Search Publications
Exploring the properties of the M31 halo globular cluster system
Mackey, A. D.; Chapman, S. C.; Tanvir, N. R. +6 more
Following on from our discovery of a significant population of M31 outer halo globular clusters (GCs), and updates to the Revised Bologna Catalogue of M31 GCs, we investigate the GC system of M31 out to an unprecedented radius (≈120 kpc). We derive various ensemble properties, including the magnitude, colour and metallicity distributions, as well …
Star-forming galaxies at z≈ 8-9 from Hubble Space Telescope/WFC3: implications for reionization
Wilkins, Stephen M.; Bunker, Andrew J.; Caruana, Joseph +3 more
We present a search for galaxies at 7.6 < z < 9.8 using the latest Hubble Space Telescope/Wide Field Camera 3 (WFC3) near-infrared data, based on the Lyman-break technique. We search for galaxies which have large (Y-J) colours (the 'Y-drops') on account of the Lyman α forest absorption, and with (J-H) colours inconsistent with being low-reds…
The morphology of galaxies in the Baryon Oscillation Spectroscopic Survey
Ross, Nicholas P.; Schneider, Donald P.; Weaver, Benjamin A. +17 more
We study the morphology and size of the luminous and massive galaxies at 0.3 < z < 0.7 targeted in the Baryon Oscillation Spectroscopic Survey (BOSS) using publicly available Hubble Space Telescope (HST) imaging, and catalogues, from the COSMic Origins Survey (COSMOS). Our sample (240 objects) provides a unique opportunity to check the visua…
Filamentary infall of cold gas and escape of Lyα and hydrogen ionizing radiation from an interacting high-redshift galaxy
Ravindranath, Swara; Rauch, Michael; Haehnelt, Martin G. +3 more
We present observations of a peculiar Lyα-emitting galaxy at redshift z = 3.344, discovered in a deep, blind spectroscopic survey for faint Lyα emitters with the Magellan II telescope in the Hubble Ultra Deep Field. The galaxy exhibits complex Lyα emission, including an extended, asymmetric component that is partially suppressed by damped Lyα abso…
Geometry and inclination of the broad-line region in blazars
Treves, A.; Decarli, R.; Dotti, M.
We study the properties of the broad-line region in blazars by comparing the virial estimate of black hole masses with that derived from the mass of the host galaxies. The former is sensitive to the width of broad lines, i.e. to the projection of the velocity of line-emitting clouds along the line of sight; the latter is not. This comparison allow…
Feeding and feedback in the active nucleus of Mrk 1157 probed with the Gemini Near-Infrared Integral-Field Spectrograph
Storchi-Bergmann, Thaisa; Riffel, Rogemar A.
We have mapped the stellar and gaseous kinematics, as well as the emission-line flux distributions and ratios, from the inner ≈450 pc radius of the Seyfert 2 galaxy Mrk 1157, using two-dimensional near-infrared J- and Kl-band spectra obtained with the Gemini Near-Infrared Integral-Field Spectrograph instrument at a spatial resolution of…
The SWELLS survey - I. A large spectroscopically selected sample of edge-on late-type lens galaxies
Treu, Tommaso; Marshall, Philip J.; Auger, Matthew W. +5 more
The relative contribution of baryons and dark matter to the inner regions of spiral galaxies provides critical clues to their formation and evolution, but it is generally difficult to determine. For spiral galaxies that are strong gravitational lenses, however, the combination of lensing and kinematic observations can be used to break the disc-hal…
The bright unidentifiedγ-ray source 1FGL J1227.9-4852: can it be associated with a low-mass X-ray binary?
Hill, A. B.; Camilo, F.; Dubois, R. +10 more
We present an analysis of high energy (HE; 0.1-300 GeV) γ-ray observations of 1FGL J1227.9-4852 with the Fermi Gamma-ray Space Telescope, follow-up radio observations with the Australia Telescope Compact Array, Giant Metrewave Radio Telescope and Parkes radio telescopes of the same field and follow-up optical observations with the ESO VLT. We also…
GRB 090618: detection of thermal X-ray emission from a bright gamma-ray burst
Campana, S.; McBreen, S.; Pandey, S. B. +9 more
GRB 090618 was an extremely bright burst, detected across the electromagnetic spectrum. It has a redshift of 0.54 and a supernova (SN) was identified in ground-based photometry. We present a thorough analysis of the prompt and early afterglow emission using data from Swift, Fermi Gamma-ray Burst Monitor and ROTSE, in which we track the evolution o…
Direct observational evidence for a large transient galaxy population in groups at 0.85 < z < 1
Mulchaey, John S.; Balogh, Michael L.; Finoguenov, Alexis +7 more
We introduce our survey of galaxy groups at 0.85 < z < 1, as an extension of the Group Environment and Evolution Collaboration. Here we present the first results, based on Gemini GMOS-S nod-and-shuffle spectroscopy of seven galaxy groups selected from spectroscopically confirmed, extended XMM detections in COSMOS. We use photometric redshift…