Characterizing EP241107a: multiwavelength observations of an <i>Einstein Probe</i> -detected fast X-ray transient
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. K. Sahu (ORCID: https://orcid.org/0000-0002-6688-0800)
- Sudhanshu Barway (ORCID: https://orcid.org/0000-0002-3927-5402)
- Jonathan Carney (ORCID: https://orcid.org/0000-0001-8544-584X)
- D. Eappachen (ORCID: https://orcid.org/0000-0001-7841-0294)
- V. Bhalerao (ORCID: https://orcid.org/0000-0002-6112-7609)
- Vishwajeet Swain (ORCID: https://orcid.org/0000-0002-7942-8477)
- Antonio C. Rodriguez (ORCID: https://orcid.org/0000-0003-4189-9668)
- James Freeburn (ORCID: https://orcid.org/0009-0006-7990-0547)
- G. Waratkar (ORCID: https://orcid.org/0000-0003-3630-9440)
- G. C. Anupama (ORCID: https://orcid.org/0000-0003-3533-7183)
- Arvind Balasubramanian (ORCID: https://orcid.org/0000-0003-0477-7645)
- Igor Andreoni (ORCID: https://orcid.org/0000-0002-8977-1498)
- Tomás Ahumada (ORCID: https://orcid.org/0000-0002-2184-6430)
- M. M. Kasliwal (ORCID: https://orcid.org/0000-0002-5619-4938)
- T.R. Rama Mohan
Institutions
- University of North Carolina at Chapel Hill (US)
- California Institute of Technology (US)
- Indian Institute of Astrophysics (IN)
- Indian Institute of Technology Bombay (IN)
- Center for Astrophysics Harvard & Smithsonian (US)
Publication Details
- Journal
- Monthly Notices of the Royal Astronomical Society
- Published
- 2025-11-20
- DOI
- https://doi.org/10.1093/mnras/staf2062
- Citations
- 1
- Primary Topic
- Gamma-ray bursts and supernovae
- Type
- article
- Field-Weighted Citation Impact
- 1.15
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