Search Publications
On the Isothermality of Solar Plasmas
Klimchuk, J. A.; Landi, E.
Recent measurements have shown that the quiet unstructured solar corona observed at the solar limb is close to isothermal, at a temperature that does not appear to change over wide areas or with time. Some individual active region loop structures have also been found to be nearly isothermal both along their axis and across their cross section. Eve…
Suzaku X-ray Spectra and Pulse Profile Variations During the Superorbital Cycle of LMC X-4
Vrtilek, Saeqa D.; Hickox, Ryan C.; Hung, Li-Wei +1 more
We present results from spectral and temporal analyses of Suzaku and RXTE observations of the high-mass X-ray binary LMC X-4. Using the full 13 years of available RXTE/all-sky monitor data, we apply the ANOVA and Lomb Normalized Periodogram methods to obtain an improved superorbital period measurement of 30.32 ± 0.04 days. The phase-averaged X-ray…
Calibration of Hyperspectral Imaging Data: VIRTIS-M Onboard Venus Express
Drossart, Pierre; Piccioni, Giuseppe; Filacchione, Gianrico +2 more
The Visible and InfraRed Thermal Imaging Spectrometer (VIRTIS) is flying onboard the European Space Agency mission Venus Express and orbiting around Venus since April 11, 2006, providing very valuable remote sensing data of the planet. The instrument combines a double capability: a high-resolution imaging in the visible-infrared range (0.28-5 um) …
Latitudinal variations in Titan’s methane and haze from Cassini VIMS observations
Sotin, Christophe; Baines, Kevin H.; Buratti, Bonnie J. +9 more
We analyze observations taken with Cassini's Visual and Infrared Mapping Spectrometer (VIMS), to determine the current methane and haze latitudinal distribution between 60°S and 40°N. The methane variation was measured primarily from its absorption band at 0.61 µm, which is optically thin enough to be sensitive to the methane abundance at 20…
Early-type galaxies at large galactocentric radii - I. Stellar kinematics and photometric properties
Forbes, Duncan A.; Couch, Warrick J.; Hau, George K. T. +1 more
We present the results of a combined analysis of the kinematic and photometric properties at large galactocentric radii of a sample of 14 low-luminosity early-type galaxies in the Fornax and Virgo clusters. From Gemini South GMOS long-slit spectroscopic data, we measure radial profiles of the kinematic parameters vrot, σ, h3 …
The clusters Abell 222 and Abell 223: a multi-wavelength view
Bertin, E.; Adami, C.; Durret, F. +1 more
Context. The Abell 222 and 223 clusters are located at an average redshift z ~ 0.21 and are separated by 0.26 deg. Signatures of mergers have been previously found in these clusters, both in X-rays and at optical wavelengths, thus motivating our study. In X-rays, they are relatively bright, and Abell 223 shows a double structure. A filament has al…
A strong high altitude narrow jet detected at Saturn's equator
Hueso, R.; Sánchez-Lavega, A.; García-Melendo, E. +2 more
Here we report the discovery at the upper cloud level of an extremely narrow and strong prograde jet, centered in the middle of the broad equatorial jet. Measurements from images obtained by the Cassini Imaging Science Subsystem (ISS) show that the jet reaches 430 ms-1 ± 16 m s-1 with a peak speed difference of 180 ms-1<…
XMM-Newton RGS observation of the warm absorber in Mrk 279
Kaastra, J. S.; Kriss, G. A.; Arav, N. +5 more
Context. The Seyfert 1 galaxy Mrk 279 was observed by XMM-Newton in November 2005 on three consecutive orbits, showing significant short-scale variability (average soft band variation in flux ~20%). The source is known to host a two-component warm absorber with distinct ionisation states from a previous Chandra observation.
Aims: We study the…
Spatially resolved detection of crystallized water ice in a T Tauri object
Wolf, S.; Schegerer, A. A.
Aims: We search for frozen water and its processing around young stellar objects (YSOs of class I/II). We try to detect potential, regional differences in water ice evolution within YSOs, which is relevant to understanding the chemical structure of the progenitors of protoplanetary systems and the evolution of solid materials. Water plays an …
Differences in solar wind cross-helicity and residual energy during the last two solar minima
Perri, S.; Balogh, A.
The minimum of solar cycle 23 exhibited anomalous characteristics with respect to its predecessors. Other than the differences in the standard indicators of activity, such as sunspots, polar magnetic fields were also found to be different. These differences had a range of effects in the solar wind. In this work we study the Alfvénicity and the res…