Search Publications
Seasonal variations of the martian CO over Hellas as observed by OMEGA/Mars Express
Bibring, J. -P.; Gondet, B.; Langevin, Y. +6 more
The OMEGA imaging spectrometer aboard Mars Express has been used to study the evolution of the CO abundance over the Hellas basin, as a function of the seasonal cycle. In spite of significant uncertainties, due to the low intensity of the (2-0) CO band at 2.3 µm, these data allow to search for spatial variations over Hellas, where the surfac…
The Tully-Fisher relation of distant field galaxies
Milvang-Jensen, B.; Aragón-Salamanca, A.; Bamford, S. P.
We examine the evolution of the Tully-Fisher relation (TFR) using a sample of 89 field spirals for which we have measured confident rotation velocities (Vrot). This sample covers the redshift range 0.1 <~z<~ 1, with a median of <z>= 0.33. The best-fitting TFR has a slope consistent with that measured locally, and we find no …
Hydrogen exosphere at Mars: Pickup protons and their acceleration at the bow shock
Barabash, S.; Lundin, R.; Yamauchi, M. +3 more
Pickup protons (PIs) with a ring-beam distribution originating from the extended hydrogen exosphere of Mars are observed by the ASPERA-3 experiment onboard the Mars Express spacecraft at solar minimum conditions. PIs can contribute ~1% to the solar wind number density at close distances to the flank bow shock. The observed fluxes of PIs indicate t…
E+A Galaxies with Blue Cores: Active Galaxies in Transition
Zabludoff, Ann I.; Zaritsky, Dennis; Yang, Yujin +1 more
Hubble Space Telescope (HST) ACS images reveal blue cores in four E+A, or post-starburst, galaxies. Follow-up spectroscopy shows that these cores have LINER spectra. The existence of LINERs, consistent with those in many elliptical galaxies, is yet one more piece of evidence that these postmerger, post-starburst, bulge-dominated galaxies will evol…
High-metallicity, photoionized gas in intergalactic large-scale filaments
Frye, Brenda L.; Bowen, David V.; Tripp, Todd M. +3 more
We present high-resolution ultraviolet spectra of absorption-line systems towards the low-z quasi-stellar object (QSO) HS 0624+6907 (zQSO= 0.3700). Coupled with ground-based imaging and spectroscopic galaxy redshifts, we find evidence that many of these absorbers do not arise in galaxy haloes but rather are truly intergalactic gas cloud…
Near-Infrared and Optical Limits for the Central X-Ray Point Source in the Cassiopeia A Supernova Remnant
Pavlov, G. G.; Fesen, R. A.; Sanwal, D.
We set new near-infrared and optical magnitude limits for the central X-ray point source (XPS) in the Cassiopeia A supernova remnant based on HST images. Near-infrared images of the center of Cas A taken with the NICMOS 2 camera in combination with the F110W and F160W filters (~J and H bands) have magnitude limits >=26.2 and >=24.6, respecti…
MARSIS radar sounder evidence of buried basins in the northern lowlands of Mars
Stofan, Ellen R.; Clifford, Stephen M.; Safaeinili, Ali +7 more
A hemispheric dichotomy on Mars is marked by the sharp contrast between the sparsely cratered northern lowland plains and the heavily cratered southern highlands. Mechanisms proposed to remove ancient crust or form younger lowland crust include one or more giant impacts, subcrustal transport by mantle convection, the generation of thinner crust by…
On the cross-correlation of sub-mm sources and optically selected galaxies
Mobasher, Bahram; Pope, Alexandra; Scott, Douglas +1 more
Bright submillimetre (sub-mm) galaxies are expected to arise in massive highly biased haloes, and hence exhibit strong clustering. We argue that a valuable tool for measuring these clustering properties is the cross-correlation of sub-mm galaxies with faint optically selected sources. We analyse populations of sub-mm detected and optical galaxies …
Experimental and theoretical study of hydrocarbon photochemistry applied to Titan stratosphere
Vuitton, V.; Raulin, F.; Doussin, J. -F. +2 more
None of the Titan photochemical models currently available have been able to reproduce the full set of stratospheric molecular mixing ratios inferred from observations. In order to assess how well reaction sets describe hydrocarbon chemistry, theoretical modeling predictions were compared to the results of a laboratory experiment. A CH 4
A far-infrared molecular and atomic line survey of the Orion KL region
Barlow, M. J.; Cernicharo, J.; Goicoechea, J. R. +8 more
We have carried out a high spectral resolution (λ/Δλ ~ 6800-9700) line survey towards the Orion Kleinmann-Low (KL) cluster from 44 to 188 µm. The observations were taken with the Long Wavelength Spectrometer (LWS) in Fabry-Pérot mode, on board the Infrared Space Observatory (ISO). A total of 152 lines are clearly detected and a further 34 fe…