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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}
}
  • 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 galaxymore » 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. As a result, with upcoming data from the DES, KiDS, and HSC surveys, we can expect significant improvements in the study of halo boundaries.« less
  • We combine the measurements of luminosity dependence of bias with the luminosity dependent weak lensing analysis of dark matter around galaxies to derive the galaxy bias and constrain amplitude of mass fluctuations. We take advantage of theoretical and simulation predictions that predict that, while halo bias is rapidly increasing with mass for high masses, it is nearly constant in low mass halos. We use a new weak lensing analysis around the same Sloan Digital Sky Survey (SDSS) galaxies to determine their halo mass probability distribution. We use these halo mass probability distributions to predict the bias for each luminosity subsample.more » Galaxies below L{sub *} are antibiased with b<1 and for these galaxies bias is only weakly dependent on luminosity. In contrast, for galaxies above L{sub *} bias is rapidly increasing with luminosity. These observations are in an excellent agreement with theoretical predictions based on weak lensing halo mass determination combined with halo bias-mass relations. We find that for standard cosmological parameters theoretical predictions are able to explain the observed luminosity dependence of bias over six magnitudes in absolute luminosity. We combine the bias constraints with those from the Wilkinson Microwave Anisotropy Probe (WMAP) and the SDSS power spectrum analysis to derive new constraints on bias and {sigma}{sub 8}. For the most general parameter space that includes running and neutrino mass, we find {sigma}{sub 8}=0.88{+-}0.06 and b{sub *}=0.99{+-}0.07. In the context of spatially flat models we improve the limit on the neutrino mass for the case of three degenerate families from m{sub {nu}}<0.6 eV without bias to m{sub {nu}}<0.18 eV with bias (95% C.L.), which is weakened to m{sub {nu}}<0.24 eV if running is allowed. The corresponding limit for 3 massless+1 massive neutrino is 1.37 eV.« less
  • We study the galaxy populations in 74 Sunyaev–Zeldovich effect selected clusters from the South Pole Telescope survey, which have been imaged in the science verification phase of the Dark Energy Survey. The sample extends up to z ~ 1.1 with 4 × 10 14 M⊙ ≤ M200 ≤ 3 × 10 15M⊙. Using the band containing the 4000 Å break and its redward neighbour, we study the colour–magnitude distributions of cluster galaxies to ~m* + 2, finding that: (1)The intrinsic rest frame g – r colour width of the red sequence (RS) population is ~0.03 out to z ~ 0.85 with a preference for an increase to ~0.07 at z = 1, and (2) the prominence of the RS declines beyond z ~ 0.6. The spatial distribution of cluster galaxies is well described by the NFW profile out to 4R200 with a concentration of c g = 3.59more » $$+0.20\atop{–0.18}$$, 5.37$$+0.27\atop{-0.24}$$ and 1.38$$+0.21\atop{-0.19}$$ for the full, the RS and the blue non-RS populations, respectively, but with ~40 per cent to 55 per cent cluster to cluster variation and no statistically significant redshift or mass trends. The number of galaxies within the virial region N200 exhibits a mass trend indicating that the number of galaxies per unit total mass is lower in the most massive clusters, and shows no significant redshift trend. The RS fraction within R200 is (68 ± 3) per cent at z = 0.46, varies from ~55 per cent at z = 1 to ~80 per cent at z = 0.1 and exhibits intrinsic variation among clusters of ~14 per cent. Finally, we discuss a model that suggests that the observed redshift trend in RS fraction favours a transformation time-scale for infalling field galaxies to become RS galaxies of 2–3 Gyr.« less
  • We study the galaxy populations in 74 Sunyaev Zeldovich Effect (SZE) selected clusters from the South Pole Telescope (SPT) survey that have been imaged in the science verification phase of the Dark Energy Survey (DES). The sample extends up tomore » $$z\sim 1.1$$ with $$4 \times 10^{14} M_{\odot}\le M_{200}\le 3\times 10^{15} M_{\odot}$$. Using the band containing the 4000~\AA\ break and its redward neighbor, we study the color-magnitude distributions of cluster galaxies to $$\sim m_*+2$$, finding: (1) the intrinsic rest frame $g-r$ color width of the red sequence (RS) population is $$\sim$$0.03 out to $$z\sim0.85$$ with a preference for an increase to $$\sim0.07$$ at $z=1$ and (2) the prominence of the RS declines beyond $$z\sim0.6$$. The spatial distribution of cluster galaxies is well described by the NFW profile out to $$4R_{200}$$ with a concentration of $$c_{\mathrm{g}} = 3.59^{+0.20}_{-0.18}$$, $$5.37^{+0.27}_{-0.24}$$ and $$1.38^{+0.21}_{-0.19}$$ for the full, the RS and the blue non-RS populations, respectively, but with $$\sim40$$\% to 55\% cluster to cluster variation and no statistically significant redshift or mass trends. The number of galaxies within the virial region $$N_{200}$$ exhibits a mass trend indicating that the number of galaxies per unit total mass is lower in the most massive clusters, and shows no significant redshift trend. The red sequence (RS) fraction within $$R_{200}$$ is $$(68\pm3)$$\% at $z=0.46$, varies from $$\sim$$55\% at $z=1$ to $$\sim$$80\% at $z=0.1$, and exhibits intrinsic variation among clusters of $$\sim14$$\%. We discuss a model that suggests the observed redshift trend in RS fraction favors a transformation timescale for infalling field galaxies to become RS galaxies of 2 to 3~Gyr.« less