Search Publications
Magnetofrictional Modeling of an Erupting Pseudostreamer
Reeves, Katharine K.; DeLuca, Edward E.; Savcheva, Antonia +4 more
In this study, we present the magnetic configuration of an erupting pseudostreamer observed on 2015 April 19, on the southwest limb of the Sun, with a prominence cavity embedded inside. The eruption resulted in a partial halo coronal mass ejection. The prominence eruption begins with a slow rise and then evolves to a fast-rise phase. We analyze th…
The Weizmann Fast Astronomical Survey Telescope (W-FAST): System Overview
Gal-Yam, Avishay; Ofek, Eran O.; Yaron, Ofer +8 more
A relatively unexplored phase space of transients and stellar variability is that of second and sub-second timescales. We describe a new optical observatory operating in the Negev desert in Israel, with a 55 cm aperture, a field of view of 2°6 × 2°6 (≈7 deg2) equipped with a high frame rate, low read noise, CMOS camera. The system can o…
LASCO-C3 Observations of the K- and F-Coronae over 24 Years (1996 - 2019): Photopolarimetry and Electron Density Distribution
Lamy, Philippe; Quémerais, Eric; Gilardy, Hugo +2 more
We present the polarimetric analysis of the white-light images of the corona obtained with the Large-Angle Spectrometric COronagraph LASCO-C3 onboard the Solar and Heliospheric Observatory (SOHO) from 1996 to 2019, leading to the separation of the K- and F-components and the derivation of the electron-density distribution. The analysis makes use o…
Vertical Structure of Galactic Disk Kinematics from LAMOST K Giants
Zhao, Gang; Zhu, Zi; Yang, Chengqun +3 more
We examine the vertical structure of Galactic disk kinematics over a Galactocentric radial distance range of R = 5-15 kpc and up to 3 kpc away from the Galactic plane, using the K-type giants surveyed by LAMOST. Based on robust measurements of three-dimensional velocity moments, a wobbly disk is detected in a phenomenological sense. An outflow dom…
INTEGRAL reloaded: Spacecraft, instruments and ground system
Mereghetti, Sandro; Kretschmar, Peter; Götz, Diego +85 more
The European Space Agency's INTErnational Gamma-Ray Astrophysics Laboratory (ESA/INTEGRAL) was launched aboard a Proton-DM2 rocket on 17 October 2002 at 06:41 CEST, from Baikonur in Kazakhstan. Since then, INTEGRAL has been providing long, uninterrupted observations (up to about 47 h, or 170 ksec, per satellite orbit of 2.7 days) with a large fiel…
A possible planet candidate in an external galaxy detected through X-ray transit
Soria, Roberto; Urquhart, Ryan; Kashyap, Vinay L. +4 more
Many lines of reasoning suggest that external galaxies should host planetary systems, but detecting them by methods typically used in our own Galaxy is not possible. An alternative approach is to study the temporal behaviour of X-rays emitted by bright extragalactic X-ray sources, where an orbiting planet would temporarily block the X-rays and cau…
Intrinsic metallicity variation in the intermediate mass type II globular cluster NGC 1261
Sarajedini, Ata; Monaco, L.; Geisler, D. +5 more
Globular Clusters (GCs) are now well known to almost universally show multiple populations (MPs). The HST UV Legacy Survey of a large number of Galactic GCs in UV filters optimized to explore MPs finds that a small fraction of GCs, termed Type II, also display more complex, anomalous behaviour. Several well-studied Type II GCs show intrinsic Fe ab…
The Pre-He White Dwarfs in Eclipsing Binaries. II. WASP 0843-11
Koo, Jae-Rim; Han, Cheongho; Hong, Kyeongsoo +5 more
We present the Transiting Exoplanet Survey Satellite (TESS) photometry and our high-resolution spectra of the EL CVn-type star 1SWASP J084356.46-113327.5 (WASP 0843-11), which consists of an F-type main-sequence (MS) star and a hotter low-mass helium white dwarf precursor (pre-He WD). In a spectral analysis, double-lined radial velocities (RVs) we…
Detection of an extremely strong magnetic field in the double-degenerate binary merger product HD 144941
Owocki, S. P.; Shultz, M. E.; Kochukhov, O. +2 more
HD 144941 is an extreme He (EHe) star, a rare class of subdwarf OB star formed from the merger of two white dwarf (WD) stars. Uniquely amongst EHe stars, its light curve has been reported to be modulated entirely by rotation, suggesting the presence of a magnetic field. Here, we report the first high-resolution spectropolarimetric observations of …
Joint Suzaku and Chandra observations of the MKW4 galaxy group out to the virial radius
Kraft, Ralph; Gastaldello, Fabio; Sarkar, Arnab +5 more
We present joint Suzaku and Chandra observations of MKW4. With a global temperature of 1.6 keV, MKW4 is one of the smallest galaxy groups that have been mapped in X-rays out to the virial radius. We measure its gas properties from its centre to the virial radius in the north, east, and north-east directions. Its entropy profile follows a power law…