Search Publications
Binarity and Accretion in AGB Stars: HST/STIS Observations of UV Flickering in Y Gem
Sahai, R.; Sánchez Contreras, C.; Sanz-Forcada, J. +3 more
Binarity is believed to dramatically affect the history and geometry of mass loss in AGB and post-AGB stars, but observational evidence of binarity is sorely lacking. As part of a project to search for hot binary companions to cool AGB stars using the GALEX archive, we discovered a late-M star, Y Gem, to be a source of strong and variable UV and X…
Distance, Energy, and Variability of Quasar Outflows: Two HST/COS Epochs of LBQS 1206+1052
Xu, Xinfeng; Kriss, Gerard A.; Arav, Nahum +4 more
We analyze new HST/COS spectra for two quasar absorption outflows seen in the quasi-stellar object LBQS 1206+1052. These data cover, for the first time, absorption troughs from S IV, Si II, and P V. From the ratio of the S IV* to S IV column densities, we measure the electron number density of the higher-velocity (-1400 km s-1, v1400) o…
The shape of galaxy dark matter haloes in massive galaxy clusters: insights from strong gravitational lensing
Massey, Richard; Jauzac, Mathilde; Harvey, David
We assess how much unused strong lensing information is available in the deep Hubble Space Telescope imaging and Very Large Telescope/Multi Unit Spectroscopic Explorer spectroscopy of the Frontier Field clusters. As a pilot study, we analyse galaxy cluster MACS J0416.1-2403 (z = 0.397, M(R < 200 kpc) = 1.6 × 1014 M⊙), whic…
Pillars of Creation among Destruction: Star Formation in Molecular Clouds near R136 in 30 Doradus
Guzmán, Viviana V.; Elmegreen, Bruce G.; Zinnecker, Hans +3 more
We present new sensitive CO(2-1) observations of the 30 Doradus region in the Large Magellanic Cloud. We identify a chain of three newly discovered molecular clouds that we name KN1, KN2, and KN3 lying within 2-14 pc in projection from the young massive cluster R136 in 30 Doradus. Excited H2 2.12 µm emission is spatially coinciden…
Alone on a wide wide sea. The origin of SECCO 1, an isolated star-forming gas cloud in the Virgo cluster*†‡
Bellazzini, M.; Testa, V.; Beccari, G. +12 more
SECCO 1 is an extremely dark, low-mass (M⋆ ≃ 105 M⊙), star-forming stellar system lying in the low-velocity cloud (LVC) substructure of the Virgo cluster of galaxies, and hosting several H II regions. Here, we review our knowledge of this remarkable system, and present the results of (a) additional analysis of our …
Presolar Isotopic Signatures in Meteorites and Comets: New Insights from the Rosetta Mission to Comet 67P/Churyumov-Gerasimenko
Hoppe, Peter; Altwegg, Kathrin; Rubin, Martin
Comets are considered the most primitive planetary bodies in our Solar System, i.e., they should have best preserved the solid components of the matter from which our Solar System formed. ESA's recent Rosetta mission to Jupiter family comet 67P/Churyumov-Gerasimenko (67P/CG) has provided a wealth of isotope data which expanded the existing data se…
Planetary Radio Interferometry and Doppler Experiment (PRIDE) technique: A test case of the Mars Express Phobos Flyby. II. Doppler tracking: Formulation of observed and computed values, and noise budget
Bocanegra-Bahamón, T. M.; Molera Calvés, G.; Gurvits, L. I. +5 more
Context. Closed-loop Doppler data obtained by deep space tracking networks, such as the NASA Deep Space Network (DSN) and the ESA tracking station network (Estrack), are routinely used for navigation and science applications. By shadow tracking the spacecraft signal, Earth-based radio telescopes involved in the Planetary Radio Interferometry and D…
Robust Transiting Exoplanet Radii in the Presence of Starspots from Ingress and Egress Durations
Hawley, Suzanne L.; Hebb, Leslie; Agol, Eric +1 more
We typically measure the radii of transiting exoplanets from the transit depth, which are given by the ratio of cross-sectional areas of the planet and star. However, if a star has dark starspots (or bright regions) distributed throughout the transit chord, the transit depth will be biased toward smaller (larger) values, and thus the inferred plan…
The PHEMU15 catalogue and astrometric results of the Jupiter's Galilean satellite mutual occultation and eclipse observations made in 2014-2015
Delcroix, M.; Colas, F.; Carry, B. +116 more
During the 2014-2015 mutual events season, the Institut de Mécanique Céleste et de Calcul des Éphémérides (IMCCE), Paris, France, and the Sternberg Astronomical Institute (SAI), Moscow, Russia, led an international observation campaign to record ground-based photometric observations of Galilean moon mutual occultations and eclipses. We focused on …
Discovery of a jet-like structure with overionized plasma in the SNR IC 443
Greco, Emanuele; Miceli, Marco; Orlando, Salvatore +3 more
Context. IC 443 is a supernova remnant (SNR) located in a quite complex environment since it interacts with nearby clouds. Indications for the presence of overionized plasma have been found though the possible physical causes of overionization are still debated. Moreover, because of its peculiar position and proper motion, it is not clear if the p…