Search Publications
Slitless Grism Spectroscopy with the Hubble Space Telescope Advanced Camera for Surveys
Larsen, S.; Walsh, J. R.; Kümmel, M. +2 more
The Advanced Camera for Surveys on board the Hubble Space Telescope is equipped with one grism and three prisms for low-resolution, slitless spectroscopy in the range 1150-10500 Å. The G800L grism provides optical spectroscopy between 5500 Å and >1 µm, with a mean dispersion of 39 and 24 Å pixel-1 (in the first spectral order) …
X-ray spectral variations of U Gem from quiescence to outburst
Göǧüş, E.; Güver, T.; Uluyazı, C. +1 more
In this paper, we report the discovery of a high-energy component of the X-ray spectra of U Gem, which can be observed while the source is in outburst. We used Chandra and XMM-Newton observations to compare the quiescence and outburst X-ray spectra of the source. The additional component may be the result of the reflection of X-rays emitted from a…
The UV spectrum of HS 1700+6416. I. Predicting the metal line content of the far UV spectrum
Reimers, D.; Sargent, W. L. W.; Fechner, C. +3 more
Aims.In preparation of a study of the He II/H I ratio towards the bright QSO
Methods: .For that purpose, we investigate the s…
Color, Structure, and Star Formation History of Dwarf Galaxies over the Last ~3 Gyr with GEMS and SDSS
Bell, Eric F.; Wolf, Christian; Rix, Hans-Walter +7 more
We present a study of the colors, structural properties, and star formation histories for a sample of ~1600 dwarfs over look-back times of ~3 Gyr (z=0.002-0.25). The sample consists of 401 distant dwarfs drawn from the Galaxy Evolution from Morphologies and SEDs (GEMS) survey, which provides high-resolution Hubble Space Telescope (HST) Advanced Ca…
The Deuterium, Oxygen, and Nitrogen Abundance toward LSE 44
Sembach, K. R.; Chayer, P.; Hébrard, G. +2 more
We present measurements of the column densities of interstellar D I, O I, N I, and H2 made with the Far Ultraviolet Spectroscopic Explorer (FUSE) and of H I made with the International Ultraviolet Explorer (IUE) toward the sdO star LSE 44 [(l, b)=(313.37d, +13.49d) d=554+/-66 pc; z=+129+/-15 pc]. This target is among the seven most dist…
Titan's bright spots: Multiband spectroscopic measurement of surface diversity and hazes
Genzel, R.; Eisenhauer, F.; de Pater, I. +3 more
Spatially resolved near-infrared spectra of Titan, which simultaneously cover two CH4 absorption bands (from 1.45 to 2.45 µm), have been obtained using the SINFONI integral-field spectrometer with adaptive optics at the Very Large Telescope (VLT) of the European Southern Observatory. We observe the enhancement in 2 µm surfac…
Possible remnants of a frozen mud lake in southern Elysium, Mars
Smith, Michael D.; Markiewicz, Wojciech J.; Page, David +2 more
In this work we estimate the minimum persistence time of subsurface ice in water rich sediment layers remaining after sublimation of a martian lake. We simulate sublimation of ice from layers of different granulations and thicknesses. Presented results assume insolation and atmospheric conditions characteristic for the present day southern Elysium…
Red active galactic nuclei in XMM-Newton/Sloan Digital Sky Survey fields
Georgantopoulos, I.; Akylas, A.; Georgakakis, A. E.
In this paper we combine archival and proprietary XMM-Newton observations (about 5deg2) that overlap with the Sloan Digital Sky Survey to explore the nature of the moderate-z X-ray population. We focus on X-ray sources with optically red colours (g - r > 0.4), which we argue are important for understanding the origin of the X-ray bac…
Non-gravitational motion of the Jupiter-family comet 81P/Wild 2. I. The dynamical evolution
Szutowicz, S.; Królikowska, M.
We investigated the influence of the non-gravitational effects on the orbital motion of 81P/Wild 2. First, the non-gravitational accelerations on cometary nucleus throughout all five revolutions around the sun were analysed using both the symmetrical and the asymmetrical g(r)-function. Next, the symmetric model was used to examine the past and fut…
CCD astrometric observations of Phoebe in 2003-2004
Qiao, R. C.; Yu, Y.; Shen, K. X. +5 more
In 2003-2004, we obtained 115 new observations of Phoebe, the 9th Saturnian faint satellite (visual magnitude of about 16.5). We used a large CCD detector (2048×2048 pixels) mounted on the 1.56 m astrometric reflector at the Sheshan Station, near Shanghai. In our reduction, an up-to-date catalogue of stars, UCAC2 (Zacharias et al. 2004), was chose…