Search Publications
Identification of gully debris flow deposits in Protonilus Mensae, Mars: Characterization of a water-bearing, energetic gully-forming process
Head, J. W.; Dickson, J. L.; Fassett, C. I. +3 more
Gullies are a class of geologically recent landform on Mars that show evidence of downslope transport of sedimentary material from recessed alcoves, through incised channels, to distributary fans or aprons. The mechanisms invoked to account for the formation of gullies on Mars range from completely dry, granular flows or landslides, to debris flow…
Ismenius Cavus, Mars: A deep paleolake with phyllosilicate deposits
Mangold, N.; Le Mouélic, S.; Poulet, F. +2 more
Ismenius Cavus is a basin where several fluvial valleys converge. Three depositional fan deltas are observed at the valleys outlets at similar elevations. These fans suggest long-term fluvial activity accompanied by a lake inside the basin. The elevational difference between the delta plains and the deepest part of the basin floor implies that thi…
Analysis of Cassini/CIRS limb spectra of Titan acquired during the nominal mission II: Aerosol extinction profiles in the 600-1420 cm -1 spectral range
Bézard, Bruno; Vinatier, Sandrine; Nixon, Conor A. +10 more
We have analyzed the continuum emission of limb spectra acquired by the Cassini/CIRS infrared spectrometer in order to derive information on haze extinction in the 3-0.02 mbar range (∼150-350 km). We focused on the 600-1420 cm -1 spectral range and studied nine different limb observations acquired during the Cassini nominal mission at 5…
X-Ray Spectroscopy of Galactic Hot Gas along the PKS 2155-304 Sight Line
Mitsuda, Kazuhisa; Yamasaki, Noriko Y.; Wang, Q. Daniel +5 more
We present a detailed spectroscopic study of the hot gas in the Galactic halo toward the direction of a blazer PKS 2155-304 (z = 0.117). The OVII and OVIII absorption lines were measured with the Low and High Energy Transmission Grating Spectrographs aboard Chandra, and the OVII, OVIII, and NeIX emission lines produced in an adjacent field of the …
Ortho-to-para ratio of interstellar heavy water
Falgarone, E.; Maret, S.; Henning, T. +65 more
Context. Despite the low elemental deuterium abundance in the Galaxy, enhanced molecular D/H ratios have been found in the environments of low-mass star-forming regions, and in particular the Class 0 protostar IRAS 16293-2422.
Aims: The CHESS (Chemical HErschel Surveys of Star forming regions) key program aims to study the molecular complexit…
Spatial, Temporal, and Spectral Properties of X-ray Emission from the Magnetar SGR 0501+4516
Kouveliotou, Chryssa; Göǧüş, Ersin; Kaneko, Yuki +3 more
SGR 0501+4516 was discovered with the Swift satellite on 2008 August 22 after it emitted a series of very energetic bursts. Since then, the source was extensively monitored with Swift and the Rossi X-ray Timing Explorer (RXTE) and observed with Chandra and XMM-Newton, providing a wealth of information about its outburst behavior and burst-induced …
X-ray reflection in a sample of X-ray bright ultraluminous X-ray sources
Fabian, A. C.; Caballero-García, M. D.
We apply a reflection-based model to the best available XMM-Newton spectra of X-ray bright ultraluminous X-ray sources (NGC 1313 X-1, NGC 1313 X-2, M 81 X-6, Holmberg IX X-1, NGC 5408 X-1 and Holmberg II X-1). A spectral drop is apparent in the data of all the sources at energies 6-7keV. The drop is interpreted here in terms of relativistically bl…
The origin of mid-infrared emission in massive young stellar objects: multi-baseline VLTI observations of W33A
Lumsden, S. L.; Hoare, M. G.; de Wit, W. J. +1 more
Aims: In this paper we aim to determine the structure on 100 AU scales of the massive young stellar object W33A, using interferometric observations in the mid-infrared. This emission could be caused by a variety of elements, for example, the inner protostellar envelope, outflow cavity walls, or a dusty or gaseous accretion disk.
Methods:…
Accelerating Waves in Polar Coronal Holes as Seen by EIS and SUMER
Teriaca, L.; Gupta, G. R.; Banerjee, D. +2 more
We present EIS/Hinode and SUMER/SOHO observations of propagating disturbances detected in coronal lines in inter-plume and plume regions of a polar coronal hole. The observation was carried out on 2007 November 13 as part of the JOP196/HOP045 program. The SUMER spectroscopic observation gives information about fluctuations in radiance and on both …
The Type Ia Supernova Rate in Redshift 0.5-0.9 Galaxy Clusters
Donahue, Megan; Voit, G. Mark; Filippenko, Alexei V. +14 more
Supernova (SN) rates are potentially powerful diagnostics of metal enrichment and SN physics, particularly in galaxy clusters with their deep, metal-retaining potentials and relatively simple star formation histories. We have carried out a survey for SNe in galaxy clusters, at a redshift range of 0.5 < z < 0.9, using the Advanced Camera for …