Search Publications
Absolute dimensions of solar-type eclipsing binaries. NY Hya: A test for magnetic stellar evolution models
Stahl, O.; Morales, J. C.; Yılmaz, M. +29 more
Context. The binary star NY Hya is a bright, detached, double-lined eclipsing system with an orbital period of just under five days with two components each nearly identical to the Sun and located in the solar neighbourhood.
Aims: The objective of this study is to test and confront various stellar evolution models for solar-type stars based o…
Kinematical and ellipsoidal properties of the inner-halo hot subdwarfs observed in Gaia DR3 and LAMOST DR7
Elsanhoury, W. H.
Studying the kinematics of inner-halo hot subdwarfs with Gaia DR3 and LAMOST DR7. Three sets of program stars were considered including subsections namely sdB and sdO. Estimating their inner kinematics and velocity ellipsoid parameters. Determine the average local Galactic rotational constants (i.e., Oort's constants).
A New Cosmic-Ray Rejection Routine for HST WFC3/UVIS via Label-free Training of deepCR
Williams, Benjamin F.; Zhang, Keming; Durbin, Meredith +1 more
deepCR is a deep-learning-based cosmic-ray (CR) rejection framework originally presented by Zhang & Bloom. The original approach requires a dedicated training set that consists of multiple frames of the same fields, enabling automatic CR labeling through comparison with their median coadds. Here, we present a novel training approach that circu…
Hemispheric analysis of the magnetic flux in regular and irregular solar active regions
Zhukova, A.
Studying the hemispheric distribution of active regions (ARs) with different magnetic morphologies may clarify the features of the dynamo process that is hidden under the photospheric level. The magnetic flux data for 3047 ARs from the CrAO catalogue (https://sun.crao.ru/databases/catalog-mmc-ars), between May 1996 and December 2021 (cycles 23 and…
Following the tidal trail: a history of modeling the Magellanic Stream
Lucchini, Scott
The formation of the Magellanic Stream has puzzled astronomers for decades. In this review, we outline the history of our understanding of the Magellanic System highlighting key observations that have revolutionized thinking of its evolution. We also walk through the major models and theoretical advances that have led to our current paradigm ‑ (1)…
Unveiling the complex circumgalactic medium: a comparative study of merging and non-interacting galaxy groups
Kacprzak, Glenn G.; Barone, Tania M.; Fisher, Deanne B. +5 more
While most galaxies live in group environments where they undergo an accelerated evolution, the characteristics of their circumgalactic medium (CGM) remain uncertain. We present an analysis of the CGM of two galaxy groups in different stages of interaction: (G1) a close pair of galaxies (z = 0.043) separated by 87 kpc that do not show signs of int…
Automatic crater shape retrieval using unsupervised and semi-supervised systems
Tewari, Atal; Jain, Vikrant; Khanna, Nitin
Impact craters are depressions formed due to impacts on the surface of planetary bodies. Recent deep learning-based crater detection methods assume craters as circular-shaped without much attention to extracting craters' shape and morphology. Craters' shape information (i.e., instance segmentation map for craters) can be helpful for many advanced …
Modeling the TESS Light Curve of Ap Si Star MX TrA
Pakhomov, Yury; Potravnov, Ilya; Romanovskaya, Anna +1 more
The TESS light curve of the silicon Ap star MX TrA was modeled using the observational surface distribution of silicon, iron, helium, and chromium obtained previously with the Doppler Imaging technique. The theoretical light curve was calculated using a grid of synthetic fluxes from line-by-line stellar atmosphere models with individual chemical a…
CHARA Near-infrared Imaging of the Yellow Hypergiant Star ρ Cassiopeiae: Convection Cells and Circumstellar Envelope
Gies, Douglas R.; Monnier, John D.; Schaefer, Gail H. +18 more
Massive evolved stars such as red supergiants and hypergiants are potential progenitors of Type II supernovae, and they are known for ejecting substantial amounts of matter, up to half their initial mass, during their final evolutionary phases. The rate and mechanism of this mass loss play a crucial role in determining their ultimate fate and the …
Differencing and Coadding JWST Images with Matched Point-spread Function
Wang, Lifan; Hu, Lei
We present an algorithm to derive difference images for data taken with JWST with matched point-spread functions (PSFs). It is based on the saccadic fast Fourier transform method but with revisions to accommodate the rotations and spatial variations of the PSFs. It allows for spatially varying kernels in B-spline form with separately controlled ph…