Search Publications
Revealing the dust grain polarization properties as a function of extinction and distance towards NGC 1893
Jose, Jessy; Wang, Jia-Wei; Lai, Shih-Ping +5 more
Dust polarization observations at optical wavelengths help us to understand the dust grain properties and trace the plane-of-the-sky component of the magnetic field. In this study, we make use of the I-band polarization data acquired from AIMPOL along with the distances (d) and extinction (AV) data to study the variation of polarization…
TESS search for substellar companions through pulsation timing of δ Scuti stars. I. Discovery of companions around Chang 134 and V393 Car
Piotto, G.; Nascimbeni, V.; Vaulato, V.
Early-type main-sequence pulsating stars such as δ Scuti variables are one of the least explored class of targets in the search for exoplanets. Pulsation timing (PT) is an alternative technique to the most effective search methods. It exploits the light-travel-time effect (LTTE) to infer the presence of additional massive bodies around a pulsating…
The pre-He white dwarfs in eclipsing binaries - III. WASP 1625-04
Hong, Kyeongsoo; Lee, Jae Woo; Park, Jang-Ho
1SWASP J162545.15-043027.9 (WASP 1625-04) has been announced as one of EL CVn candidates showing total primary eclipses and ellipsoidal variations. This paper presents the absolute properties of the binary star, based on our high-resolution spectroscopy conducted from 2015 through 2020. From the spectral analysis, the radial velocities (RVs) for b…
Constraints on the uncertainty, timing, and magnitude of potential Mars oceans from topographic deformation models
Rivera-Hernández, Frances; Sholes, Steven F.
Proposed ocean paleoshorelines on Mars have faced criticism over their genetic interpretation and because they deviate significantly from an expected equipotential surface (by many kilometers). Multiple geophysical deformation models have been proposed to explain this large topographic range and deviation including true polar wander and direct Tha…
A speckle-imaging search for close and very faint companions to the nearest and brightest Wolf-Rayet stars
Moffat, Anthony F. J.; Howell, Steve B.; Shara, Michael M. +4 more
Gravitationally bound companions to stars enable determinations of their masses, and offer clues to their formation, evolution, and dynamical histories. So motivated, we have carried out a speckle imaging survey of eight of the nearest and brightest Wolf-Rayet (WR) stars to directly measure the frequency of their resolvable companions, and to sear…
Kinematical Analysis of Substructure in the Southern Periphery of the Large Magellanic Cloud
Monachesi, Antonela; Choi, Yumi; Majewski, Steven R. +10 more
We report the first 3D kinematical measurements of 88 stars in the direction of several recently discovered substructures in the southern periphery of the Large Magellanic Cloud (LMC) using a combination of Gaia proper motions and radial velocities from the APOGEE-2 survey. More specifically, we explore stars in assorted APOGEE-2 pointings in a re…
The C/M Ratio of AGB Stars in the Local Group Galaxies
Yang, Ming; Ren, Yi; Jiang, Biwei +1 more
The number ratio of carbon-rich to oxygen-rich asymptotic giant branch (AGB) stars (the so-called C/M ratio) is closely related to the evolution environment of the host galaxy. This work studies the C/M ratio in 14 galaxies within the Local Group with the most complete and clean sample of member stars identified in our previous works. The borderli…
Radiative Magnetohydrodynamic Simulation of the Confined Eruption of a Magnetic Flux Rope: Magnetic Structure and Plasma Thermodynamics
Ding, Mingde; Chen, Feng; Wang, Can +1 more
It is widely believed that magnetic flux ropes are the key structure of solar eruptions; however, their observable counterparts are not clear yet. We study a flare associated with flux rope eruption in a comprehensive radiative magnetohydrodynamic simulation of flare-productive active regions, especially focusing on the thermodynamic properties of…
Identification of new M 31 star cluster candidates from PAndAS images using convolutional neural networks
Liu, Wei; Chen, Bingqiu; Ma, Jun +7 more
Context. Identification of new star cluster candidates in M 31 is fundamental for the study of the M 31 stellar cluster system. The machine-learning method convolutional neural network (CNN) is an efficient algorithm for searching for new M 31 star cluster candidates from tens of millions of images from wide-field photometric surveys.
Aims: W…
New globular cluster candidates in the M81 group
Bell, Eric F.; Monachesi, Antonela; Bailin, Jeremy +7 more
The study of outer halo globular cluster (GC) populations can give insight into galaxy merging, GC accretion, and the origin of GCs. We use archival Subaru Hyper Suprime-Cam (HSC) data in concert with space-based GALEX, IRAC, and Gaia EDR3 data to select candidate GCs in the outer halo of the M81 group for confirmation and future study. We use a s…