Search Publications
A connection between accretion state and Fe K absorption in an accreting neutron star: black hole-like soft-state winds?
Ponti, Gabriele; Muñoz-Darias, Teodoro; Fender, Robert P.
High-resolution X-ray spectra of accreting stellar-mass black holes reveal the presence of accretion disc winds, traced by high-ionization Fe K lines. These winds appear to have an equatorial geometry and to be observed only during disc-dominated states in which the radio jet is absent. Accreting neutron star systems also show equatorial high-ioni…
A sub-kpc-scale binary active galactic nucleus with double narrow-line regions
Komossa, S.; Husemann, Bernd; Park, Daeseong +3 more
We present the kinematic properties of a type-2 Quasi stellar object (QSO), SDSS J132323.33-015941.9 at z ∼ 0.35, based on the analysis of Very Large Telescope integral field spectroscopy and Hubble Space Telescope (HST) imaging, which suggest that the target is a binary active galactic nucleus (AGN) with double narrow-line regions. The QSO featur…
The curious time lags of PG 1244+026: discovery of the iron K reverberation lag.
Fabian, A. C.; Uttley, P.; Cackett, E. M. +2 more
High-frequency iron K reverberation lags, where the red wing of the line responds before the line centroid, are a robust signature of relativistic reflection off the inner accretion disc. In this Letter, we report the discovery of the Fe K lag in PG 1244+026 from ∼120 ks of data (one orbit of the XMM-Newton telescope). The amplitude of the lag wit…
A wide search for obscured active galactic nuclei using XMM-Newton and WISE
Alexander, D. M.; Georgakakis, A.; Comastri, A. +8 more
Heavily obscured and Compton-thick active galactic nuclei (AGNs) are missing even in the deepest X-ray surveys, and indirect methods are required to detect them. Here we use a combination of the XMM-Newton serendipitous X-ray survey with the optical Sloan Digital Sky Survey (SDSS), and the infrared WISE all-sky survey in order to check the efficie…
Star formation in the cluster CLG0218.3-0510 at z = 1.62 and its large-scale environment: the infrared perspective
Altieri, B.; Valtchanov, I.; Dickinson, M. +7 more
The galaxy cluster CLG0218.3-0510 at z = 1.62 is one of the most distant galaxy clusters known, with a rich multiwavelength data set that confirms a mature galaxy population already in place. Using very deep, wide-area (20 Mpc × 20 Mpc) imaging by Spitzer MIPS at 24 µm, in conjunction with Herschel five-band imaging from 100 to 500 µm,…
The decomposed bulge and disc size-mass relations of massive galaxies at 1 < z < 3 in CANDELS
Ferguson, H. C.; Bowler, R. A. A.; McLure, R. J. +15 more
We have constructed a mass-selected sample of M* > 1011 M⊙ galaxies at 1 < z < 3 in the CANDELS UKIDSS UDS and COSMOS fields and have decomposed these systems into their separate bulge and disc components according to their H160-band morphologies. By extending this analysis to multiple bands, we…
Seeing in the dark - II. Cosmic shear in the Sloan Digital Sky Survey
Mandelbaum, Rachel; Schlegel, David; Seljak, Uroš +3 more
Statistical weak lensing by large-scale structure - cosmic shear - is a promising cosmological tool, which has motivated the design of several large upcoming surveys. Here, we present a measurement of cosmic shear using co-added Sloan Digital Sky Survey (SDSS) imaging in 168 square degrees of the equatorial region, with r < 23.5 and i < 22.5…
The XMM-LSS survey: the Class 1 cluster sample over the extended 11 deg2 and its spatial distribution
Smith, G. P.; Altieri, B.; Pierre, M. +10 more
This paper presents 52 X-ray bright galaxy clusters selected within the 11 deg2 XMM-LSS survey. 51 of them have spectroscopic redshifts (0.05 < z < 1.06), one is identified at zphot = 1.9, and all together make the high-purity `Class 1' (C1) cluster sample of the XMM-LSS, the highest density sample of X-ray-selected clu…
The progenitors of calcium-rich transients are not formed in situ*
Lyman, J. D.; Davies, M. B.; Levan, A. J. +2 more
We present deep Very Large Telescope and Hubble Space Telescope observations of the nearest examples of Ca-rich `gap' transients - rapidly evolving transient events, with a luminosity intermediate between novae and supernovae. These sources are frequently found at large galactocentric offsets, and their progenitors remain mysterious. Our observati…
A new precise mass for the progenitor of the Type IIP SN 2008bk
Ramirez-Ruiz, Enrico; Mattila, Seppo; Eldridge, John J. +1 more
The progenitor of the Type IIP supernova (SN) 2008bk was discovered in pre-explosion g'r'i'IYJHKs images, acquired with European Southern Observatory Very Large Telescope FOcal Reducer and low dispersion Spectrograph, High Acuity Wide field K-band Imager and Infrared Spectrometer and Array Camera instrum…