Characterizing EP241107a: multiwavelength observations of an Einstein Probe -detected fast X-ray transient
Year: 2025
Type: article
Abstract: ABSTRACT Fast X-ray transients (FXTs) represent a new class of highly luminous transients in soft X-rays ($\sim$0.3–10 keV) associated with violent astrophysical processes. They manifest as short, singular flashes of X-ray photons with durations lasting from minutes to hours. Their origin remains unclear, and they have been associated with various progenitor mechanisms. The newly launched X-ray survey, Einstein Probe (EP), is revolutionizing this field by enabling the discovery and immediate follow-up of FXTs. Here, we present the multiwavelength observations of EP-discovered FXT EP241107a and the discovery of its radio counterpart. Comparison of the optical and radio observations of EP241107a and its host properties with other extragalactic transients suggests a gamma-ray burst (GRB) origin. Through our afterglow modelling, we infer the GRB jet properties for EP241107a, yielding a jet of the isotropic-equivalent kinetic energy $E_{\mathrm{K,iso}} \sim 10^{51}$ erg, with a half opening angle $\theta _{c}$ $\approx 15^{\circ }$, viewed at an angle of $\theta _{\rm obs}$ $\approx 9^{\circ }$. We also evaluate EP241107a in the landscape of both EP-discovered FXTs as well as the FXTs discovered from Chandra, XMM–Newton, and Swift-X-ray Telescope.
Authors: D Eappachen, A Balasubramanian, Vishwajeet Swain, G C Anupama, D K Sahu, V Bhalerao, T Ahumada, I Andreoni, Sudhanshu Barway, J Carney, J Freeburn, M M Kasliwal, Tanishk Mohan, A C Rodriguez, G Waratkar
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,046
Funders: National Science Foundation, National Aeronautics and Space Administration, W. M. Keck Foundation, California Institute of Technology, Michigan State University, Indian National Science Academy, Tata Institute of Fundamental Research, Indo-US Science and Technology Forum, Ministério da Ciência, Tecnologia e Inovação, Indian Institute of Technology Bombay, College of Engineering, Michigan State University, University of North Carolina at Chapel Hill, Science and Engineering Research Board, Core Research for Evolutional Science and Technology
Award: G5613623313
OpenAlex ID: W4416470740