EP J115415.8-501810: eROSITA constraints on onset of X-ray-bright phase
ATel #16553; Arne Rau (MPE), Axel Schwope (AIP)
on 22 Mar 2024; 14:19 UT
Credential Certification: Arne Rau (arau@mpe.mpg.de)
Subjects: X-ray, Cataclysmic Variable
The location of the highly variable X-ray source and CV candidate EP J115415.8-501810 (Ling et al., ATel#16546; Rodriguez & Kulkarni, ATel#16549) was observed with eROSITA (Predehl et al. 2021) onboard SRG (Sunyaev et al. 2021) during four all-sky surveys between January 2020 and November 2021).
As reported in Ling et al. (ATel#16546) and included in the Supplement Catalogue accompanying the eROSITA DR1 data release (Merloni et al. 2024), the source was faint in the first all-sky survey. Subsequently, it was found to have brightened by a factor of 50-100 to a flux comparable with the Swift observation in July 2021 and the XMM observations in January 2022.
#MJD_mid Flux(0.2-2.3keV)
58855.0 2.9(+/-1.4)E-14 erg/cm^2/s
59037.4 1.6(+/-0.1)E-12 erg/cm^2/s
59219.9 1.2(+/-0.1)E-12 erg/cm^2/s
59407.1 3.3(+/-0.1)E-12 erg/cm^2/s
Considering the non-detection of the source in Swift and XMM observations between 2009 and 2011, eROSITA constraints the onset of the X-ray bright phase of EP J115415.8-501810 to be sometime between MJD 58855 (2020 Jan 7) and MJD 59037 (2020 Jul 7).
