scholarly journals Environmental Effects on Galaxy Evolution: Multifrequency study of nearby clusters

2015 ◽  
Vol 11 (S319) ◽  
pp. 112-112
Author(s):  
H. Bravo-Alfaro ◽  
Y. Venkatapathy ◽  
F. Durret ◽  
C. A. Caretta ◽  
V. Gamez
Keyword(s):  
Galaxy Evolution ◽  
Environmental Effects ◽  
Pressure Effects ◽  
X Ray ◽  
Cluster Galaxies ◽  
Abell Clusters ◽  
Ram Pressure ◽  
First Results

AbstractWe show first results of a multifrequency survey focused on the mechanisms driving the transformation of cluster galaxies, from late to earlier S0-types. We compare the ram-pressure effects seen on 21cm-HI images with those mechanisms affecting the old stellar disks seen on deep optical and NIR images. Our targets are the Abell clusters A85, A496, A2670, which span different relaxation degrees, masses and X-ray luminosities.

scholarly journals The XXL Survey

2018 ◽  
Vol 620 ◽  
pp. A20 ◽  
Author(s):  
E. Koulouridis ◽  
M. Ricci ◽  
P. Giles ◽  
C. Adami ◽  
M. Ramos-Ceja ◽  
...  
Keyword(s):  
Galaxy Evolution ◽  
High Redshift ◽  
High Mass ◽  
Host Galaxy ◽  
Gas Stripping ◽  
X Ray ◽  
Cluster Galaxies ◽  
Cluster Mass ◽  
Ram Pressure ◽  
Low Mass

Context. We present the results of a study of the active galactic nucleus (AGN) density in a homogeneous and well-studied sample of 167 bona fide X-ray galaxy clusters (0.1 < z < 0.5) from the XXL Survey, from the cluster core to the outskirts (up to 6r500). The results can provide evidence of the physical mechanisms that drive AGN and galaxy evolution within clusters, testing the efficiency of ram pressure gas stripping and galaxy merging in dense environments. Aims. The XXL cluster sample mostly comprises poor and moderately rich structures (M = 1013–4 × 1014 M⊙), a poorly studied population that bridges the gap between optically selected groups and massive X-ray selected clusters. Our aim is to statistically study the demographics of cluster AGNs as a function of cluster mass and host galaxy position. Methods. To investigate the effect of the environment on AGN activity, we computed the fraction of spectroscopically confirmed X-ray AGNs (LX [0.5-10 keV] > 1042 erg cm−1) in bright cluster galaxies with Mi* − 2 < M < Mi* + 1, up to 6r500 radius. The corresponding field fraction was computed from 200 mock cluster catalogues with reshuffled positions within the XXL fields. To study the mass dependence and the evolution of the AGN population, we further divided the sample into low- and high-mass clusters (below and above 1014M⊙, respectively) and two redshift bins (0.1–0.28 and 0.28–0.5). Results. We detect a significant excess of X-ray AGNs, at the 95% confidence level, in low-mass clusters between 0.5r500 and 2r500, which drops to the field value within the cluster cores (r < 0.5r500). In contrast, high-mass clusters present a decreasing AGN fraction towards the cluster centres, in agreement with previous studies. The high AGN fraction in the outskirts is caused by low-luminosity AGNs, up to LX [0.5-10 keV] = 1043 erg cm−1. It can be explained by a higher galaxy merging rate in low-mass clusters, where velocity dispersions are not high enough to prevent galaxy interactions and merging. Ram pressure stripping is possible in the cores of all our clusters, but probably stronger in deeper gravitational potentials. Compared with previous studies of massive or high-redshift clusters, we conclude that the AGN fraction in cluster galaxies anti-correlates strongly with cluster mass. The AGN fraction also increases with redshift, but at the same rate with the respective fraction in field galaxies.

scholarly journals The Chemical Evolution of the Intra-Cluster Medium

2004 ◽  
Vol 217 ◽  
pp. 464-465
Author(s):  
Wilfried Domainko ◽  
Wolfgang Kapferer ◽  
Sabine Schindler ◽  
Eelco van Kampen ◽  
Stefan Kimeswenger ◽  
...  
Keyword(s):  
Chemical Evolution ◽  
Active Galaxies ◽  
Metal Enrichment ◽  
Hydrodynamic Simulations ◽  
X Ray ◽  
Cluster Galaxies ◽  
Galactic Winds ◽  
Processed Material ◽  
Ram Pressure ◽  
First Results

We present numerical simulations of the dynamical and chemical evolution of galaxy clusters. from X-ray spectra it is evident that the Intra-Cluster Medium (ICM) is abundant in metals. As heavy elements are only produced in stars the processed material must have been ejected by cluster galaxies into the ICM. Several different mechanisms for interaction between the cluster galaxies and the ICM are possible but their efficiency of metal enrichment of the cluster and their time evolution are still not known. Suggested processes which remove enriched material from the galaxies are ram-pressure stripping, galactic winds, superwinds driven by starburst activity and jets from active galaxies. First results of high resolution hydrodynamic simulations on cluster scales are presented to investigate the effect of these different pollution mechanisms.

scholarly journals The Strong Transformation of Spiral Galaxies Infalling into Massive Clusters at z~ 0.2

2006 ◽  
Vol 2 (S235) ◽  
pp. 198-198
Author(s):  
L. Cortese ◽  
D. Marcillac ◽  
J. Richard ◽  
H. Bravo-Alfaro ◽  
J.-P. Kneib ◽  
...  
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Hubble Space Telescope ◽  
Galactic Disk ◽  
Type System ◽  
Neutral Hydrogen ◽  
Cluster Galaxies ◽  
Tidal Interactions ◽  
Ram Pressure ◽  
Cluster Environment

AbstractWe report the discovery of two peculiar galaxies infalling into the lensing clusters of galaxies Abell 1689 (z~ 0.18) and 2667 (z~ 0.23). Hubble Space Telescope images show extraordinary trails composed by blue bright knots and stellar streams associated with both these systems, an ~L* and ~0.1L* galaxy. Under the combined action of tidal interaction with the cluster potential and of ram pressure by the intra-cluster medium the morphologies and star formation histories of these two galaxies are strongly perturbed. While in the massive system tidal interactions are the dominant effect and are able to produce a sinking of gas towards the galaxy center triggering a strong burst of star formation and changing galaxy's morphology, in the smaller galaxy the effects of gravitation are reduced by ram pressure stripping which blows away the neutral hydrogen from the galactic disk, quenching the star formation activity and transforming a gas rich late type spiral into quiescent disk dominated early type system. This result is a new additional evidence that galaxy mass represents the main driver of galaxy evolution, even during their dive into the harsh cluster environment and can give additional insights on the origin of S0s and dwarf cluster galaxies.

scholarly journals Stellar formation in Brightest Cluster Galaxies

2009 ◽  
Vol 5 (S262) ◽  
pp. 450-451
Author(s):  
Tatiana Zapata Pichinao ◽  
Gastão B. Lima Neto
Keyword(s):  
Star Formation ◽  
Stellar Population ◽  
External Source ◽  
Star Formation History ◽  
Dynamic State ◽  
X Ray ◽  
Cluster Galaxies ◽  
Brightest Cluster Galaxies ◽  
First Results ◽  
Low Metallicity

AbstractWe study the interplay between stellar population of the Brightest Cluster Galaxies (BCG) and cluster global properties. We use X-ray properties from Chandra, ROSAT and ASCA observations and BCGs spectra from SDSS-DR6. Using STARLIGHT we determined the star formation history of the BCGs and look for relations with the intra-cluster gas properties. Our first results show no correlation between the recent star formation with x-ray temperature and dynamic state. An important star formation is happening in cool-core Cluster. This new stellar population has low metallicity, pointing to an external source of cold gas to form stars.

scholarly journals Why are some brightest cluster galaxies forming stars?

2007 ◽  
Vol 3 (S245) ◽  
pp. 185-188
Author(s):  
Christopher P. O'Dea ◽  
Alice Quillen ◽  
Nicholas Zufelt ◽  
Jaehong Park ◽  
Alastair Edge ◽  
...  
Keyword(s):  
Star Formation ◽  
Formation Rate ◽  
Line Emission ◽  
Optical Emission ◽  
Infrared Emission ◽  
X Ray ◽  
Cluster Galaxies ◽  
Brightest Cluster Galaxies ◽  
First Results ◽  
Optical Line

AbstractWe present first results from an imaging survey with the Spitzer Space Telescope of 62 brightest cluster galaxies with optical line emission located in the cores of X-ray luminous clusters selected from the ROSAT All-Sky Survey. We find that 1/3 of these sources have signs of excess infrared emission; 22 objects of 62 are detected at 70 μm and 19 have 8 to 5.8 μm flux ratios above 0.98. The strength of the excess emission correlates with the luminosity of the optical emission lines. Excluding the four systems dominated by an AGN, the excess mid-infrared emission in the remaining brightest cluster galaxies is likely powered by star formation. We find a correlation between mass deposition rate from a cooling flow model for the X-ray emission and the star formation rate estimated from the infrared luminosity. The star formation rates are 1/10 to 1/100 of the mass deposition rates expected in the absence of heating suggesting that the re-heating of the ICM is generally very effective in reducing the amount of mass cooling from the hot phase.

scholarly journals Environmental Effects on Evolution of Cluster Galaxies

2003 ◽  
Vol 208 ◽  
pp. 435-436
Author(s):  
Takashi Okamoto ◽  
Masahiro Nagashima
Keyword(s):  
Star Formation ◽  
Structure Formation ◽  
Hierarchical Structure ◽  
Galaxy Formation ◽  
Environmental Effects ◽  
Formation Model ◽  
Cluster Galaxies ◽  
Hot Gas ◽  
Ram Pressure ◽  
The Hierarchical Structure

Using a combination of a cosmological N-body simulation and a semi-analytic galaxy formation model, we investigate environmental effects on cluster galaxies with the ACDM cosmology. We find that stripping of hot gas from galacitc halos as they infall into larger objects sufficiently suppresses star formation in the cluster and successfully reproduces the observed gradients of SFR when we normalize our model to reproduce the observed properties of local galaxies. Consequently, the effect of ram-pressure stripping of cold gas from galactic disks becomes quite small and it is observationally negligible. Therefore, the deficiency of galaxies with intermediate bulge-to-disk luminosity ratios under the hierarchical structure formation cannot be resolved even if we include the ram-pressure stripping in our modeling.

scholarly journals Environmental Effects on the Kinematics of Virgo Cluster Galaxies

2004 ◽  
Vol 217 ◽  
pp. 468-470
Author(s):  
L. Chemin ◽  
V. Cayatte ◽  
C. Balkowski ◽  
P. Amram ◽  
M. Marcelin ◽  
...  
Keyword(s):  
Velocity Field ◽  
Galaxy Evolution ◽  
Environmental Effects ◽  
Spiral Galaxies ◽  
Virgo Cluster ◽  
Distribution Map ◽  
Ionized Gas ◽  
Cluster Galaxies ◽  
Gas Kinematics ◽  
Fabry Perot

We present results from an ongoing survey of the ionized gas kinematics in Virgo cluster spiral galaxies using Fabry-Perot (FP) interferometry. Our goal is to study the environmental effects on galaxy evolution in the Virgo cluster. We report here on the Hα distribution map and velocity field of NGC 4438, an interacting galaxy near the centre of the cluster.

scholarly journals The XXL Survey

2020 ◽  
Vol 642 ◽  
pp. A124
Author(s):  
A. Trudeau ◽  
C. Garrel ◽  
J. Willis ◽  
M. Pierre ◽  
F. Gastaldello ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Galaxy Evolution ◽  
Near Infrared ◽  
Host Galaxy ◽  
Distant Galaxy ◽  
X Ray ◽  
Cluster Galaxies ◽  
Stellar Component ◽  
Galaxy Masses ◽  
Galaxy Populations

Context. Distant galaxy clusters provide an effective laboratory in which to study galaxy evolution in dense environments and at early cosmic times. Aims. We aim to identify distant galaxy clusters as extended X-ray sources that are coincident with overdensities of characteristically bright galaxies. Methods. We used optical and near-infrared data from the Hyper Suprime-Cam and VISTA Deep Extragalactic Observations (VIDEO) surveys to identify distant galaxy clusters as overdensities of bright, zphot ≥ 0.8 galaxies associated with extended X-ray sources detected in the ultimate XMM extragalactic survey (XXL). Results. We identify a sample of 35 candidate clusters at 0.80 ≤ z ≤ 1.93 from an approximately 4.5 deg2 sky area. This sample includes 15 newly discovered candidate clusters, ten previously detected but unconfirmed clusters, and ten spectroscopically confirmed clusters. Although these clusters host galaxy populations that display a wide variety of quenching levels, they exhibit well-defined relations between quenching, cluster-centric distance, and galaxy luminosity. The brightest cluster galaxies (BCGs) within our sample display colours that are consistent with a bimodal population composed of an old and red sub-sample together with a bluer, more diverse sub-sample. Conclusions The relation between galaxy masses and quenching seem to already be in place at z ∼ 1, although there is no significant variation in the quenching fraction with the cluster-centric radius. The BCG bimodality might be explained by the presence of a younger stellar component in some BCGs, but additional data are needed to confirm this scenario.

Quasar host galaxies and environments in the GAMA survey

2019 ◽  
Vol 15 (S356) ◽  
pp. 170-170
Author(s):  
Jari Kotilainen
Keyword(s):  
Galaxy Evolution ◽  
Large Scale ◽  
Group Membership ◽  
Host Galaxy ◽  
Host Galaxies ◽  
Cluster Group ◽  
First Results ◽  
Triggering Mechanisms ◽  
Mass Assembly

AbstractWe present first results from our study of the host galaxies and environments of quasars in Galaxy And Mass Assembly (GAMA), a multiwavelength photometric and spectroscopic survey for ∼300,000 galaxies over ∼300 deg2, to a limiting magnitude of r ∼ 20 mag. We use a GAIA-selected sample of ∼350 quasars at z < 0.3 in GAMA. For all the quasars, we determine all surrounding GAMA galaxies and measure their star formation (SF) rate and SF history, and the host galaxy morphology and group membership of the quasars. As a comparison sample of inactive galaxies, we use 1000 subsets of galaxies in GAMA, matched in redshift and galaxy stellar mass to the quasars. We find that quasar activity does not depend on the large-scale environment (cluster/group/void), although quasars tend to prefer satellite location in their environment. Compared to inactive galaxies, quasars are preferentially hosted in bulge-dominated galaxies and have higher SF rates, both overall and averaged over the last 10 and 100 Myr. Quasars also have shorter median SF timescales, shorter median time since the last SF burst, and higher metallicity than inactive galaxies. We discuss these results in terms of triggering mechanisms of the quasar activity and the role of quasars in galaxy evolution.

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