相关论文: The Frequency of Active and Quiescent Galaxies wit…
We analyze the idea that nuclear activity, either AGN or star formation, can be triggered by interactions, studying the percentage of active, HII and quiescent galaxies with companions. Our sample was selected from the Palomar survey, and…
We present the results of a survey of nearby, quiescent, non-peculiar, extremely isolated galaxies to search for the gaseous remnants of galaxy formation. Such remnants are predicted to persist around galaxies into the present day by galaxy…
Previous studies have shown that galaxies with minor companions exhibit an elevated star formation rate. We reverse this inquiry, constructing a volume-limited sample of \simL\star (Mr \leq -19.5 + 5 log h) galaxies from the Sloan Digital…
I study the VLA HI survey of HII galaxies by Taylor et al. (1995, ApJS, 99, 427; 1996, ApJS, 102, 189) and the VLA HI survey of low surface brightness (LSB) dwarf galaxies by Taylor et al. (1996, ApJS, in press) to investigate the role of…
Without the interference of a number of events, galaxies may suffer in crowded environments (e.g., stripping, harassment, strangulation); isolated elliptical galaxies provide a control sample for the study of galaxy formation. We present…
(Abridged) We investigate the number of physical companion galaxies for a sample of relatively isolated elliptical galaxies. NED has been used to reinvestigate the incidence of satellite galaxies for a sample of 34 elliptical galaxies,…
Neutral hydrogen is an important component of the interstellar medium in elliptical galaxies as well as a potentially valuable mass tracer. Until recently, HI surveys of early-type galaxies have been sparse and inhomogeneous but this has…
We calculated the median values of the following parameters for 87 groups of galaxies with three to eight components: the mean rms velocity of the galaxies in the group, S_v = 166 km/s; the harmonic mean radius, R_h = 29 kpc; and the…
We explore the properties of galaxies in the proximity (within a $\sim$2 Mpc radius sphere) of Type I quasars at 0.1<z<0.35, to check whether and how an active galaxy influences the properties of its neighbors. We further compare these with…
We have used the VLA to search for gaseous remnants of the galaxy formation process around six extremely isolated galaxies. We found two distinct HI clouds around each of two galaxies in our sample (UGC 9762 & UGC 11124). These clouds are…
We analyse a sample of about 2000 galaxies in 40 regular clusters, to look for evidence of segregation with respect to galaxy luminosities and morphological types. We find evidence of luminosity segregation for galaxies brighter than $M_R <…
Recent morphological studies (Telles \& Terlevich 1994) of HII galaxies, i.e. dwarf galaxies dominated by a very luminous starburst, have indicated that luminous HII galaxies tend to show distorted morphology suggestive of tidal…
We assess the morphology-density relation, H-alpha linewidth-density relation, and the effects of nearby companions for 300 galaxies selected from low-density environments of the Center for Astrophysics Redshift Survey. Both the…
The abundance of elliptical, S0 and spiral galaxies in clusters is presented as a function of redshift comparing the results of the HST distant cluster studies with new data at z~0.2 and with the standard local comparison samples. This…
Several measures of galaxy size and mass obtained from the neutral hydrogen mapping of 70 dwarf irregular galaxies presented in Paper I (Hoffman et al. 1996) are compared statistically to those for the set of all available HI-mapped dwarfs…
Observations show that galaxies in galaxy clusters are strongly influenced by their environment. There is growing evidence that some galaxies in groups show similar properties to galaxies in clusters, such as redder colours and gas…
We analyze the photometry of 117 OGLE stars with periodic transit events for the presence of ellipsoidal light variations, which indicate the presence of massive companions. We find that ~50% of objects may have stellar companions, mostly…
We have investigated the role that different galaxy types have in galaxy-galaxy interactions in compact groups. N-body simulations of 6 galaxies consisting of a differing mixture of galaxy types were run to compare the relative importance…
The distributions of galaxy properties vary with environment, and are often multimodal, suggesting that the galaxy population may be a combination of multiple components. The behaviour of these components versus environment holds details…
A technique is described that permits the robust decomposition of the bulge and disk components of a sample of Seyfert galaxies, as well as a (control) sample of non-active galaxies matched to the Seyferts in the distributions of redshift,…