北京大学物理学院和科维理天文与天体物理研究所江林华教授和博士生姜丹阳研究团队使用韦布空间望远镜(JWST)观测数据,获得活动星系核(AGN)对宇宙再电离贡献的严格上限,明确排除AGN作为再电离峰值时期主导电离源的可能性,结果表明恒星形成星系提供了宇宙再电离的主要电离光子。研究成果以“AGNs ruled out as the dominant source of cosmic reionization”为题于2025年10月7日在线发表在《自然·天文》(Nature Astronomy)期刊上。
|
类星体是宇宙中最明亮的“灯塔”之一,其能量来自中心超大质量黑洞吞噬气体所释放的巨大能量。尽管它们的亮度极高,可以照亮数百亿光年的距离,但其极端遥远的位置让天文学家一直难以看清黑洞周围最核心区域的细节。如今,天文学家首次在红移 4 的类星体上直接分辨出内部结构——此时宇宙诞生还不到 15 亿年——为研究早期宇宙中黑洞的生长开辟了一扇新的窗口。
|
With excellent sensitivity and spatial and spectral resolutions, the James Webb Space Telescope (JWST) presents an unprecedented opportunity to promote our understanding of the evolutionary processes of galaxies. Taking advantage of a recently available set of JWST observations taken with Medium Resolution Spectrograph (MRS) on the Mid-Infrared Instrument (MIRI), Dr. Lulu Zhang, who got his PhD degree this July from Peking University under the supervision of Prof. Luis C. Ho at the Kavli Institute for Astronomy and Astrophysics at Peking University, ascertained whether and the manner in which AGN feedback influences the circumnuclear star formation of the well-studied nearby luminous infrared galaxy, NGC 7469, which also hosts a powerful type 1 active galactic nucleus (AGN). Their findings appear in The Astrophysical Journal Letters (2023, 953, L9).
|
A new paper entitled “Evolutionary Paths of Active Galactic Nuclei and Their Host Galaxies” published on 17 August 2023 in Nature Astronomy provides critical new insights on the co-evolution of supermassive black holes and their host galaxies. The research, conducted by Dr. Ming-Yang Zhuang, who graduated from Peking University in 2022 and currently affiliated with the University of Illinois Urbana-Champaign, and Prof. Luis C. Ho from the Kavli Institute for Astronomy and Astrophysics at Peking University, derived structural and photometric properties of host galaxies of nearly 11,500 redshift ≤ 0.35 unobscured active galactic nuclei (AGNs) using data from Pan-STARRS1 3PI Steradian Survey to explore the connections between black hole mass and the properties of host galaxies in the nearby Universe. Peking University is the primary affiliation of the paper.
|
A group of Chinese scientists has recently found key evidence for the existence of nanohertz gravitational waves, marking a new era in nanohertz gravitational wave research. The research was based on pulsar timing observations carried out with the Five-hundred-meter Aperture Spherical Telescope (FAST).The research was conducted by the Chinese Pulsar Timing Array (CPTA) collaboration. Researchers (Prof. Kejia Lee, Post-Doc. Siyuan Chen, PhD students Jiangwei Xu, and Zihan Xue) from Department of Astronomy School of physics and Kavli Institute of Astronomy and Astrophysics of Peking University played vital roles in the collaboration. Their findings were published online in the academic journal Research in Astronomy and Astrophysics (RAA).
|
New images from the James Webb Space Telescope (JWST) have revealed, for the first time, starlight from two massive galaxies hosting actively growing black holes – quasars – seen less than a billion years after the Big Bang. The black holes have masses are close to a billion times that of the Sun, and the host galaxy masses are almost one hundred times larger, a ratio similar to what is found in the more recent universe. A powerful combination of the wide-field survey of the Subaru Telescope and the JWST has paved a new path to study the distant universe, reports a new study in Nature.
|