Search Publications
Discovery of a second pulsating intermediate helium-enriched sdOB star
Latour, M.; Green, E. M.; Fontaine, G.
We present the discovery of long-period, low-amplitude, g-mode pulsations in the intermediate He-rich hot subdwarf (sdOB) star Feige 46. So far, only one other He-enriched sdOB star (LS IV-14 ° 116) was known to exhibit such pulsations. From our ground-based light curves of Feige 46, we extracted five independent periodicities ranging from 2294 s …
Masses of the Hyades white dwarfs. A gravitational redshift measurement
Pasquini, L.; Pala, A. F.; Ludwig, H. -G. +3 more
Context. It is possible to accurately measure the masses of the white dwarfs (WDs) in the Hyades cluster using gravitational redshift, because the radial velocity of the stars can be obtained independently of spectroscopy from astrometry and the cluster has a low velocity dispersion.
Aims: We aim to obtain an accurate measurement of the Hyade…
Decade‑long X‑ray observations of HESS J0632+057
Santangelo, Andrea; Pühlhofer, Gerd; Chernyakova, Maria +1 more
We present the results of a decade of X‑ray observations of the gamma ray loud binary HESS J0632+057 and interpret the available broadband data in view of the system geometry and emission mechanisms. We have performed an analysis of all X‑ray data available to date from Swift, XMM‑Newton, Chandra, NuSTAR, and Suzaku. We refine the orbital period o…
A Dynamical Study of Extraplanar Diffuse Ionized Gas in NGC 5775
Gallagher, J. S., III; Boettcher, Erin; Zweibel, Ellen G.
The structure and kinematics of gaseous, disk-halo interfaces are imprinted with the processes that transfer mass, metals, and energy between galactic disks and their environments. We study the extraplanar diffuse ionized gas (eDIG) layer in the interacting, star-forming galaxy NGC 5775 to better understand the consequences of star formation feedb…
First Observations of the Disruption of the Earth's Foreshock Wave Field During Magnetic Clouds
Escoubet, C. P.; Dandouras, I.; Palmroth, M. +8 more
The foreshock, extending upstream of Earth's bow shock, is a region of intense electromagnetic wave activity and nonlinear phenomena, which can have global effects on geospace. It is also the first geophysical region encountered by solar wind disturbances journeying toward Earth. Here, we present the first observations of considerable modification…
Physical conditions in the gas phases of the giant H II region LMC-N 11. II. Origin of [C II] and fraction of CO-dark gas
Lebouteiller, V.; Madden, S. C.; Galliano, F. +11 more
Context. The ambiguous origin of the [C II] 158µm line in the interstellar medium complicates its use for diagnostics concerning the star-formation rate and physical conditions in photodissociation regions.
Aims: We investigate the origin of [C II] in order to measure the total molecular gas content, the fraction of CO-dark H2
The Eclipsing δ Scuti Star EPIC 245932119
Kristiansen, Martti H.; Hong, Kyeongsoo; Lee, Jae Woo
We present the physical properties of EPIC 245932119 (K p = +9.82) exhibiting both eclipses and pulsations from the K2 photometry. The binary modeling indicates that the eclipsing system is in detached or semi-detached configurations with a mass ratio of 0.283 or 0.245, respectively, and that its light-curve parameters are almost unaffe…
Sea level changes and vertical land motion from altimetry and tide gauges in the Southern Levantine Basin
Mohamed, Bayoumy; Mohamed, Abdallah; Alam El-Din, Khaled +2 more
We have investigated the sea level rise (SLR) in the Southern Levantine region of the Mediterranean Sea during the period 1993-2015 using satellite altimetry and tide gauge data. Satellite altimetry indicated a positive SLR with a mean of 3.51 ± 0.62 mm/year, which is slightly higher than the global averaged mean SLR that was reported about 3.19 ±…
The HD 181433 Planetary System: Dynamics and a New Orbital Solution
Kane, Stephen R.; Wittenmyer, Robert A.; Horner, Jonathan +7 more
We present a detailed analysis of the orbital stability of the HD 181433 planetary system, finding it to exhibit strong dynamical instability across a wide range of orbital eccentricities, semimajor axes, and mutual inclinations. We also analyze the behavior of an alternative system architecture, proposed by Campanella, and find that it offers gre…
A systematic study of soft X-ray pulse profiles of magnetars in quiescence
Ho, Wynn C. G.; Hu, Chin-Ping; Ng, C. -Y.
Magnetars are neutron stars with extremely high surface magnetic fields. They show diverse X-ray pulse profiles in the quiescent state. We perform a systematic Fourier analysis of their soft X-ray pulse profiles. We find that most magnetars have a single-peaked profile and hence have low amplitudes of the second Fourier harmonics (A2). …