AI 中文总结
本研究利用大型星系目录绘制本地宇宙恒星质量与SFR天球分布，发现其各向异性随光度距离增大而减弱，且与核心坍缩超新星分布一致，可为未来河外瞬变源巡天提供参考。
AI 中文摘要
在过去几十年中，各类巡天项目已在近邻星系中发现越来越多的瞬变源。与宇宙学距离处的天体物理现象不同，本地宇宙中的瞬变源在天球分布上呈现出显著的各向异性。因此，采用合适的巡天策略对提升本地宇宙瞬变源搜寻的效率至关重要。本研究利用大型星系目录，绘制了不同光度距离阈值及天球网格角分辨率下的恒星质量与恒星形成率（SFR）的天球分布。这些图可进一步用于表征近邻河外瞬变源的各向异性空间分布。对于天球的不同角分辨率，研究发现星系的恒星质量天球分布在主要各向异性结构中与SFR分布相似；随着光度距离阈值增大，天球分布的各向异性结构变得更接近各向同性。研究计算了给定角分辨率下恒星质量与SFR天球分布的角功率谱及涨落，发现角功率谱与涨落随光度距离阈值增大而快速下降。最后，通过将核心坍缩超新星的天球分布与本研究的SFR天球分布进行定性比较，发现二者在多个显著结构中呈现一致模式。恒星质量与SFR的天球分布图可作为未来河外瞬变源搜寻巡天的重要参考。
英文摘要
Over the past few decades, an increasing number of transients in nearby galaxies have been discovered through various survey projects. Unlike astrophysical phenomena at cosmological distances, transients in the local universe exhibit a pronounced anisotropy in their sky distribution. Consequently, adopting an appropriate survey strategy is essential to improve the efficiency of transient searches in the local universe. In this work, we utilized a large galaxy catalog to map the sky distributions of stellar mass and star formation rate (SFR) across different luminosity distance thresholds and angular resolutions of the grid on the celestial sphere. These maps can further serve to characterize the anisotropic spatial distribution of nearby extragalactic transients. For different angular resolutions of the celestial sphere, we find that the sky distributions of stellar mass of galaxies are similar to those of the SFR in the main anisotropic structures. As the luminosity distance threshold increases, the anisotropic structures of the sky distributions become more isotropic. We calculate the angular power spectra and fluctuations of the sky distribution of stellar mass and SFR at a given angular resolution and find that the angular power spectra and fluctuations decrease rapidly as the luminosity distance threshold increases. Finally, by qualitatively comparing the sky distribution of core-collapse supernovae with our SFR sky distribution, we find that the two exhibit consistent patterns in several prominent structures. The mapped sky distributions of stellar mass and SFR can serve as valuable references for future surveys in searching for extragalactic transients.
Comments17 pages, 7 figures and 2 tables. Accepted for publication in ApJ. Related code and sky map data are available on Zenodo: https://doi.org/10.5281/zenodo.20695048
