标题： X射线测量$^{44}$钛在四个超新星遗迹中的情况 显示英文标题

标题： X-ray Measurements of $^{44}$Ti in Four Supernova Remnants

摘要： 我们展示了对来自四个年轻超新星遗迹中钛$^{44}$电子捕获衰变产生的钪 K$_\alpha$X射线荧光的搜索结果。 我们分析了来自Tycho's SNR、Kepler's SNR、Cassiopeia A和SN 1987A的档案XMM-Newton数据。 我们用最多四个组分（热和幂律）对感兴趣区域的X射线谱进行拟合，根据需要拟合谱线，并添加一个高斯函数以测试额外的Sc发射。 虽然所有情况都要求具有适度置信度的线，但它们单独来看都不是明确的检测，并且都与之前对$^{44}$钛质量的伽马射线检测或限制一致。 显示英文摘要

摘要： We present the results of a search for scandium K$_\alpha$ X-ray fluorescence resulting from $^{44}$Ti 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 $^{44}$Ti mass.