AI 中文总结
本研究开发光谱分解技术，对1000多个低红移延展类星体的宿主星系分析，发现其多为宁静星系，与致密类星体宿主星系性质不同，补充了相关研究且揭示宿主星系多样性。
AI 中文摘要
以往对低红移类星体宿主星系的研究多聚焦于致密类星体，发现其宿主星系主要为恒星形成星系。本文开展地面光学图像中形态延展类星体的宿主星系研究，选取DESI分类为延展天体、红移0.1<z<1的1000多个1型类星体样本，结合DESI高分辨率光谱与Subaru HSC高质量图像，开发光谱分解技术，将每个类星体迭代分解为活动星系核（AGN）成分及其宿主星系，该技术可有效打破AGN与宿主成分间的简并性，捕获宿主的光谱特征。研究结果显示，多数类星体宿主星系的恒星形成率（SFR）与比恒星形成率较低，属于宁静星系，且许多宿主星系呈现显著的后星暴特征，存在大量老年恒星族群，这些性质与宿主星系为恒星形成星系的致密类星体截然不同。此外，本样本的黑洞质量与恒星质量关系大体符合经典局域关系，该研究补充了此前的工作，表明低红移类星体的宿主星系比以往认为的更多样。
英文摘要
Previous works of low-redshift quasar host galaxies have focused on compact quasars and found that their host galaxies are mainly star-forming galaxies. Here we present a study of host galaxies for quasars with extended morphologies in ground-based optical images. We select a sample of more than 1000 type 1 quasars at redshift $0.1<z<1$ that are classified as extended objects by DESI. Combining high-resolution spectra from DESI and high-quality images from Subaru HSC, we develop a spectrophotometric decomposition technique to iteratively decompose each quasar into an AGN component and its host galaxy. The technique can effectively break the degeneracy between the AGN and host components and capture the host spectral features. Our results show that the host galaxies of most quasars have low star-formation rates (SFRs) and low specific SFRs, indicating that they are quiescent galaxies. Many of them exhibit prominent post-starburst features with the existence of significant old stellar populations. These properties are quite different from the nature of compact quasars with star-forming host galaxies. In addition, the relation between the black hole mass and stellar mass for our sample is broadly consistent with the canonical local relations. This work is complementary to the previous studies and suggests that the host galaxies of low-redshift quasars are more diverse than what was thought.
CommentsPublished in The Astrophysical Journal, 1004, 13 (2026), 20 pages, 20 figures
Journal refThe Astrophysical Journal, 1004, 13 (2026)
