Search Publications
The frequency and infrared brightness of circumstellar discs at white dwarfs
Gänsicke, B. T.; Rocchetto, M.; Farihi, J. +1 more
White dwarfs whose atmospheres are polluted by terrestrial-like planetary debris have become a powerful and unique tool to study evolved planetary systems. This paper presents results for an unbiased Spitzer Infrared Array Camera search for circumstellar dust orbiting a homogeneous and well-defined sample of 134 single white dwarfs. The stars were…
Active volcanism on Venus in the Ganiki Chasma rift zone
Head, J. W.; Ignatiev, N. I.; Basilevsky, A. T. +3 more
Venus is known to have been volcanically resurfaced in the last third of solar system history and to have undergone a significant decrease in volcanic activity a few hundred million years ago. However, fundamental questions remain: Is Venus still volcanically active today, and if so, where and in what geological and geodynamic environment? Here we…
The Multithermal and Multi-stranded Nature of Coronal Rain
Rouppe van der Voort, L.; Pereira, T. M. D.; Scullion, E. +2 more
We analyze coordinated observations of coronal rain in loops, spanning chromospheric, transition region (TR), and coronal temperatures with sub-arcsecond spatial resolution. Coronal rain is found to be a highly multithermal phenomenon with a high degree of co-spatiality in the multi-wavelength emission. EUV darkening and quasi-periodic intensity v…
ALMA and Herschel reveal that X-ray-selected AGN and main-sequence galaxies have different star formation rate distributions
Daddi, E.; Elbaz, D.; Dickinson, M. +15 more
Using deep Herschel and ALMA observations, we investigate the star formation rate (SFR) distributions of X-ray-selected active galactic nucleus (AGN) host galaxies at 0.5 < z < 1.5 and 1.5 < z < 4, comparing them to that of normal, star-forming (i.e. `main-sequence', or MS) galaxies. We find that 34-55 per cent of AGNs in our sample ha…
A Suzaku search for dark matter emission lines in the X-ray brightest galaxy clusters
Simionescu, A.; Kaastra, J. S.; Allen, S. W. +3 more
We present the results of a search for unidentified emission lines in deep Suzaku X-ray spectra of the central regions of the X-ray brightest galaxy clusters: Perseus, Coma, Virgo and Ophiuchus. We analyse an optimized energy range (3.2-5.3 keV) that is relatively free of instrumental features, and a plasma emission model incorporating the abundan…
Planck intermediate results. XXIII. Galactic plane emission components derived from Planck with ancillary data
Kneissl, R.; Miville-Deschênes, M. -A.; Boulanger, F. +189 more
Planck data when combined with ancillary data provide a unique opportunity to separate the diffuse emission components of the inner Galaxy. The purpose of the paper is to elucidate the morphology of the various emission components in the strong star-formation region lying inside the solar radius and to clarify the relationship between the various …
Interstellar Neutral Helium in the Heliosphere from IBEX Observations. III. Mach Number of the Flow, Velocity Vector, and Temperature from the First Six Years of Measurements
Wurz, P.; McComas, D. J.; Fuselier, S. A. +10 more
We analyzed observations of interstellar neutral helium (ISN He) obtained from the Interstellar Boundary Explorer (IBEX) satellite during its first six years of operation. We used a refined version of the ISN He simulation model, presented in the companion paper by Sokół et al. (2015b), along with a sophisticated data correlation and uncertainty s…
Homologous Helical Jets: Observations By IRIS, SDO, and Hinode and Magnetic Modeling With Data-Driven Simulations
Golub, L.; Tian, H.; Cheung, Mark C. M. +18 more
We report on observations of recurrent jets by instruments on board the Interface Region Imaging Spectrograph, Solar Dynamics Observatory (SDO), and Hinode spacecraft. Over a 4 hr period on 2013 July 21, recurrent coronal jets were observed to emanate from NOAA Active Region 11793. Far-ultraviolet spectra probing plasma at transition region temper…
Thin Current Sheets and Associated Electron Heating in Turbulent Space Plasma
Vaivads, A.; Sahraoui, F.; Khotyaintsev, Yu. V. +6 more
Intermittent structures, such as thin current sheets, are abundant in turbulent plasmas. Numerical simulations indicate that such current sheets are important sites of energy dissipation and particle heating occurring at kinetic scales. However, direct evidence of dissipation and associated heating within current sheets is scarce. Here, we show a …
Size-frequency distribution of boulders ≥7 m on comet 67P/Churyumov-Gerasimenko
Bertaux, Jean-Loup; Da Deppo, Vania; Naletto, Giampiero +55 more
Aims: We derive for the first time the size-frequency distribution of boulders on a comet, 67P/Churyumov-Gerasimenko (67P), computed from the images taken by the Rosetta/OSIRIS imaging system. We highlight the possible physical processes that lead to these boulder size distributions.
Methods: We used images acquired by the OSIRIS Narrow …