Search Publications
The X-ray emission of the most luminous 3CR radio sources
Salvati, M.; Risaliti, G.; Véron, P. +1 more
Context: Although many radio-loud quasars and galaxies have been observed in X-rays, systematic studies of well defined samples are rare.
Aims: We investigate the X-ray properties of the most luminous radio sources in the 3CR catalogue, in order to assess whether they are similar to the most luminous radio-quiet quasars, for instance in the X-…
Normal Globular Cluster Systems in Massive Low Surface Brightness Galaxies
Jordán, Andrés; Kissler-Patig, Markus; Goudfrooij, Paul +2 more
We present the results of a study of the globular cluster systems of six massive spiral galaxies, originally cataloged as low surface brightness (LSB) but here shown to span a wide range of surface brightness values, including two intermediate to LSB galaxies. We used the Advanced Camera for Surveys on-board Hubble Space Telescope to obtain photom…
Modeling the arrival at Earth of the interplanetary shock following the 12 May 1997 solar event using HAFv2 and 3-D MHD HHMS models
Dryer, M.; Fry, C. D.; Sun, W. +3 more
The 12 May 1997 solar event is used to demonstrate the improvements that have been made in recent years in the accuracy of predicting, in the operational environment, the time of arrival at Earth of solar-caused interplanetary shocks. This event provides a simple test case because it was both well isolated in time from other events and well docume…
Suzaku Detection of an Intense X-Ray Flare from an A-Type Star, HD161084
Sugawara, Yasuharu; Maeda, Yoshitomo; Tsujimoto, Masahiro +4 more
We report on a serendipitous detection of an intense X-ray flare from the Tycho reference source on HD161084 during a Suzaku observation of the galactic center region for ∼20ks. The X-ray Imaging Spectrometer recorded a flare from this A1-type dwarf or subgiant star with a flux of ∼1.4 × 10-12 erg s-1 cm-2 (0.5--10…
Sources of SEP Acceleration during a Flare - CME Event
Vainio, R.; Valtonen, E.; Huttunen-Heikinmaa, K. +3 more
A high-speed, halo-type coronal mass ejection (CME), associated with a GOES M4.6 soft X-ray flare in NOAA AR 0180 at S12W29 and an EIT wave and dimming, occurred on 9 November 2002. A complex radio event was observed during the same period. It included narrow-band fluctuations and frequency-drifting features in the metric wavelength range, type II…
The emission-line spectrum of the UV deficient quasar Ton 34: evidence of shock excitation?
Binette, L.; Krongold, Y.
Context: Emission lines in quasars are believed to originate from a photoionized plasma. There are, however, some emission features that appear to be collisionally excited, such as the Fe II multiplet bands. Shortward of Lyα, there are also a few permitted lines of species from low to intermediate ionization.
Aims: Ton 34 (z_q=1.928) exhibits …
Light curve analyses of new eclipsing binary systems with eccentric orbits
Bulut, İ.; Demircan, O.
A photometric study of seven new eclipsing binary systems with eccentric orbits, namely, V466 Car, V493 Car, V529 Car, MN TrA, V398 Lac, V402 Lac and V821 Cas, is presented. The photometric data analyzed were taken from the Hipparcos database. The secondary minima in all systems were shifted by different amounts from the phase 0.5 giving clear evi…
Upstream proton cyclotron waves at Venus
Russell, C. T.; Wei, H. Y.; Zhang, T. L. +2 more
Data from the magnetometer MAG aboard the Venus Express S/C are investigated for the occurrence of cyclotron wave phenomena upstream of the Venus bow shock. For an unmagnetized planet such as Venus and Mars the neutral exosphere extends into the on-flowing solar wind and pick-up processes can play an important role in the removal of particles from…
A study of the Martian water vapor over Hellas using OMEGA and PFS aboard Mars Express
Bibring, J. -P.; Gondet, B.; Langevin, Y. +8 more
We used the OMEGA imaging spectrometer aboard Mars Express to study the evolution of the water vapor abundance over the Hellas basin, as a function of the seasonal cycle. The H2O column density is found to range from very low values (between southern fall and winter) up to more than 15 pr-µm during southern spring and summer. The general beh…
Venus Express/VIRTIS observations of middle and lower cloud variability and implications for dynamics
Baines, K. H.; Momary, T. W.; McGouldrick, K. +1 more
We present an analysis of Venus Express Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) data, carried out to characterize the morphological, geographical, and evolutionary trends of the middle and lower cloud features that are observed in the atmosphere of Venus as variations in brightness temperatures in specific near-infrared waveleng…