A recent study suggests that the quasar HE 0450−2958 is hosted by a galaxy substantially fainter than that inferred from the correlation between black hole mass and bulge luminosity. As this result has significant bearings on galaxy and black hole evolution, we revisit the issue by performing an independent analysis of the data, using a two-dimensional image fitting technique. We indeed find no...

We present HST/WFPC2 images in Hα+[N II]λλ6548,6583 lines and continuum radiation and a VLA map at 8 GHz of the H2O gigamaser galaxy TXS2226-184. This galaxy has the most luminous H2Omaser emission known to date. Our red continuum images reveal a highly elongated galaxy with a dust lane crossing the nucleus. The surface brightness profile is best fitted by a bulge plus exponential disk model, f...

We examine the properties of central dust in nearby quiescent and active early-type galaxies. The active galaxies are low-power radio galaxies with Fanaroff & Riley Type I or I/II radio jets. We focus on (a) the comparison of the dust distributions in the active and quiescent galaxy samples and (b) the relation between the radio jet and dust orientations. Our main observational conclusions are:...

Non-thermal TeV γ-ray emission within a multiparsec has been observed from the center region of our Galaxy. We argue that these γ-rays are the result of transient activity of the massive black hole Sgr A that resides at the Galactic Center. Several thousand years ago, the black hole may have experienced an active phase by capturing a red giant star and forming an accretion disk, temporarily beh...

Non-thermal TeV γ-ray emission within multi-pc scale has been observed from the center region of our galaxy. We argue that these γ-rays are the result of a transient activity of the massive black hole Sgr A which resides at the Galactic center. About thousands of years ago, the black hole may have experienced an active phase by capturing a red giant star and forming an accretion disk, temporari...

The problem of galaxy formation and its dependence on thermodynamic properties is addressed by using Eulerian hydrodynamic numerical simulations of large scale structure formation. Global galaxy properties are explored in simulations including gravitation, shock heating and cooling processes, and following self-consistently the chemical evolution of a primordial composition hydrogen-helium plas...

We analyse the environment of low redshift, z < 0.2, SDSS quasars using the spectral and photometric information of galaxies from the Sloan Digital Sky Survey Third Data Release (SDSS-DR3). We compare quasar neighbourhoods with field and high density environments through an analysis on samples of typical galaxies and groups. We compute the surrounding surface number density of galaxies finding ...

A multi-wavelength set of photometric data including UV (GALEX), optical, near-IR, infrared (Spitzer) and radio (VLA 20cm) images and spectro-scopic observations are used to map the dust-obscured and unobscured star formation in the galaxy pair ARP 32. The system consists of an actively star-forming galaxy and another one with depressed star formation. The most active galaxy has disrupted morph...

We report interferometric imaging of CO(J=3→2) emission toward the z=2.846 submillimeterselected galaxy SMMJ04135+10277, using the Combined Array for Research in Millimeter-wave Astronomy (CARMA). SMMJ04135+10277 was previously thought to be a gas-rich, submillimeterselected quasar, with the highest molecular gas mass among high-z quasars reported in the literature. Our maps at ∼6× improved lin...

We present a deep image of the radio galaxy MRC 1138–262 taken with the Hubble Space Telescope (HST) at a redshift of z = 2.2. The galaxy is known to have properties of a cD galaxy progenitor and be surrounded by a 3 Mpc-sized structure, identified with a protocluster. The morphology shown on the new deep HST ACS image is reminiscent of a spider’s web. More than 10 individual clumpy features ar...