Start year
2004
Organizational Unit
Organizing institutions
Grants related:
General
Description
Galaxies in the universe can be located in different environments, some of them are isolated or in low density regions and they are usually called field galaxies. The others can be located in galaxy associations, going from loose groups to clusters or even superclusters of galaxies. One of the foremost challenges of the modern Astrophysics is to achieve a complete theory about galaxy evolution. This theory should explain the relation between the environment and galaxy evolution. Galaxy clusters are high density environments where galaxies interact one to each other and with the intracluster material (ICM). In addition, the cluster dynamics is driven by the high density and quantity of dark matter present in them. Therefore, galaxy clusters are complex systems with multiple components (galaxies, ICM, dark matter) which are tightly bounded. The mix of all these components, as well as their interactions, makes galaxy clusters ideal laboratories to study the different mechanisms which cause the different evolution of galaxies in this high density environments with respect to field galaxies.
The objective of this project is to study the formation and evolution of galaxies in these dense environments. The ‘Galaxy Evolution in Clusters’ group intend to understand in what environment each of the mechanisms proposed by numerical simulations to transform the galaxies dominates and how the evolution of the different types of galaxies (both bright and dwarf) occurs in the clusters. Quantifying observationally the efficiency of these mechanisms is not an easy task since many of them act at the same time, they do it in very different time scales, and in diverse regions of the cluster. However, there are some observational evidences that can be directly contrasted: i) morphological and structural distribution of the galaxies of the clusters; ii) luminosity function of galaxies in clusters; iii) diffuse light (quantity and distribution); iv) presence of galactic substructures within the clusters; v) spectro-photometric properties of dwarf and bright galaxies; vi) ICM properties. All these observables provide the necessary information to understand the relationship between environment and galactic evolution. These are the quantities this project aims at measuring for large samples of galaxy clusters.
Members
Principal investigator
Jairo
Méndez Abreu
Project staff
Rafael Delfin
Barrena Delgado
Casiana
Muñoz Tuñón
Claudio
Dalla Vecchia
Dr.
Walter Boschin
José Alfonso
López Aguerri
LILIAN FÁTIMA
DOMÍNGUEZ PALMERO
Collaborators
Dr.
E.M. Corsini
Dr.
L. Morelli
Dr.
J.M. Vílchez
Dr.
J. Iglesias
Dr.
C. del Burgo
Dr.
E. Jiménez Bailon
Dr.
S. Sánchez
Dr.
S. Borgani
Dr.
A. Biviano
Dr.
V. Debattista
Dr.
E. D'Onghia
Dr.
M. Arnaboldi
Dr.
O. Gerhard
Dr.
R. Sánchez Janssen
Dr.
A. Diaferio
Dr.
V. Wild
Dr.
S. Zarattini
Dr.
A. Aragón Salamanca
Dr.
R. Peletier
Dr.
S. Trager
Dr.
G. Dalton
Dr.
M. Girardi
Dr.
L. Constatin
Results
- Intrinsic Shape of Galactic Bars. We find, for the first time, that 52% (16%) of bulges are thicker (flatter) than the surrounding bar. We suggest that these percentages might be representative of the fraction of classical and disc-like bulges in our sample, respectively.
- The Influence of the Environment in the Star Formation Quenching. Our results indicate that in low-density environments, post-starburst galaxies are formed by gas-rich minor mergers or accretions, whereas for high-density environments PSBs would be produced by the removal of the gas reservoirs of emission line galaxies by ram-pressure stripping.
- Morpho-Kinematic Properties of Galactic Bulges. We find that photometric diagnostics to separate different types of bulges (disc-like versus classical) might not be useful for S0 galaxies. Using the morpho-kinematics properties of S0 bulges derived in this paper we suggest that they are mainly formed by dissipational processes happening at high redshift.
Scientific activity
Related publications
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Internal dynamics of the galaxy cluster Abell 545. The ideal case where to study the simultaneous formation of a galaxy system and its brightest galaxyContext. The mechanisms giving rise to diffuse radio emission in galaxy clusters, and in particular their connection with cluster mergers, are still debated. Aims: We seek to explore the internal dynamics of the cluster Abell 545, which has been shown to host a radio halo. Abell 545 is also peculiar for hosting in its center a very bright, redBarrena, R. et al.
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52011 -
Internal dynamics of Abell 2294: a massive, likely merging clusterContext. The mechanisms giving rise to diffuse radio emission in galaxy clusters, and in particular their connection with cluster mergers, are still debated. Aims: We seek to explore the internal dynamics of the cluster Abell 2294, which has been shown to host a radio halo. Methods: Our analysis is mainly based on redshift data for 88 galaxiesGirardi, M. et al.
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72010 -
Internal dynamics of Abell 2254: a merging galaxy cluster with a clumpy, diffuse radio emissionContext. The mechanisms giving rise to diffuse radio emission in galaxy clusters and, in particular, their connection with cluster mergers are still being debated. Aims: We explore the internal dynamics of Abell 2254, which has been shown to host a very clumpy and irregular radio halo. Methods: Our analysis is mainly based on redshift data for 128Girardi, M. et al.
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122011 -
Internal dynamics of Abell 1240: a galaxy cluster with symmetric double radio relicsContext: The mechanisms giving rise to diffuse radio emission in galaxy clusters, and in particular their connection with cluster mergers, are still debated. Aims: We aim to obtain new insights into the internal dynamics of the cluster Abell 1240, which appears to contain two roughly symmetric radio relics, separated by ~2 h_70-1 Mpc. Methods: OurBarrena, R. et al.
Advertised on:
82009 -
Glancing Views of the Earth: From a Lunar Eclipse to an Exoplanetary TransitIt has been posited that lunar eclipse observations may help predict the in-transit signature of Earth-like extrasolar planets. However, a comparative analysis of the two phenomena addressing in detail the transport of stellar light through the planet's atmosphere has not yet been presented. Here, we proceed with the investigation of both phenomenaGarcía-Muñoz, A. et al.
Advertised on:
82012 -
Environmental effects on the bright end of the galaxy luminosity function in galaxy clustersContext. The dependence of the luminosity function (LF) of cluster galaxies on the evolutionary state of the parent cluster is still an open question, in particular concerning the formation/evolution of the brightest cluster galaxies. Aims: We study the bright part of the LFs of a sample of very unrelaxed clusters ("DARC" clusters showing evidenceBarrena, R. et al.
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42012 -
Earth's transmission spectrum from lunar eclipse observationsOf the 342 planets so far discovered orbiting other stars, 58 `transit' the stellar disk, meaning that they can be detected through a periodic decrease in the flux of starlight. The light from the star passes through the atmosphere of the planet, and in a few cases the basic atmospheric composition of the planet can be estimated. As we get closerPallé, Enric et al.
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62009 -
Cluster Abell 520: a perspective based on member galaxies. A cluster forming at the crossing of three filaments?Context: The connection of cluster mergers with the presence of extended, diffuse radio sources in galaxy clusters is still debated. An interesting case is the rich, merging cluster Abell 520, containing a radio halo. A recent gravitational analysis has shown in this cluster the presence of a massive dark core suggested to be a possible problem forGirardi, M. et al.
Advertised on:
112008 -
Abell 1758N from an optical point of view: new insights on a merging cluster with diffuse radio emissionContext. The mechanisms producing the diffuse radio emission in galaxy clusters, and in particular their connection with cluster mergers, are still debated. Aims: We seek to explore the internal dynamics of the cluster Abell 1758N, which has been shown to host a radio halo and two relics, and is known to be a merging bimodal cluster. Methods: OurBoschin, W. et al.
Advertised on:
42012 -
Which Galaxies Host Bars and Disks? A Study of the Coma ClusterWe present a study of the bar fraction in the Coma Cluster galaxies based on a sample of ~190 galaxies selected from the Sloan Digital Sky Survey Data Release 6 and observed with the Hubble Space Telescope (HST) Advanced Camera for Survey (ACS). The unprecedented resolution of the HST-ACS images allows us to explore the presence of bars, detectedMéndez-Abreu, J. et al.
Advertised on:
32010 -
Thin discs, thick dwarfs and the effects of stellar feedbackWe investigate the role of stellar mass in shaping the intrinsic thickness of galaxy discs by determining the probability distribution of apparent axial ratios (b/a) for two different samples that probe the faint end of the galaxy luminosity function. We find that the b/a distribution has a characteristic `U-shape' and identify a limiting mass M* ~Sánchez-Janssen, R. et al.
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72010 -
The redshift and broad-band spectral energy distribution of NRAO 150Context. NRAO 150 is one of the brightest radio and mm AGN sources in the northern sky, and is an interesting source to study extreme relativistic jet phenomena. However, its cosmological distance has not yet been calibrated, because of its optical faintness due to strong Galactic extinction. Aims: We measure the redshift of NRAO 150, to enable usAcosta-Pulido, J. A. et al.
Advertised on:
92010 -
The population of barred galaxies in the local universe. I. Detection and characterisation of barsContext: Bars are very common in the centre of the disc galaxies, and they drive the evolution of their structure. The state-of-the-art imaging and redshift surveys of galaxies allow us to study the relationships between the properties of the bars and those of their hosts in statistically significant samples. Aims: A volume-limited sample of 2106Aguerri, J. A. L. et al.
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22009 -
The ionized gas in the CALIFA early-type galaxies. I. Mapping two representative cases: NGC 6762 and NGC 5966As part of the ongoing CALIFA survey, we have conducted a thorough bidimensional analysis of the ionized gas in two E/S0 galaxies, NGC 6762 and NGC 5966, aiming to shed light on the nature of their warm ionized ISM. Specifically, we present optical (3745-7300 Å) integral field spectroscopy obtained with the PMAS/PPAK integral fieldKehrig, C. et al.
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42012 -
The intrinsic dispersion in the Faber-Jackson relation for early-type galaxies as function of the mass and redshiftContext. It has been reported that the intrinsic dispersion at constant magnitude in the structural relations of early-type galaxies is a useful tool to study the universality of these structural relations, that is to say, to study whether the structural relations depend on luminosity, wavelength, redshift, and/or environment. Aims: We study theNigoche-Netro, A. et al.
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102011 -
The host in blue compact galaxies.. Structural properties and scaling relationsAims: We characterise the underlying stellar host in a sample of 20 blue compact galaxies (BCGs), by fitting their two-dimensional light distributions. Their derived host structural parameters and those of eight other BCGs already obtained in a previous paper are related to galaxy properties, such as colours and gas content. These properties areAmorín, R. et al.
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72009 -
The Faber-Jackson relation for early-type galaxies: dependence on the magnitude rangeAims: Previous studies have found that the coefficients and intrinsic dispersions of both the Kormendy relation and the Fundamental Plane depend on the magnitude range within which the galaxies are contained. We study whether this type of behaviour is also present for the Faber-Jackson relation. Methods: We take a sample of early-type galaxies fromNigoche-Netro, A. et al.
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62010 -
The edge of the M 87 halo and the kinematics of the diffuse light in the Virgo cluster coreAims: We study the kinematics and dynamics of the extreme outer halo of M 87, the central galaxy in the Virgo cluster, and its transition to the intracluster light (ICL). Methods: We present high resolution FLAMES/VLT spectroscopy of intracluster planetary nebula (PN) candidates, targeting three new fields in the Virgo cluster core with surfaceDoherty, M. et al.
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82009 -
The bright galaxy population of five medium redshift clusters. II. Quantitative galaxy morphologyAims: Following the study presented in our previous paper, based on the Nordic Optical Telescope (NOT) sample, which consists of five clusters of galaxies within the redshift range 0.18 ≤ z ≤ 0.25 imaged in the central 0.5-2 Mpc in very good seeing conditions, we have studied the quantitative morphology of their bright galaxy population Methods: WeAscaso, B. et al.
Advertised on:
112009 -
The bright galaxy population of five medium redshift clusters. I. Color-magnitude relation, blue fractions, and visual morphologyAims: Using data from five clusters of galaxies within the redshift range 0.15 ≤ z ≤ 0.25, imaged with the Nordic Optical Telescope (NOT) in the central ≈1 Mpc2 in very good seeing conditions, we have performed an exhaustive inspection of their bright galaxy population. That range of redshift, where only a small amount of data with the requiredAscaso, B. et al.
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82008
