Related papers: HI in Early-Type Galaxies
We report a tight linear relation between the HI circular velocity measured at 6 $R_{\rm e}$ and the stellar velocity dispersion measured within 1 $R_{\rm e}$ for a sample of 16 early-type galaxies with stellar mass between $10^{10}$ and…
We review the physical properties of nearby, relatively luminous galaxies, using results from newly available massive data sets together with more detailed observations. First, we present the global distribution of properties, including the…
The dust properties of all early-type galaxies imaged with the Planetary Camera of the HST in cycles I-III are examined. Dust is detected in 31 out of 64 galaxies, although the sample is biased against the detection of dust. From the…
We investigate the neutral hydrogen (HI) content of sixteen groups for which we have multi-wavelength data including X-ray observations. Wide-field imaging of the groups was obtained with the 20-cm multibeam system on the 64-m Parkes…
The morphological dependence of the luminosity function is studied using a sample containing approximately 1500 bright galaxies classified into Hubble types by visual inspections for a homogeneous sample obtained from the Sloan Digital Sky…
Color gradients in early-type galaxies contain valuable clues about their formation and evolutionary histories and mechanisms. We examine color gradients in 1,700 early-type galaxies in 159 galaxy clusters spanning a redshift range of 0.05…
Neutral intergalactic clouds are so greatly out numbered by galaxies that their integral HI content is negligible in comparison to that contained in optically luminous galaxies. In fact, no HI cloud that is not associated with a galaxy or…
A sample of nearly 9000 early-type galaxies, in the redshift range 0.01<z<0.3, was selected from the Sloan Digital Sky Survey using morphological and spectral criteria. The sample was used to study how early-type galaxy observables,…
The surface brightness profiles of early-type galaxies have central cusps. Two characteristic profile types are observed with HST: `core' profiles have a break at a resolved radius and logarithmic cusp slope gamma < 0.3 inside that radius;…
New 21cm observations with the Green Bank Telescope show that a significant fraction of the HI in the inner Galaxy's halo 1 kpc from the midplane exists in the form of discrete clouds. Some look very much like a Spitzer ``standard'' diffuse…
We present first results of a program to study the dynamics of undisturbed bulgeless, low surface density disk galaxies in order to probe the underlying structure of dark matter halos. High resolution H-alpha rotation curves are combined…
Close examination of so-called "pseudobulges" in several early-type disk galaxies indicates that they are actually composite structures consisting of both a flattened, kinematically cool disklike structure ("disky pseudobulge") and a…
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 <…
Lopsidedness is common in disk galaxies, yet its origin and evolution remain unclear. Previous studies typically examined stellar and gas asymmetries separately, but a combined analysis offers a stronger probe of the mechanisms driving…
We present high resolution R-band images of the central regions of 67 early-type galaxies obtained with the Wide Field and Planetary Camera 2 (WFPC2) aboard the Hubble Space Telescope (HST). Our sample strikingly confirms the complex…
Observations of turbulent velocity dispersions in the HI component of galactic disks show a characteristic floor in galaxies with low star formation rates and within individual galaxies the dispersion profiles decline with radius. We carry…
This talk investigates the formation of early-type galaxies from a deliberately observational view point. I begin by reviewing the conclusions that can be reached by comparing the detailed properties of galaxies in present-day clusters,…
Using a large galaxy group catalogue constructed from the SDSS, we investigate the correlation between various galaxy properties and halo mass. We split the population of galaxies in early types, late types, and intermediate types, based on…
The disk positions for galaxies of various morphological and nuclear-activity types (normal galaxies, QSO, Sy, E/S0, low-surface brightness galaxies, etc.) on the "central surface brightness - exponential scalelength" plane are considered.…
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…