Search Publications
The initial conditions of isolated star formation - IX. Akari mapping of an externally heated pre-stellar core
Ward-Thompson, D.; Nutter, D.; Stamatellos, D.
We present observations of L1155 and L1148 in the Cepheus molecular cloud, taken using the Far Infrared Surveyor (FIS) instrument on the Akari satellite. We compare these data to submillimetre data taken using the Submillimetre Common-User Bolometer Array (SCUBA) camera on the James Clerk Maxwell Telescope, and far-infrared data taken with the ima…
Discovery of a large and bright bow shock nebula associated with low-mass X-ray binary SAX J1712.6-3739
Read, A. M.; Degenaar, N.; Wijnands, R. +6 more
In a multiwavelength programme dedicated to identifying optical counterparts of faint persistent X-ray sources in the Galactic bulge, we find an accurate X-ray position of SAX J1712.6-3739 through Chandra observations, and discover its faint optical counterpart using our data from EFOSC2 on the ESO 3.6-m telescope. We find this source to be a high…
Broad-band X-ray spectral evolution of GX 339-4 during a state transition
Gehrels, N.; Homan, J.; van der Klis, M. +8 more
We report on X-ray and soft γ-ray observations of the black hole candidate GX 339-4 during its 2007 outburst, performed with the RXTE and INTEGRAL satellites. The hardness-intensity diagram of all RXTE/PCA data combined shows a q-shaped track similar to that observed in previous outbursts. The evolution in the diagram suggested that a transition f…
Spectral energy distributions of type 2 quasi-stellar objects: obscured star formation at high redshifts
Rigopoulou, D.; Hasinger, G.; Mainieri, V. +6 more
We present new mid-infrared and submillimetre observations for a sample of eight high-redshift type 2 quasi-stellar objects (QSOs) located in the Chandra Deep Field-South. The sources are X-ray absorbed with luminosities in excess of 1044 ergs-1. Two of the targets have robust detections, S/N > 4, while further three targe…
The supergiant fast X-ray transient IGRJ18483-0311 in quiescence: XMM-Newton, Swift and Chandra observations
Campana, S.; Israel, G.; Stella, L. +7 more
IGRJ18483-0311 was discovered with INTEGRAL in 2003 and later classified as a supergiant fast X-ray transient. It was observed in outburst many times, but its quiescent state is still poorly known. Here, we present the results of XMM-Newton, Swift and Chandra observations of IGRJ18483-0311. These data improved the X-ray position of the source, and…
Twist and turn: weak lensing image distortions to second order
Bacon, David J.; Schäfer, Björn Malte
We account for all the image distortions relevant to weak gravitational lensing to second order. Besides the familiar shear, convergence, rotation and flexions, we find a new image distortion with two distinct descriptions, the twist and the turn. Like rotation, this distortion is not activated gravitationally to first order, but will be activated…
A survey for post-common-envelope binary stars using GALEX and SDSS photometry
Gänsicke, B. T.; Marsh, T. R.; Maxted, P. F. L. +5 more
We report the first results of our programme to obtain multi-epoch radial velocity measurements of stars with a strong far-ultraviolet excess to identify post-common-envelope binaries (PCEBs). The targets have been identified using optical photometry from Sloan Digital Sky Survey (SDSS) DR4, ultraviolet photometry from Galaxy Evolution Explorer (G…
Spectropolarimetery of umbral fine structures from Hinode: evidence for magnetoconvection
Jain, Rajmal; Bharti, Lokesh; Joshi, Chandan +1 more
We present spectropolarimetric analysis of umbral dots and a light bridge fragment that show dark lanes in G-band images. Umbral dots show upflow as well as associated positive Stokes V area asymmetry in their central parts. Larger umbral dots show downflow patches in their surrounding parts that are associated with negative Stokes V area asymmetr…
Gemini 3D spectroscopy of BAL+IR+FeII QSOs - II. IRAS 04505-2958, an explosive QSO with hypershells and a new scenario for galaxy formation and galaxy end phase
Taniguchi, Y.; Zheng, W.; Terlevich, R. +8 more
From a study of broad absorption line (BAL) + infrared (IR) + FeII quasi-stellar objects (QSOs) [using deep Gemini Multi-Object Spectrograph Integral Field Unit (GMOS-IFU) spectroscopy], new results are presented for IRAS 04505-2958. Specifically, we have studied in detail the outflow (OF) process at two large galactic scales: (i) two blobs/shells…
On the identification of the Fermi/LAT source 0FGL J2001.0+4352 with a BL Lac
Masetti, N.; Ubertini, P.; Parisi, P. +3 more
We report on the identification of the gamma-ray source 0FGL J20001.0+4352 listed in the Fermi bright source catalogue. This object, which has an observed 1-100 GeV flux of (7.8 +/- 1.2) × 10-9phcm-2s-1 and is located close to the Galactic plane, is not associated with any previously known high-energy source. We us…