Search Publications
A possible new dipping X-ray source in the field of M 31
Stella, L.; Israel, G. L.; Mangano, V.
We report the discovery of the new dipping X-ray source, XMMU J004308.6+411247, in M 31, during a systematic search for periodicities in XMM-Newton archival observations. During the 2002 January 6 observation, the dips recur with a 107 min period and the source count rate is consistent with zero at the dip minimum. Dips with the same modulation an…
Broadband X-ray spectrum of intermediate polar V1223 Sgr
Sunyaev, R.; Revnivtsev, M.; Lutovinov, A. +2 more
We present the broadband phase averaged spectrum of one of the brightest intermediate polars V1223 Sgr, obtained with INTEGRAL and RXTE observatories (3-100 keV). Good statistical quality of the spectrum in a hard X-ray energy band (INTEGRAL/IBIS and RXTE/HEXTE) allowed us to disentangle contributions of a direct optically thin plasma emission and…
High resolution solar magnetometry with the spectrograph of the Pic du Midi Turret Dome
Roudier, Th.; Muller, R.; Mein, P. +2 more
We present the first results obtained with a new Ferroelectric Liquid Crystal (FLC) polarimeter operating with the spectrograph of the Pic du Midi Turret Dome, since September 2003. We observed the solar granulation around active region NOAA 0459 with the Multichannel Subtractive Double Pass (MSDP) operating mode and analysed the circular polariza…
New insight into the blinker phenomenon and the dynamics of the solar transition region
Doyle, J. G.; Madjarska, M. S.; Roussev, I. I.
We present, for the first time, blinker phenomena being associated with brightenings in pre-existing coronal loops registered by the Extreme-ultraviolet Imaging Telescope (EIT) in Fe XII 195 Å. The brightenings occur during the emergence of new magnetic flux as registered by the Big Bear Solar Observatory (BBSO) magnetograph. The blinkers were ide…
XMM-Newton observations of the dwarf nova YZ Cnc in quiescence
Ramsay, G.; Hakala, P.; Wheatley, P. +2 more
We present results from the XMM-Newton observations of the dwarf nova YZ Cnc in a quiescent state. We have performed a detailed time series analysis of the resulting light curves. Unusually, we do not detect any orbital modulation in the UV, with only marginal evidence for X-ray modulation on this period. Although there are peaks in the X-ray peri…
The nuclear radio-optical properties of intermediate-redshift FR II radio galaxies and quasars
Macchetto, F. D.; Capetti, A.; Chiaberge, M. +1 more
We extend the study of the nuclei of 3CR objects as seen with the HST to higher-redshift FR II radio sources (0.4<z<0.6). Our results reflect what has been found for FR II of lower redshift. The position of the nuclei in the plane formed by optical and radio luminosities is related to their optical spectral classification: the nuclei of both…
ISOPHOT 95 µm observations in the Lockman Hole. The catalogue and an assessment of the source counts
Rodighiero, G.; Franceschini, A.
We report results from a new analysis of a deep 95 µm imaging survey with ISOPHOT on board the Infrared Space Observatory, over a ∼1 deg2 area within the Lockman Hole, which extends the statistics of our previous study (Rodighiero et al. \cite{Rodighiero03}). Within the survey area we detect sixty-four sources with S/N>3 (rough…
Modulation in the solar irradiance due to surface magnetism during cycles 21, 22 and 23
Jain, K.; Hasan, S. S.
Magnetic field indices derived from synoptic magnetograms of the Mt. Wilson Observatory, i.e. Magnetic Plage Strength Index (MPSI) and Mt. Wilson Sunspot Index (MWSI), are used to study the effects of surface magnetism on total solar irradiance variability during solar cycles 21, 22 and 23. We find that most of the solar cycle variation in the tot…
XMM-Newton spectra of hard spectrum Rosat AGN: X-ray absorption and optical reddening
Page, M. J.; Carrera, F. J.; Mittaz, J. P. D.
We present the XMM-Newton spectra of three low-redshift intermediate Seyferts (one Sy 1.5, and two Sy 1.8), from our survey of hard spectrum Rosat sources. The three AGN are well fitted by absorbed powerlaws, with intrinsic nuclear photoelectric absorption from column densities between 1.3 and 4.0 × 1021 cm-2. In the brightes…
INTEGRAL observation of 3EG J1736-2908
Gehrels, N.; Grandi, P.; Chaty, S. +10 more
The possible identification by INTEGRAL of the EGRET source 3EG J1736-2908 with the active galactic nucleus GRS 1734-292 is discussed. The latter was discovered in 1990 and later identified with a Seyfert 1 galaxy. At the time of the compilation of the 3rd EGRET Catalog, it was not considered as a possible counterpart of the source 3EG J1736-2908,…