发表机构
Yunnan Observatories, Chinese Academy of Sciences (CAS); International Centre of Supernovae (ICESUN), Yunnan Key Laboratory of Supernova Research; University of Chinese Academy of Sciences（中国科学院云南天文台; 超新星国际研究中心，云南省超新星研究重点实验室; 中国科学院大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究Ia型超新星标准化光度对宿主星系属性的依赖性，通过比较局部光度加权年龄与全局质量，发现年轻环境中SNe Ia更暗，年龄步长显著，质量步长在考虑年龄后不显著，强调局部年龄校正对下一代宇宙学的必要性。
AI 中文摘要
背景。Ia型超新星（SNe Ia）标准化光度对宿主星系属性的依赖性在宇宙学中构成了重大系统误差。然而，广泛使用的经验质量步长作为间接全局代理，掩盖了与前身环境的直接物理联系，从而限制了SNe Ia光度标准化的精度。目的。我们通过比较局部光度加权年龄（LWA）与全局质量来研究这些依赖性的根本起源，测试质量步长是否是前身年龄的代理。方法。使用SDSS-MaNGA Pipe3D，我们在1 kpc孔径内测量了56颗SNe Ia的局部LWA，并进行联合似然分析以分离局部年龄和质量对哈勃残差的影响。结果。年轻环境中的SNe Ia比年老环境中的明显更暗，标准化后显示出0.163星等（5.2-西格玛）的年龄步长。虽然最初检测到全局和局部质量步长（分别为0.071星等，2.0-西格玛和0.087星等，2.4-西格玛），但在考虑年龄后两者都变得不显著。全局质量步长降至0.028星等（0.9-西格玛），而年龄步长仍为0.156星等（4.9-西格玛）。同样，局部质量步长降至0.012星等（0.3-西格玛），而年龄步长仍为0.157星等（4.4-西格玛）。包括局部LWA年龄步长将哈勃残差色散（wRMS）从0.1550降至0.1376星等。结论。我们的结果提供了强有力的证据，表明恒星质量步长中约50%-60%的方差是由于对前身年龄的环境依赖性。如果忽略与年龄相关的光度演化，可能会在暗能量状态方程参数中引入系统偏差，突出了下一代宇宙学中局部年龄校正的必要性。
英文摘要
Context. The dependence of Type Ia supernova (SN Ia) standardised luminosity on host galaxy properties is a major source of uncertainty in cosmology. As next-generation surveys like LSST and HLTDS reduce statistical uncertainties, cosmological precision will be limited by astrophysical systematics. However, the empirical mass step, an indirect global proxy, may obscure the physical link to the progenitor environment. Aims. We test whether local luminosity-weighted age (LWA), used as a statistical proxy for the age of the stellar population associated with SN Ia progenitors, is more closely related to the physical driver of standardised-luminosity variations than host galaxy mass. Methods. Using SDSS-MaNGA Pipe3D, we extracted local LWA within a 1 kpc aperture for 56 SNe Ia and performed a joint likelihood analysis of local age and mass effects on Hubble residuals. Results. SNe Ia in younger environments are significantly fainter than those in older ones, with a step amplitude of 0.163 mag (5.2 sigma) after standardisation. Global and local mass steps are initially observed (0.071 mag, 2.0 sigma and 0.087 mag, 2.4 sigma), but both become insignificant when age and mass are fitted simultaneously: the global mass step decreases to 0.028 mag (0.9 sigma), while the age step remains robust at 0.156 mag (4.9 sigma). Similarly, the local mass step becomes insignificant (0.012 mag, 0.3 sigma), whereas the age step persists at 0.157 mag (4.4 sigma). The weighted Hubble residual decreases from 0.1550 to 0.1376 mag after introducing the local LWA step. Conclusions. The mass step is substantially reduced when local LWA is included. The inferred dark energy equation of state parameter (w) could be affected by local LWA, highlighting the importance of environmental effects for next-generation SN Ia cosmology.
Comments20 pages,12 figures, 7tables. Accepted by Astronomy & Astrophysics
