Pith. sign in

REVIEW 8 cited by

EP240801a/XRF 240801B: An X-ray Flash Detected by the Einstein Probe and Implications of its Multiband Afterglow

Not yet reviewed by Pith; the record is open.

Re-run · record.json Download PDF Read on arXiv ↗

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv 2503.04306 v1 pith:GFAIUR6H submitted 2025-03-06 astro-ph.HE

Shuai-Qing Jiang , Dong Xu , Agnes P. C. van Hoof , Wei-Hua Lei , Yuan Liu , Hao Zhou , Yong Chen , Shao-Yu Fu
show 84 more authors
Jun Yang Xing Liu Zi-Pei Zhu Alexei V. Filippenko Peter G. Jonker A. S. Pozanenko He Gao Xue-Feng Wu Bing Zhang Gavin P Lamb Massimiliano De Pasquale Shiho Kobayashi Franz Erik Bauer Hui Sun Giovanna Pugliese Jie An Valerio D'Elia Johan P. U. Fynbo WeiKang Zheng Alberto J. C. Tirado Yi-Han Iris Yin Yuan-Chuan Zou Adam T. Deller N. S. Pankov A. A. Volnova A. S. Moskvitin O. I. Spiridonova D. V. Oparin V. Rumyantsev O. A. Burkhonov Sh. A. Egamberdiyev V. Kim M. Krugov A. M. Tatarnikov R. Inasaridze Andrew J. Levan Daniele Bj{o}rn Malesani Maria E. Ravasio Jonathan Quirola-Vásquez Joyce N. D. van Dalen Javi Sánchez-Sierras Daniel Mata Sánchez Stuart P. Littlefair Jennifer A. Chacón Manuel A. P. Torres Ashley A. Chrimes Nikhil Sarin Antonio Martin-Carrillo Vik Dhillon Yi Yang Thomas G. Brink Rebecca L. Davies Sheng Yang Amar Aryan Ting-Wan Chen Albert K. H. Kong Wen-Xiong Li Rui-Zhi Li Jirong Mao Ignacio Pérez-García Emilio J. Fernández-García Moira Andrews Joseph Farah Zhou Fan Estefania Padilla Gonzalez D. Andrew Howell Dieter Hartmann Jing-Wei Hu Páll Jakobsson Cheng-Kui Li Zhi-Xing Ling Curtis McCully Megan Newsome Benjamin Schneider Kaew Samaporn Tinyanont Ning-Chen Sun Giacomo Terreran Qing-Wen Tang Wen-Xin Wang Jing-Jing Xu Wei-Min Yuan Bin-Bin Zhang Hai-Sheng Zhao Juan Zhang
This is my paper · ORCID
classification astro-ph.HE
keywords modelep240801aenergyafterglowtwo-componentx-raysanalysisburst
verification ladder T0 review T1 audit T2 compute T3 formal
0 comments
abstract

We present multiband observations and analysis of EP240801a, a low-energy, extremely soft gamma-ray burst (GRB) discovered on August 1, 2024 by the Einstein Probe (EP) satellite, with a weak contemporaneous signal also detected by Fermi/GBM. Optical spectroscopy of the afterglow, obtained by GTC and Keck, identified the redshift of $z = 1.6734$. EP240801a exhibits a burst duration of 148 s in X-rays and 22.3 s in gamma-rays, with X-rays leading by 80.61 s. Spectral lag analysis indicates the gamma-ray signal arrived 8.3 s earlier than the X-rays. Joint spectral fitting of EP/WXT and Fermi/GBM data yields an isotropic energy $E_{\gamma,\rm{iso}} = (5.57^{+0.54}_{-0.50})\times 10^{51}\,\rm{erg}$, a peak energy $E_{\rm{peak}} = 14.90^{+7.08}_{-4.71}\,\rm{keV}$, a fluence ratio $\rm S(25-50\,\rm{keV})/S(50-100\,\rm{keV}) = 1.67^{+0.74}_{-0.46}$, classifying EP240801a as an X-ray flash (XRF). The host-galaxy continuum spectrum, inferred using Prospector, was used to correct its contribution for the observed outburst optical data. Unusual early $R$-band behavior and EP/FXT observations suggest multiple components in the afterglow. Three models are considered: two-component jet model, forward-reverse shock model and forward-shock model with energy injection. Both three provide reasonable explanations. The two-component jet model and the energy injection model imply a relatively small initial energy and velocity of the jet in the line of sight, while the forward-reverse shock model remains typical. Under the two-component jet model, EP240801a may resemble GRB 221009A (BOAT) if the bright narrow beam is viewed on-axis. Therefore, EP240801a can be interpreted as an off-beam (narrow) jet or an intrinsically weak GRB jet. Our findings provide crucial clues for uncovering the origin of XRFs.

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 8 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. A JWST redshift for the host galaxy of EP250207b of z=3.2: a collapsar origin is viable

    astro-ph.HE 2026-08 conditional novelty 6.0 of 10

    JWST spectroscopy shows a z=3.2 background galaxy at the position of the fast X-ray transient EP250207b, overturning the earlier z=0.082 merger association.

  2. Detectability of Gravitational-wave counterparts of EP-FXTs observed during the O4b LIGO-Virgo-KAGRA Observing Run

    astro-ph.HE 2026-07 conditional novelty 6.0 of 10

    No gravitational-wave counterpart is statistically associated with any of 47 Einstein Probe fast X-ray transients in the O4b run; 90% exclusion distances of ~178 Mpc (BNS) and ~349 Mpc (NSBH) disfavor nearby compact-b...

  3. EP250827b/SN 2025wkm: An X-ray Flash-Supernova Powered by a Central Engine and Circumstellar Interaction

    astro-ph.HE 2025-12 conditional novelty 6.0 of 10

    EP250827b/SN 2025wkm is an X-ray flash supernova at z=0.1194 powered by a long-lived magnetar and disk winds interacting with extended circumstellar medium, without an on-axis relativistic jet.

  4. Multi-Instrument Search for Gamma-Ray Counterpart of X-ray Transients detected by EP/WXT

    astro-ph.HE 2025-06 conditional novelty 6.0 of 10

    A multi-instrument search pipeline called ETJASMIN finds gamma-ray counterparts for 14 of 63 EP/WXT X-ray transients, with improved upper limits for the rest.

  5. Multi-wavelength Constraints on the Transient EP250905a

    astro-ph.HE 2026-07 conditional novelty 5.0 of 10

    EP250905a is best explained as a mildly off-axis structured-jet afterglow at z=2.714, possibly weakly magnified by a foreground galaxy at z=0.374.

  6. Divergence-free unfitted finite element discretisations for the Darcy problem

    math.NA 2026-03 unverdicted novelty 5.0 of 10

    An unfitted H(div)–discontinuous-pressure Darcy scheme with flux and mixed stabilisations is claimed to be cut-robust, locally mass-conserving, and optimally convergent.

  7. Spectral Hardening Reveals Afterglow Emergence in Long-Duration Fast X-ray Transients: A Case Study of GRB 250404A/EP250404a

    astro-ph.HE 2025-05 conditional novelty 5.0 of 10

    The soft-hard-flat spectral evolution in GRB 250404A/EP250404a traces the transition from the fading prompt emission to the external-shock afterglow, with the X-ray prompt phase lasting about 300 s.

  8. Ground Calibration Result of the Wide-field X-ray Telescope (WXT) onboard the Einstein Probe

    astro-ph.IM 2025-05 conditional novelty 4.0 of 10

    Ground calibration of three Einstein Probe WXT flight modules yields a median 4.2 arcmin PSF FWHM and 2-3 cm2 effective area at 1.25 keV, with 120-140 eV energy resolution.

Pith tools