13 papers · 1 filter
A new activity phase of the blazar 3C 454.3. Multifrequency observations by the WEBT and XMM-Newton in 2007-2008
C. M. Raiteri, M. Villata, V. M. Larionov +2
We present and analyse the WEBT multifrequency observations of 3C 454.3 in the 2007-2008 observing season, including XMM-Newton observations and near-IR spectroscopic monitoring, a…
The ultraluminous X-ray source NGC 1313 X-2 - Its optical counterpart and environment
F. Grisé, M. W. Pakull, R. Soria +4
NGC 1313 X-2 is one of the brightest ultraluminous X-ray sources in the sky, at both X-ray and optical wavelengths; therefore, quite a few studies of available ESO VLT and HST data…
The high activity of 3C 454.3 in autumn 2007. Monitoring by the WEBT during the AGILE detection
C. M. Raiteri, M. Villata, W. P. Chen +5
The quasar-type blazar 3C 454.3 underwent a phase of high activity in summer and autumn 2007, which was intensively monitored in the radio-to-optical bands by the Whole Earth Blaza…
Multifrequency monitoring of the blazar 0716+714 during the GASP-WEBT-AGILE campaign of 2007
M. Villata, C. M. Raiteri, V. M. Larionov +5
Since the CGRO operation in 1991-2000, one of the primary unresolved questions about the blazar gamma-ray emission has been its possible correlation with the low-energy (in particu…
Radio-to-UV monitoring of AO 0235+164 by the WEBT and Swift during the 2006--2007 outburst
C. M. Raiteri, M. Villata, V. M. Larionov +2
The blazar AO 0235+164 was claimed to show a quasi-periodic behaviour in the radio and optical bands. Moreover, an extra emission component contributing to the UV and soft X-ray fl…
Multifrequency Observations of the Blazar 3C 279 in January 2006
WEBT Collaboration, W. Collmar, M. Böttcher +13
We report first results of a multifrequency campaign from radio to hard X-ray energies of the prominent gamma-ray blazar 3C 279, which was organised around an INTEGRAL ToO observat…