eROSITA All-Sky Survey (First 6 Months) X-Ray (0.2-2.3 keV) Source Catalog

The 5466 sources detected in the less sensitive but harder 2.3-5keV band is the result of the first true imaging survey of the entire sky above 2keV. The sources in the hard catalog (only the strongly associated ones) have been linked to eRASS1HARD in this catalog. The reference paper presents methods to identify and flag potential spurious sources in the catalogs, which were applied for this work, and the authors tested and validated the astrometric accuracy via cross-comparison with other X-ray and multi-wavelength catalogs.

They show that the number counts of X-ray sources in eRASS1 are consistent with those derived over narrower fields by past X-ray surveys of a similar depth, and they explore the number counts variation as a function of the location in the sky. Adopting a uniform all-sky flux limit (at 50% completeness) of F<sub>(0.5-2keV)</sub> > 5 x 10<sup>-14</sup> erg/s/cm<sup>2</sup>, the authors estimate that the eROSITA all-sky survey resolves into individual sources about 20% of the cosmic X-ray background in the 1-2keV range.

The catalogs form part of the first data release (DR1) of the SRG/eROSITA all-sky survey. Beyond the X-ray catalogs, DR1 contains all detected and calibrated event files, source products (light curves and spectra), and all-sky maps. The data files are linked to the table and also accessible from the <a href="/docs/srg/erosita/">HEASARC eROSITA</a> and <a href="erosita.mpe.mpg.de/dr1/">eROSITA-DE ERASS1</a> websites.

The catalog uses the following designation for indicating the bands for the different measurement: <pre> Band Energy range (keV) 0,1 0.2 - 2.3 P1 0.2 - 0.5 P2 0.5 - 1.0 P3 1.0 - 2.0 P4 2.0 - 5.0 P5 5.0 - 8.0 P6 4.0 - 10.0 P7 5.1 - 6.1 P8 6.2 - 7.1 P9 7.2 - 8.2 S 0.5 - 2.0 </pre> This database table was ingested by the HEASARC in June 2024 and is based upon the <a href="cdsarc.cds.unistra.fr/ftp/cats/J/A+A/682/A34">CDS Catalog J/A+A/682/A34</a> file erass1-m.dat.

In some cases, the HEASARC has altered the original field names, as per HEASARC conventions, and provides the original field names in square brackets. This is a service provided by NASA HEASARC .