We present the results of a search for scandium Kα X-ray fluorescence resulting from 44Ti electron capture decay in four young supernova remnants. We analyzed archival XMM-Newton data from Tycho's SNR, Kepler's SNR, Cassiopeia A, and SN 1987A. We fit the X-ray spectra in regions of interest with up to four components, thermal and power-law, as needed to fit the spectrum, and add a gaussian to test for extra Sc emission. While all require the line with modest confidence, none represent definitive detections on their own, and all are consistent with previous gamma-ray detections or limits on the 44Ti mass.
@article{arxiv.2507.11647,
title = {X-ray Measurements of $^{44}$Ti in Four Supernova Remnants},
author = {Tyler E. Hanover and Mark D. Leising},
journal= {arXiv preprint arXiv:2507.11647},
year = {2025}
}