REVERSAL OF FORTUNE: CONFIRMATION OF AN INCREASING STAR FORMATION–DENSITY RELATION IN A CLUSTER AT z = 1.62

By K. Tran, C. Papovich, A. Saintonge, M. Brodwin, J. Dunlop, D. Farrah, K. Finkelstein, S. Finkelstein, J. Lotz, R. McLure and 2 more. 2010

177 citations recorded by the source corpus.

We measure the rest-frame colors (dust-corrected), infrared luminosities, star formation rates, and stellar masses of 92 galaxies in a Spitzer-selected cluster at z = 1.62. By fitting spectral energy distributions (SEDs) to 10-band photometry (0.4 μm<λobs < 8 μm) and measuring 24 μm fluxes for the 12 spectroscopically confirmed and 80 photometrically selected members, we discover an exceptionally high level of star formation in the cluster core of ∼1700 M☉ yr−1 Mpc−2. The cluster galaxies define a strong blue sequence in (U–V) color and span a range in color. We identify 17 members with LIR>1011 L☉, and these IR luminous members follow the same trend of increasing star formation with stellar mass that is observed in the field at z ∼ 2. Using rates derived from both the 24 μm imaging and SED fitting, we find that the relative fraction of star-forming members triples from the lowest to highest galaxy density regions; e.g., the IR luminous fraction increases from ∼8% at Σ ∼ 10 gal Mpc−2 to ∼25% at Σ ≳ 100 gal Mpc−2. The observed increase is a reversal of the well-documented trend at z < 1 and signals that we have reached the epoch when massive cluster galaxies are still forming a substantial fraction of their stars.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/4105203daf5bb60763df0bb068f9b2de117c0834

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In Astronomy and Astrophysics

1. M. Cappellari
2. P. Hopkins
3. L. Hernquist
4. P. V. van Dokkum
5. T. Naab
6. C. Conroy
7. R. Dav'e
8. M. Franx

In Instrumentation

1. M. Cappellari
2. P. V. van Dokkum
3. P. Hopkins
4. L. Hernquist
5. C. Conroy
6. M. Franx
7. T. Naab
8. R. Dav'e

Citations in the corpus

• A mature cluster with X-ray emission at z = 2.07 (2010, background): “This formative epoch is often put atz & 2, as supported by evidence found in recent years of increased activity (Elbaz et al. 2007, Hayashi et al. 2010, Hilton et al. 2010, Tran et al. 2010) and steeper age gradients (Rosati et al. 2009) in clusters and overdense regions atz ∼ 1− 1.6.”
• ZFIRE: THE KINEMATICS OF STAR-FORMING GALAXIES AS A FUNCTION OF ENVIRONMENT AT z ∼ 2 (2016, background): “However, at z ∼ 2 little evidence for environmental effects on SFR and the Mass-Metallicity Relation (Tran et al. 2010; Kacprzak et al. 2015) and minor effects on size (Allen et al. 2015) have been observed.”
• The VISTA deep extragalactic observations (VIDEO) survey (2012, background): “Once found, such galaxy clusters can be studied in great detail in terms of their galaxy populations (e.g. Papovich et al. 2010; Tran et al. 2010), and AGN content (e.g. van Breukelen et al. 2009; Martini, Sivakoff & Mulchaey 2009), to trace how galaxies form and evolve in closed and dense…”
• THE GEMINI CLUSTER ASTROPHYSICS SPECTROSCOPIC SURVEY (GCLASS): THE ROLE OF ENVIRONMENT AND SELF-REGULATION IN GALAXY EVOLUTION AT z ∼ 1 (2011, background): “Interestingly, there is some evidence that at z > 1.4 even the cores of clusters are becoming increasingly active (e.g., Tran et al. 2010; Hilton et al. 2010; Hayashi et al. 2010; Kuiper et al. 2010; Hatch et al. 2011), although this effect is not seen in all clusters (e.g., Tanaka et al. 2010;…”
• The ATLAS3D Project – XXX. Star formation histories and stellar population scaling relations of early-type galaxies (2015, background): “…where an apparent ‘reversal’ of the low-redshift behaviour (where star formation is lower in highdensity regions) occurs, and dense environments exhibit enhanced star formation compared to the field (Elbaz et al. 2007; Tran et al. 2010), potentially driven by cold flows (Khochfar & Silk 2009).”
• On the evolution and environmental dependence of the star formation rate versus stellar mass relation since z ∼ 2 (2013, background): “2012), and some recent studies suggest that the star formatin– density relation may be reversed atz >∼ 1 (Elbaz et al. 2007; Cooper et al. 2008; Ideue et al. 2009; Tran et al. 2010).”
• The realm of the galaxy protoclusters (2016, background): “…although these systems also frequently host star-forming or starbursting galaxies not seen at the lower redshifts (e.g., Hilton et al., 2010; Tran et al., 2010; Fassbender et al., 2011; Gobat et al., 2013; Brodwin et al., 2013; Strazzullo et al., 2013; Lee et al., 2015; Mei et al., 2015;…”
• THE ERA OF STAR FORMATION IN GALAXY CLUSTERS (2013, background): “We confirm the high fraction of star-forming members in z & 1.4 clusters reported by previous groups in individual clusters (e.g., Tran et al. 2010; Hilton et al. 2010; Lemaux et al. 2010; Hayashi et al. 2011; Fassbender et al. 2011a; Tadaki et al. 2012).”
• ANCIENT LIGHT FROM YOUNG COSMIC CITIES: PHYSICAL AND OBSERVATIONAL SIGNATURES OF GALAXY PROTO-CLUSTERS (2013, background): “…are found to experience enhanced star formation, interactions, and/or accelerated evolution, and active galactic nucleus (AGN) activity (Elbaz et al. 2007; Tran et al. 2010; Grützbauch et al. 2011; Koyama et al. 2013; Martini et al. 2013) although a full consensus has not yet been reached.”