Search Publications
Discovery of an Extremely r-process-enhanced Thin-disk Star with [Eu/H] = +0.78
Shi, Jianrong; Beers, Timothy C.; Allende Prieto, Carlos +9 more
Highly r-process-enhanced (RPE) stars are rare and usually metal poor ([Fe/H] < ‑1.0), and they mainly populate the Milky Way halo and dwarf galaxies. This study presents the discovery of a relatively bright (V = 12.72), highly RPE (r-II) star ([Eu/Fe] = +1.32, [Ba/Eu] = ‑0.95), LAMOST J020623.21+494127.9. This star was selected from the Large …
Analysis of the Gaia Data Release 3 parallax bias in the Galactic plane
Ding, Ye; Liao, Shilong; Qi, Zhaoxiang +2 more
Context. Systematic errors are inevitable in Gaia published astrometric data. A global recipe has been proposed to correct for the GEDR3 parallax zero-point offset, but this does not take the Galactic plane into consideration. The applicability of their correction model to the Galactic plane remains uncertain. Aims. We attempt to carry out an inde…
A clustering (DBSCAN+GMM) investigation of the young open cluster NGC 6649
Gao, Xinhua
We investigate the spatial structure and dynamical properties of the young (~60 Myr), richly populated open cluster NGC 6649 based on reliable cluster members from Gaia-DR3 data. The density-based spatial clustering of applications with noise is used to estimate membership probabilities for 25045 sample stars in the field of the cluster. More than…
Unveiling the origin of XMM-Newton soft proton flares: I. Design and validation of a response matrix for proton spectral analysis
Cappi, M.; Molendi, S.; Gastaldello, F. +8 more
Context. Low-energy (<300 keV) protons entering the field of view of XMM-Newton can scatter with the X-ray mirror surface and reach the focal plane. They are observed in the form of a sudden increase in the background level, the so-called soft proton flares, affecting up to 40% of the mission observing time. Soft protons can hardly be disentang…
Detection of a new sample of Galactic white dwarfs in the direction of the Small Magellanic Cloud
Arun, R.; Stalin, C. S.; Bhattacharyya, S. +7 more
Aims. In this study, we demonstrate the efficacy of the Ultraviolet Imaging Telescope (UVIT) in identifying and characterizing white dwarfs (WDs) within the Milky Way Galaxy. Methods. Leveraging the UVIT point-source catalogue towards the Small Magellanic Cloud and cross-matching it with Gaia DR3 data, we identified 43 single WDs (37 new detection…
The Missing Symbiotic Stars: A Joint Analysis with Gaia, GALEX, and XMM-Newton Data
Shao, Yong; Li, Xiang-Dong; Xu, Xiao-jie
The existence of a population of low-accretion-rate symbiotic stars (SySts), consisting of a giant star and a compact companion (usually a white dwarf), has been proposed recently. However, their population has not been fully understood. In this work, we present an investigation on SySts candidates consisting of asymptotic giant branch stars (AGBs…
TIC 435850195: The Second Triaxial Tidally Tilted Pulsator
Rappaport, Saul A.; Gagliano, Robert; Jayaraman, Rahul +8 more
The Transiting Exoplanet Survey Satellite (TESS) has enabled the discovery of numerous tidally tilted pulsators (TTPs), which are pulsating stars in close binaries where the presence of a tidal bulge has the effect of tilting the primary star's pulsation axes into the orbital plane. Recently, the modeling framework developed to analyze TTPs has be…
Interstellar Polarization Survey. IV. Characterizing the Magnetic Field Strength and Turbulent Dispersion Using Optical Starlight Polarization in the Diffuse Interstellar Medium
Magalhães, A. M.; Kawabata, Koji S.; Rodrigues, C. V. +5 more
Angular dispersion functions are typically used to estimate the fluctuations in polarization angle around the mean magnetic field orientation in dense regions, such as molecular clouds. The technique provides accurate turbulent-to-regular magnetic field ratios, , which are often underestimated by the classic Davis–Chandrasekhar–Fermi method. We as…
New tools for studying planarity in galaxy satellite systems: Milky Way satellite planes are consistent with ΛCDM
Pichon, C.; Dubois, Y.; Kaviraj, S. +8 more
We introduce a new concept - termed 'planarity' - which aims to quantify planar structure in galaxy satellite systems without recourse to the number or thickness of planes. We use positions and velocities from the Gaia EDR3 to measure planarity in Milky Way (MW) satellites and the extent to which planes within the MW system are kinematically suppo…
Exploring the links between quasar winds and radio emission along the main sequence at high redshift
Marziani, P.; del Olmo, A.; Deconto-Machado, A.
Context. Despite the increasing prevalence of radio-loud (RL) sources at cosmic noon, our understanding of the underlying physics that governs the accretion disc outflows in these particular sources and its dissimilarity with radio-quiet (RQ) quasars remains somewhat limited. Aims. Disentangling the real impact of the radio-loudness and accretion …