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To exploit synergies between the Herschel Space Observatory and next generation radio facilities, we have extended the semi-empirical extragalactic radio continuum simulation of Wilman et al. to the mid- and far-infrared. Here, we describe the assignment of infrared spectral energy distributions (SEDs) to the star-forming galaxies and active galactic nuclei, using Spitzer 24, 70 and 160 μm and SCUBA 850 μm survey results as the main constraints. Star-forming galaxies dominate the source counts, and a model in which their far-infrared–radio correlation and infrared SED assignment procedure are invariant with redshift underpredicts the observed 24 and 70 μm source counts. The 70 μm deficit can be eliminated if the star-forming galaxies undergo stronger luminosity evolution than originally assumed for the radio simulation, a requirement which may be partially ascribed to known non-linearity in the far-infrared–radio correlation at low luminosity if it evolves with redshift. At 24 μm, the shortfall is reduced if the star-forming galaxies develop SEDs with cooler dust and correspondingly stronger polycyclic aromatic hydrocarbon emission features with increasing redshift at a given far-infrared luminosity, but this trend may reverse at in order not to overproduce the submillimetre source counts. The resulting model compares favourably with recent Balloon-borne Large Aperture Submillimetre Telescope ( BLAST) results, and we have extended the simulation data base to aid the interpretation of Herschel surveys. Such comparisons may also facilitate further model refinement and revised predictions for the Square Kilometre Array and its precursors. [ABSTRACT FROM AUTHOR]

We report observations of Lyman alpha blob 1 (LAB1) in the SSA 22 protocluster region with the integral-field spectrograph SAURON. We increased the signal-to-noise ratio in the spectra by more than a factor of 3 compared to our previous observations. This allows us to probe the structure of the LAB system in detail, examining its structure in the spatial and wavelength dimensions. We find that the emission from the system comes largely from five distinct blobs. Two of the emission regions are associated with Lyman break galaxies, while a third appears to be associated with a heavily obscured submillimeter galaxy. The fourth and fifth components do not appear to be associated with any galaxy despite the deep imaging that is available in this field. If we interpret wavelength shifts in the line centroid as velocity structure in the underlying gas, many of these emission systems show evidence of velocity shear. It remains difficult to distinguish between an underlying rotation of the gas and an outflow driven by the central object. We have examined all of the line profiles for evidence of strong absorption features. While several systems are better fitted by the inclusion of a weak absorption component, we do not see evidence for a large-scale coherent absorption feature such as that seen in LAB2. [ABSTRACT FROM AUTHOR]

We measure the two-point correlation function, , between galaxies and quasar absorption-line systems at , using the data set of Morris & Jannuzi on 16 lines-of-sight (LOS) with ultraviolet (UV) spectroscopy and galaxy multi-object spectroscopy (Paper I). The measurements are made in 2D redshift space out to Mpc (comoving) along the LOS and out to Mpc projected; as a function of H i column density in the range , also for C iv absorption systems, and as a function of galaxy spectral type. This extends the absorber–galaxy pair analysis of Paper I. We find that the amplitude of the peak in at the smallest separations increases slowly as the lower limit on is increased from 1013 to , and then jumps sharply (albeit with substantial uncertainties) for . For C iv absorbers, the peak strength of is roughly comparable to that of H i absorbers with , consistent with the finding that the C iv absorbers are associated with strong H i absorbers. We do not reproduce the differences reported by Chen et al. between 1D measurements using galaxy subsamples of different spectral types. However, the full impact on the measurements of systematic differences in our samples is hard to quantify. We compare the observations with smoothed particle hydrodynamical (SPH) simulations and discover that in the observations is more concentrated to the smallest separations than in the simulations. The latter also display a ‘finger of god’ elongation of along the LOS in redshift space, which is absent from our data, but similar to that found by Ryan-Weber for the cross-correlation of quasar absorbers and H i-emission-selected galaxies. The physical origin of these ‘fingers of god’ is unclear, and we thus highlight several possible areas for further investigation. [ABSTRACT FROM AUTHOR]

We present optical integral field spectroscopy of the Hα-luminous central cluster galaxies in the cores of the cooling flow clusters A1664, A1835, A2204 and Zw8193. From the [N ii]+Hα complex in these moderate resolution (70–150 km s−1) spectra we derive 2D views of the distribution and kinematics of the emission-line gas, and further diagnostics from the [S ii] and [O i] lines. The Hα emission shows a variety of disturbed morphologies, ranging from smooth but distorted to clumpy and filamentary, with velocity gradients and splittings of several hundred km s−1 on spatial scales of 20 kpc or more. Despite the small sample size, there are some generic features. The most disturbed Hα emission appears to be associated with secondary galaxies within 10–20 kpc (projected) of the central galaxy and close in velocity to the Hα. The global Hα kinematics match those of the CO(1–0) emission in single-dish data. The [N ii]/Hα, [S ii]/Hα and [O i]/Hα ratios vary little with position, local Hα surface brightness or between clusters. We propose that the Hα and CO emission arise in molecular clouds heated by a starburst, and that the latter has been triggered by interaction with a secondary galaxy. Such CO emission is known to trace massive compact (<20 kpc) reservoirs of cool molecular gas, and it is plausible that an infalling galaxy would disturb this gas, distorting the Hα morphology and initiating widespread star formation. We also examine the role of cloud–cloud collisions in the undisturbed molecular gas reservoir, and suggest that they might be an important source of excitation for the emission-line gas in the cores of lower Hα luminosity clusters with less intense star formation. [ABSTRACT FROM AUTHOR]

We present near-infrared integral field spectroscopy of the central kiloparsec of NGC 1275 at the heart of the Perseus cluster of galaxies, obtained with the Integral Field Unit (IFU) of the United Kingdom Infrared Telescope (UKIRT) Imaging Spectrometer (UIST). The nuclear ro-vibrational H2 emission is spatially resolved and is likely to originate approximately 50 pc from the active nucleus. The Paα emission is, by contrast, spatially unresolved. The requirements for thermal excitation of the H2 by nuclear X-radiation, its kinematics on subarcsec scales and its stability against self-gravity together suggest that the observed H2 is part of a clumpy disc rotating about the radio-jet axis. The sharp jump in the H2 velocity across the nucleus implies a black hole mass of, with a systematic error of±0.18 dex due to the uncertainty in the radio-jet inclination. This agrees well with the value implied by the empirical correlation between black hole mass and stellar velocity dispersion for nearby elliptical galaxies, and is∼100 times the stellar mass in this region. [ABSTRACT FROM AUTHOR]