Search Publications
Lithium and Beryllium Isotopes with the PAMELA Experiment
Castellini, G.; Sarkar, R.; Ricci, M. +56 more
The cosmic ray (CR) lithium and beryllium (6Li, 7Li, 7Be, 9Be, 10Be) isotopic composition has been measured with the satellite-borne experiment PAMELA, which was launched into low-Earth orbit on board the Resurs-DK1 satellite on 2006 June 15. The rare lithium and beryllium isotopes in CRs are …
A NIKA view of two star-forming infrared dark clouds: Dust emissivity variations and mass concentration
Aussel, H.; Adam, R.; Benoît, A. +39 more
Context. The thermal emission of dust grains is a powerful tool for probing cold, dense regions of molecular gas in the interstellar medium, and so constraining dust properties is key to obtaining accurate measurements of dust mass and temperature.
Aims: By placing constraints on the dust emissivity spectral index, β, towards two star-forming…
New Galactic star clusters discovered in the disc area of the VVVX survey
Minniti, D.; Chené, A. -N.; Hempel, M. +9 more
The `VISTA Variables in the Vía Láctea eXtended (VVVX)' ESO Public Survey is a near-infrared photometric sky survey that covers nearly 1700 deg2 towards the Galactic disc and bulge. It is well-suited to search for new open clusters, hidden behind dust and gas. The pipeline processed and calibrated KS-band tile images of 40 pe…
Dusk/dawn atmospheric asymmetries on tidally-locked satellites: O2 at Europa
Leblanc, François; Johnson, Robert E.; Oza, Apurva V.
We use a simple analytic model to examine the effect of the atmospheric source properties on the spatial distribution of a volatile in a surface-bounded atmosphere on a satellite that is tidally-locked to its planet. Spatial asymmetries in the O2 exosphere of Europa observed using the Hubble Space Telescope appear to reveal on average a…
The Multi-Temporal Database of Planetary Image Data (MUTED): A web-based tool for studying dynamic Mars
Jaumann, R.; Hiesinger, H.; Bernhardt, H. +4 more
Multi-temporal spacecraft observations are key to detect and understand surface changes and time-critical processes on Mars. Since the 1970s, the number of orbital observations of Mars has increased to over one million images. The observations have revealed that the surface of Mars is changing due to exogenic processes, including eolian activity, …
Mapping Circumstellar Matter with Polarized Light: The Case of Supernova 2014J in M82
Baade, Dietrich; Sparks, William B.; Wang, Lifan +11 more
Optical polarimetry is an effective way of probing the environment of a supernova for dust. We acquired linear HST ACS/WFC polarimetry in bands F475W, F606W, and F775W of the supernova (SN) 2014J in M82 at six epochs from ∼277 days to ∼1181 days after the B-band maximum. The polarization measured at day 277 shows conspicuous deviations from other …
A deep X-ray view of the bare AGN Ark 120. III. X-ray timing analysis and multiwavelength variability
Grosso, N.; Porquet, D.; Reeves, J. N. +3 more
We present the spectral/timing properties of the bare Seyfert galaxy Ark 120 through a deep ∼420 ks XMM-Newton campaign plus recent NuSTAR observations and a ∼6-month Swift monitoring campaign. We investigate the spectral decomposition through fractional rms, covariance and difference spectra, finding the mid- to long-time-scale (∼day-year) variab…
VLTI-GRAVITY measurements of cool evolved stars. I. Variable photosphere and extended atmosphere of the Mira star R Peg
Chiavassa, A.; Wood, P. R.; Höfner, S. +7 more
Context. Dynamic model atmospheres of Mira stars predict variabilities in the photospheric radius and in atmospheric molecular layers which are not yet strongly constrained by observations.
Aims: Here we measure the variability of the oxygen-rich Mira star R Peg in near-continuum and molecular bands.
Methods: We used near-infrared K-band…
Hall effect in the coma of 67P/Churyumov-Gerasimenko
Altwegg, K.; Huang, Z.; Jia, X. +8 more
Magnetohydrodynamics simulations have been carried out in studying the solar wind and cometary plasma interactions for decades. Various plasma boundaries have been simulated and compared well with observations for comet 1P/Halley. The Rosetta mission, which studies comet 67P/Churyumov-Gerasimenko, challenges our understanding of the solar wind and…
HST Astrometry in the 30 Doradus Region. II. Runaway Stars from New Proper Motions in the Large Magellanic Cloud
Walborn, Nolan R.; van der Marel, Roeland P.; Sana, Hugues +12 more
We present a catalog of relative proper motions for 368,787 stars in the 30 Doradus region of the Large Magellanic Cloud (LMC), based on a dedicated two-epoch survey with the Hubble Space Telescope and supplemented with proper motions from our pilot archival study. We demonstrate that a relatively short epoch difference of three years is sufficien…