scholarly journals [ITAL]Hubble Space Telescope[/ITAL] Imaging of Brightest Cluster Galaxies

2003 ◽  
Vol 125 (2) ◽  
pp. 478-505 ◽  
Author(s):  
Seppo Laine ◽  
Roeland P. van der Marel ◽  
Tod R. Lauer ◽  
Marc Postman ◽  
Christopher P. O’Dea ◽  
...  
Keyword(s):  
Hubble Space Telescope ◽  
Space Telescope ◽  
Cluster Galaxies ◽  
Brightest Cluster Galaxies

scholarly journals FUV Emission in Cool-Core Clusters

2009 ◽  
Vol 5 (S267) ◽  
pp. 463-463
Author(s):  
J. B. R. Oonk ◽  
W. Jaffe ◽  
M. N. Bremer ◽  
N. Hatch
Keyword(s):  
Hubble Space Telescope ◽  
Global Structure ◽  
Ionized Gas ◽  
Space Telescope ◽  
Cluster Galaxies ◽  
Brightest Cluster Galaxies ◽  
Central Regions ◽  
Far Ultraviolet

AbstractFar ultraviolet (FUV) emission is observed in the central regions of cool-core clusters with the Hubble Space Telescope (HST). It is traced out to 20 kpc from the nuclei of the brightest cluster galaxies and found to be distributed in clumps and filaments, as shown in Figure 1. The FUV emission matches the global structure of the ionized gas nebulae. If produced by stars, this emission can account for the ionization but not the temperature of the gas (Voit & Donahue 1997; Oonk et al. in preparation).

scholarly journals Life in Low Density Environments – Field Galaxies from z=1.0 to the Present

2015 ◽  
Vol 11 (S319) ◽  
pp. 127-127
Author(s):  
Inger Jørgensen ◽  
Scott Fisher ◽  
Charity Woodrum ◽  
Teiler Kwan ◽  
Jacob Bieker
Keyword(s):  
Hubble Space Telescope ◽  
Galaxy Cluster ◽  
Stellar Populations ◽  
Low Density ◽  
Space Telescope ◽  
Cluster Galaxies ◽  
Preliminary Results ◽  
Spectroscopic Observations ◽  
Future Work

AbstractWe present results on the stellar populations of bulge-dominated field galaxies at redshifts up to ≈1.0. The sample consists of non-cluster galaxies observed as part of the spectroscopic observations for the Gemini/HST Galaxy Cluster Project (GCP). Our preliminary results show that the bulge-dominated field galaxies contain younger stellar populations than cluster galaxies at similar redshifts. Future work will include photometry from Hubble Space Telescope and will be aimed at establishing the evolution of the sizes and the mass-to-light ratios for the field galaxies.

scholarly journals Shapes and alignments of dark matter haloes and their brightest cluster galaxies in 39 strong lensing clusters

2020 ◽  
Vol 496 (3) ◽  
pp. 2591-2604 ◽  
Author(s):  
Taizo Okabe ◽  
Masamune Oguri ◽  
Sébastien Peirani ◽  
Yasushi Suto ◽  
Yohan Dubois ◽  
...  
Keyword(s):  
Dark Matter ◽  
Gravitational Lensing ◽  
Hubble Space Telescope ◽  
Mean Value ◽  
Cluster Galaxies ◽  
Brightest Cluster Galaxies ◽  
Strong Lensing ◽  
The Mean ◽  
The Difference ◽  
Massive Clusters

ABSTRACT We study shapes and alignments of 45 dark matter (DM) haloes and their brightest cluster galaxies (BCGs) using a sample of 39 massive clusters from Hubble Frontier Field (HFF), Cluster Lensing And Supernova survey with Hubble (CLASH), and Reionization Lensing Cluster Survey (RELICS). We measure shapes of the DM haloes by strong gravitational lensing, whereas BCG shapes are derived from their light profiles in Hubble Space Telescope images. Our measurements from a large sample of massive clusters presented here provide new constraints on DM and cluster astrophysics. We find that DM haloes are on average highly elongated with the mean ellipticity of 0.482 ± 0.028, and position angles of major axes of DM haloes and their BCGs tend to be aligned well with the mean value of alignment angles of 22.2 ± 3.9 deg. We find that DM haloes in our sample are on average more elongated than their BCGs with the mean difference of their ellipticities of 0.11 ± 0.03. In contrast, the Horizon-AGN cosmological hydrodynamical simulation predicts on average similar ellipticities between DM haloes and their central galaxies. While such a difference between the observations and the simulation may well be explained by the difference of their halo mass scales, other possibilities include the bias inherent to strong lensing measurements, limited knowledge of baryon physics, or a limitation of cold DM.

scholarly journals The “entropy floor” is porous – remarks on the coexistence of star formation and kinetic AGN feedback

2013 ◽  
Vol 9 (S304) ◽  
pp. 331-334
Author(s):  
Grant R. Tremblay
Keyword(s):  
Star Formation ◽  
Hubble Space Telescope ◽  
Formation Rate ◽  
Mechanical Power ◽  
Continuum Emission ◽  
Morphological Evidence ◽  
Cluster Galaxies ◽  
Star Forming ◽  
Brightest Cluster Galaxies ◽  
Far Ultraviolet

AbstractWe discuss the morphology of star forming clouds and filaments in the central (≲ 50 kpc) regions of 16 low redshift (z<0.3) cool core brightest cluster galaxies (BCGs). The sample spans decades-wide ranges of X-ray mass deposition and star formation rates as well as active galactic nucleus (AGN) mechanical power, encompassing both high and low extremes of the supposed intracluster medium (ICM) cooling and AGN heating feedback cycle. Amid evidence that the gas fueling both star formation and AGN activity has condensed from the hot atmosphere, we present new and archival Hubble Space Telescope (HST) images of far ultraviolet (FUV) continuum emission directly associated with young stars, acting as a calorimeter for the degree to which the suppression of star formation by AGN mechanical feedback may be spatially or temporally inefficient. We discuss evidence for temporal and possibly cyclical variation in star formation rate, wherein elevated cooling episodes are permitted when AGN feedback is in a low-power state, and vice-versa. Several sources exhibit strong morphological evidence that low levels of star formation can survive and may indeed be triggered by the passage of a propagating radio source. We conclude by discussing the apparent coexistence of feedback and star formation. If AGN mechanical power does establish an “entropy floor”, this floor must be porous, or raise and lower as the AGN varies in power.

scholarly journals Better Parallaxes and the Cosmic Distance Scale

1995 ◽  
Vol 166 ◽  
pp. 267-272
Author(s):  
Sidney Van Den Bergh
Keyword(s):  
Hubble Parameter ◽  
Main Sequence ◽  
Hubble Space Telescope ◽  
Virgo Cluster ◽  
Distance Scale ◽  
Rr Lyrae Stars ◽  
Space Telescope ◽  
Cluster Galaxies ◽  
Rr Lyrae ◽  
Lyrae Stars

It is generally agreed that the Hubble parameter lies in the range 50 < Ho (km s−1 Mpc−1) < 100. Recent observations, which are discussed in the present paper, favor Ho ≳ 75 km s−1 Mpc−1. Hubble Space Telescope observations of Cepheids in Virgo cluster galaxies will probably reduce the uncertainty in Ho to ∼ 20%. It should be possible to lower this remaining uncertainty in the Hubble parameter by strengthening the calibration of the Cepheid period-luminosity relation, the MV(RR) versus [Fe/H] relation of RR Lyrae stars, and the luminosity calibration of the subdwarf main sequence, by using parallaxes obtained with Hipparcos.

An AI scheduling environment for the Hubble Space Telescope

1991 ◽  
Author(s):  
JEFFREY SPONSLER ◽  
MARK JOHNSTON ◽  
GLENN MILLER ◽  
ANTHONY KRUEGER ◽  
MICHAEL LUCKS ◽  
...  
Keyword(s):  
Hubble Space Telescope ◽  
Space Telescope
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