Search Publications
Quantifying torque from the Milky Way bar using Gaia DR2
Kipper, Rain; Tenjes, Peeter; Tuvikene, Taavi +2 more
We determine the mass of the Milky Way bar and the torque it causes, using Gaia DR2, by applying the orbital arc method. Based on this, we have found that the gravitational acceleration is not directed towards the centre of our Galaxy but a few degrees away from it. We propose that the tangential acceleration component is caused by the bar of the …
A Catalog of Periodic Variables in Open Clusters M35 and NGC 2158
Bouma, L. G.; Bhatti, W.; Bakos, G. Á. +3 more
We present a catalog of 1143 periodic variables, compiled from our image-subtracted photometric analysis of the K2 Campaign-0 super stamp. This super stamp is centered on the open clusters M35 and NGC 2158. Approximately 46% of our periodic variables were previously unreported. Of the catalog variables, we find that 331 are members of M35 and 56 a…
SOIR/VEx observations of water vapor at the terminator in the Venus mesosphere
Vandaele, A. C.; Trompet, L.; Robert, S. +4 more
The Solar Occultation in the InfraRed (SOIR) instrument onboard Venus Express sounded the Venus mesosphere and lower thermosphere using solar occultation geometry between April 2006 and December 2014. The observations were all taken at the terminator. This paper reports on the water vapor vertical distribution above the clouds and geo-temporal var…
HST/COS Spectra of the Wind Lines of VFTS 102 and 285
Gies, Douglas R.; Lester, Kathryn V.; Wang, Luqian +5 more
Rapid rotation in massive stars imposes a latitudinal variation in the mass loss from radiatively driven winds that can lead to enhanced mass loss at the poles (with little angular momentum loss) and/or equator (with maximal angular momentum loss). Here we present an examination of the stellar wind lines of the two O-type stars with the fastest kn…
Modeling the IRIS Lines During a Flare. I. The Blue-wing Enhancement in the Mg II k Line
Ding, M. D.; Li, Ying; Hong, Jie +1 more
The Interface Region Imaging Spectrograph (IRIS) Mg II k line serves as a very good tool to diagnose the heating processes in solar flares. Recent studies have shown that apart from the usual red asymmetries that are interpreted as the result of condensation downflows, this line could also show a blue-wing enhancement. To investigate how such a bl…
A model of the 3-µm hydration band with Exponentially Modified Gaussian (EMG) profiles: Application to hydrated chondrites and asteroids
Schmitt, B.; Beck, P.; Potin, S. +2 more
We present here a new method to model the shape of the 3-µm absorption band in the reflectance spectra of meteorites and small bodies. The band is decomposed into several OH/H2O components using Exponentially Modified Gaussian (EMG) profiles, as well as possible organic components using Gaussian profiles when present. We compare t…
A Geoeffective CME Caused by the Eruption of a Quiescent Prominence on 29 September 2013
Grechnev, V. V.; Kuzmenko, I. V.
The eruption of a large prominence that occurred away of active regions in the SOL2013-09-29 event produced a fast coronal mass ejection (CME) and a shock wave. The event caused considerable geospace disturbances, including a proton enhancement that have been addressed in previous studies. Continuing with the analysis of this event, we focus on th…
A broadband X-ray view of the NLSy1 1E 0754.6+3928
Bianchi, S.; Petrucci, P. -O.; Miniutti, G. +8 more
Context. The soft X-ray band of many active galactic nuclei (AGNs) is affected by obscuration due to partially ionised matter crossing our line of sight. In this context, two past XMM-Newton observations that were six months apart and a simultaneous NuSTAR-Swift exposure of the Narrow Line Seyfert 1 galaxy 1E 0754.6+3928, which was approximately e…
Determination of the Configurations of Boundaries in Space
Russell, C. T.; Dunlop, M.; Rong, Zhaojin +5 more
This research aims to determine the geometrical configurations of boundary surfaces in the space environment, based on multiple spacecraft measurements. To achieve this, the Normal Field Analysis (NFA) method is presented here. With multipoint observations, the three-dimensional gradient of the normal of boundary layers can be obtained, and the pr…
Gaia DR2 data and the evolutionary status of eight high-velocity hot post-AGB candidates
Matsuno, Tadafumi; Aoki, Wako; Parthasarathy, Mudumba
From Gaia DR2 data of eight high-velocity hot post-AGB candidates, LS 3593, LSE 148, LS 5107, HD 172324, HD 214539, LS IV -12 111, LS III +52 24, and LS 3099, we found that six of them have accurate parallaxes which made it possible to derive their distances, absolute visual magnitudes (MV) and luminosity (log L/L⊙). All the …