scholarly journals Free-form Lens Model and Mass Estimation of the High-redshift Galaxy Cluster ACT-CL J0102-4915, “El Gordo”

2020 ◽  
Vol 904 (2) ◽  
pp. 106
Author(s):  
Jose M. Diego ◽  
S. M. Molnar ◽  
C. Cerny ◽  
T. Broadhurst ◽  
R. Windhorst ◽  
...  
Keyword(s):  
High Redshift ◽  
Galaxy Cluster ◽  
Free Form ◽  
Lens Model ◽  
Mass Estimation ◽  
Redshift Galaxy

scholarly journals More connected, more active: galaxy clusters and groups at z ∼ 1 and the connection between their quiescent galaxy fractions and large-scale environments

2019 ◽  
Vol 490 (1) ◽  
pp. 135-155 ◽  
Author(s):  
Seong-Kook Lee ◽  
Myungshin Im ◽  
Minhee Hyun ◽  
Bomi Park ◽  
Jae-Woo Kim ◽  
...  
Keyword(s):  
Star Formation ◽  
Galaxy Clusters ◽  
Large Scale ◽  
High Redshift ◽  
Galaxy Cluster ◽  
Spectroscopic Observation ◽  
Star Forming ◽  
Large Scale Structures ◽  
Photometric Redshift ◽  
Redshift Galaxy

ABSTRACT High-redshift galaxy clusters, unlike local counterparts, show diverse star formation activities. However, it is still unclear what keeps some of the high-redshift clusters active in star formation. To address this issue, we performed a multiobject spectroscopic observation of 226 high-redshift (0.8 < z < 1.3) galaxies in galaxy cluster candidates and the areas surrounding them. Our spectroscopic observation reveals six to eight clusters/groups at z ∼ 0.9 and z ∼ 1.3. The redshift measurements demonstrate the reliability of our photometric redshift measurements, which in turn gives credibility for using photometric redshift members for the analysis of large-scale structures (LSSs). Our investigation of the large-scale environment (∼10 Mpc) surrounding each galaxy cluster reveals LSSs – structures up to ∼10 Mpc scale – around many of, but not all, the confirmed overdensities and the cluster candidates. We investigate the correlation between quiescent galaxy fraction of galaxy overdensities and their surrounding LSSs, with a larger sample of ∼20 overdensities including photometrically selected overdensities at 0.6 < z < 0.9. Interestingly, galaxy overdensities embedded within these extended LSSs show a lower fraction of quiescent galaxies ($\sim 20{{\ \rm per\ cent}}$) than isolated ones at similar redshifts (with a quiescent galaxy fraction of $\sim 50 {{\ \rm per\ cent}}$). Furthermore, we find a possible indication that clusters/groups with a high quiescent galaxy fraction are more centrally concentrated. Based on these results, we suggest that LSSs are the main reservoirs of gas and star-forming galaxies to keep galaxy clusters fresh and extended in size at z ∼ 1.

scholarly journals Mass dependent Evolution of Field Early-Type Galaxies Since z=1

2009 ◽  
Vol 5 (S262) ◽  
pp. 335-336
Author(s):  
Alexander Fritz ◽  
Inger Jørgensen ◽  
Ricardo P. Schiavon
Keyword(s):  
High Redshift ◽  
Galaxy Cluster ◽  
Early Type ◽  
Data Set ◽  
Redshift Galaxy ◽  
Slope Change ◽  
Formation And Evolution ◽  
Distant Field ◽  
Mass Dependent ◽  
Homogeneous Data

AbstractWe present the Fundamental Plane (FP) of field early-type galaxies at 0.5 < z < 1.0. Our project is a continuation of our efforts to understand the formation and evolution of early-type galaxies in different environments. The target galaxies were selected from the comprehensive and homogeneous data set of the Gemini/HST Galaxy Cluster Project. The distant field early-type galaxies follow a steeper FP relation compared to the local FP. The change in the slope of the FP can be interpreted as a mass-dependent evolution. Similar results have been found for cluster early-type galaxies in high redshift galaxy clusters at 0.8 < z <1. Therefore, the slope change of the FP appears to be independent of the environment of the galaxies.

scholarly journals XMM-Newtonobservations of the relaxed, high-redshift galaxy cluster ClJ0046.3+8530 atz= 0.62

2004 ◽  
Vol 354 (1) ◽  
pp. 1-9 ◽  
Author(s):  
B. J. Maughan ◽  
L. R. Jones ◽  
D. Lumb ◽  
H. Ebeling ◽  
P. Gondoin
Keyword(s):  
High Redshift ◽  
Galaxy Cluster ◽  
Redshift Galaxy

scholarly journals Precise weak lensing constraints from deep high-resolution Ks images: VLT/HAWK-I analysis of the super-massive galaxy cluster RCS2 J 232727.7−020437 at z = 0.70

2018 ◽  
Vol 610 ◽  
pp. A85 ◽  
Author(s):  
Tim Schrabback ◽  
Mischa Schirmer ◽  
Remco F. J. van der Burg ◽  
Henk Hoekstra ◽  
Axel Buddendiek ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
High Redshift ◽  
Galaxy Cluster ◽  
Weak Lensing ◽  
Data Sets ◽  
Redshift Distribution ◽  
Model And Simulation ◽  
Single Orbit ◽  
Redshift Galaxy ◽  
Massive Galaxy

We demonstrate that deep good-seeing VLT/HAWK-I Ks images complemented with g + z-band photometry can yield a sensitivity for weak lensing studies of massive galaxy clusters at redshifts 0.7 ≲ z ≲ 1.1, which is almost identical to the sensitivity of HST/ACS mosaics of single-orbit depth. Key reasons for this good performance are the excellent image quality frequently achievable for Ks imaging from the ground, a highly effective photometric selection of background galaxies, and a galaxy ellipticity dispersion that is noticeably lower than for optically observed high-redshift galaxy samples. Incorporating results from the 3D-HST and UltraVISTA surveys we also obtained a more accurate calibration of the source redshift distribution than previously achieved for similar optical weak lensing data sets. Here we studied the extremely massive galaxy cluster RCS2 J232727.7−020437 (z = 0.699), combining deep VLT/HAWK-I Ks images (point spread function with a 0.′′35 full width at half maximum) with LBT/LBC photometry. The resulting weak lensing mass reconstruction suggests that the cluster consists of a single overdensity, which is detected with a peak significance of 10.1σ. We constrained the cluster mass to M200c/(1015 M⊙) = 2.06−0.26+0.28(stat.) ± 0.12(sys.) assuming a spherical Navarro, Frenk & White model and simulation-based priors on the concentration, making it one of the most massive galaxy clusters known in the z ≳ 0.7 Universe. We also cross-checked the HAWK-I measurements through an analysis of overlapping HST/ACS images, yielding fully consistent estimates of the lensing signal.

scholarly journals Dissecting cold gas in a high-redshift galaxy using a lensed background quasar

2018 ◽  
Vol 619 ◽  
pp. A142 ◽  
Author(s):  
J.-K. Krogager ◽  
P. Noterdaeme ◽  
J. M. O’Meara ◽  
M. Fumagalli ◽  
J. P. U. Fynbo ◽  
...  
Keyword(s):  
High Redshift ◽  
Gas Absorption ◽  
Line Of Sight ◽  
Lens Model ◽  
Physical Separation ◽  
Redshift Galaxy ◽  
Solar Metallicity ◽  
The Individual ◽  
Relative Excitation ◽  
Cold Gas

We present a study of cold gas absorption from a damped Lyman-α absorber (DLA) at redshift zabs = 1.946 toward two lensed images of the quasar J144254.78+405535.5 at redshift zQSO = 2.590. The physical separation of the two lines of sight at the absorber redshift is dabs = 0.7 kpc according to our lens model. We observe absorption lines from neutral carbon and H2 along both lines of sight, indicating that cold gas is present on scales larger than dabs. We measure the column densities of H I to be log N(HI) = 20.27 ± 0.02 and 20.34 ± 0.05 and those of H2 to be log N(H2) = 19.7 ± 0.1 and 19.9 ± 0.2. The metallicity inferred from sulphur is consistent with solar metallicity for both sightlines: [S/H]A = 0.0 ± 0.1 and [S/H]B = −0.1 ± 0.1. Based on the excitation of low rotational levels of H2, we constrain the temperature of the cold gas phase to be T = 109 ± 20 and T = 89 ± 25 K for the two lines of sight. From the relative excitation of fine-structure levels of C I, we constrain the hydrogen volumetric densities to lie in the range of 40 − 110 cm−3. Based on the ratio of observed column density and volumetric density, we infer the average individual “cloud” size along the line of sight to be l ≈ 0.1 pc. Using the transverse line-of-sight separation of 0.7 kpc together with the individual cloud size, we are able to place an upper limit to the volume filling factor of cold gas of fvol < 0.1%. Nonetheless, the projected covering fraction of cold gas must be large (close to unity) over scales of a few kpc in order to explain the presence of cold gas in both lines of sight. Compared to the typical extent of DLAs (∼10 − 30 kpc), this is consistent with the relative incidence rate of C I absorbers and DLAs.

scholarly journals Methods for identifying high‐redshift galaxy cluster candidates

2019 ◽  
Vol 340 (7) ◽  
pp. 618-621
Author(s):  
Sandor Pinter ◽  
Lajos G. Balázs ◽  
Zsolt Bagoly ◽  
Istvan Horvath ◽  
István I. Rácz ◽  
...  
Keyword(s):  
High Redshift ◽  
Galaxy Cluster ◽  
Redshift Galaxy

scholarly journals LOFAR Discovery of a Radio Halo in the High-redshift Galaxy Cluster PSZ2 G099.86+58.45

2019 ◽  
Vol 881 (1) ◽  
pp. L18 ◽  
Author(s):  
R. Cassano ◽  
A. Botteon ◽  
G. Di Gennaro ◽  
G. Brunetti ◽  
M. Sereno ◽  
...  
Keyword(s):  
High Redshift ◽  
Galaxy Cluster ◽  
Radio Halo ◽  
Redshift Galaxy

scholarly journals Planck’s dusty GEMS

2018 ◽  
Vol 620 ◽  
pp. A60 ◽  
Author(s):  
R. Cañameras ◽  
N. P. H. Nesvadba ◽  
M. Limousin ◽  
H. Dole ◽  
R. Kneissl ◽  
...  
Keyword(s):  
Star Formation ◽  
Near Infrared ◽  
Infrared Imaging ◽  
High Redshift ◽  
Dust Emission ◽  
Galaxy Cluster ◽  
Star Forming ◽  
The Galaxy ◽  
Mass Outflow ◽  
Gas Accretion

We report the discovery of a molecular wind signature from a massive intensely star-forming clump of a few 109 M⊙, in the strongly gravitationally lensed submillimeter galaxy “the Emerald” (PLCK_G165.7+49.0) at z = 2.236. The Emerald is amongst the brightest high-redshift galaxies on the submillimeter sky, and was initially discovered with the Planck satellite. The system contains two magnificient structures with projected lengths of 28.5″ and 21″ formed by multiple, near-infrared arcs, falling behind a massive galaxy cluster at z = 0.35, as well as an adjacent filament that has so far escaped discovery in other wavebands. We used HST/WFC3 and CFHT optical and near-infrared imaging together with IRAM and SMA interferometry of the CO(4–3) line and 850 μm dust emission to characterize the foreground lensing mass distribution, construct a lens model with LENSTOOL, and calculate gravitational magnification factors between 20 and 50 in most of the source. The majority of the star formation takes place within two massive star-forming clumps which are marginally gravitationally bound and embedded in a 9 × 1010 M⊙, fragmented disk with 20% gas fraction. The stellar continuum morphology is much smoother and also well resolved perpendicular to the magnification axis. One of the clumps shows a pronounced blue wing in the CO(4–3) line profile, which we interpret as a wind signature. The mass outflow rates are high enough for us to suspect that the clump might become unbound within a few tens of Myr, unless the outflowing gas can be replenished by gas accretion from the surrounding disk. The velocity offset of –200 km s−1 is above the escape velocity of the clump, but not that of the galaxy overall, suggesting that much of this material might ultimately rain back onto the galaxy and contribute to fueling subsequent star formation.

Sign in / Sign up

Export Citation Format

Share Document