Search Publications
The importance of major mergers in the build up of stellar mass in brightest cluster galaxies at z = 1
Demarco, R.; Lidman, C.; Meyers, J. +22 more
Recent independent results from numerical simulations and observations have shown that brightest cluster galaxies (BCGs) have increased their stellar mass by a factor of almost 2 between z ∼ 0.9 and z ∼ 0.2. The numerical simulations further suggest that more than half this mass is accreted through major mergers. Using a sample of 18 distant galax…
Dust and star formation properties of a complete sample of local galaxies drawn from the Planck Early Release Compact Source Catalogue
Baccigalupi, C.; Bonavera, L.; Clements, D. L. +16 more
We combine Planck High Frequency Instrument data at 857, 545, 353 and 217 GHz with data from Wide-field Infrared Survey Explorer (WISE), Spitzer, IRAS and Herschel to investigate the properties of a well-defined, flux-limited sample of local star-forming galaxies. A 545 GHz flux density limit was chosen so that the sample is 80 per cent complete a…
A simplified view of blazars: the γ-ray case
Polenta, G.; Giommi, P.; Padovani, P.
We have recently proposed a new simplified scenario where blazars are classified as flat spectrum radio quasars (FSRQs) or BL Lacs according to the prescriptions of unified schemes, and to a varying combination of Doppler-boosted radiation from the jet, emission from the accretion disc, the broad line region and light from the host galaxy. Here we…
Comparing the ancient star formation histories of the Magellanic Clouds
Dolphin, Andrew E.; Skillman, Evan D.; Cole, Andrew A. +4 more
We present preliminary results from a new Hubble Space Telescope (HST) archival program aimed at tightly constraining the ancient (>4 Gyr ago) star formation histories (SFHs) of the field populations of the Small Magellanic Cloud (SMC) and Large Magellanic Cloud (LMC). We demonstrate the quality of the archival data by constructing HST/Wide Fie…
Uncovering obscured luminous AGN with WISE
Blain, A.; Carrera, F. J.; Caccianiga, A. +4 more
Mateos et al. presented a highly reliable and efficient mid-infrared (MIR) colour-based selection technique for luminous active galactic nuclei (AGN) using the Wide-field Infrared Survey Explorer (WISE) survey. Here, we evaluate the effectiveness of this technique to identify obscured AGN missed in X-ray surveys. To do so we study the WISE propert…
The horizontal branch in the UV colour-magnitude diagrams - II. The case of M3, M13 and M79
Dalessandro, E.; Salaris, M.; Mucciarelli, A. +2 more
We present a detailed comparison between far-ultraviolet (UV)/optical colour-magnitude diagrams obtained with high-resolution Hubble Space Telescope data and suitable theoretical models for three Galactic globular clusters: M3, M13 and M79.
These systems represents a `classical' example of clusters in the intermediate-metallicity regime that,…Connecting stellar mass and star-formation rate to dark matter halo mass out to z ∼ 2
Ivison, R. J.; Ilbert, O.; Béthermin, M. +17 more
We have constructed an extended halo model (EHM) which relates the total stellar mass and star-formation rate (SFR) to halo mass (Mh). An empirical relation between the distribution functions of total stellar mass of galaxies and host halo mass, tuned to match the spatial density of galaxies over 0 < z < 2 and the clustering prope…
A giant elliptical galaxy with a lightweight initial mass function
Lucey, John R.; Smith, Russell J.
We present new observations of the closest known strong-lensing galaxy, the σ ≈ 330 km s- 1 giant elliptical ESO325-G004, made with the ESO Very Large Telescope. The low redshift of the lens (zl = 0.035) results in arcs being formed at a small fraction of the effective radius (REin = 2.85 arcsec ≈ Reff/4…
The bright end of the exo-Zodi luminosity function: disc evolution and implications for exo-Earth detectability
Wyatt, M. C.; Kennedy, G. M.
We present the first characterisation of the 12 µm warm dust (`exo-Zodi') luminosity function around Sun-like stars, focusing on the dustiest systems that can be identified by the WISE mission. We use the sample of main-sequence stars observed by Hipparcos within 150 pc as an unbiased sample, and report the detection of six new warm dust can…
Formation of the compact jets in the black hole GX 339-4.
Aussel, H.; Tomsick, J. A.; Rodriguez, J. +15 more
Galactic black hole binaries produce powerful outflows which emit over almost the entire electromagnetic spectrum. Here, we report the first detection with the Herschel observatory of a variable far-infrared source associated with the compact jets of the black hole transient GX 339-4 during the decay of its recent 2010-2011 outburst, after the tra…