X-ray observations of Type II supernovae (SNe II) probe the physics of supernova (SN) shocks and the mass-loss histories of their progenitor stars. We present multi-epoch, X-ray observations of SN II 2024ggi (D≈7.2Mpc) from Swift-XRT, Chandra and XMM, which cover ∼1−344 days since first light. We analyze these observations using a new open-source Python package called XSNAP, which standardizes a unified command-line interface for instrument-specific reduction and spectral extraction. XSNAP introduces application programming interfaces for per-epoch spectral modeling through PyXspec and emcee Markov chain Monte Carlo fitting. We employ XSNAP to model the multi-epoch X-ray spectra of SN 2024ggi with an absorbed thermal bremsstrahlung model and calculate a steady progenitor mass-loss rate of (6.2±0.2)×10−5M⊙yr−1(vwind=20kms−1), for which the detected X-ray emission traces the final 117 years before explosion. The software is publicly available on GitHub, with a released package on the Python Package Index (PyPI).
@article{arxiv.2511.10744,
title = {XSNAP: An X-ray Supernova Analysis Pipeline with Application to the Type II Supernova 2024ggi},
author = {Ferdinand and W. V. Jacobson-Galán and M. M. Kasliwal and Erez A. Zimmerman},
journal= {arXiv preprint arXiv:2511.10744},
year = {2026}
}
Comments
12 pages, 4 figures, 2 tables, accepted to ApJ. Software code is available at https://xsnap.org or https://pypi.org/p/xsnap/