Search Publications
Flares from a candidate Galactic magnetar suggest a missing link to dim isolated neutron stars
Hanlon, L.; McBreen, B.; Bremer, M. +39 more
Magnetars are young neutron stars with very strong magnetic fields of the order of 1014-1015G. They are detected in our Galaxy either as soft γ-ray repeaters or anomalous X-ray pulsars. Soft γ-ray repeaters are a rare type of γ-ray transient sources that are occasionally detected as bursters in the high-energy sky. No optical…
The characteristics of the IR emission features in the spectra of Herbig Ae stars: evidence for chemical evolution
Waters, L. B. F. M.; Henning, T.; Tielens, A. G. G. M. +4 more
Context: Infrared (IR) spectra provide a prime tool to study the characteristics of polycyclic aromatic hydrocarbon (PAH) molecules in regions of star formation. Herbig Ae/Be stars are a class of young pre-main sequence stellar objects of intermediate mass. They are known to have varying amounts of natal cloud material still present in their direc…
Carriers of the mid-IR emission bands in PNe reanalysed. Evidence of a link between circumstellar and interstellar aromatic dust
Joblin, C.; Szczerba, R.; Berné, O. +1 more
Context: It has been shown that the diversity of the aromatic emission features can be rationalized into different classes of objects, in which differences between circumstellar and interstellar matter are emphasised.
Aims: We probe the links between the mid-IR emitters observed in planetary nebulae (PNe) and their counterparts in the interste…
Recent advances in observations and modeling of the solar ultraviolet and X-ray spectral irradiance
Woods, Thomas N.
There have been significant, recent advances in understanding the solar ultraviolet (UV) and X-ray spectral irradiance from several different satellite missions and from new efforts in modeling the variations of the solar spectral irradiance. The recent satellite missions with solar UV and X-ray spectral irradiance observations include the X-ray S…
The Dust Halo of Saturn’s Largest Icy Moon, Rhea
Coates, A. J.; Krupp, N.; Woch, J. +32 more
Saturn’s moon Rhea had been considered massive enough to retain a thin, externally generated atmosphere capable of locally affecting Saturn’s magnetosphere. The Cassini spacecraft’s in situ observations reveal that energetic electrons are depleted in the moon’s vicinity. The absence of a substantial exosphere implies that Rhea’s magnetospheric int…
Spectral Study of the Galactic Ridge X-Ray Emission with Suzaku
Tsujimoto, Masahiro; Kokubun, Motohide; Koyama, Katsuji +7 more
In order to carry out a precise spectral study of the Galactic Ridge X-ray Emission using Suzaku, we have observed a typical Galactic plane field at (l,b) = (28°46, -0°20), which is already deeply observed with Chandra, and known to be devoid of bright X-ray point sources. Thanks to the low background and high spectral resolution of Suzaku, we wer…
X-Ray Emission from Active Galactic Nuclei with Intermediate-Mass Black Holes
Rao, A. R.; Dewangan, G. C.; Mathur, S. +1 more
We present a systematic X-ray study of eight active galactic nuclei (AGNs) with intermediate-mass black holes (MBH ~ 8-95 × 104 M⊙) based on 12 XMM-Newton observations. The sample includes the two prototype AGNs in this class—NGC 4395 and POX 52 and six other AGNs discovered with the Sloan Digitized Sky Survey. The…
Auroral polar dawn spots: Signatures of internally driven reconnection processes at Jupiter's magnetotail
Bonfond, B.; Clarke, J. T.; Gérard, J. -C. +2 more
We report the presence of polar spots located in the dawn auroral region, based on the HST ACS 2007 campaign. We study the location of these features in the equatorial plane as well as their time scales and periodicities, based on a comprehensive series of images taken between February 21 and June 11, 2007. It is shown that the majority of polar d…
MOST Space-based Photometry of the Transiting Exoplanet System HD 209458: Transit Timing to Search for Additional Planets
Moffat, Anthony F. J.; Rucinski, Slavek M.; Rowe, Jason F. +7 more
We report on the measurement of transit times for the HD 209458 planetary system from photometry obtained with the MOST (Microvariability and Oscillations of Stars) space telescope. Deviations from a constant orbital period can indicate the presence of additional planets in the system that are yet undetected, potentially with masses approaching an…
The Red Sequence of High-Redshift Clusters: A Comparison with Cosmological Galaxy Formation Models
Demarco, R.; Rosati, P.; Gobat, R. +4 more
We compare the results from a state-of-the-art semianalytic model of galaxy formation with spectrophotometric observations of distant galaxy clusters observed in the range 0.8 <= z<= 1.3. We investigate the properties of their red sequence (RS) galaxies and compare them with those of the field at the same redshift. In our model we find that …