Search Publications
Atmospheric parameters of the B-supergiant HD 198478 from the UV spectra
Jurkić, Tomislav; Sarta Deković, Mariza; Dominis Prester, Dijana +1 more
We determined atmospheric parameters of the Galactic early B-supergiant HD 198478 (55 Cyg) from the UV silicon lines taken from the high-resolution 1150–1980 Å IUE spectra. TLUSTY numerical code was used to model the stellar atmosphere and to determine the temperature and surface gravity assuming a non-LTE plane parallel hydrostatic stellar atmosp…
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…
10 Years of the optical & UV monitor (OM) on-board XMM-Newton
Talavera, Antonio; OMCal Team
The XMM-Newton X-ray observatory was launched at the end of 1999 and it is still successfully operated. In addition to the X-ray instruments, the payload carries a small telescope, the Optical Monitor, which provides simultaneous imaging and spectroscopic observations in the optical and UV ranges. In this report we review the status of the OM and …
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…
The PL calibration for Milky Way Cepheids and its implications for the distance scale
Turner, David G.
The rationale behind recent calibrations of the Cepheid PL relation using the Wesenheit formulation is reviewed and reanalyzed, and it is shown that recent conclusions regarding a possible change in slope of the PL relation for short-period and long-period Cepheids are tied to a pathological distribution of HST calibrators within the instability s…
Supernova remnants, planetary nebulae and the distance to NGC 4214
Mutchler, Max; Windhorst, Rogier; Blair, William P. +23 more
We present narrow band, continuum subtracted Hα, [S II], Hβ, [O III] and [O II] data taken with the Wide Field Camera 3 on the Hubble Space Telescope in the nearby dwarf starburst galaxy NGC 4214. From these images, we identify seventeen new planetary nebula candidates, and seven supernova remnant candidates. We use the observed emission line lumi…
CoRoT 102931335: a candidate γ Dor in an eclipsing binary
Cardini, D.; Ribas, I.; Balaguer-Núñez, L. +3 more
We present an on-going study of CoRoT 102931335. Our preliminary results indicate that the target is an eclipsing binary system with an orbital period of
Dark mammoth trunks in the merging galaxy NGC 1316 and a mechanism of cosmic double helices
Carlqvist, Per
NGC 1316 is a giant, elliptical galaxy containing a complex network of dark, dust features. The morphology of these features has been examined in some detail using a Hubble Space Telescope, Advanced Camera for Surveys image. It is found that most of the features are constituted of long filaments. There also exist a great number of dark structures …
EC 11481–2303—a peculiar subdwarf OB star revisited
Rauch, Thomas; Werner, Klaus; Kruk, Jeffrey W.
EC 11481–2303 is a peculiar, hot, high-gravity pre-white dwarf. Previous optical spectroscopy revealed that it is a sdOB star with Teff=41 790 K, log g=5.84, and He/H = 0.014 by number. We present an on-going spectral analysis by means of non-LTE model-atmosphere techniques based on high-resolution, high-S/N optical (VLT-UVES) and ultra…