Search Publications
SRGA J181414.6-225604: A New Galactic Symbiotic X-Ray Binary Outburst Triggered by an Intense Mass-loss Episode of a Heavily Obscured Mira Variable
Soria, Roberto; Boyer, Martha L.; Conroy, Charlie +24 more
We present the discovery and multiwavelength characterization of SRGA J181414.6-225604, a Galactic hard X-ray transient discovered during the ongoing SRG/ART-XC sky survey. Using data from the Palomar Gattini-IR survey, we identify a spatially and temporally coincident variable infrared (IR) source, IRAS 18111-2257, and classify it as a very-late-…
A 16 hr Transit of Kepler-167 e Observed by the Ground-based Unistellar Telescope Network
Esposito, Thomas M.; Wagner, Kevin; Dalba, Paul A. +35 more
More than 5000 exoplanets have been confirmed and among them almost 4000 were discovered by the transit method. However, few transiting exoplanets have an orbital period greater than 100 days. Here we report a transit detection of Kepler-167 e, a "Jupiter analog" exoplanet orbiting a K4 star with a period of 1071 days, using the Unistellar ground-…
Tidal Quality of the Hot Jupiter WASP-12b
Makarov, Valeri V.; Efroimsky, Michael
WASP-12b stands out among the planets of its class of hot Jupiters because of the observed fast orbital decay attributed to tidal dissipation. The measured rate of the orbital period change is Pṡorb=‑29±3ms/yr= ‑(9.2±1.0)×10‑10s/s. In the literature heretofore, all attempts to explain this high rate were based on the assumption that the orbital ev…
The peculiar abundances of HE 1005-1439. A carbon-enhanced extremely metal-poor star contaminated with products of both s- and i-process nucleosynthesis
Goswami, Aruna; Goswami, Partha Pratim
Context. Understanding the surface chemical composition of carbon-enhanced metal-poor (CEMP) stars with enhanced abundances of heavy elements remains problematic.
Aims: One of the primary objectives is to investigate the origin of the peculiar abundance pattern observed in the carbon-enhanced extremely metal-poor object HE 1005-1439, which is…
Improved Modeling of Mars' HDO Cycle Using a Mars' Global Climate Model
Montmessin, Franck; Trokhimovskiy, Alexander; Korablev, Oleg +11 more
HDO and the D/H ratio are essential to understand Mars past and present climate, in particular with regard to the evolution through ages of the Martian water cycle. We present here new modeling developments of the HDO cycle with the Laboratoire de Météorologie Dynamique Mars Global Climate Model (GCM). The present study aims at exploring the behav…
Plausibility of ultraviolet burst generation in the low solar chromosphere
Cheng, Guanchong; Ni, Lei; Lin, Jun
Context. Ultraviolet (UV) bursts and Ellerman bombs (EBs) are small-scale magnetic reconnection events taking place in the highly stratified, low solar atmosphere. The plasma density, reconnection mechanisms, radiative cooling and transfer processes clearly differ from one layer of the atmosphere to the next. In particular, EBs are believed to for…
Radio Jet Proper-motion Analysis of Nine Distant Quasars above Redshift 3.5
Frey, Sándor; Gabányi, Krisztina Éva; An, Tao +2 more
Up to now, jet kinematic studies of radio quasars have barely reached beyond the redshift range z > 3.5. This significantly limits our knowledge of high-redshift jets, which can provide key information for understanding the jet nature and the growth of black holes in the early universe. In this paper, we selected nine radio-loud quasars at z &g…
The Milky Way Revealed by Variable Stars. I. Sample Selection of RR Lyrae Stars and Evidence for Merger History
Zhao, Gang; Shi, Jian-Rong; Ablimit, Iminhaji +2 more
In order to study the Milky Way, RR Lyrae (RRL) variable stars identified by Gaia, ASAS-SN, and ZTF sky survey projects have been analyzed as tracers in this work. Photometric and spectroscopic information of 3417 RRLs including proper motions, radial velocity, and metallcity are obtained from observational data of Gaia, LAMOST, GALAH, APOGEE, and…
Probing computational methodologies in predicting mid-infrared spectra for large polycyclic aromatic hydrocarbons
Rigopoulou, D.; García-Bernete, I.; Roche, P. F. +3 more
We extend the prediction of vibrational spectra to large sized polycyclic aromatic hydrocarbon (PAH) molecules comprising up to ~1500 carbon atoms by evaluating the efficiency of several computational chemistry methodologies. We employ classical mechanics methods (Amber and Gaff) with improved atomic point charges, semi-empirical (PM3, and density…
Constraining density and metallicity of the Milky Way's hot gas halo from O VII spectra and ram-pressure stripping
Martynenko, Nickolay
Milky Way's (MW) hot gaseous halo extends up to the Galactic virial radius (~200 kpc) and contains a significant component of baryon mass of the Galaxy. The halo properties can be constrained from X-ray spectroscopic observations and from satellite galaxies' ram-pressure stripping studies. Results of the former method crucially depend on the gas m…