests. With upcoming data from the DES, KiDS, and HSC surveys, we can expect significant improvements in the study of halo boundaries.

Original languageEnglish (US)
Article number18
JournalAstrophysical Journal
Volume841
Issue number1
DOIs
StatePublished - May 20 2017

Fingerprint

halos
galaxies
profiles
color
accretion
systematic errors
catalogs
star formation
modeling
simulation
orbits
estimates
approximation
test

Keywords

  • cosmology: observations
  • galaxies: clusters: general

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Baxter, E., Chang, C., Jain, B., Adhikari, S., Dalal, N., Kravtsov, A., ... Sheth, R. K. (2017). The Halo Boundary of Galaxy Clusters in the SDSS. Astrophysical Journal, 841(1), [18]. https://doi.org/10.3847/1538-4357/aa6ff0

The Halo Boundary of Galaxy Clusters in the SDSS. / Baxter, Eric; Chang, Chihway; Jain, Bhuvnesh; Adhikari, Susmita; Dalal, Neal; Kravtsov, Andrey; More, Surhud; Rozo, Eduardo; Rykoff, Eli; Sheth, Ravi K.

In: Astrophysical Journal, Vol. 841, No. 1, 18, 20.05.2017.

Research output: Contribution to journalArticle

Baxter, E, Chang, C, Jain, B, Adhikari, S, Dalal, N, Kravtsov, A, More, S, Rozo, E, Rykoff, E & Sheth, RK 2017, 'The Halo Boundary of Galaxy Clusters in the SDSS', Astrophysical Journal, vol. 841, no. 1, 18. https://doi.org/10.3847/1538-4357/aa6ff0
Baxter E, Chang C, Jain B, Adhikari S, Dalal N, Kravtsov A et al. The Halo Boundary of Galaxy Clusters in the SDSS. Astrophysical Journal. 2017 May 20;841(1). 18. https://doi.org/10.3847/1538-4357/aa6ff0
Baxter, Eric ; Chang, Chihway ; Jain, Bhuvnesh ; Adhikari, Susmita ; Dalal, Neal ; Kravtsov, Andrey ; More, Surhud ; Rozo, Eduardo ; Rykoff, Eli ; Sheth, Ravi K. / The Halo Boundary of Galaxy Clusters in the SDSS. In: Astrophysical Journal. 2017 ; Vol. 841, No. 1.
@article{ccba42eda1a34bf18476b36fed318c8d,
title = "The Halo Boundary of Galaxy Clusters in the SDSS",
abstract = "Analytical models and simulations predict a rapid decline in the halo density profile associated with the transition from the {"}infalling{"} regime outside the halo to the {"}collapsed{"} regime within the halo. Using data from SDSS, we explore evidence for such a feature in the density profiles of galaxy clusters using several different approaches. We first estimate the steepening of the outer galaxy density profile around clusters, finding evidence for truncation of the halo profile. Next, we measure the galaxy density profile around clusters using two sets of galaxies selected on color. We find evidence of an abrupt change in galaxy colors that coincides with the location of the steepening of the density profile. Since galaxies that have completed orbits within the cluster are more likely to be quenched of star formation and thus appear redder, this abrupt change in galaxy color can be associated with the transition from single-stream to multi-stream regimes. We also use a standard model comparison approach to measure evidence for a {"}splashback{"}-like feature, but find that this approach is very sensitive to modeling assumptions. Finally, we perform measurements using an independent cluster catalog to test for potential systematic errors associated with cluster selection. We identify several avenues for future work: improved understanding of the small-scale galaxy profile, lensing measurements, identification of proxies for the halo accretion rate, and other tests. With upcoming data from the DES, KiDS, and HSC surveys, we can expect significant improvements in the study of halo boundaries.",
keywords = "cosmology: observations, galaxies: clusters: general",
author = "Eric Baxter and Chihway Chang and Bhuvnesh Jain and Susmita Adhikari and Neal Dalal and Andrey Kravtsov and Surhud More and Eduardo Rozo and Eli Rykoff and Sheth, {Ravi K.}",
year = "2017",
month = "5",
day = "20",
doi = "10.3847/1538-4357/aa6ff0",
language = "English (US)",
volume = "841",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "1",

}

TY - JOUR

T1 - The Halo Boundary of Galaxy Clusters in the SDSS

AU - Baxter, Eric

AU - Chang, Chihway

AU - Jain, Bhuvnesh

AU - Adhikari, Susmita

AU - Dalal, Neal

AU - Kravtsov, Andrey

AU - More, Surhud

AU - Rozo, Eduardo

AU - Rykoff, Eli

AU - Sheth, Ravi K.

PY - 2017/5/20

Y1 - 2017/5/20

N2 - Analytical models and simulations predict a rapid decline in the halo density profile associated with the transition from the "infalling" regime outside the halo to the "collapsed" regime within the halo. Using data from SDSS, we explore evidence for such a feature in the density profiles of galaxy clusters using several different approaches. We first estimate the steepening of the outer galaxy density profile around clusters, finding evidence for truncation of the halo profile. Next, we measure the galaxy density profile around clusters using two sets of galaxies selected on color. We find evidence of an abrupt change in galaxy colors that coincides with the location of the steepening of the density profile. Since galaxies that have completed orbits within the cluster are more likely to be quenched of star formation and thus appear redder, this abrupt change in galaxy color can be associated with the transition from single-stream to multi-stream regimes. We also use a standard model comparison approach to measure evidence for a "splashback"-like feature, but find that this approach is very sensitive to modeling assumptions. Finally, we perform measurements using an independent cluster catalog to test for potential systematic errors associated with cluster selection. We identify several avenues for future work: improved understanding of the small-scale galaxy profile, lensing measurements, identification of proxies for the halo accretion rate, and other tests. With upcoming data from the DES, KiDS, and HSC surveys, we can expect significant improvements in the study of halo boundaries.

AB - Analytical models and simulations predict a rapid decline in the halo density profile associated with the transition from the "infalling" regime outside the halo to the "collapsed" regime within the halo. Using data from SDSS, we explore evidence for such a feature in the density profiles of galaxy clusters using several different approaches. We first estimate the steepening of the outer galaxy density profile around clusters, finding evidence for truncation of the halo profile. Next, we measure the galaxy density profile around clusters using two sets of galaxies selected on color. We find evidence of an abrupt change in galaxy colors that coincides with the location of the steepening of the density profile. Since galaxies that have completed orbits within the cluster are more likely to be quenched of star formation and thus appear redder, this abrupt change in galaxy color can be associated with the transition from single-stream to multi-stream regimes. We also use a standard model comparison approach to measure evidence for a "splashback"-like feature, but find that this approach is very sensitive to modeling assumptions. Finally, we perform measurements using an independent cluster catalog to test for potential systematic errors associated with cluster selection. We identify several avenues for future work: improved understanding of the small-scale galaxy profile, lensing measurements, identification of proxies for the halo accretion rate, and other tests. With upcoming data from the DES, KiDS, and HSC surveys, we can expect significant improvements in the study of halo boundaries.

KW - cosmology: observations

KW - galaxies: clusters: general

UR - http://www.scopus.com/inward/record.url?scp=85019703365&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85019703365&partnerID=8YFLogxK

U2 - 10.3847/1538-4357/aa6ff0

DO - 10.3847/1538-4357/aa6ff0

M3 - Article

VL - 841

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

M1 - 18

ER -