Galaxy overdensities around <scp>3C</scp> radio galaxies and quasars at 1 &lt; <i>z</i> &lt; 2.5 revealed by <i>Spitzer</i> 3.6/4.5 µm and Pan‐<scp>STARRS</scp>

Ghaffari, Zohreh; Westhues, C.; Haas, Martín; Chini, R.; Willner, S. P.; Wilkes, B. J.

doi:10.1002/asna.201713389

Cited by 7 publications

(15 citation statements)

References 33 publications

(52 reference statements)

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“…We calculate the COD (= SDC -SDP) by two approaches, one using for each 3C its individual periphery and one using the average of all peripheries. Finally we compare with previous findings by Kotyla et al (2016) and Ghaffari et al (2017).…”

Section: Significance and Frequency Of Overdensitiessupporting

confidence: 60%

“…Based on Sloan Digital Sky Survey (SDSS) data of about 500 galaxies at z < 0.4, Strateva et al (2001) found that u − r = 2.22 separates passive and and star-forming galaxies, as expected from their different stellar populations. Secondly, we have cross matched the two-filter-detected HST sample with the Spitzer/IRAC 3C sample of Ghaffari et al (2017). For (the limited number of) unique matches, the supposed red sources at z > 1 with F140W −[3.6] > 1 show an average color F606W -F140W = 2.8 ± 0.8.…”

Section: Color-magnitude Diagramsmentioning

confidence: 99%

“…Numerous teams have found galaxy overdensities (ODs) around distant active galactic nuclei (AGN) and RGs, e.g., Best (2000); Best et al (2003); Pentericci et al (2000); Venemans et al (2007); Haas et al (2009); Falder et al (2010Falder et al ( , 2011; Galametz et al (2012); Wylezalek et al (2013); Hatch et al (2014); Kotyla et al (2016); Ghaffari et al (2017). A similar strategy, using sub-millimeter galaxies as distant mass beacons, has found proto-clusters up to z ∼ 5 (Steidel et al 1998;Capak et al 2011;Cai et al 2017;Martinache et al 2018;Miller et al 2018Miller et al , 2020.…”

Section: Introductionmentioning

confidence: 99%

“…The complete high-redshift 3C sample has been mapped with IRAC at the Spitzer Space Telescope albeit with moderate sensitivity (5σ detection limit of 22.4 mag at 4.5 µm). Using these IRAC data in combination with optical photometry (mostly upper limits) from Pan-STARRS, Ghaffari et al (2017) searched for galaxy ODs. They selected candidate cluster member galaxies by color and magnitude cuts.…”

Section: Introductionmentioning

confidence: 99%

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Clustering of red and blue galaxies around high-redshift 3C radio sources as seen by the Hubble Space Telescope

Ghaffari,

Haas,

Chiaberge

et al. 2020

Preprint

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Galaxy surface density maps reveal the clustering of red and blue galaxies around 3C radio galaxies and quasars at 1 < z < 2.5. The maps are made from optical and near-infrared HS T images with a 2 ′ field-of-view, where the filters encompass the 4000 Å break. 16 of 21 radio sources lie inside a galaxy overdensity of less than 250 kpc (30 ′′ ) projected radius; the overdensity is defined as 3σ above the mean galaxy density of the periphery (30 ′′ − 60 ′′ ). We find a spatial galaxy segregation with brightness and color as well as evolution with redshift. At z < 1.5, the overdensity is dominated by red galaxies, while blue galaxies are more frequent in the periphery. With a few exceptions, the fainter galaxies contributing to the overdensity are bluer than the brighter galaxies. The derived number of central luminous red galaxies is comparable to that of the Coma cluster core. This and the brightness and color segregation of candidate cluster member galaxies leads us to conclude that at 1 < z < 1.5 the 3C sources are not just becoming galaxy groups. Rather we suggest that the foundation of a galaxy cluster with luminous red galaxies has largely been set, and the formation of the red sequence is still going on from a reservoir of blue galaxies in the periphery. At z > 1.5, overdensities are less frequent and progressively composed of blue galaxies. Compared to z < 1.5, the lower galaxy concentration and bluer nature of potential cluster member galaxies indicate that a 3C cluster at z > 1.5 is in an earlier assembly phase. The clustering of galaxies around high-redshift 3C sources appears to precede with a few exceptions the assembly of detectable mass concentrations and of extended hot X-ray gas found for most of the lower-redshift 3C sources.

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Section: Significance and Frequency Of Overdensitiessupporting

confidence: 60%

Section: Color-magnitude Diagramsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Clustering of red and blue galaxies around high-redshift 3C radio sources as seen by the Hubble Space Telescope

Ghaffari,

Haas,

Chiaberge

et al. 2020

Preprint

Self Cite

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“…In the host galaxy of 3C 298, there is currently insufficient molecular gas for the galaxy to grow in stellar mass to match the mass predicted by the local scaling relationship. Furthermore, the quasar 3C 298 does not appear to live in an overdense environment based on the number count of galaxies seen with the Spitzer Space Telescope imaging data (Ghaffari et al 2017). The open question is, how do these galaxies obtain the stellar mass necessary to grow into the massive galaxies we see today?…”

Section: Offset From Local Scaling Relationsmentioning

confidence: 99%

A Spatially Resolved Survey of Distant Quasar Host Galaxies. II. Photoionization and Kinematics of the ISM

Vayner

Wright

Murray

et al. 2021

ApJ

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We present detailed observations of photoionization conditions and galaxy kinematics in 11 z = 1.39-2.59 radioloud quasar host galaxies. Data were taken with the OSIRIS integral field spectrograph and the adaptive optics system at the W. M. Keck Observatory that targeted nebular emission lines (Hβ, [O III], Hα, [N II]) redshifted into the near-infrared (1-2.4 μm). We detect extended ionized emission on scales ranging from 1 to 30 kpc photoionized by stars, shocks, and active galactic nuclei (AGN). Spatially resolved emission-line ratios indicate that our systems reside off the star formation and AGN-mixing sequence on the Baldwin, Phillips, & Terlevich diagram at low redshift. The dominant cause of the difference between line ratios of low-redshift galaxies and our sample is due to lower gas-phase metallicities, which are 2-5× less compared to galaxies with AGN in the nearby universe. Using gas velocity dispersion as a proxy to stellar velocity dispersion and dynamical mass measurement through inclined disk modeling, we find that the quasar host galaxies are undermassive relative to their central supermassive black hole mass, with all systems residing off the local scaling (M • -σ, M • -M * ) relationship. These quasar host galaxies require substantial growth, up to an order of magnitude in stellar mass, to grow into presentday massive elliptical galaxies. Combining these results with part I of our sample paper, we find evidence for winds capable of causing feedback before the AGN host galaxies land on the local scaling relation between black hole and galaxy stellar mass, and before the enrichment of the interstellar medium to a level observed in local galaxies with AGN. Unified Astronomy Thesaurus concepts: Radio loud quasars (1349); Galaxy winds (626); Emission line galaxies (459); M-sigma relation (2026); Supermassive black holes (1663); Observational astronomy (1145); Astronomical techniques (1684); Near infrared astronomy (1093)

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Clustering of red and blue galaxies around high-redshift 3C radio sources as seen by the Hubble Space Telescope

Ghaffari

Haas

Chiaberge

et al. 2021

A&A

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To properly understand the evolution of high-redshift galaxy clusters, both passive and star-forming galaxies have to be considered. Here we study the clustering environment of 21 radio galaxies and quasars at 1 < z < 2.5 from the third Cambridge catalog (3C). We use optical and near-infrared Hubble Space Telescope images with a 2′ field-of-view, where the filters encompass the rest-frame 4000 Å break. Passive red and star-forming blue galaxies were separated in the color–magnitude diagram using a redshift-dependent cut derived from galaxy evolution models. We find that about 16 of 21 radio sources inhabit a galaxy overdensity on scales of 250 kpc (30″) projected radius. The sample shows a diversity of red and blue overdensities and also sometimes a deficiency of blue galaxies in the center. The following tentative evolutionary trends are seen: extended proto-clusters with only weak overdensities at z > 1.6, red overdensities at 1.2 < z < 1.6, and red overdensities with an increased deficit of central blue galaxies at z < 1.2. Only a few 3C sources show a blue overdensity tracing active star-formation in the cluster centers; this rarity could indicate that the powerful quasar activity may quench star-formation in the vicinity of most radio sources. The derived number of central luminous red galaxies and the radial density profiles are comparable to those found in local clusters, indicating that some 3C clusters are already mass-rich and compact.

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Galaxy overdensities around 3C radio galaxies and quasars at 1 < z < 2.5 revealed by Spitzer 3.6/4.5 µm and Pan‐STARRS

Cited by 7 publications

References 33 publications

Clustering of red and blue galaxies around high-redshift 3C radio sources as seen by the Hubble Space Telescope

Clustering of red and blue galaxies around high-redshift 3C radio sources as seen by the Hubble Space Telescope

A Spatially Resolved Survey of Distant Quasar Host Galaxies. II. Photoionization and Kinematics of the ISM

Clustering of red and blue galaxies around high-redshift 3C radio sources as seen by the Hubble Space Telescope

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