Search Publications
VIRTIS/VEX observations of Venus: overview of selected scientific results
Drossart, Pierre; Piccioni, Giuseppe; Haus, Rainer +2 more
After six years in a polar Venus orbit, the visible and infrared thermal imaging spectrometer (VIRTIS) on ESA's Venus Express mission provided an enormous amount of new data, including a three-dimensional view of the atmosphere and information on global surface properties of the planet. An overview is given of selected scientific results achieved …
Multi-wavelength GOALS Observations of Star Formation and Active Galactic Nucleus Activity in the Luminous Infrared Galaxy IC 883
Sanders, D. B.; Kim, D. -C.; Surace, J. A. +11 more
New optical Hubble Space Telescope (HST), Spitzer Space Telescope, Galaxy Evolution Explorer, and Chandra observations of the single-nucleus, luminous infrared galaxy (LIRG) merger IC 883 are presented. The galaxy is a member of the Great Observatories All-sky LIRG Survey and is of particular interest for a detailed examination of a luminous late-…
A Search for Infrared Emission from Core-collapse Supernovae at the Transitional Phase
Onaka, Takashi; Arimatsu, Ko; Matsuhara, Hideo +7 more
Most of the observational studies of supernova (SN) explosions are limited to early phases (<a few years after the explosion) of extragalactic SNe and observations of SN remnants (>100 yr) in our Galaxy or very nearby galaxies. SNe at the epoch between these two, which we call the "transitional" phase, have not been explored in detail except…
Disc scalelengths out to redshift 5.8
Hatziminaoglou, E.; Fathi, K.; Epinat, B. +1 more
We compute the exponential disc scalelength for 686 disc galaxies with spectroscopic redshifts out to redshift 5.8 based on Hubble Space Telescope archival data. We compare the results with our previous measurements based on 30 000 nearby galaxies from the Sloan Digital Sky Survey. Our results confirm the presence of a dominating exponential compo…
Discovery of a magnetic field in the early B-type star σ Lupi
Wade, G. A.; Kolenberg, K.; Grunhut, J. H. +6 more
Context. Magnetic early B-type stars are rare. Indirect indicators are needed to identify them before investing in time-intensive spectropolarimetric observations.
Aims: We use the strongest indirect indicator of a magnetic field in B stars, which is periodic variability of ultraviolet (UV) stellar wind lines occurring symmetric about the app…
Cross helicity at the solar surface by simulations and observations
Küker, M.; Schnerr, R. S.; Rüdiger, G.
A result of the quasilinear mean-field theory for driven magnetohydrodynamic (MHD) turbulence is that the observed cross helicity ⟨u·b⟩ may directly yield the magnetic eddy diffusivity ηT of the quiet Sun. In order to model the cross helicity at the solar surface, magnetoconvection under the presence of a vertical large-scale magnetic f…
Observations of the Interaction of Acoustic Waves and Small-scale Magnetic Fields in a Quiet Sun
Kariyappa, R.; Chitta, Lakshmi Pradeep; Jefferies, Stuart M. +1 more
The effect of the magnetic field on photospheric intensity and velocity oscillations at the sites of small-scale magnetic fields (SMFs) in a quiet Sun near the solar disk center is studied. We use observations made by the G-band filter in the Solar Optical Telescope on board Hinode for intensity oscillations; Doppler velocity, magnetic field, and …
Coronal Diagnostics from Narrowband Images Around 30.4 nm
Andretta, V.; Del Zanna, G.; Telloni, D.
Images taken in the band centered at 30.4 nm are routinely used to map the radiance of the He II Ly α line on the solar disk. That line is one of the strongest, if not the strongest, line in the EUV observed in the solar spectrum, and one of the few lines in that wavelength range providing information on the upper chromosphere or lower transition …
The orientation and current density of the magnetotail current sheet: A statistical study of the effect of geomagnetic conditions
Lester, M.; Milan, S. E.; Fear, R. C. +2 more
We examine the orientation and current density of the current sheet during current sheet crossings from Cluster's 2001-2007 tail seasons. The curlometer technique is used to estimate the current density and is combined with Minimum Variance Analysis (MVA) to calculate the direction of the current sheet normal. The SYM-H and AE indices at the time …
On the Detectability of a Predicted Mesolensing Event Associated with the High Proper Motion Star VB 10
Lépine, Sébastien; DiStefano, Rosanne
Extrapolation of the astrometric motion of the nearby low-mass star VB 10 indicates that sometime in late 2011 December or during the first 2-3 months of 2012, the star will make a close approach to a background point source. Based on astrometric uncertainties, we estimate a 1 in 2 chance that the distance of closest approach ρmin will …