Search Publications
The impact of a slow interplanetary coronal mass ejection on Venus
Barabash, Stas; Futaana, Yoshifumi; Collinson, Glyn A. +8 more
We present Venus Express observations of the impact of a slow interplanetary coronal mass ejection (ICME), which struck Venus on 23 December 2006, creating unusual quasi steady state upstream conditions for the 2 h close to periapsis: an enhanced (∼ nT) interplanetary magnetic field (IMF), radially aligned with the Sun-Venus line; and a dense (∼ c…
Fine-structure line deficit in S 140
Ossenkopf, V.; van der Tak, F. F. S.; Okada, Y. +5 more
Aims: We try to understand the gas heating and cooling in the S 140 star-forming region by spatially and spectrally resolving the distribution of the main cooling lines with GREAT/SOFIA and combining our data with existing ground-based and Herschel observations that trace the energy input and the density and temperature structure of the sourc…
The far-ultraviolet spectra of "cool" PG 1159 stars
Rauch, T.; Werner, K.; Kruk, J. W.
We present a comprehensive study of Far Ultraviolet Spectroscopic Explorer (FUSE) spectra (912-1190 Å) of two members of the PG 1159 spectral class, which consists of hydrogen-deficient (pre-) white dwarfs with effective temperatures in the range Teff = 75 000-200 000 K. As two representatives of the cooler objects, we have selected PG …
FUSE, STIS and Keck spectroscopic analysis of the UV-bright star vZ 1128 in M3 (NGC 5272)
Chayer, P.; Fullerton, A. W.; Dixon, W. V. +2 more
We present a spectral analysis of the ultraviolet-bright star vZ 1128 in M3 based on observations with the Far Ultraviolet Spectroscopic Explorer (FUSE), the Space Telescope Imaging Spectrograph (STIS), and the Keck High Resolution Echelle Spectrometer (HIRES). By fitting the H I, He I, and He II lines in the Keck spectrum with non-local thermodyn…
What is the nature of magnetosheath FTEs?
Robert, Patrick; Louarn, Philippe; Fontaine, Dominique +3 more
Cluster multipoint measurements are used to study two successive magnetosheath flux transfer events (FTEs). Magnetic field lines in the leading region are found to be closed magnetospheric field lines. For event 1 these field lines are wounded up by a large current structure oriented eastward and moving poleward. Conversely, the trailing region co…
Mapping High-velocity Hα and Lyα Emission from Supernova 1987A
Smith, Nathan; Garnavich, Peter; France, Kevin +12 more
We present new Hubble Space Telescope images of high-velocity Hα and Lyα emission in the outer debris of SN 1987 A. The Hα images are dominated by emission from hydrogen atoms crossing the reverse shock (RS). For the first time we observe emission from the RS surface well above and below the equatorial ring (ER), suggesting a bipolar or conical st…
Multiplicity among F-type stars. II.
Chini, R.; Fuhrmann, K.
In continuation of our previous study we present an updated census of new companions and model atmosphere analyses for some 50 southern dwarfs, mostly in the mass range 0.90≤slant M≤slant 1.10 {M}⊙ . For the common-proper-motion companions µ Vir B, HR 2225 B, HD 67199 B, and HD 114853 B, we confirm their physical association from …
Deep Multi-telescope Photometry of NGC 5466. II. The Radial Behavior of the Mass Function Slope
Dalessandro, E.; Bellazzini, M.; Beccari, G. +3 more
We use a combination of data acquired with the Advanced Camera for Survey on board the Hubble Space Telescope and the Large Binocular Camera (LBC-blue) mounted on the Large Binocular Telescope to sample the main sequence (MS) stars of the globular cluster (GC) NGC 5466 in the mass range 0.3 < M/M⊙ < 0.8. We derive the cluster's Lu…
Initiation of CMEs associated with filament eruption, and the nature of CME related shocks
Fainshtein, V. G.; Egorov, Ya. I.
Using data from SDO, PROBA2 and other spacecraft, Fainshtein and Egorov (2013) have discovered processes accompanying initiation of six limb CMEs and have studied features of their motion. The said CMEs occurred after eruption of prominence or hot emission loop and were associated with X-ray flares. The follow-up study of the CMEs, associated with…
A study of purely astrometric selection of extragalactic point sources with Gaia
Fynbo, J. P. U.; Heintz, K. E.; Høg, E.
Context. Selection of extragalactic point sources, e.g., quasi-stellar objects (QSOs), is often hampered by significant selection effects causing existing samples to have rather complex selection functions.
Aims: We explore whether a purely astrometric selection of extragalactic point sources, e.g., QSOs, is feasible with the ongoing Gaia mis…