Protoclusters associated with z > 2 radio galaxies - I. Characteristics of high redshift protoclusters

By B. Venemans, H. Rottgering, G. Miley, W. Breugel, C. De Breuck, J. Kurk, L. Pentericci, S. Stanford, R. Overzier, S. Croft and 12 more. 2006

316 citations recorded by the source corpus.

We present the results of a large program conducted with the Very Large Telescope and augmented by observations with the Keck telescope to search for forming clusters of galaxies near powerful radio galaxies at $2.0 α emitting galaxies in ~$3\times3$ Mpc 2 areas near the radio galaxies. A total of 300 candidate emitters were found with a rest-frame Ly α equivalent width of EW $_0 > 15$ A and significance $\Sigma \equiv {\it EW}_0/\Delta {\it EW}_0 > 3$. Follow-up spectroscopy was performed on 152 candidates in seven of the radio galaxy fields. Of these, 139 were confirmed to be Ly α emitters, four were low redshift interlopers and nine were non-detections. With the adopted criteria the success rate is $139/152 = 91$%. In addition, 14 objects with EW $_0 α emitters. Combined with the 15 Ly α emitters near MRC 1138-262, we have determined Ly α redshifts for 168 objects near eight radio galaxies. At least six of our eight fields are overdense in Ly α emitters by a factor 3-5 as compared to the field density of Ly α emitters at similar redshifts, although the statistics in our highest redshift field ($z = 5.2$) are poor. Also, the emitters show significant clustering in velocity space. In the overdense fields, the width of the velocity distributions of the emitters is a factor 2-5 smaller than the width of the narrow-band filters. Taken together, we conclude that we have discovered six forming clusters of galaxies (protoclusters). We estimate that roughly 75% of powerful ($L_\mathrm{2.7\,GHz} > 10^{33}$ erg s -1 Hz -1 sr -1 ) high redshift radio galaxies reside in a protocluster. The protoclusters have sizes of at least 1.75 Mpc, which is consistent with the structure sizes found by other groups. By using the volume occupied by the overdensities and assuming a bias parameter of $b=3{-}6$, we estimate that the protoclusters have masses in the range $2{-}9 \times 10^{14}$ $M_{\odot}$. These protoclusters are likely to be progenitors of present-day (massive) clusters of galaxies. For the first time, we have been able to estimate the velocity dispersion of cluster progenitors from $z\sim5$ to ~2. The velocity dispersion of the emitters increases with cosmic time, in agreement with the dark matter velocity dispersion in numerical simulations of forming massive clusters.

Subfields: Astronomy and Astrophysics, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/a19d8130897bd0e647e2e3788a088eeadbcb779a

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Citations in the corpus

ANCIENT LIGHT FROM YOUNG COSMIC CITIES: PHYSICAL AND OBSERVATIONAL SIGNATURES OF GALAXY PROTO-CLUSTERS (2013, methodology): “Overdensities of narrowband-selected emission line galaxies have been found around highly biased tracers like radio galaxies (Pentericci et al. 2000; Kurk et al. 2000, 2004; Venemans et al. 2002, 2004, 2007; Galametz et al. 2010) and in “random” fields.”
Distant radio galaxies and their environments (2008, methodology): “The measured overdensities of Lyα emitters in the radio-selected protoclusters are factors of 3 - 5 larger than the field density of Lyα emitters at similar redshifts (Venemans et al 2005, 2007).”
The realm of the galaxy protoclusters (2016, background): “More evidence for protoclusters around radio galaxies has been uncovered since the seminal work of Venemans et al. (2007), such as some newly identified protoclusters around other radio galaxies (Matsuda et al., 2009; Hatch et al., 2011b; Hayashi et al., 2012; Cooke et al., 2014; Shimakawa et al.,…”
DRIVING OUTFLOWS WITH RELATIVISTIC JETS AND THE DEPENDENCE OF ACTIVE GALACTIC NUCLEUS FEEDBACK EFFICIENCY ON INTERSTELLAR MEDIUM INHOMOGENEITY (2012, background): “…feedback) may be very relevant at higher redshifts in gas-rich galaxies and proto-galactic environments (De Young 1989; Bicknell et al. 2000; Reuland et al. 2003; Klamer et al. 2004; Miley et al. 2006; Villar-Martı́n 2007; Venemans et al. 2007; Miley & De Breuck 2008; Hayashi et al. 2012).”
The Subaru/XMM-Newton Deep Survey (SXDS). IV. Evolution of Lyα Emitters from z = 3.1 to 5.7 in the 1 deg2 Field: Luminosity Functions and AGN (2007, background): “…several hundred (e.g., Hu et al. 2002;Ouchi et al. 2003;Malhotra&Rhoads 2004; Taniguchi et al. 2005; Shimasaku et al. 2006; Kashikawa et al. 2006; Venemans et al. 2007), and the numbers are increasing from recent and ongoing wide-field projects such as the WFILAS (Westra et al. 2005, 2006),…”
An Extreme Protocluster of Luminous Dusty Starbursts in the Early Universe (2017, background): “…the idea that, at least in some cases, bright DSFGs trace dense environments, which agrees with several previous findings (e.g., Stevens et al. 2003; Venemans et al. 2007; Tamura et al. 2009; Ivison et al. 2013; Dannerbauer et al. 2014; Umehata et al. 2014, 2015; Casey et al. 2015; Wang et al.…”
Evidence for powerful AGN winds at high redshift: dynamics of galactic outflows in radio galaxies during the “Quasar Era” (2008, background): “HzRGs have very irregular environments with gaseous halos (e.g., Villar-Mart́ın et al. 2003), satellite galaxy overdensities (e.g. Venemans et al. 2007), and perhaps infalling gas clouds, which will influence the distribution and density of the sourrounding medium.”
EVOLUTION OF THE COLOR–MAGNITUDE RELATION IN GALAXY CLUSTERS AT z ∼ 1 FROM THE ACS INTERMEDIATE REDSHIFT CLUSTER SURVEY (2008, background): “…to redshifts as high as 2 < z < 4 by targeting known proto-clusters believed to be the progenitors of 1014−15 M galaxy clusters that later virialize between z ∼ 1 and z = 0 (Steidel et al. 1998, 2005; Pentericci et al. 2000; Venemans et al. 2002, 2007; Kurk et al. 2004; Overzier et al. 2008).”
Galaxy Protoclusters as Drivers of Cosmic Star Formation History in the First 2 Gyr (2017, background): “…C1400, Austin, TX 78712, USA 4 Department of Physics, Institute for Astronomy, ETH Zurich, CH-8093 Zurich, Switzerland in which these processes can be directly observed (Venemans et al. 2007; Wylezalek et al. 2013; Chiang et al. 2014; Planck Collaboration et al. 2015; Toshikawa et al. 2016).”
Quasar quartet embedded in giant nebula reveals rare massive structure in distant universe (2015, unknown): “References used are: (1) Venemans et al. 2007 (13); (2) Prescott et al. 2008 (19); (3) Nestor et al. 2011 (106).”
A SPITZER-SELECTED GALAXY CLUSTER AT z = 1.62 (2010, background): “…around distant radio galaxies require the presence of a massive central galaxy (e.g., Kurk et al. 2000; Miley et al. 2004; Stern et al. 2003; Kodama et al. 2007; Venemans et al. 2007; Zirm et al. 2008; Chiaberge et al. 2010), which may not be an intrinsic property of cluster progenitors.”
TWO BRIGHT SUBMILLIMETER GALAXIES IN A z = 4.05 PROTOCLUSTER IN GOODS-NORTH, AND ACCURATE RADIO-INFRARED PHOTOMETRIC REDSHIFTS (2008, background): “It is interesting to compare the GN20 environment with other structures previously discovered at high redshift around powerful steep-spectrum radio galaxies (Kurk et al. 2000; Venemans et al. 2002; 2007; Miley & de Breuck 2008 and references therein).”
Evolution in the properties of Lyman-α emitters from redshifts z ~ 3 to z ~ 2 (2008, background): “(2001), Fynbo et al. (2002, 2003a, 2003b), Francis et al. (2004) and Venemans et al. (2007).”
The first appearance of the red sequence of galaxies in proto-clusters at 2 <~ z <~ 3 (2007, background): “…we discuss later, these proto-clusters already seem to contain an evolved galaxy population as well as young Lyα/Hα emitters (Kurk et al. 2004a; 2004b; Venemans et al. 2007) which tend to be much less massive, typically by more than an order of magnitude (Gawiser et al. 2006; Venemans et al.…”