Search Publications
OMEGA/Mars Express: South Pole Region, water vapor daily variability
Langevin, Y.; Forget, F.; Maltagliati, L. +8 more
Polar regions on Mars are the most suitable places to observe water vapor daily variability because in any observation crossing the Pole we can observe very different local time and because the poles are considered to be the main permanent and seasonal water reservoir of the planet. We report on a daily variability of water vapor in the South Pole…
On the Solar Origin of the Signal at 220.7 µHz: A Possible Component of a g-Mode?
García, R. A.; Jiménez, A.
Gravity modes in the Sun have been the object of a long and difficult search in recent decades. Thanks to the data accumulated with the last generation of instruments (BiSON, GONG, and three helioseismic instruments aboard the Solar and Heliospheric Observatory (SOHO)), scientists have been able to find signatures of their presence. However, the i…
MAGIC upper limits to the VHE gamma-ray flux of 3C 454.3 in high emission state
Maraschi, L.; Covino, S.; Antonelli, L. A. +146 more
Aims: We report upper limits to the very high energy flux (E>100 GeV) of the flat spectrum radio quasar 3C 454.3 (z=0.859) derived by the Cherenkov telescope MAGIC during the high states of July/August and November/December 2007. We compare the upper limits derived in both time slots with the available quasi-simultaneous MeV-GeV data from the A…
New faint optical spectrophotometric standards: hot white dwarfs from the Sloan Digital Sky Survey
Hubeny, Ivan; Allende Prieto, Carlos; Smith, J. Allyn
The spectral energy distributions for pure-hydrogen (DA) hot white dwarfs can be accurately predicted by model atmospheres. This makes it possible to define spectrophotometric calibrators by scaling the theoretical spectral shapes with broad-band photometric observations - a strategy successfully exploited for the spectrographs onboard the Hubble …
A New X-Ray Analysis of the Open Cluster Blanco 1 Using Wide-Field BVIc Photometric and Proper Motion Surveys
James, D. J.; Platais, I.; Cargile, P. A.
We perform a new analysis of the extant ROSAT and XMM-Newton X-ray surveys of the southern open cluster Blanco 1, utilizing new BVIc photometric and proper motion data sets. In our study, we match optical counterparts to 47 X-ray sources associated with Blanco 1 cluster members, six of which were listed in previous X-ray studies as clus…
Constraint of Non-Thermal X-Ray Emission from the On-Going Merger Cluster Abell 3376 with Suzaku
Isobe, Naoki; Fukazawa, Yasushi; Kokubun, Motohide +10 more
Clusters of galaxies are among the best candidates for particle acceleration sources in the universe, a signature of which is non-thermal hard X-ray emission from the accelerated relativistic particles. We present early results on Suzaku observations of non-thermal emission from Abell 3376, which is a nearby on-going merger cluster. Suzaku observe…
New Fe IX Line Identifications Using Solar and Heliospheric Observatory/Solar Ultraviolet Measurement of Emitted Radiation and Hinode/EIS Joint Observations of the Quiet Sun
Young, P. R.; Landi, E.
In this work, we study joint observations of Hinode/EUV Imaging Spectrometer (EIS) and Solar and Heliospheric Observatory/Solar Ultraviolet Measurement of Emitted Radiation of Fe IX lines emitted by the same level of the high energy configuration 3s 23p 54p. The intensity ratios of these lines are dependent on atomic physics …
INTEGRAL and XMM-Newton observations of AX J1845.0-0433
Walter, R.; Zurita Heras, J. A.
Aims: AX J1845.0-0433 is a transient high-mass X-ray binary discovered by ASCA. The source displays bright and short flares observed by INTEGRAL. The transient behaviour and bright and short flares are studied to understand both the accretion mechanisms and nature of the source.
Methods: Public INTEGRAL data and a pointed XMM-Newton observatio…
The plasma filling factor of coronal bright points. II. Combined EIS and TRACE results
Dere, K. P.
Aims: In a previous paper, the volumetric plasma filling factor of coronal bright points was determined from spectra obtained with the Extreme ultraviolet Imaging Spectrometer (EIS). The analysis of these data showed that the median plasma filling factor was 0.015. One interpretation of this result was that the small filling factor was consistent …
Two Rapidly Variable Galactic X-ray Transients Observed with Chandra, XMM-Newton, and Suzaku
Heinke, C. O.; Grindlay, J. E.; Tomsick, J. A. +1 more
We have identified two moderately bright, rapidly variable transients in new and archival X-ray data near the Galactic center. Both objects show strong, flaring variability on timescales of tens to thousands of seconds, evidence of NH variability, and hard spectra. XMMU J174445.5-295044 is seen at 2-10 keV fluxes of 3 × 10-11…