Search Publications
Multi-epoch UV–X-Ray Spectral Study of NGC 4151 with AstroSat
Papadakis, I. E.; Singh, K. P.; Dewangan, G. C. +8 more
We present a multiwavelength spectral study of NGC 4151 based on five epochs of simultaneous AstroSat observations in the near-ultraviolet (NUV) to hard X-ray band (∼0.005–80 keV) during 2017–2018. We derived the intrinsic accretion disk continuum after correcting for internal and Galactic extinction, contributions from broad- and narrow-line regi…
The Nature of a Recently Discovered Wolf–Rayet Binary: Archetype of Stripping?
Massey, Philip; Morrell, Nidia I.; Penny, Laura R. +2 more
LMCe055-1 was recently discovered in a survey for Wolf–Rayets (WRs) in the Large Magellanic Cloud, and classified as a WN4/O4, a lower-excitation version of the WN3/O3 class discovered as part of the same survey. Its absolute magnitude precluded it from being a WN4+O4 binary. Optical Gravitational Lensing Experiment photometry shows shallow primar…
NIKA2 observations of starless cores in Taurus and Perseus
Berta, S.; Aussel, H.; Adam, R. +49 more
Dusty starless cores play an important role in regulating the initial phases of the formation of stars and planets. In their interiors, dust grains coagulate and ice mantles form, thereby changing the millimeter emissivities and hence the ability to cool. We mapped four regions with more than a dozen cores in the nearby Galactic filaments of Tauru…
Asteroid (4337) Arecibo: Two ice-rich bodies forming a binary. Based on Gaia astrometric data
Hestroffer, Daniel; David, Pedro; Desmars, Josselin +1 more
Context. Binary asteroids are present in all populations of the Solar System, from near-Earth to trans-Neptunian regions. As is true for the small Solar System bodies (SSSBs), binary asteroids generally offer valuable insights into the formation of the Solar System, as well as its collisions and dynamic evolution. In particular, the binaries provi…
Investigation of the Nonthermal X-Ray Emission from the Supernova Remnant CTB 37B Hosting the Magnetar CXOU J171405.7-381031
An, Hongjun; Mori, Kaya; Safi-Harb, Samar +4 more
We present a detailed X-ray investigation of a region (S1) exhibiting nonthermal X-ray emission within the supernova remnant (SNR) CTB 37B hosting the magnetar CXOU J171405.7‑381031. Previous analyses modeled this emission with a power law (PL), inferring various values for the photon index (Γ) and absorbing column density (N H). Based …
Search for spectroscopic binaries using rotational velocities in five open clusters observed by ESO
Kovalev, Mikhail; Asa'd, Randa; Ahmed, Mariyam
In this paper we detect double-lined spectroscopic binaries (SB2) in five open clusters: NGC 2243, NGC 2420, NGC 3532, NGC 6253, and NGC 6705 (M 11) using a method based on high values of the projected rotational velocity when they are fitted with single star spectral model. Observed spectra were obtained from the European Southern Observatory arc…
Evidence for a Close-in Tertiary Orbiting around the Algol-type System HZ Dra with Tidal Splitting and Spots Activities
Matekov, Azizbek; Li, Lin-Jia; Qian, Sheng-Bang +7 more
We report a cyclic variation of the O ‑ C diagram with a semiamplitude of 0.0033 days and a period of 1.05 yr for the pulsating eclipsing binary HZ Dra. The cyclic variation can be explained by the light travel-time effect via the presence of a close-in third body orbiting around HZ Dra in an elliptical orbit with a maximum semimajor axis of 0.89 …
The Radiative–Convective Gap: Fact or Fiction?
Brandner, Wolfgang; Röser, Siegfried; Schilbach, Elena +1 more
Gaia characterizes the stellar populations of nearby open clusters with unprecedented precision. We investigate the Böhm-Vitense gap, which has been found as a prominent feature in the stellar sequence of open clusters. Using PARSEC isochrone fitting, we derive astrophysical parameters for more than 1100 bona fide single stars each in Praesepe, id…
Perturbation effect of solar radiation pressure on the Sun-Earth co-orbital motion
Zhao, Mingxu; Qi, Yi; Qiao, Dong
Sun-Earth co-orbital motions have an important value in deep space explorations due to their unique orbital characteristics and spatial configurations. In this paper, we investigate the influence of the solar radiation pressure (SRP) on the Sun-Earth co-orbital motion. Firstly, we derive several analytical formulas of the effect of the SRP on orbi…
Infrared colours and bolometric corrections of SiO masing stars in the inner Milky Way
Messineo, Maria
Aims: We analysed a sample of SiO-masing late-type stars located in the inner Galaxy with the goal of setting better constraints on their obscuration.
Methods: This reference sample has allowed us to define mathematical relations between their dereddened infrared colours and the observed colours (e.g. Ks-[8], Ks-[24…