Stellar Dynamics and Star Formation Histories of z ~ 1 Radio-loud Galaxies

Galaxie

A spitzer-IRS spectroscopic atlas of early-type galaxies in the Revised shapley-ames catalog

We produce an atlas of homogeneously reduced and calibrated low-resolution IRS spectra of the nuclear regions of nearby early-type galaxies (ETGs, i.e. Es and S0s), in order to build a reference sample in the mid-infrared window. From the Spitzer Heritage Archive we extract ETGs in the Revised Shapley-Ames Catalog of Bright Galaxies having an IRS SL and/or LL spectrum. We recover 91 spectra out of 363 galaxies classified as ETGs in the catalogue: 56 E (E0-E6), 8 mixed E/S0+S0/E and 27 S0 (both normal and barred - SB0) plus mixed types SB0/Sa+SB0/SBa. For each galaxy, we provide the fully reduced and calibrated spectrum and the intensity of nebular and molecular emission lines as well as of the polycyclic aromatic hydrocarbons (PAHs) after a template spectrum of a passively evolving ETG has been subtracted. Spectra are classified into five mid-infrared classes, ranging from active galactic nuclei (class-4) and star-forming nuclei (class-3), to transition class-2 (with PAHs) and class-1 (no-PAHs), to passively evolving nuclei (class-0). A demographic study of mid-infrared spectra shows that Es are significantly more passive than S0s: 46(-10)(+11) per cent of Es and 20(-7)(+11) per cent of S0s have a spectrum of class-0. Emission lines are revealed in 64(-6)(+12) per cent of ETGs. The H2S(1) line is found with similar rate in Es (34(-8)(+10) per cent) and in S0s (51(-12)(+15) per cent). PAHs are detected in 47(-7)(+8) per cent of ETGs, but only 9(-3)(+4) per cent have PAH ratios typical of star-forming galaxies. Several indicators, such as peculiar morphologies and kinematics, the irregular shape of dust-lanes, and radio and X-ray properties, suggest that mid-infrared spectral classes are associated with phases of accretion/feedback phenomena occurring in the nuclei of ETGs

Prisons, public opinion and the new punitiveness

Using the Australia Telescope Compact Array (ATCA), ATLAS (Australia Telescope Large Area Survey) is imaging two fields totalling 7 square degrees down to 10μJy beam⁻¹ at 1.4 GHz. We have found 6 wide-angle tail galaxies (WATs), 4 of which have sufficient data to identify associated galaxy overdensities. The largest WAT, at a red-shift of 0.22, appears to be associated with an overdensity of galaxies that is spread over an unusually large extent of 12 Mpc, with a velocity range of 4500 km s⁻¹. Here we present the WATs in ATLAS and discuss the implications of these observations for future large-scale radio surveys such as ASKAP-EMU