Search Publications
A double white dwarf with a paradoxical origin?
Gal-Yam, A.; Hermes, J. J.; Gänsicke, B. T. +14 more
We present Hubble Space Telescope UV spectra of the 4.6-h-period double white dwarf SDSS J125733.63+542850.5. Combined with Sloan Digital Sky Survey optical data, these reveal that the massive white dwarf (secondary) has an effective temperature T2 = 13 030 ± 70 ± 150 K and a surface gravity log g2 = 8.73 ± 0.05 ± 0.05 (stati…
Herschel* Observations of Interstellar Chloronium. II. - Detections toward G29.96-0.02, W49N, W51, and W3(OH), and Determinations of the Ortho-to-Para and 35Cl/37Cl Isotopic Ratios
Menten, Karl M.; Neufeld, David A.; Herbst, Eric +14 more
We report additional detections of the chloronium molecular ion, H2Cl+, toward four bright submillimeter continuum sources: G29.96-0.02, W49N, W51, and W3(OH). With the use of the HIFI instrument on board the Herschel Space Observatory, we observed the {2}12-{1}01 transition of ortho-H{}2…
Spectral analysis of BD+30°623, the peculiar binary central star of the planetary nebula NGC 1514★
Montesinos, B.; Solano, E.; Ulla, A. +2 more
NGC 1514 is a complex planetary nebula with a peculiar binary central star (BD+30°623) consisting of a cool star and a hot companion. To date, the parameters of the two stars have not been firmly established. We present a detailed spectral analysis of BD+30°623 based on intermediate-resolution Calar Alto Faint Object Spectrograph optical spectra a…
An extremely high-altitude plume seen at Mars' morning terminator
Phillips, J.; Sánchez-Lavega, A.; Delcroix, M. +10 more
The Martian limb (that is, the observed `edge' of the planet) represents a unique window into the complex atmospheric phenomena occurring there. Clouds of ice crystals (CO2 ice or H2O ice) have been observed numerous times by spacecraft and ground-based telescopes, showing that clouds are typically layered and always confined…
Gaia astrometry for stars with too few observations. A Bayesian approach
Michalik, Daniel; Lindegren, Lennart; Hobbs, David +1 more
Context. The astrometric solution for Gaia aims to determine at least five parameters for each star, representing its position, parallax, and proper motion, together with appropriate estimates of their uncertainties and correlations. This requires at least five distinct observations per star. In the early data reductions the number of observations…
Landform assemblage in Isidis Planitia, Mars: Evidence for a 3 Ga old polythermal ice sheet
Bourgeois, Olivier; Pochat, Stéphane; Souček, Ondřej +1 more
The floor of Isidis Planitia, a giant impact basin located close to the martian equator, exhibits a landform assemblage, nicknamed Thumbprint Terrain, made of Arcuate Ridges, Aligned Cones, Isolated Cones, Cone Fields, associated with a peripheral network of Sinuous Ridges, Linear Depressions, and Mounds. From a new comprehensive mapping initiativ…
The Three-mm Ultimate Mopra Milky Way Survey. II.Cloud and Star Formation near the Filamentary Ministarburst RCW 106
Martin, Peter G.; Fuller, Gary A.; Barnes, Peter J. +10 more
We report here a study of gas, dust, and star formation rates (SFRs) in the molecular cloud complexes (MCCs) surrounding the giant H ii region RCW 106 using 12CO and 13CO(1-0) data from the Three-mm Ultimate Mopra Milky way Survey and archival data. We separate the emission in the Galactic Plane around l = 330°-335° and b = -…
Exploring the parameter space of warm-inflation models
Berera, Arjun; Bastero-Gil, Mar; Kronberg, Nico
Warm inflation includes inflaton interactions with other fields throughout the inflationary epoch instead of confining such interactions to a distinct reheating era. Previous investigations have shown that, when certain constraints on the dynamics of these interactions and the resultant radiation bath are satisfied, a low-momentum-dominated dissip…
A Spectroscopic and Photometric Exploration of the C/M Ratio in the Disk of M31
Williams, Benjamin F.; Gilbert, Karoline M.; Boyer, Martha L. +12 more
We explore the ratio (C/M) of carbon-rich to oxygen-rich thermally pulsing asymptotic giant branch (TP-AGB) stars in the disk of M31 using a combination of moderate-resolution optical spectroscopy from the Spectroscopic Landscape of Andromeda’s Stellar Halo survey and six-filter Hubble Space Telescope photometry from the Panchromatic Hubble Androm…
HST/COS Detection of the Spectrum of the Subdwarf Companion of KOI-81
Gies, Douglas R.; Latham, David W.; Quinn, Samuel N. +5 more
KOI-81 is a totally eclipsing binary discovered by the Kepler mission that consists of a rapidly rotating B-type star and a small, hot companion. The system was forged through large-scale mass transfer that stripped the mass donor of its envelope and spun up the mass gainer star. We present an analysis of UV spectra of KOI-81 that were obtained wi…