Search Publications
CONSERT suggests a change in local properties of 67P/Churyumov-Gerasimenko's nucleus at depth
Lasue, J.; Plettemeier, D.; Kofman, W. +5 more
Context. After the successful landing of Philae on the nucleus of 67P/Churyumov-Gerasimenko, the Rosetta mission provided the first opportunity of performing measurements with the CONSERT tomographic radar in November 2014. CONSERT data were acquired during this first science sequence. They unambiguously showed that propagation through the smaller…
A treatment procedure for VLT/SINFONI data cubes: application to NGC 5643
Ricci, T. V.; Steiner, J. E.; May, D. +3 more
In this second paper of a series, we present a treatment procedure for data cubes obtained with the Spectrograph for Integral Field Observations in the Near Infrared of the Very Large Telescope. We verified that the treatment procedure improves significantly the quality of the images of the data cubes, allowing a more detailed analysis. The images…
Magnetosphere-ionosphere mapping at Jupiter: Quantifying the effects of using different internal field models
Bunce, Emma J.; Khurana, Krishan K.; Kivelson, Margaret G. +5 more
The lack of global field models accurate beyond the inner magnetosphere (<30 RJ) makes it difficult to relate Jupiter's polar auroral features to magnetospheric source regions. We recently developed a model that maps Jupiter's equatorial magnetosphere to the ionosphere using a flux equivalence calculation that requires equal flux at …
Simultaneous X-ray and optical spectroscopy of the Oef supergiant λ Cephei
Schmitt, J. H. M. M.; Gosset, E.; Nazé, Y. +8 more
Context. Probing the structures of stellar winds is of prime importance for the understanding of massive stars. Based on their optical spectral morphology and variability, it has been suggested that the stars in the Oef class feature large-scale structures in their wind.
Aims: High-resolution X-ray spectroscopy and time-series of X-ray observ…
A New Reduction of the Blanco Cosmology Survey: An Optically Selected Galaxy Cluster Catalog and a Public Release of Optical Data Products
Gladders, M. D.; Rest, A.; Bleem, L. E. +5 more
The Blanco Cosmology Survey is a four-band (griz) optical-imaging survey of ~80 deg2 of the southern sky. The survey consists of two fields centered approximately at (R.A., decl.) = (23h, -55°) and (5h30m, -53°) with imaging sufficient for the detection of L sstarf galaxies at redshift z <=…
Optical polarization map of the Polaris Flare with RoboPol
Pearson, T. J.; Papadakis, I.; Blinov, D. +26 more
The stages before the formation of stars in molecular clouds are poorly understood. Insights can be gained by studying the properties of quiescent clouds, such as their magnetic field structure. The plane-of-the-sky orientation of the field can be traced by polarized starlight. We present the first extended, wide-field (∼10 deg2) map of…
Hubble Space Telescope Observations of the NUV Transit of WASP-12b
Goad, M.; Nichols, J. D.; Clarke, J. T. +6 more
We present new observations of four closely spaced near-ultraviolet (NUV) transits of the hot Jupiter-like exoplanet WASP-12b using Hubble Space Telescope (HST)/Cosmic Origins Spectrograph (COS), significantly increasing the phase resolution of the observed NUV light curve relative to previous observations, while minimizing the temporal variation …
SN Hunt 248: a super-Eddington outburst from a massive cool hypergiant
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Smith, Nathan +8 more
We present observations of SN Hunt 248, a new supernova (SN) impostor in NGC 5806, which began a multistage outburst in 2014 May. The `2014a' discovery brightening exhibited an absolute magnitude of M ≈ -12 and the spectral characteristics of a cool, dense outflow, including P Cygni lines of Fe II, H I, and Na I, and line blanketing from metals. T…
Hubble Space Telescope Near-Ultraviolet Spectroscopy of Bright CEMP-s Stars
Smith, Verne V.; Beers, Timothy C.; Placco, Vinicius M. +14 more
We present an elemental-abundance analysis, in the near-ultraviolet (NUV) spectral range, for the bright carbon-enhanced metal-poor (CEMP) stars HD 196944 (V=8.40, [Fe/H] = -2.41) and HD 201626 (V=8.16, [Fe/H] = -1.51), based on data acquired with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope. Both of these stars be…
The heavy ion diffusion region in magnetic reconnection in the Earth's magnetotail
Kistler, L. M.; Mouikis, C. G.; Wang, S. +3 more
While the plasma in the Earth's magnetotail predominantly consists of protons and electrons, there are times when a significant amount of oxygen is present. When magnetic reconnection occurs, the behavior of these heavy ions can be significantly different from that of the protons, due to their larger gyroradius. In this study, we investigate the h…