Search Publications
Hydrogen ENA-cloud observation and modeling as a tool to study star-exoplanet interaction
Holmström, M.; Lammer, H.; Khodachenko, M. L. +2 more
During the previous years spacecraft observations of so-called Energetic Neutral Atoms (ENAs) have become an important remote-sensing technique in planetary science for analyzing the solar wind plasma flow around the upper atmospheric environments of Solar System bodies. ENAs are produced whenever solar- or stellar wind protons interact via charge…
Open issues on the synthesis of evolved stellar populations at ultraviolet wavelengths
Chavez, Miguel; Bertone, Emanuele
In this paper we briefly review three topics that have motivated our (and others') investigations in recent years within the context of evolutionary population synthesis techniques. These are: The origin of the FUV up-turn in elliptical galaxies, the age-metallicity degeneracy, and the study of the mid-UV rest-frame spectra of distant red galaxies…
HST-COS observations of the transiting extrasolar planetary system HD 209458b
France, Kevin; Stocke, John T.; Yang, Hao +2 more
We summarize results from deep spectroscopic observations of the HD 209458 planetary system, carried out with the Hubble SpaceTelescope—Cosmic Origins Spectrograph. Orbitally resolved observations are used to show that hot gas emission lines, arising only in the stellar atmosphere, are not variable, while lower ionizations species found in the upp…
Gravitationally lensed QSOs in the ISSIS/WSO-UV era
Gil-Merino, R.; Goicoechea, L. J.; Shalyapin, V. N.
Gravitationally lensed QSOs (GLQs) at 1≤z≤2 play a key role in understanding the cosmic evolution of the innermost parts of active galaxies (black holes, accretion disks, coronas and internal jets), as well as the structure of galaxies at intermediate redshifts. With respect to studies of normal QSOs, GLQ programmes have several advantages. For ex…
UV spectroscopy of the hot bare stellar core H1504+65 with the HST Cosmic Origins Spectrograph
Rauch, T.; Werner, K.
We present new ultraviolet spectra of the hottest known, peculiar white dwarf H1504+65, obtained with the Cosmic Origins Spectrograph on the Hubble Space Telescope. H1504+65 is the hottest known white dwarf (Teff=200 000 K) and has an atmosphere mainly composed by carbon and oxygen, augmented with high amounts of neon and magnesium. Thi…