Search Publications
Missions
Journals
Publication Years
Performance and surface scattering models for the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS)
Gurnett, D. A.; Johnson, W. T. K.; Orosei, R. +10 more
The primary scientific objective of the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS), which will be on board Mars Express mission scheduled for launch in 2003, is to map the distribution and depth of the liquid water/ice interface in the upper kilometres of the crust of Mars. MARSIS will also provide unique information to he…
The Far-Infrared Spectrum of the Sagittarius B2 Region: Extended Molecular Absorption, Photodissociation, and Photoionization
Cernicharo, José; Goicoechea, Javier R.; Rodríguez-Fernández, Nemesio J.
We present large-scale 9'×27' (~25pc×70pc) far-IR observations around Sgr B2 using the Long-Wavelength Spectrometer (LWS) on board the Infrared Space Observatory (ISO). The spectra are dominated by the strong continuum emission of dust, the widespread molecular absorption of light hydrides (OH, CH, and H2O), and th…
The Stellar Populations of Low-Luminosity Active Galactic Nuclei. I. Ground-based Observations
Heckman, Timothy; Schaerer, Daniel; Leitherer, Claus +6 more
We present a spectroscopic study of the stellar populations of low-luminosity active galactic nuclei (LLAGNs). Our main goal is to determine whether the stars that live in the innermost (100 pc scale) regions of these galaxies are in some way related to the emission-line properties, which would imply a link between the stellar population and the i…
Mass segregation in young Magellanic Cloud star clusters: Four clusters observed with HST
Bellas-Velidis, I.; Kontizas, M.; Kontizas, E. +2 more
We present the results of our investigation on the phenomenon of mass segregation in young star clusters in the Magellanic Clouds. HST/WFPC2 observations on NGC 1818, NGC 2004 and NGC 2100 in the Large Magellanic Cloud and NGC 330 in the Small Magellanic Cloud have been used for the application of diagnostic tools for mass segregation: i) the radi…
A Slow Merger History of Field Galaxies since z ~ 1
Conselice, Christopher J.; Ellis, Richard S.; Kodama, Tadayuki +2 more
Using deep infrared observations conducted with the CISCO imager on the Subaru Telescope, we investigate the field-corrected pair fraction and the implied merger rate of galaxies in redshift survey fields with Hubble Space Telescope (HST) imaging. In the redshift interval, 0.5<z<1.5, the fraction of infrared-selected pairs increases only mod…
The Optical Counterpart of an Ultraluminous X-Ray Source in NGC 5204
Bregman, Joel N.; Seitzer, Patrick; Liu, Ji-Feng
Ultraluminous X-ray (ULX) sources are extranuclear point sources in external galaxies with LX=1039-1041 ergs s-1 and are among the most poorly understood X-ray sources. To help understand their nature, we are trying to identify their optical counterparts by combining images from the Hubble Space Telescop…
FUSE and STIS Observations of the Warm-hot Intergalactic Medium toward PG 1259+593
Richter, Philipp; Tripp, Todd M.; Sembach, Kenneth R. +1 more
We use Far Ultraviolet Spectroscopic Explorer (FUSE) and Space Telescope Imaging Spectrograph (STIS) spectra to study intergalactic absorption toward the quasar PG 1259+593 (zem=0.478), with a particular emphasis on the warm-hot intergalactic medium (WHIM). The combined FUSE and STIS spectrum of PG 1259+593 covers the full wavelength ra…
Flare Ribbon Expansion and Energy Release Rate
Shibata, Kazunari; Masuda, Satoshi; Shimojo, Masumi +3 more
We have examined the relation between the evolution of the Hα flare ribbons and the released magnetic energy in a solar flare that occurred on 2001 April 10. Based on the magnetic reconnection model, the released energy was quantitatively calculated by using the photospheric magnetic field strengths and separation speeds of the fronts of the Hα fl…
The 2003 shell event in η Carinae
Breedt, Elmé; Whitelock, Patricia A.; Feast, Michael W. +1 more
Near-infrared, JHKL, photometry of η Car is reported covering the period 2000-2004. This includes the 2003 shell event which was the subject of an international multiwavelength campaign. The fading that accompanied this event was similar to, although slightly deeper than, that which accompanied the previous one. The period between these events is …
CME-Flare Association Deduced from Catastrophic Model of CMEs
Lin, Jun
Based on our previous works regarding solar eruptions, we focus on the relationships among different eruptive phenomena, such as solar flares, eruptive prominences and coronal mass ejections (CMEs). The three processes show clear correlations under certain circumstances. The correlation between a CME and solar flare depends the energy that stored …