Issue |
A&A
Volume 687, July 2024
|
|
---|---|---|
Article Number | A313 | |
Number of page(s) | 12 | |
Section | Catalogs and data | |
DOI | https://doi.org/10.1051/0004-6361/202449973 | |
Published online | 26 July 2024 |
The time-variable ultraviolet sky: Active galactic nuclei, stars, and white dwarfs★
1
Deutsches Elektronen-Synchrotron DESY,
Platanenallee 6,
15735
Zeuthen,
Germany
e-mail: rolf.buehler@desy.de
2
Institut für Physik, Humboldt-Universität zu Berlin,
Newtonstrasse 15,
12489
Berlin,
Germany
e-mail: julian.schliwinksi@desy.de
Received:
14
March
2024
Accepted:
12
May
2024
Here, we present the first catalog of Ultraviolet time-VAriable sources (1UVA). We describe a new analysis pipeline called VAriable Source Clustering Analysis (VASCA). We applied this pipeline to 10 yr of data from the Galaxy Evolution Explorer (GALEX) satellite. We analyzed a sky area 302 deg2, and detected 4,202 time-variable ultraviolet (UV) sources. We cross-correlated these sources with multi-frequency data from the Gaia satellite and the Set of Identifications, Measurements and Bibliography for Astronomical Data (SIMBAD) database, finding an association for 3,655 sources. The source sample was dominated by active galactic nuclei (≈73%) and stars (≈24%). We examined the UV and multi-frequency properties of these sources, focusing on the stellar population. We found UV variability for four white dwarfs (WDs). One of them, WD J004917.14–252556.81, was recently found to be the most massive pulsating WD. Its spectral energy distribution shows no sign of a stellar companion. The observed flux variability was unexpected and difficult to explain.
Key words: catalogs / surveys / Hertzsprung-Russell and C-M diagrams / white dwarfs / quasars: general
The catalog is available at the CDS via anonymous ftp to cdsarc.cds.unistra.fr (130.79.128.5) or via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/687/A313
© The Authors 2024
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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