I will review the basic properties of S0 galaxies in the local Universe in relation to both elliptical and spiral galaxies, their neighbours on the Hubble sequence, and also in relation to dwarf spheroidal (dSph) galaxies. This will include colours, luminosities, spectral features, information about the age and metallicity composition of their stellar populations and globular clusters, about th...

From the analysis of sensitive H i 21-cm line observations, we find evidence for vertically extended H i emission (|z| <∼2.4 kpc) in the edge-on, low surface brightness spiral galaxy UGC 7321. Three-dimensional modelling suggests that the H i disk of UGC 7321 is both warped and flared, but that neither effect can fully reproduce the spatial distribution and kinematics of the highest z-height ga...

We present a map of the area near the Local Group dwarf galaxy LGS 3, centered on an H i cloud ′ ′ 93 # 93 30 away from the galaxy. Previous authors associated this cloud with LGS 3 but relied on observations made with a 36 beam. Our high-resolution (3 .4), wide-field Arecibo observations of the region reveal that the H i cloud is distinct from the galaxy and suggest an interaction between the ...

We present a ROSAT and ASCA study of the Einstein source X-9 and its relation to a shock-heated shell-like optical nebula in a tidal arm of the M81 group of interacting galaxies. Our ASCA observation of the source shows a flat and featureless X-ray spectrum well described by a multi-color disk blackbody model. The source most likely represents an optically thick accretion disk around an interme...

We report the detection of broad (FWHM 270 km s) H I z 21 cm absorption toward the compact (,15 h pc) radio nucleus of the nearby powerful radio galaxy Cygnus A. The absorption corresponds to a column density of hydrogen atoms of at least 2.54H 0.44 3 10 Tspin cm. Observations of OH and H2CO yielded upper limits. While other possibilities exist, we argue that the observed H I absorption plausib...

The non-circular streaming motions in barred galaxies are sensitive to the mass of the bar and can be used to lift the degeneracy between disk and dark matter halo encountered when fitting axisymmetric rotation curves of disk galaxies. In this paper, we present photometric and kinematic observations of NGC 4123, a barred galaxy of modest size (Vrot = 130 km s , L = 0.7L∗), which reveal strong n...

We present models for dusty high–redshift Lyα emitting galaxies by combining the Press–Schechter formalism with a treatment of inhomogeneous dust distribution inside galaxies. These models reproduce the surface density of emitters inferred from recent observations, and also agree with previous non–detections. Although a detailed determination of the individual model parameters is precluded by u...

We have used the Keck I Telescope to measure K-band surface brightness fluctuations (SBFs) of NGC 4874, the dominant elliptical galaxy in the Coma cluster. We use deep HST WFPC2 optical imaging to account for the contamination due to faint globular clusters and improved analysis techniques to derive measurements of the SBF apparent magnitude. Using a new SBF calibration which accounts for the d...

We summarize the H i properties of early-type galaxies, in particular the differences in H i morphologies observed in early-type galaxies of different luminosities. We find that in lowluminosity early-type galaxies the H i is almost always in a disk-like structure, with central surface densities high enough for star formation to occur. In a few luminous early-type galaxies the H i is also in a ...

We report the detection of broad (FWHM 270kms 1) H I 21 cm absorption toward the compact (<15h 1 pc) radio nucleus of the nearby powerful radio galaxy Cygnus A. The absorption corresponds to a column density of hydrogen atoms of at least 2.54 0.44 1019 Tspin cm 2. Observations of OH and H2CO yielded upper limits. While other possibilities exist, we argue that the observed H I absorption plausib...