Search Publications

Modelling the atmospheric CO ₂ 10-µm non-thermal emission in Mars and Venus at high spectral resolution

Sornig, M.; Sonnabend, G.; Kroetz, P. +1 more

A study of the CO ₂ atmospheric emissions at 10-µm in the upper atmospheres of Mars and Venus is performed in order to explain a number of ground-based measurements of these emissions recently taken at very high spectral resolution in both planets. The measurements are normally used to derive atmospheric temperatures and winds, bu…

Hot gas in Mach cones around Virgo cluster spiral galaxies

Bomans, D. J.; Ehle, M.; Weżgowiec, M. +5 more

Context. The detailed comparison between observations and simulations of ram-pressure stripped spiral galaxies in the Virgo cluster has led to a 3D view of the galaxy orbits within the hot intracluster medium. The 3D velocities and Mach numbers derived from simulations can be used to derive simple Mach cone geometries for Virgo spiral galaxies.

Herschel/HIFI Observations of IRC+10216: Water Vapor in the Inner Envelope of a Carbon-rich Asymptotic Giant Branch Star

Cernicharo, José; Szczerba, Ryszard; González-Alfonso, Eduardo +6 more

We report the results of observations of 10 rotational transitions of water vapor toward the carbon-rich asymptotic giant branch (AGB) star IRC+10216 (CW Leonis), carried out with Herschel's HIFI instrument. Each transition was securely detected by means of observations using the dual beam switch mode of HIFI. The measured line ratios imply that w…

A close look at the Centaurus A group of galaxies. II. Intermediate-age populations in early-type dwarfs

Rejkuba, M.; Crnojević, D.; Grebel, E. K. +2 more

Aims: We investigate the resolved stellar content of early-type dwarf galaxies in the Centaurus A group, to estimate their intermediate-age population fractions.
Methods: We use near-infrared photometric data taken with the VLT/ISAAC instrument, together with previously analyzed archival HST/ACS data. The combination of the optical and i…

Chandrayaan-1 observation of distant secondary craters of Copernicus exhibiting central mound morphology: Evidence for low velocity clustered impacts on the Moon

Kiran Kumar, A. S.; Gopala Krishna, B.; Senthil Kumar, P. +3 more

Analysis of the Chandrayaan-1 Terrain Mapping Camera image of a 20 km×27 km area in the Mare Imbrium region revealed a cluster of thousands of fresh and buried impact craters in the size range of 20-1300 m. A majority of the large fresh craters with diameter ranging from 160 to 1270 m exhibit near-circular mounds (30-335 m diameter and 10-40 m hei…

Geological, geomorphological, facies and allostratigraphic maps of the Eberswalde fan delta

Rossi, A. P.; Pondrelli, M.; Platz, T. +3 more

Geological, facies, geomorphological and allostratigraphic map of the Eberswalde fan delta area are presented. The Eberswalde fan delta is proposed as a sort of prototype area to map sedimentary deposits, because of its excellent data coverage and its variability in depositional as well as erosional morphologies and sedimentary facies. We present …

Broad-band spectral analysis of Aql X-1

Dewangan, Gulab; Misra, Ranjeev; Raichur, Harsha

We present the results of a broad-band spectral study of the transient low-mass X-ray binary Aql X-1 observed by the Suzaku and Rossi X-ray Timing Explorer satellites. The source was observed during its 2007 outburst in the high/soft (Banana) state and in the low/hard (Extreme Island) state. Both the Banana state and the Extreme Island state spect…

Preservation of layered paleodeposits in high-latitude pedestal craters on Mars

Head, James W.; Kadish, Seth J.

An outstanding question in Mars' climate history is whether or not pedestal craters represent the armored remnants of ice-rich paleodeposits. We address this question using new high-resolution images; in a survey of several hundred high-latitude pedestal craters, we have identified 12 examples in which visible and/or topographically expressed laye…

AKARI Observations of Brown Dwarfs. II. CO₂ as Probe of Carbon and Oxygen Abundances in Brown Dwarfs

Yamamura, Issei; Sorahana, Satoko; Tsuji, Takashi

Recent observations with the infrared astronomical satellite AKARI have shown that the CO₂ bands at 4.2 µm in three brown dwarfs are much stronger than expected from the unified cloudy model (UCM) based on recent solar C & O abundances. This result has been a puzzle, but we now find it is simply due to the effect of C & O …

Far-ultraviolet emission in the A2597 and A2204 brightest cluster galaxies

Jaffe, W.; van Weeren, R. J.; Bremer, M. N. +2 more

We use the Hubble Space Telescope Advanced Camera for Surveys (ACS)/Solar Blind Channel (SBC) and Very Large Telescope (VLT) Focal Reducer/low dispersion Spectrograph (FORS) cameras to observe the brightest cluster galaxies (BCGs) in Abell 2597 and Abell 2204 in the far-ultraviolet (FUV) F150LP and optical U, B, V, R, I Bessel filters.

The FU…