The K-Band Hubble Diagram for X-Ray Selected Brightest Cluster Galaxies

1997 ◽  
pp. 339-341
Author(s):  
R. G. Mann ◽  
C. A. Collins
Keyword(s):  
Hubble Diagram ◽  
X Ray ◽  
Cluster Galaxies ◽  
Brightest Cluster Galaxies ◽  
K Band

scholarly journals The K-Band Hubble Diagram for X-Ray Selected Brightest Cluster Galaxies

1998 ◽  
Vol 179 ◽  
pp. 339-341
Author(s):  
R.G. Mann ◽  
C.A. Collins
Keyword(s):  
Star Formation ◽  
List Type ◽  
Type Number ◽  
Hubble Diagram ◽  
Technical Problems ◽  
X Ray ◽  
Cluster Galaxies ◽  
Brightest Cluster Galaxies ◽  
The Absolute ◽  
Small Dispersion

The Hubble (magnitude-redshift) diagram for brightest cluster galaxies (BCGs) is a classic cosmological tool, widely studied because of the remarkably small dispersion (∼ 0.3 mag) in the absolute optical magnitudes of low redshift BCGs (Postman and Lauer 1995). Extending the BCG Hubble diagram to higher redshifts would greatly enhance its role as a cosmological probe, but this has been frustrated by several technical problems: – the conventional means of cluster selection in the optical become increasingly compromised by projection effects at z > 0.1– at higher redshifts the interpretation of optical magnitudes becomes increasingly complicated by the effects of possible star formation.

scholarly journals The K-Band Hubble Diagram for the Brightest Cluster Galaxies: A Test of Galaxy Formation Models

1999 ◽  
Vol 186 ◽  
pp. 407-407
Author(s):  
A. Aragón-Salamanca ◽  
C.M. Baugh ◽  
G. Kauffmann
Keyword(s):  
Galaxy Formation ◽  
Stellar Mass ◽  
Hubble Diagram ◽  
Redshift Range ◽  
Cluster Galaxies ◽  
Brightest Cluster Galaxies ◽  
Galaxy Formation And Evolution ◽  
Absolute Magnitudes ◽  
Luminosity Evolution ◽  
K Band

We analyze the K-band Hubble diagram for a sample of brightest cluster galaxies (BCGs) in the redshift range 0 < z < 1. We confirm that the scatter in the absolute magnitudes of the galaxies is small (0.3 magnitudes). The BCGs exhibit very little luminosity evolution in this redshift range: if q0 = 0.0 we detect no luminosity evolution; for q0 = 0.5 we measure a small negative evolution (i.e., BCGs were about 0.5 magnitudes fainter at z = 1 than today). If the mass in stars of these galaxies had remained constant over this period of time, substantial positive luminosity evolution would be expected: BCGs should have been brighter in the past since their stars were younger. A likely explanation for the observed zero or negative evolution is that the stellar mass of the BCGs has been assembled over time through merging and accretion, as expected in hierarchical models of galaxy formation. The colour evolution of the BCGs is consistent with that of an old stellar population (zform > 2) that is evolving passively. We can thus use evolutionary population synthesis models to estimate the rate of growth in stellar mass for these systems. We find that the stellar mass in a typical BCG has grown by a factor ≃ 2 since z ≃ 1 if q0 = 0.0 or by factor ≃ 4 if q0 = 0.5. These results are in remarkably good agreement with the predictions of semi-analytic models of galaxy formation and evolution set in the context of a hierarchical scenario for structure formation.

scholarly journals Brightest cluster galaxies: the centre can(not?) hold

2020 ◽  
Vol 500 (1) ◽  
pp. 310-318
Author(s):  
Roberto De Propris ◽  
Michael J West ◽  
Felipe Andrade-Santos ◽  
Cinthia Ragone-Figueroa ◽  
Elena Rasia ◽  
...  
Keyword(s):  
Dark Matter ◽  
Local Environment ◽  
Major Axis ◽  
Theoretical Models ◽  
Dark Matter Halo ◽  
Gas Distribution ◽  
X Ray ◽  
Cluster Galaxies ◽  
Peculiar Velocities ◽  
Brightest Cluster Galaxies

ABSTRACT We explore the persistence of the alignment of brightest cluster galaxies (BCGs) with their local environment. We find that a significant fraction of BCGs do not coincide with the centroid of the X-ray gas distribution and/or show peculiar velocities (they are not at rest with respect to the cluster mean). Despite this, we find that BCGs are generally aligned with the cluster mass distribution even when they have significant offsets from the X-ray centre and significant peculiar velocities. The large offsets are not consistent with simple theoretical models. To account for these observations BCGs must undergo mergers preferentially along their major axis, the main infall direction. Such BCGs may be oscillating within the cluster potential after having been displaced by mergers or collisions, or the dark matter halo itself may not yet be relaxed.

scholarly journals Spectroscopic Evidences for Star Formation in Cooling Flow Galaxies

1996 ◽  
Vol 171 ◽  
pp. 349-349
Author(s):  
N. Cardiel ◽  
J. Gorgas ◽  
A. Aragon-Salamanca
Keyword(s):  
Star Formation ◽  
Galaxy Clusters ◽  
X Ray ◽  
Cluster Galaxies ◽  
Cooling Flows ◽  
Cooling Flow ◽  
Brightest Cluster Galaxies

X-ray observations have led to the conclusion that many galaxy clusters are hosting cooling flows. The brightest cluster galaxies could have accreted masses of the order of 1011–1012M⊙, but is still uncertain what the final fate of the accreted gas may be.

scholarly journals Stellar population gradients in brightest cluster galaxies

2012 ◽  
Vol 8 (S295) ◽  
pp. 316-316
Author(s):  
S. I. Loubser ◽  
P. Sánchez-Blázquez
Keyword(s):  
Stellar Population ◽  
Velocity Dispersion ◽  
Elliptical Galaxies ◽  
Negative Slope ◽  
High Quality ◽  
X Ray ◽  
Cluster Galaxies ◽  
Central Galaxy ◽  
Brightest Cluster Galaxies

AbstractWe present the stellar population and velocity dispersion gradients for a sample of 24 brightest cluster galaxies (BCGs) in the nearby Universe for which we have obtained high quality long-slit spectra at the Gemini telescopes. With the aim of studying the possible connection between the formation of the BCGs and their host clusters, we explore the relations between the stellar population gradients and properties of the host clusters, as well as the possible connections between the stellar population gradients and other properties of the galaxies. We find mean stellar population gradients (negative Δ[Z/H]/log r gradient of − 0.285 ± 0.064; small positive Δlog(age)/log r gradient of +0.069 ± 0.049; and null Δ[E/Fe]/log r gradient of -0.008 ± 0.032), that are consistent with those of normal massive elliptical galaxies. However, we find a trend between metallicity gradients and velocity dispersion (with a negative slope of − 1.616 ± 0.539), that is not found for the most massive ellipticals. Furthermore, we find trends between the metallicity gradients and K-band luminosities (with a slope of 0.173 ± 0.081) as well as the distance from the BCG to the X-ray peak of the host cluster (with a slope of − 7.546 ± 2.752). The latter indicates a possible relation between the formation of the cluster and that of the central galaxy.

scholarly journals Evolution of brightest cluster galaxies in X ray clusters

2002 ◽  
Vol 329 (2) ◽  
pp. L53-L56 ◽  
Author(s):  
S. Brough ◽  
C. A. Collins ◽  
D. J. Burke ◽  
R. G. Mann ◽  
P. D. Lynam
Keyword(s):  
X Ray ◽  
Cluster Galaxies ◽  
Brightest Cluster Galaxies

scholarly journals Near-infrared evolution of brightest cluster galaxies in the most X-ray luminous clusters since z = 1

2008 ◽  
Vol 384 (4) ◽  
pp. 1502-1510 ◽  
Author(s):  
J. P. Stott ◽  
A. C. Edge ◽  
G. P. Smith ◽  
A. M. Swinbank ◽  
H. Ebeling
Keyword(s):  
Near Infrared ◽  
X Ray ◽  
Cluster Galaxies ◽  
Brightest Cluster Galaxies
Sign in / Sign up

Export Citation Format

Share Document