Search Publications
The SWELLS survey - III. Disfavouring 'heavy' initial mass functions for spiral lens galaxies
Treu, Tommaso; Marshall, Philip J.; Auger, Matthew W. +6 more
We present gravitational lens models for 20 strong gravitational lens systems observed as part of the Sloan WFC Edge-on Late-type Lens Survey (SWELLS) project. 15 of the lenses are taken from Paper I, while five are newly discovered systems. The systems are galaxy-galaxy lenses where the foreground deflector has an inclined disc, with a wide range…
The rotation of field stars from CoRoT data
Micela, G.; Favata, F.; Affer, L. +1 more
We present period measurements of a large sample of field stars in the solar neighbourhood, observed by the COnvection ROtation and planetary Transits (CoRoT) satellite in two different directions of the Galaxy. The presence of a period was detected using the Lomb-Scargle normalized periodogram technique and the autocorrelation analysis. The asses…
Broad-band observations of the Be/X-ray binary pulsar RX J0440.9+4431: discovery of a cyclotron absorption line
Tsygankov, S. S.; Lutovinov, A. A.; Krivonos, R. A.
We report the results of an analysis of data obtained with the International Gamma-Ray Astrophysics Laboratory (INTEGRAL), Swift and Rossi X-ray Timing Explorer (RXTE) observatories during the 2010 April and September outbursts of the X-ray pulsar RX J0440.9+4431. The temporal and spectral properties of the pulsar in a wide energy band (0.6-120 ke…
The universal Einstein radius distribution from 10 000 SDSS clusters
Broadhurst, Tom; Oguri, Masamune; Zitrin, Adi +5 more
We present results from strong lens modelling of 10 000 Sloan Digital Sky Survey (SDSS) clusters, to establish the universal distribution of Einstein radii. Detailed lensing analyses have shown that the inner mass distribution of clusters can be accurately modelled by assuming light traces mass, successfully uncovering large numbers of multiple im…
X-ray spectral states and metallicity in the ultraluminous X-ray sources NGC 1313 X-1 and X-2
Pintore, Fabio; Zampieri, Luca
We present a systematic analysis of the X-ray spectra of NGC 1313 X-1 and NGC 1313 X-2, using three years of XMM-Newton observations. We fitted the continuum with a Comptonization model plus a multicolour blackbody disc, which describes the effects of an accretion disc plus a corona. We checked the consistency of this spectral model on the basis o…
The nature of the jet-driven outflow in the radio galaxy 3C 305
Bianchi, S.; Hardcastle, M. J.; Siemiginowska, A. +6 more
We present Chandra X-ray and Very Large Array radio observations of the radio galaxy 3C 305. The X-ray observations reveal the details of the previously known extended X-ray halo around the radio galaxy. We show using X-ray spectroscopy that the X-ray emission is consistent with being shock-heated material and can be modelled with standard collisi…
The nature of the unresolved extragalactic cosmic soft X-ray background
Finoguenov, A.; Vignali, C.; Gilli, R. +12 more
In this paper we investigate the power spectrum of the unresolved 0.5-2 keV cosmic X-ray background (CXB) with deep Chandra 4-Msec (Ms) observations in the Chandra Deep Field South (CDFS). We measured a signal that, on scales >30 arcsec, is significantly higher than the shot noise and is increasing with angular scale. We interpreted this signal…
Charge-exchange X-ray emission of nearby star-forming galaxies
Wang, Q. Daniel; Liu, Jiren; Mao, Shude
Properties of hot gas outflows from galaxies are generally measured from associated X-ray line emission assuming that it represents atomic transitions in thermally excited hot gas. X-ray line emission, however, can also arise from the charge exchange between highly ionized ions and neutral species. The Kα triplet of He-like ions can be used as a p…
Strong outburst activity of the X-ray pulsar X Persei during 2001-2011
Tsygankov, S.; Lutovinov, A.; Chernyakova, M.
We present the results of a comprehensive analysis of the X-ray pulsar X Persei over the period 1996-2011, encompassing the quite low state and subsequent strong outburst activity. Using data from the Rossi X-ray Timing Explorer (RXTE) and Swift, we detected several consecutive outbursts, during which the source luminosity increased by a factor of…
Detecting gravitationally lensed Population III galaxies with the Hubble Space Telescope and the James Webb Space Telescope
Broadhurst, Tom; Schaerer, Daniel; Östlin, Göran +6 more
Small galaxies consisting entirely of Population III (pop III) stars may form at high redshifts, and could constitute one of the best probes of such stars. Here, we explore the prospects of detecting gravitationally lensed pop III galaxies behind the galaxy cluster J0717.5+3745 (J0717) with both the Hubble Space Telescope (HST) and the upcoming Ja…