XRISM/Xtend Transient Search (XTS) detected an outburst from a white dwarf candidate
Links to Files
Permanent Link
Author/Creator
Author/Creator ORCID
Date
Department
Program
Citation of Original Publication
Nagashima, N., K. Fukushima, Y. Kanemaru, K. Pottschmidt, et al. “XRISM/Xtend Transient Search (XTS) Detected an Outburst from a White Dwarf Candidate.” The Astronomer’s Telegram, April 14, 2025. https://www.astronomerstelegram.org/?read=17145.
Rights
This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.
Subjects
Abstract
XRISM/Xtend Transient Search (XTS) detected an X-ray outburst from an X-ray source XRISM J1826-3651 on 2025-04-12 TT. The source position is determined to be (R.A., Dec.) = (276.543, -36.849), with a systematic error of ~40 arcsec. A plausible counterpart is a white dwarf candidate Gaia DR3 6728071049507752320, which is located ~16 arcsec apart from the position of XRISM J1826-3651.
The XRISM observation was started at 2025-04-12T18:07:19 TT, where the flux was estimated to be 8 × 10⁻¹⁴ erg s⁻¹ cm⁻² (0.4 – 10.0 keV). The source flux was increased by an order of magnitude (8 × 10⁻¹³ erg s⁻¹ cm⁻²) by 2025-04-12 at ~22:52 TT. The outburst was continuing at the end of the observation, 2025-04-13T02:55:13 TT. Corresponding luminosities were 3 × D₁.₇ ₖₚ꜀² × 10³¹ erg s⁻¹ and 3 × D₁.₇ ₖₚ꜀² × 10³² erg s⁻¹, respectively by assuming the distance to XRISM J1826-3651 of D₁.₇ ₖₚ꜀.
We derived the above systematic error for the flux by comparing our derived values for the sources detected with XTS in several observations with those for the corresponding X-ray counterparts. We estimated the systematic error for the source position from the separations between the detected sources with the corresponding counterparts in the same field of view.