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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 severalmore » 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.« less

Authors:
; ;  [1]; ;  [2]; ;  [3];  [4];  [5];  [6]
  1. Center for Particle Cosmology, Department of Physics, University of Pennsylvania, Philadelphia, PA 19104 (United States)
  2. Kavli Institute for Cosmological Physics, The University of Chicago, Chicago, IL 60637 (United States)
  3. Department of Astronomy, University of Illinois at Urbana-Champaign, Champaign, IL 61801 (United States)
  4. Kavli Institute for the Physics and Mathematics of the Universe (WPI), Tokyo Institutes for Advanced Study, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8583 (Japan)
  5. Department of Physics, University of Arizona, Tucson, AZ 85721 (United States)
  6. Kavli Institute for Particle Astrophysics and Cosmology, P.O. Box 2450, Stanford University, Stanford, CA 94305 (United States)
Publication Date:
OSTI Identifier:
22663594
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 841; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CATALOGS; COLOR; COMPARATIVE EVALUATIONS; COSMOLOGY; DENSITY; GALAXIES; GALAXY CLUSTERS; ORBITS; SIMULATION; STANDARD MODEL; STARS; STREAMS

Citation Formats

Baxter, Eric, Jain, Bhuvnesh, Sheth, Ravi K., Chang, Chihway, Kravtsov, Andrey, Adhikari, Susmita, Dalal, Neal, More, Surhud, Rozo, Eduardo, and Rykoff, Eli, E-mail: ebax@sas.upenn.edu. The Halo Boundary of Galaxy Clusters in the SDSS. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA6FF0.
Baxter, Eric, Jain, Bhuvnesh, Sheth, Ravi K., Chang, Chihway, Kravtsov, Andrey, Adhikari, Susmita, Dalal, Neal, More, Surhud, Rozo, Eduardo, & Rykoff, Eli, E-mail: ebax@sas.upenn.edu. The Halo Boundary of Galaxy Clusters in the SDSS. United States. doi:10.3847/1538-4357/AA6FF0.
Baxter, Eric, Jain, Bhuvnesh, Sheth, Ravi K., Chang, Chihway, Kravtsov, Andrey, Adhikari, Susmita, Dalal, Neal, More, Surhud, Rozo, Eduardo, and Rykoff, Eli, E-mail: ebax@sas.upenn.edu. Sat . "The Halo Boundary of Galaxy Clusters in the SDSS". United States. doi:10.3847/1538-4357/AA6FF0.
@article{osti_22663594,
title = {The Halo Boundary of Galaxy Clusters in the SDSS},
author = {Baxter, Eric and Jain, Bhuvnesh and Sheth, Ravi K. and Chang, Chihway and Kravtsov, Andrey and Adhikari, Susmita and Dalal, Neal and More, Surhud and Rozo, Eduardo and Rykoff, Eli, E-mail: ebax@sas.upenn.edu},
abstractNote = {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.},
doi = {10.3847/1538-4357/AA6FF0},
journal = {Astrophysical Journal},
number = 1,
volume = 841,
place = {United States},
year = {Sat May 20 00:00:00 EDT 2017},
month = {Sat May 20 00:00:00 EDT 2017}
}