Results 31 to 40 of about 12,741,185 (402)

NGC 741—Mergers and AGN Feedback on a Galaxy-group Scale [PDF]

open access: yes, 2017
Low-mass galaxy cluster systems and groups will play an essential role in upcoming cosmological studies, such as those to be carried out with eROSITA. Though the effects of active galactic nuclei (AGNs) and merging processes are of special importance to ...
G. Schellenberger   +7 more
semanticscholar   +1 more source

Optical observations of M81 galaxy group in narrow band [SII] and Hα filters: Holmberg IX [PDF]

open access: yesSerbian Astronomical Journal, 2009
We present observations of the nearby tidal dwarf galaxy Holmberg IX in M81 galaxy group in narrow band [SII] and Hα filters, carried out in March and November 2008 with the 2m RCC telescope at NAO Rozhen, Bulgaria.
Arbutina B.   +5 more
doaj   +1 more source

Pre-Processing and Post-Processing in Group-Cluster Mergers [PDF]

open access: yes, 2013
Galaxies in clusters are more likely to be of early type and to have lower star formation rates than galaxies in the field. Recent observations and simulations suggest that cluster galaxies may be `pre-processed' by group or filament environments and ...
Ricker, Paul M., Vijayaraghavan, Rukmani
core   +1 more source

The Shapes of Galaxy Groups

open access: yesThe Astrophysical Journal, 1993
The shape of groups of galaxies has been since now a disregarded topic in the literature, mainly due to the fact that individual ellipticity estimates of poor systems are strongly biased toward higher values. Such a bias turns out to depend on both the ellipticity itself and on the richness of the group. In this paper we have devised a modified version
G. Fasano   +3 more
openaire   +5 more sources

X-ray analysis of the galaxy group UGC 03957 beyond R200 with Suzaku [PDF]

open access: yes, 2016
Context. In the last few years, the outskirts of galaxy clusters have been studied in detail and the analyses have brought up interesting results such as indications of possible gas clumping and the breakdown of hydrostatic, thermal, and ionization ...
Sophia Thölken   +4 more
semanticscholar   +1 more source

Deep Chandra observations of the stripped galaxy group falling into Abell 2142 [PDF]

open access: yes, 2017
In the local Universe, the growth of massive galaxy clusters mainly operates through the continuous accretion of group-scale systems. The infalling group in Abell 2142 is the poster child of such an accreting group, and as such, it is an ideal target to ...
D. Eckert   +10 more
semanticscholar   +1 more source

Redshifts of the Gravitational Lenses MG0414+0534 and MG0751+2716 [PDF]

open access: yes, 1998
We report redshifts in two gravitational lens systems, MG0414+0534 and MG0751+2716. The lens galaxy in MG0414+0534 lies at z_l=0.9584+/-0.0002. The luminosity and extreme red color of the lens are then typical of a passively evolving, early-type, ~2L ...
Christopher S. Kochanek   +5 more
core   +2 more sources

Age Estimates for Galaxies in Groups [PDF]

open access: yesInternational Astronomical Union Colloquium, 2000
AbstractWe discuss recent developments on the age and metallicity distribution for early type galaxies in different environments.
A. I. Terlevich, Duncan A. Forbes
openaire   +3 more sources

H0LiCOW - II. Spectroscopic survey and galaxy-group identification of the strong gravitational lens system HE 0435-1223 [PDF]

open access: yes, 2016
Galaxies located in the environment or along the line of sight towards gravitational lenses can significantly affect lensing observables, and can lead to systematic errors on the measurement of H-0 from the time-delay technique. We present the results of
D. Sluse   +17 more
semanticscholar   +1 more source

Spectroscopic confirmation of a galaxy cluster associated with 7C1756+6520 at z=1.416 [PDF]

open access: yes, 2010
We present spectroscopic follow-up of an overdensity of galaxies photometrically selected to be at 1 ...
A. Galametz   +38 more
core   +2 more sources

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