Search Publications
Nuclear interaction gamma-ray lines from the Galactic center region
Cheng, K. S.; Ip, W. H.; Tatischeff, V. +3 more
Aims. The accretion of stars onto the central supermassive black hole at the center of the Milky Way is predicted to generate large fluxes of subrelativistic ions in the Galactic center region. We analyze the intensity, shape, and spatial distribution of de-excitation gamma-ray lines produced by nuclear interactions of these energetic particles wi…
MAGIC upper limits to the VHE gamma-ray flux of 3C 454.3 in high emission state
Maraschi, L.; Covino, S.; Antonelli, L. A. +146 more
Aims: We report upper limits to the very high energy flux (E>100 GeV) of the flat spectrum radio quasar 3C 454.3 (z=0.859) derived by the Cherenkov telescope MAGIC during the high states of July/August and November/December 2007. We compare the upper limits derived in both time slots with the available quasi-simultaneous MeV-GeV data from the A…
INTEGRAL and XMM-Newton observations of AX J1845.0-0433
Walter, R.; Zurita Heras, J. A.
Aims: AX J1845.0-0433 is a transient high-mass X-ray binary discovered by ASCA. The source displays bright and short flares observed by INTEGRAL. The transient behaviour and bright and short flares are studied to understand both the accretion mechanisms and nature of the source.
Methods: Public INTEGRAL data and a pointed XMM-Newton observatio…
The plasma filling factor of coronal bright points. II. Combined EIS and TRACE results
Dere, K. P.
Aims: In a previous paper, the volumetric plasma filling factor of coronal bright points was determined from spectra obtained with the Extreme ultraviolet Imaging Spectrometer (EIS). The analysis of these data showed that the median plasma filling factor was 0.015. One interpretation of this result was that the small filling factor was consistent …
The spectroscopically confirmed huge cosmic structure at z = 0.55
Finoguenov, A.; Tanaka, M.; Koyama, Y. +3 more
We report on the spectroscopic confirmation of a huge cosmic structure around the CL0016 cluster at z=0.55. We made wide-field imaging observations of the surrounding regions of the cluster and identified more than 30 concentrations of red galaxies near the cluster redshift. The follow-up spectroscopic observations of the most prominent part of th…
A dam around the Water Fountain Nebula?. The dust shell of IRAS16342-3814 spatially resolved with VISIR/VLT
Waters, L. B. F. M.; Peletier, R. F.; Verhoelst, T. +4 more
Context: Bipolar morphologies in planetary nebulae (PNe) are believed to be closely linked to binary central stars. Either by collimating a fast stellar wind or by driving a jet via accretion in the central system, dusty torii or stable disks may be crucial ingredients for the shaping of PNe.
Aims: We study the dust distribution in the very yo…
Galaxy evolution by color-log(n) type since redshift unity in the Hubble Ultra Deep Field
Cameron, E.; Driver, S. P.
Aims: We explore the use of the color-log(n) (where n is the global Sérsic index) plane as a tool for subdividing the galaxy population in a physically-motivated manner out to redshift unity. We thereby aim to quantify surface brightness evolution by color-log(n) type, accounting separately for the specific selection and measurement biases against…
Constraints on the kinematics of the 44Ti ejecta of Cassiopeia A from INTEGRAL/SPI
Knödlseder, J.; Decourchelle, A.; Vink, J. +2 more
Context: The medium-lived 44Ti isotope is synthesised by explosive Si-burning in core-collapse supernovae. It is extremely sensitive to the dynamics of the explosion and therefore can be used to indirectly probe the explosion scenario. The young supernova remnant Cassiopeia A is to date the only source of gamma-ray lines from 44
An XMM-Newton view of the dipping low-mass X-ray binary XTE J1710-281
Boirin, L.; Younes, G.; Sabra, B.
Context: Studying the spectral changes during the dips exhibited by almost edge-on, low-mass X-ray binaries (LMXBs) is a powerful means of probing the structure of accretion disks. The XMM-Newton, Chandra, or Suzaku discovery of absorption lines from Fe xxv and other highly-ionized species in many dippers has revealed a highly-ionized atmosphere a…
Non-thermal emission in the core of Perseus: results from a long XMM-Newton observation
Molendi, S.; Gastaldello, F.
We employ a long XMM-Newton observation of the core of the Perseus cluster to validate claims of a non-thermal component discovered with Chandra. From a meticulous analysis of our dataset, which includes a detailed treatment of systematic errors, we find the 2-10 keV surface brightness of the non-thermal component to be less than about 5 × 10…