Search Publications
Reddening law and interstellar dust properties along Magellanic sight-lines
Zagury, Frédéric
This study establishes that SMC, LMC and Milky Way extinction curves obey the same extinction law which depends on the 2200 Å bump size and one parameter, and generalizes the Cardelli, Clayton and Mathis (Cardelli et al., Astrophys. J. 345, 245, 1989) relationship. This suggests that extinction in all three galaxies is of the same nature. The role…
Unveiling soft gamma-ray repeaters with INTEGRAL
Mereghetti, Sandro; Hurley, Kevin; Götz, Diego
Thanks to INTEGRAL's long exposures of the Galactic Plane, the two brightest Soft Gamma-Ray Repeaters, SGR 1806-20 and SGR 1900+14, have been monitored and studied in detail for the first time at hard-X/soft gamma rays. This has produced a wealth of new scientific results, which we will review here. Since SGR 1806-20 was particularly active during…
New INTEGRAL sources and TeV emission
Walter, Roland
INTEGRAL is operational since more than three years and producing high quality data that allows to detect fainter new hard X-ray sources. The new sources, identified until now, are mostly active galactic nuclei and absorbed or transient high mass X-ray binaries. TeV emission could be expected from the new high mass X-ray binaries accreting dense c…
Deep Hubble space telescope ultraviolet imaging of the M87 jet
Perlman, Eric S.; Sparks, William B.; Harris, D. E. +3 more
Near-ultraviolet imaging with HST offers the best possible spatial resolution currently available for optical/UV astronomical imaging. The giant elliptical galaxy M87 hosts one of the most spectacular, best studied and nearest (d=16 Mpc) galactic-scale relativistic (synchrotron emitting plasma) jets. We have extracted from the HST archive all 220 …
Infrared study of the extreme carbon stars based on IRAS, 2MASS and ISO data
Chen, Pei-Sheng; Shan, Hong-Guang
We collected 55 galactic extreme carbon stars from the published literature in this paper. Observational data from IRAS, 2MASS and ISO were analyzed. The results show that the infrared properties of extreme carbon stars are quite different to those for ordinary visual carbon stars. It is shown from IRAS and 2MASS photometric data that extreme carb…
Photometric study of the W UMa eclipsing binaries VW LMi and BX Dra
García-Melendo, E.; Gómez-Forrellad, J. M.; Sánchez-Bajo, F.
New ephemeris and the absolute parameters—masses, radii and luminosities—of the contact systems VW LMi and BX Dra have been obtained, by means of the analysis of the minima data available in the literature (for the determination of the ephemeris) and combining the previously published spectroscopic information and the results of the Wilson-Devinne…
INTEGRAL observations of TeV plerions
Santangelo, A.; Horns, D.; Hoffmann, A. I. D.
Amongst the sources seen in very high gamma-rays several are associated with Pulsar Wind Nebulae ("TeV plerions"). The study of hard X-ray/soft gamma-ray emission is providing an important insight into the energetic particle population present in these objects. The unpulsed emission from pulsar/pulsar wind nebula systems in the energy range access…
Evidence for a binary companion to the central compact object 1E 1207.4-5209
Pavlov, George G.; Zavlin, Vyacheslav E.; Woods, Peter M.
Unique among neutron stars, 1E 1207.4-5209 is an X-ray pulsar with a spin period of 424 ms that contains at least two strong absorption features in its energy spectrum. This neutron star is positionally coincident with the supernova remnant PKS 1209-51/52 and has been identified as a member of the growing class of radio-quiet compact central objec…
XMM-Newton observations of the isolated neutron star 1RXS J214303.7+065419/RBS1774
Cropper, Mark; Turolla, Roberto; Zampieri, Luca +4 more
We report XMM-Newton observations of the isolated neutron star RBS1774 and confirm its membership as an XDINS. The X-ray spectrum is best fit with an absorbed blackbody with temperature kT=101 eV and absorption edge at 0.7 keV. No power law component is required. An absorption feature in the RGS data at 0.4 keV is not evident in the EPIC data, but…
The black-hole candidate XTE J1817-330 as seen by XMM-Newton and INTEGRAL
Haberl, Frank; Greiner, Jochen; Sala, Gloria +1 more
The new black hole candidate XTE J1817-330, discovered on 26 January 2006 with RXTE, was observed with XMM-Newton and INTEGRAL in February and March 2006, respectively. The X-ray spectrum is dominated by the thermal emission of the accretion disk in the soft band, with a low absorption column density (NH=1.77(±0.01)×1021 cm