Search Publications
The 21 cm "Outer Arm" and the Outer-galaxy High-velocity Clouds: Connected by Kinematics, Metallicity, and Distance
Tripp, Todd M.; Song, Limin
Using high-resolution ultraviolet spectra obtained with the Hubble Space Telescope Space Telescope Imaging Spectrograph and the Far Ultraviolet Spectroscopic Explorer, we study the metallicity, kinematics, and distance of the gaseous "outer arm" (OA) and the high-velocity clouds (HVCs) in the outer Galaxy. We detect the OA in a variety of absorpti…
Periglacial mass-wasting landforms on Mars suggestive of transient liquid water in the recent past: Insights from solifluction lobes on Svalbard
Hiesinger, H.; Hauber, E.; Johnsson, A. +4 more
On Earth, periglacial solifluction is a slow mass-wasting process related to freeze-thaw activity. We compare the morphology of small-scale lobate features on Mars to solifluction lobes in Svalbard to constrain their processes of formation. The analysis is based on high-resolution satellite imagery of Mars (HiRISE, ∼25 cm/pxl), aerial images of Sv…
Modelling a high-mass red giant observed by CoRoT
Auvergne, M.; Baudin, F.; Michel, E. +15 more
Context. The advent of space-borne photometers such as CoRoT and Kepler has opened up new fields in asteroseismology. This is especially true for red giants as only a few of these stars were known to oscillate with small amplitude, solar-like oscillations before the launch of CoRoT.
Aims: The G6 giant HR 2582 (HD 50890) was observed by CoRoT …
Dynamic Martian magnetosphere: Transient twist induced by a rotation of the IMF
Dubinin, E.; Modolo, R.; Chanteur, G. M.
Simulation studies of the Martian environment are usually restricted to stationary situations under various steady conditions of the solar wind and solar radiation. Dynamic transients and their implications have so far attracted little attention although global simulation models can provide valuable insights to understand disagreements between sim…
GNSS measurement of EUV photons flux rate during strong and mid solar flares
Hernández-Pajares, M.; García-Rigo, A.; Juan, J. M. +3 more
A new GNSS Solar Flare Activity Indicator (GSFLAI) is presented, given by the gradient of the ionospheric Vertical Total Electron Content (VTEC) rate, in terms of the solar-zenithal angle, measured from a global network of dual-frequency GPS receivers. It is highly correlated with the Extreme Ultraviolet (EUV) photons flux rate at the 26-34 nm spe…
Temperature and Extreme-ultraviolet Intensity in a Coronal Prominence Cavity and Streamer
Landi, E.; Gibson, S. E.; Kucera, T. A. +2 more
We analyze the temperature and EUV line emission of a coronal cavity and surrounding streamer in terms of a morphological forward model. We use a series of iron line ratios observed with the Hinode Extreme-ultraviolet Imaging Spectrograph (EIS) on 2007 August 9 to constrain temperature as a function of altitude in a morphological forward model of …
The AGN content in luminous infrared galaxies at z∼ 2 from a global SED analysis including Herschel data
Berta, S.; Magnelli, B.; Nordon, R. +16 more
We use Herschel-PACS far-infrared (IR) data, combined with previous multiband information and mid-IR spectra, to properly account for the presence of an active nucleus and constrain its energetic contribution in luminous IR sources at z∼ 2. The sample is composed of 24 sources in the GOODS-South field, with typical IR luminosity of 1012…
HST and Optical Data Reveal White Dwarf Cooling, Spin, and Periodicities in GW Librae 3-4 Years after Outburst
Hermes, J. J.; Winget, D. E.; Szkody, Paula +9 more
Since the large amplitude 2007 outburst which heated its accreting, pulsating white dwarf, the dwarf nova system GW Librae has been cooling to its quiescent temperature. Our Hubble Space Telescope ultraviolet spectra combined with ground-based optical coverage during the third and fourth year after outburst show that the fluxes and temperatures ar…
Estimating erosional exhumation on Titan from drainage network morphology
Black, Benjamin A.; Perron, J. Taylor; Burr, Devon M. +1 more
Drainage networks on Titan, Earth, and Mars provide the only known examples of non-volcanic fluvial activity in our solar system. The drainage networks on Titan are apparently the result of a methane-ethane cycle similar to Earth's water cycle. The scarcity of impact craters and the uneven distribution of fluvial dissection on Titan suggest that t…
First Three-dimensional Reconstructions of Coronal Loops with the STEREO A+B Spacecraft. IV. Magnetic Modeling with Twisted Force-free Fields
DeRosa, Marc L.; Nitta, Nariaki V.; Aschwanden, Markus J. +3 more
The three-dimensional coordinates of stereoscopically triangulated loops provide strong constraints for magnetic field models of active regions in the solar corona. Here, we use STEREO/A and B data from some 500 stereoscopically triangulated loops observed in four active regions (2007 April 30, May 9, May 19, and December 11), together with SOHO/M…