Search Publications
High-resolution mapping of dust via extinction in the M31 bulge
Lauer, Tod R.; Wang, Q. D.; Dalcanton, Julianne J. +5 more
We map the dust distribution in the central 180 arcsec (∼680 pc) region of the M31 bulge, based on HST WFC3 and ACS observations in ten bands from near-ultraviolet (2700 Å) to near-infrared (1.5 µm). This large wavelength coverage gives us great leverage to detect not only dense dusty clumps, but also diffuse dusty molecular gas. We fit a pi…
The structure and evolution of a forming galaxy cluster at z = 1.62
Hartley, W. G.; Conselice, C. J.; Almaini, O. +4 more
We present a comprehensive picture of the Cl 0218.3-0510 protocluster at z = 1.623 across 10 comoving Mpc. Using filters that tightly bracket the Balmer and 4000 Å breaks of the protocluster galaxies we obtain precise photometric redshifts resulting in a protocluster galaxy sample that is 89 ± 5 per cent complete and has a contamination of only 12…
The PEP survey: evidence for intense star-forming activity in the majority of radio-selected AGN at z ≳ 1
Berta, S.; Lutz, D.; Popesso, P. +4 more
In order to investigate the far-infrared (FIR) properties of radio-active active galactic nuclei (AGN), we have considered three different fields where both radio and FIR observations are the deepest to date: GOODS-South, GOODS-North and the Lockman Hole. Out of a total of 92 radio-selected AGN, ∼64 per cent are found to have a counterpart in Hers…
Radio variability in the Phoenix Deep Survey at 1.4 GHz
Gaensler, B. M.; Hancock, P. J.; Bell, M. E. +2 more
We use archival data from the Phoenix Deep Survey to investigate the variable radio source population above 1 mJy beam-1 at 1.4 GHz. Given the similarity of this survey to other such surveys we take the opportunity to investigate the conflicting results which have appeared in the literature. Two previous surveys for variability conducte…
GW Librae: a unique laboratory for pulsations in an accreting white dwarf
Knigge, C.; Hermes, J. J.; Gänsicke, B. T. +22 more
Non-radial pulsations have been identified in a number of accreting white dwarfs in cataclysmic variables. These stars offer insight into the excitation of pulsation modes in atmospheres with mixed compositions of hydrogen, helium, and metals, and the response of these modes to changes in the white dwarf temperature. Among all pulsating cataclysmi…
The CHARA Array resolves the long-period Wolf-Rayet binaries WR 137 and WR 138
Gies, Douglas R.; Moffat, Anthony F. J.; Richardson, Noel D. +10 more
We report on interferometric observations with the CHARA Array of two classical Wolf-Rayet (WR) stars in suspected binary systems, namely WR 137 and WR 138. In both cases, we resolve the component stars to be separated by a few milliarcseconds. The data were collected in the H band, and provide a measure of the fractional flux for both stars in ea…
Morphological evolution of cluster red sequence galaxies in the past 9 Gyr
De Propris, Roberto; Phillipps, Steven; Bremer, Malcolm N.
Galaxies arrive on the red sequences of clusters at high redshift (z > 1) once their star formation is quenched and evolve passively thereafter. However, we have previously found that cluster red sequence galaxies (CRSGs) undergo significant morphological evolution subsequent to the cessation of star formation, at some point in the past 9-10 Gy…
EXTraS discovery of an 1.2-s X-ray pulsar in M 31
Salvaterra, R.; Haberl, F.; Read, A. M. +13 more
During a search for coherent signals in the X-ray archival data of XMM-Newton, we discovered a modulation at 1.2 s in 3XMM J004301.4+413017 (3X J0043), a source lying in the direction of an external arm of M 31. This short period indicates a neutron star (NS). Between 2000 and 2013, the position of 3X J0043 was imaged by public XMM-Newton observat…
X-ray timing analysis of the quasar PG 1211+143
Vaughan, S.; Reeves, J. N.; Pounds, K. +1 more
We report on a timing analysis of a new ∼630 ks XMM-Newton observation of the quasar, PG 1211+143. We find a well-defined X-ray power spectrum with a well-detected bend at ∼7 × 10-5 Hz, consistent with the established tbend-MBH correlation for luminous, accreting black holes. We find the linear rms-flux relation co…
Quantifying substructures in Hubble Frontier Field clusters: comparison with ΛCDM simulations
Liesenborgs, Jori; Mohammed, Irshad; Saha, Prasenjit +2 more
The Hubble Frontier Fields (HFFs) are six clusters of galaxies, all showing indications of recent mergers, which have recently been observed for lensed images. As such they are the natural laboratories to study the merging history of galaxy clusters. In this work, we explore the 2D power spectrum of the mass distribution PM(k) as a meas…