发表机构
Center for Cosmology and AstroParticle Physics; Department of Astronomy, The Ohio State University; Institut d’Astrophysique de Paris, CNRS-Sorbonne Université; French-Chilean Laboratory for Astronomy, IRL 3386, CNRS, Instituto de Astrofísica, Pontificia Universidad Católica de Chile（宇宙学与暗物质粒子物理中心; 俄亥俄州立大学天文学系; 巴黎天体物理学研究所，法国国家科学研究中心-索邦大学; 法智利天文学联合实验室，法国国家科学研究中心，智利天主教Pontificia大学天体物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究极贫金属II型超新星SN 2023ufx的光谱与测光，确定其前身星为25-35 M☉的红超巨星，星周环境特殊，环境金属丰度低，为研究大质量恒星演化提供了新样本。
AI 中文摘要
我们呈现了对贫金属（<0.1 Z☉）II型超新星SN 2023ufx及其宿主星系的新观测结果。在爆炸后约一年获取的深星云光谱具有三峰结构的[O I]发射轮廓，这表明爆炸是不对称的。与星云光谱模型的比较显示，其零龄主序质量M_ZAMS约为25-35 M☉，这一结果得到了约0.4的低[Ca II]/[O I]发射线比值的支持。晚期（约2年）测光中不断减弱的宽箱形Hα发射以及光变曲线的变平，表明其在爆炸前数百年至数千年间存在复杂的质量损失历史。对宿主星系的新光学和近红外成像证实，该星系是一个矮星系，恒星质量为10^(6.6±0.1) M☉，恒星形成率（SFR）为10^(-2.5±0.1) M☉/年。SED拟合和星系恒星质量-金属丰度标度关系的结果均得出环境金属丰度估计值为0.02-0.07 Z☉。综合来看，这些观测结果证实SN 2023ufx是一颗极贫金属、严重剥离的红超巨星的爆炸产物。
英文摘要
We present new observations of the metal-poor ($< 0.1$ $\rm Z_\odot$) Type II supernova 2023ufx and its host galaxy. The deep nebular spectrum, obtained roughly a year after explosion, has a triple-peaked [O I] emission profile suggesting an asymmetric explosion. Comparison to nebular spectra models suggests a zero-age main sequence mass of $ M_{\rm ZAMS} \sim 25-35$ $\rm M_\odot$, which is supported by the low [Ca II]/[O I] emission-line ratio of $\approx0.4$. The diminishing, broad, boxy H$α$ emission and flattening of the light curve in the late ($\sim2$ yr) photometry suggest a complex mass-loss history in the centuries to millennia before explosion. New optical and near-infrared imaging of the host galaxy confirms that it is a dwarf, with a stellar mass of $10^{6.6\pm0.1}$ $\rm M_\odot$ and a SFR of $10^{-2.5\pm0.1}$ $\rm M_\odot$/yr. Results from both SED fitting and galaxy stellar mass-metallicity scaling relations all lead to an environmental metallicity estimate of $0.02-0.07$ $\rm Z_\odot$. Taken together, these observations confirm that SN 2023ufx is the explosion of a very metal-poor, heavily stripped red supergiant.
Comments10 pages, 10 figures, 4 tables, to be submitted to OJA
