Search Publications

Serendipitous discovery of the magnetic cataclysmic variable SRGE J075818−612027
DOI: 10.1051/0004-6361/202345966 Bibcode: 2023A&A...672A.188O

Brink, Jaco; Buckley, David A. H.; Schwope, Axel +5 more

We report the discovery of SRGE J075818−612027, a deep stream-eclipsing magnetic cataclysmic variable found serendipitously in SRG/eROSITA calibration and performance verification phase (CalPV) observations of the open cluster NGC 2516 as an unrelated X-ray source. An X-ray timing and spectral analysis of the eROSITA data is presented and suppleme…

2023 Astronomy and Astrophysics
Gaia 2
Confirmation of two magnetic cataclysmic variables as polars: 1RXS J174320.1-042953 and YY Sex
DOI: 10.1093/mnras/stad570 Bibcode: 2023MNRAS.521.2729R

Pandey, J. C.; Potter, Stephen B.; De Becker, Michaël +5 more

We present our analysis of new and archived observations of two candidate magnetic cataclysmic variables, namely 1RXS J174320.1-042953 and YY Sex. 1RXS J174320.1-042953 was observed in two distinctive high and low states where a phase shift was seen, which could be due to changes in the shape, size, and (or) location of the accretion region. We fi…

2023 Monthly Notices of the Royal Astronomical Society
Gaia XMM-Newton 2
Investigations of Flaring Plasma Parameters during an M-class Flare Using the Differential Evolution Method and XSM/Chandrayaan-2 Observations
DOI: 10.3847/2041-8213/ad0f23 Bibcode: 2023ApJ...959L..29K

Awasthi, Arun Kumar; Sylwester, Barbara; Sylwester, Janusz +2 more

We employ the differential evolution (DE) method to analyze observations from the Solar X-Ray Monitor on board the Chandrayaan-2 spacecraft. DE belongs to the family of evolutionary algorithms that find solutions using mechanisms inspired by biological processes. This approach enables us to simultaneously calculate the distribution of the differen…

2023 The Astrophysical Journal
SolarOrbiter 2
Speckle-interferometric Study of Close Visual Binary System HIP 11253 (HD 14874) using Gaia (DR2 and EDR3)
DOI: 10.1088/1674-4527/acc91b Bibcode: 2023RAA....23g5018A

Taani, Ali; Aljboor, Hussam

We present a comprehensive set of physical and geometrical parameters for each of the components of the close visual binary system HIP 11253 (HD 14874). We present an analysis for the binary and multiple stellar systems with the aim to obtain a match between the overall observational spectral energy distribution of the system and the spectral synt…

2023 Research in Astronomy and Astrophysics
Gaia 2
The common fundamental plane of X-ray emissions from pulsars and magnetars in quiescence
DOI: 10.1093/mnras/stad2874 Bibcode: 2023MNRAS.526.1287C

Chang, Hsiang-Kuang; Chu, Che-Yen

Magnetars are a unique class of neutron stars characterized by their incredibly strong magnetic fields. Unlike normal pulsars whose X-ray emission was driven by rotational energy loss, magnetars exhibit distinct X-ray emissions thought to be driven by their strong magnetic fields. Here, we present the results of magnetar X-ray spectra analysis in …

2023 Monthly Notices of the Royal Astronomical Society
XMM-Newton 2
Detecting and Characterizing Young Quasars. III. The Impact of Gravitational Lensing Magnification
DOI: 10.3847/1538-4357/accf20 Bibcode: 2023ApJ...950..105Y

Hennawi, Joseph F.; Belli, Sirio; Tacchella, Sandro +8 more

We test the impact of gravitational lensing on the lifetime estimates of seven high-redshift quasars at redshift z ≳ 6. The targeted quasars are identified by their small observed proximity zone sizes, which indicate extremely short quasar lifetimes (t Q ≲ 105yr). However, these estimates of quasar lifetimes rely on the ass…

2023 The Astrophysical Journal
eHST 2
Magellanic System Stars Identified in SMACS J0723.3-7327 James Webb Space Telescope Early Release Observations Images
DOI: 10.3847/1538-4357/acffb9 Bibcode: 2023ApJ...958..108S

Holwerda, Benne W.; Koekemoer, Anton M.; Pirzkal, Nor +23 more

We identify 71 distant stars in James Webb Space Telescope/NIRCam early release observations (ERO) images of the field of galaxy cluster SMACS J0723.3-7327 (SMACS 0723). Given the relatively small (~10°) angular separation between SMACS 0723 and the Large Magellanic Cloud (LMC), it is likely that these stars are associated with the LMC outskirts o…

2023 The Astrophysical Journal
Gaia eHST JWST 2
The MPI + CUDA Gaia AVU-GSR Parallel Solver Toward Next-generation Exascale Infrastructures
DOI: 10.1088/1538-3873/acdf1e Bibcode: 2023PASP..135g4504C

Bucciarelli, Beatrice; Vecchiato, Alberto; Cesare, Valentina +4 more

We ported to the GPU with CUDA the Astrometric Verification Unit-Global Sphere Reconstruction (AVU-GSR) Parallel Solver developed for the ESA Gaia mission, by optimizing a previous OpenACC porting of this application. The code aims to find, with a [10, 100] µarcsec precision, the astrometric parameters of ~108 stars, the attitude …

2023 Publications of the Astronomical Society of the Pacific
Gaia 2
High-resolution Observations of the Low Atmospheric Response to Small Coronal Heating Events in an Active Region Core
DOI: 10.3847/1538-4357/acf4f1 Bibcode: 2023ApJ...956...85T

Testa, Paola; De Pontieu, Bart; Rouppe van der Voort, Luc +1 more

High-resolution spectral observations of the lower solar atmosphere (chromosphere and transition region) during coronal heating events, in combination with predictions from models of impulsively heated loops, provide powerful diagnostics of the properties of the heating in active region cores. Here, we analyze the first coordinated observations of…

2023 The Astrophysical Journal
IRIS 2
Fundamental properties of red giants from Kepler and Gaia DR3 data: diagnostic potential of the mass-metallicity diagram
DOI: 10.1093/mnras/stac3464 Bibcode: 2023MNRAS.518.5552Y

Yıldız, M.

For solar-like oscillators, the asteroseismic relations connect the stellar mean density and surface gravity to observable properties of the oscillations. Since the space missions CoRoT and Kepler, the asteroseismic relations have been massively employed out of their theoretical domain of validity, that is the main-sequence solar-type stars, in pa…

2023 Monthly Notices of the Royal Astronomical Society
Gaia 2