Search Publications
The impact of sloshing on the intragroup medium and old radio lobe of NGC 5044
Vrtilek, Jan M.; David, Laurence P.; O'Sullivan, Ewan
We present temperature and abundance maps of the central 125 kpc of the NGC 5044 galaxy group, based on a deep XMM-Newton observation. The abundance map reveals an asymmetrical abundance structure, with the centroid of the highest abundance gas offset ∼22 kpc north-west of the galaxy centre, and moderate abundances extending almost twice as far to…
Large-scale clustering measurements with photometric redshifts: comparing the dark matter haloes of X-ray AGN, star-forming and passive galaxies at z ≈ 1
Berta, S.; Magnelli, B.; Lutz, D. +11 more
We combine multi-wavelength data in the AEGIS-XD and C-COSMOS surveys to measure the typical dark matter halo mass of X-ray selected active galactic nuclei (AGN) [LX(2-10 keV) > 1042 erg s- 1] in comparison with far-infrared selected star-forming galaxies detected in the Herschel/PEP survey (PACS Evolutionary Pr…
Spectral features in isolated neutron stars induced by inhomogeneous surface temperatures
Rea, Nanda; Viganò, Daniele; Perna, Rosalba +1 more
The thermal X-ray spectra of several isolated neutron stars display deviations from a pure blackbody. The accurate physical interpretation of these spectral features bears profound implications for our understanding of the atmospheric composition, magnetic field strength and topology, and equation of state of dense matter. With specific details va…
Feedback, scatter and structure in the core of the PKS 0745-191 galaxy cluster
Fabian, A. C.; Hlavacek-Larrondo, J.; Russell, H. R. +5 more
We present Chandra X-ray Observatory observations of the core of the galaxy cluster PKS 0745-191. Its centre shows X-ray cavities caused by AGN feedback and cold fronts with an associated spiral structure. The cavity energetics imply they are powerful enough to compensate for cooling. Despite the evidence for AGN feedback, the Chandra and XMM-RGS …
X-ray reflection in oxygen-rich accretion discs of ultracompact X-ray binaries
Fabian, A. C.; García, J.; Parker, M. L. +4 more
We present spectroscopic X-ray data of two candidate ultracompact X-ray binaries (UCXBs): 4U 0614+091 and 4U 1543-624. We confirm the presence of a broad O VIII Lyα reflection line (at ≈18 Å) using XMM-Newton and Chandra observations obtained in 2012 and 2013. The donor star in these sources is a carbon-oxygen or oxygen-neon-magnesium white dwarf.…
The ALHAMBRA survey: evolution of galaxy clustering since z ∼ 1
Cepa, J.; Infante, L.; Molino, A. +29 more
We study the clustering of galaxies as function of luminosity and redshift in the range 0.35 < z < 1.25 using data from the Advanced Large Homogeneous Area Medium-Band Redshift Astronomical (ALHAMBRA) survey. The ALHAMBRA data used in this work cover 2.38 deg2 in seven independent fields, after applying a detailed angular selectio…
The behaviour of quasar C IV emission-line properties with orientation
Shang, Zhaohui; Brotherton, M. S.; Runnoe, Jessie C. +1 more
With a quasar sample designed for studying orientation effects, we investigate the orientation dependence characteristics of the C IV λ1549 broad emission line in approximately 50 Type 1 quasars with z = 0.1-1.4. Understanding the role that orientation plays in determining the observed ultraviolet spectra in quasars is of interest both for the ins…
ALMA and Herschel observations of the prototype dusty and polluted white dwarf G29-38
Wyatt, M. C.; Bonsor, A.; Sibthorpe, B. +3 more
ALMA Cycle 0 and Herschel1 PACS observations are reported for the prototype, nearest, and brightest example of a dusty and polluted white dwarf, G29-38. These long-wavelength programmes attempted to detect an outlying, parent population of bodies at 1-100 au, from which originates the disrupted planetesimal debris that is observed withi…
Fast Bayesian inference for slow-roll inflation
Ringeval, Christophe
We present and discuss a new approach increasing by orders of magnitude the speed of performing Bayesian inference and parameter estimation within the framework of slow-roll inflation. The method relies on the determination of an effective likelihood for inflation which is a function of the primordial amplitude of the scalar perturbations compleme…
The case against large intensity fluctuations in the z ∼ 2.5 He II Lyα forest
McQuinn, Matthew; Worseck, Gabor
Previous studies of the 2.2 < z < 2.7 He II Lyα forest measured much larger ionizing background fluctuations than are anticipated theoretically. We re-analyse recent Hubble Space Telescope data from the two He II sightlines that have been used to make these measurements, HE 2347-4342 and HS 1700+6416, and find that the vast majority of the a…