Velocity segregation in galaxy clusters

Biviano, A.; Girardi, M.; Giuricin, G.; Mardirossian, F.; Mezzetti, M.

doi:10.1086/171695

Cited by 68 publications

(111 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The |V rf | vs. m − m 3 relation we detected is similar to that originally shown by Biviano et al (1992). Assuming the mass-follows-light hypothesis, the faint galaxies can be described by a regime of velocity equipartition, while the bright galaxies can be better described by a regime of energy equipartition, with more massive objects being slower.…”

Section: Discussionsupporting

confidence: 86%

“…We restricted our analysis to galaxies within R 200 . Because of the non-homogeneity of the photometric data of the different clusters in our sample, we adopted the same approach as Biviano et al (1992) and normalized the magnitude of each galaxy with the magnitude of the third brightest galaxy (m 3 ). We used one of the magnitude bands listed in Table A.1, preferring red or NIR bands.…”

Section: Galaxy Luminosity Segregation In Velocity Spacementioning

confidence: 99%

“…Since the pioneering works of Tammann (1972) and Moss & Dickens (1977), several studies have reported significant differences in the velocity distributions of different galaxy populations. The velocity dispersion of the population of blue star-forming galaxies is found to be larger than that of the population of red passive galaxies (e.g., Sodré et al 1989;Biviano et al 1992Biviano et al , 1996Biviano et al , 1997Scodeggio et al 1995;Colless & Dunn 1996;Mohr et al 1996;Adami et al 1998;Dressler et al 1999;Goto 2005). Moss & Dickens (1977) suggested that VCS is evidence of an infalling population of field galaxies into the clusters.…”

Section: Introductionmentioning

confidence: 99%

“…To obtain further insights into the physical processes involved in the velocity segregation, we also analyzed the possible presence of luminosity segregation in velocity space (VLS), which is reported in the literature as a minor effect with respect to VCS (Chincarini & Rood 1977;Biviano et al 1992, and references therein). In particular, Biviano et al (1992) have found that only the most luminous galaxies are segregated in velocity, with brighter galaxies having lower velocities. This result has been confirmed in more recent papers (Adami et al 1998;Goto 2005;Ribeiro et al 2013) and in poor group environments Ribeiro et al 2010).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Velocity segregation effects in galaxy clusters at 0.4 ≲z≲ 1.5

Barsanti

Girardi

Biviano

et al. 2016

A&A

Self Cite

View full text Add to dashboard Cite

Aims. Our study is meant to extend our knowledge of the galaxy color and luminosity segregation in velocity space (VCS and VLS, respectively), to clusters at intermediate and high redshift. Methods. Our sample is a collection of 41 clusters in the 0.4 < ∼ z < ∼ 1.5 redshift range for a total of 4172 galaxies, 1674 of which are member galaxies of the clusters within 2R 200 with photometric or spectroscopic information, as taken from the literature. We perform homogeneous procedures to select cluster members, compute global cluster properties, in particular the line-of-sight (LOS) velocity dispersion σ V , and separate blue from red galaxies. Results. We find evidence of VCS in clusters out to z 0.8 (at the 97−99.99% confidence level, depending on the test), in the sense that the blue galaxy population has a 10−20% larger σ V than the red galaxy population. Poor or no VCS is found in the high-z sample at z ≥ 0.8. For the first time, we detect VLS in non-local clusters and confirm that VLS only affects the very luminous galaxies; brighter galaxies have lower velocities. The threshold magnitude of VLS is ∼m 3 + 0.5, where m 3 is the magnitude of the third brightest cluster galaxy. Current data suggest that the threshold value moves to fainter magnitudes at higher redshift. We also detect (marginal) evidence of VLS for blue galaxies. Conclusions. We conclude that segregation effects can be important tracers of the galaxy evolution and cluster assembly when they are studied up to distant clusters. We also discuss the evidence of VCS at high redshift, which is poor or absent.

show abstract

Section: Discussionsupporting

confidence: 86%

Section: Galaxy Luminosity Segregation In Velocity Spacementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Velocity segregation effects in galaxy clusters at 0.4 ≲z≲ 1.5

Barsanti

Girardi

Biviano

et al. 2016

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…In clusters, the velocity distribution of LTGs is broader than that of ETGs, i.e. LTGs have a larger line-of-sight (los hereafter) velocity dispersion (σ los hereafter) than ETGs (Tammann 1972;Moss & Dickens 1977;Sodré et al 1989;Biviano et al 1992). The difference is not only in the global σ los , but also in the σ los -profiles, "hotter" and steeper (at least in the inner regions) for the LTGs (Carlberg et al 1997b;Biviano et al 1997;Adami et al 1998a).…”

Section: Introductionmentioning

confidence: 99%

The orbital velocity anisotropy of cluster galaxies: evolution

Biviano

Poggianti

2009

A&A

Self Cite

View full text Add to dashboard Cite

Context. In nearby clusters early-type galaxies follow isotropic orbits. The orbits of late-type galaxies are instead characterized by slightly radial anisotropy. Little is known about the orbits of the different populations of cluster galaxies at redshift z > 0.3. Aims. We investigate the redshift evolution of the orbits of cluster galaxies. Methods. We use two samples of galaxy clusters spanning similar (evolutionary corrected) mass ranges at different redshifts. The sample of low-redshift (z ∼ 0.0−0.1) clusters is extracted from the ESO Nearby Abell Cluster Survey (ENACS) catalog. The sample of high-redshift (z ∼ 0.4−0.8) clusters is mostly made of clusters from the ESO Distant Cluster Survey (EDisCS). For each of these samples, we solve the Jeans equation for hydrostatic equilibrium separately for two cluster galaxy populations, characterized by the presence and, respectively, absence of emission-lines in their spectra ("ELGs" and "nELGs" hereafter). Using two tracers of the gravitational potential allows to partially break the mass-anisotropy degeneracy which plagues these kinds of analyses. Results. We confirm earlier results for the nearby cluster sample. The mass profile is well fitted by a Navarro, Frenk & White (NFW) profile with concentration c = 4. The mass profile of the distant cluster sample is also well fitted by a NFW profile, but with a slightly lower concentration, as predicted by cosmological simulations of cluster-sized halos. While the mass density profile becomes less concentrated with redshift, the number density profile of nELGs becomes more concentrated with redshift. In nearby clusters, the velocity anisotropy profile of nELGs is close to isotropic, while that of ELGs is increasingly radial with clustercentric radius. In distant clusters the projected phase-space distributions of both nELGs and ELGs are best-fitted by models with radial velocity anisotropy. Conclusions. No significant evolution is detected for the orbits of ELGs, while the orbits of nELGs evolve from radial to isotropic with time. We speculate that this evolution may be driven by the secular mass growth of galaxy clusters during their fast accretion phase. Cluster mass density profiles and their evolution with redshift are consistent with predictions for cluster-sized halos in Λ Cold Dark Matter cosmological simulations. The evolution of the nELG number density profile is opposite to that of the mass density profile, becoming less concentrated with time, probably a result of the transformation of ELGs into nELGs.

show abstract

Deprojecting the Quenching of Star Formation in and Near Clusters

Mamon¹,

Mahajan

Raychaudhury

2011

Astrophysics and Space Science Proceedings

View full text Add to dashboard Cite

Using H δ and D n 4000 as tracers of recent or ongoing efficient star formation, we analyze the fraction of SDSS galaxies with recent or ongoing efficient star formation (GORES) in the vicinity of 268 clusters. We confirm the well-known segregation of star formation, and using Abel deprojection, we find that the fraction of GORES increases linearly with physical radius and then saturates. Moreover, we find that the fraction of GORES is modulated by the absolute line-of-sight velocity (ALOSV): at all projected radii, higher fractions of GORES are found in higher ALOSV galaxies. We model this velocity modulation of GORES fraction using the particles in a hydrodynamical cosmological simulation, which we classify into virialized, infalling and backsplash according to their position in radial phase space at z = 0. Our simplest model, where the GORES fraction is only a function of class does not produce an adequate fit to our observed GORES fraction in projected phase space. On the other hand, assuming that in each class the fraction of GORES rises linearly and then saturates, we are able to find well-fitting 3D models of the fractions of GORES. In our best-fitting models, in comparison with 18% in the virial cone and 13% in the virial sphere, GORES respectively account for 34% and 19% of the infalling and backsplash galaxies, and as much as 11% of the virialized galaxies, possibly as a result of tidally induced star formation from galaxy-galaxy interactions. At the virial radius, the fraction of GORES of the backsplash population is much closer to that of the virialized population than to that of the infalling galaxies. This suggests that the quenching of efficient star formation is nearly complete in a single passage through the cluster.

show abstract

Velocity segregation in galaxy clusters

Cited by 68 publications

References 0 publications

Velocity segregation effects in galaxy clusters at 0.4 ≲z≲ 1.5

Velocity segregation effects in galaxy clusters at 0.4 ≲z≲ 1.5

The orbital velocity anisotropy of cluster galaxies: evolution

Deprojecting the Quenching of Star Formation in and Near Clusters

Contact Info

Product

Resources

About