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Extinction law in the range 0.4-4.8 µm and the 8620 Å DIB towards the stellar cluster Westerlund 1
Rubinho, M. S.; Almeida, L. A.; Damineli, A. +4 more
The young stellar cluster Westerlund 1 (Wd 1: l = 339.6°, b = -0.4°) is one of the most massive in the local Universe, but accurate parameters are pending on better determination of its extinction and distance. Based on our photometry and data collected from other sources, we have derived a reddening law for the cluster line-of-sight representativ…
Sulphur molecules in the circumstellar envelopes of M-type AGB stars
Olofsson, H.; Justtanont, K.; Black, J. H. +2 more
Aims: The sulphur compounds SO and SO2 have not been widely studied in the circumstellar envelopes of asymptotic giant branch (AGB) stars. By presenting and modelling a large number of SO and SO2 lines in the low mass-loss rate M-type AGB star R Dor, and modelling the available lines of those molecules in a further four …
Mass-loading, pile-up, and mirror-mode waves at comet 67P/Churyumov-Gerasimenko
Altwegg, K.; Glassmeier, K. -H.; Nilsson, H. +23 more
The data from all Rosetta plasma consortium instruments and from the ROSINA COPS instrument are used to study the interaction of the solar wind with the outgassing cometary nucleus of 67P/Churyumov-Gerasimenko. During 6 and 7 June 2015, the interaction was first dominated by an increase in the solar wind dynamic pressure, caused by a higher solar …
SPT-GMOS: A Gemini/GMOS-South Spectroscopic Survey of Galaxy Clusters in the SPT-SZ Survey
Bayliss, M. B.; Gladders, M. D.; Schrabback, T. +75 more
We present the results of SPT-GMOS, a spectroscopic survey with the Gemini Multi-Object Spectrograph (GMOS) on Gemini South. The targets of SPT-GMOS are galaxy clusters identified in the SPT-SZ survey, a millimeter-wave survey of 2500 deg2 of the southern sky using the South Pole Telescope (SPT). Multi-object spectroscopic observations …
Surface Albedo and Spectral Variability of Ceres
Nathues, Andreas; Schröder, Stefan E.; Russell, Christopher T. +21 more
Previous observations suggested that Ceres has active, but possibly sporadic, water outgassing as well as possibly varying spectral characteristics over a timescale of months. We used all available data of Ceres collected in the past three decades from the ground and the Hubble Space Telescope, as well as the newly acquired images by the Dawn Fra…
Close stellar conjunctions of α Centauri A and B until 2050 . An mK = 7.8 star may enter the Einstein ring of α Cen A in 2028
Kervella, P.; Mignard, F.; Thévenin, F. +1 more
The rapid proper motion of the α Cen pair (≈3.7 arcsec yr-1) and its location close to the galactic plane on a rich stellar background combine constructively to make them excellent candidates for close stellar conjunctions with more distant stars. Adding new differential astrometry to archival data, we have refined the orbital parameter…
Constraining the Properties of Dark Matter with Observations of the Cosmic Microwave Background
Kopp, Michael; Skordis, Constantinos; Thomas, Daniel B.
We examine how the properties of dark matter, parameterized by an equation-of-state parameter w and two perturbative generalized dark matter (GDM) parameters, c 2 s (the sound speed) and {c}{vis}2 (the viscosity), are constrained by existing cosmological data, particularly the Planck 2015 data release.…
Giant Metrewave Radio Telescope observations of neutral atomic hydrogen gas in the COSMOS field at z ∼ 0.37
Chengalur, Jayaram N.; Colless, Matthew; Rhee, Jonghwan +2 more
We present the results of H I spectral stacking analysis of Giant Metrewave Radio Telescope (GMRT) observations targeting the Cosmological Evolution Survey (COSMOS) field. The GMRT data cube contains 474 field galaxies with redshifts known from the zCOSMOS-bright 10 k catalogue. Spectra for the galaxies are co-added and the stacked spectrum allows…
Gaia FGK benchmark stars: new candidates at low metallicities
Gilmore, G.; Randich, S.; Soubiran, C. +10 more
Context. We have entered an era of large spectroscopic surveys in which we can measure, through automated pipelines, the atmospheric parameters and chemical abundances for large numbers of stars. Calibrating these survey pipelines using a set of "benchmark stars" in order to evaluate the accuracy and precision of the provided parameters and abunda…
A cold-wet middle-latitude environment on Mars during the Hesperian-Amazonian transition: Evidence from northern Arabia valleys and paleolakes
Moore, Jeffrey M.; Wilson, Sharon A.; Howard, Alan D. +1 more
The growing inventory of post-Noachian fluvial valleys may represent a late, widespread episode of aqueous activity on Mars, contrary to the paradigm that fluvial activity largely ceased around the Noachian-Hesperian boundary. Fresh shallow valleys (FSVs) are widespread from ~30 to 45° in both hemispheres with a high concentration in northern Arab…