Search Publications
Stereoscopic observations of the giant hard X-ray/gamma-ray solar flare on 1991 June 30 at 0255 UT
Hurley, K.; Kane, S. R.; Vilmer, N. +3 more
The hard X-ray/gamma-ray (HXR/GR) impulsive burst on 1991 June 30 ( ~ 0255 UT) was associated with a flare which occured between 2degr and 12degr behind the east limb of the Sun. The partially occulted HXR/GR emission from this flare was detected at up to 100 MeV by three instruments on Earth-orbiting spacecraft: the Burst and Transient Source Exp…
First observations of the X-ray transient EXO 2030+375 with IBIS/ISGRI
Goldoni, P.; Falanga, M.; Goldwurm, A. +3 more
We present a first INTEGRAL observation of the 42 s transient X-ray pulsar EXO 2030+375 with IBIS/ISGRI. The source was detected during Cyg X-1 observations in December 2002. We analyzed observations during the outburst period from 9 to 21 December 2002 with a total exposure time of ~ 770 kilosec. EXO 2030+375 was almost always detected during sin…
Stellar population gradient in lenticular galaxies: NGC 1023, NGC 3115 and NGC 4203
Bassin, M.; Bonatto, Ch.
We investigate the stellar population content in the lenticular galaxies NGC 1023, NGC 3115 and NGC 4203 applying a population synthesis method based on a seven component spectral basis with different ages - 2.5*E6, 10*E6, 25*E6, 75*E6, 200*E6, 1.2*E9 and older than 1010 …
JEM-X background models
Oxborrow, C. A.; Huovelin, J.; Maisala, S. +4 more
Background and determination of its components for the JEM-X X-ray telescope on INTEGRAL are discussed. A part of the first background observations by JEM-X are analysed and results are compared to predictions. The observations are based on extensive imaging of background near the Crab Nebula on revolution 41 of INTEGRAL. Total observing time used…
Spectroscopy of early-type star candidates in M 33 and NGC 6822. II
Bianchi, L.; Scuderi, S.; Catanzaro, G. +1 more
We present ground-based spectra of early-type star candidates in the Local Group galaxies M 33 and NGC 6822 taken at the 4.2 m William Herschel Telescope (La Palma, Spain). Photospheric parameters Teff and log g were derived by LTE modeling of the Balmer lines. When possible, mass-loss rates were calculated from the Halpha p…
First IBIS results on the high energy emission of Cygnus X-2
Santangelo, A.; Capitanio, F.; Ubertini, P. +4 more
The bright low-mass X-ray binary Cyg X-2 was in the field of view of the IBIS telescope during the early Cygnus region observations, executed during the INTEGRAL Performance Verification Phase. The data presented are spanning about one week and cover the rising edge of one of the two peaks of the ~82 day cycle of the Cyg X-2 light curve. The IBIS …
Erratum: The ISO-SWS spectrum of planetary nebula NGC 7027
Pottasch, S. R.; Beintema, D. A.; Bernard-Salas, J. +1 more
Based on observations with ISO, an ESA project with instruments funded by ESA Member States (especially the PI countries: France, Germany, The Netherlands and UK) and with the participation of ISAS and NASA.
First far-UV observations of KQ Puppis with FUSE
Rossi, C.; González-Riestra, R.; Viotti, R. F.
We report the first far-ultraviolet spectrum of the emission line spectroscopic binary KQ Pup (M2Iab+B0Ve), obtained with FUSE shortly after conjunction at orbital phase Phi =0.13. The spectrum presents a sharp flux cutoff at 1040 Å; longwards, it is dominated by a large amount of resonant and low excitation transitions of neutral and singly ioniz…
The CCD and readout electronics for the OMC instrument on Integral
Culhane, J. L.; Smith, A.; Jordan, B. +4 more
The Optical Monitoring Camera (OMC) on ESA's Integral gamma-ray astronomy satellite is devoted to optical wavelength observations simultaneously covering the same field-of-view as the gamma-ray and X-ray instruments. The OMC consists of a refracting telescope with a CCD as the imaging device in the focal plane. Here we describe the CCD and its ass…
The origin of X-ray emission of two distant (z >1) cluster candidates with XMM-Newton
Arnaud, M.; Arnouts, S.; Benoist, C. +8 more
We present here a study of XMM-Newton data of two distant galaxy cluster candidates. One of these was discovered serendipitously in near infrared data,