北京大学科维理天文与天体物理研究所

Featured Science

First HI snapshot of the Hydra cluster by ASKAP

Clusters of galaxies formed from the largest cosmological structures; they are the destination of galaxies traveling along the cosmic web, and serve as the best testbed for environmental effects that accelerate galaxy evolution. The Hydra cluster is the largest and most mature cluster of galaxies within 200 million light years. In a recent paper led by KIAA professor Jing Wang, the powerful new radio telescope ASKAP was used to map neutral hydrogen (HI) in the Hydra Cluster, revealing how cluster dynamics drives the evolution of infalling satellite galaxies. These discoveries are based on the widest survey of Hydra to date in HI, part of the WALLABY pilot survey with ASKAP.

Hubble Watches How a Giant Planet Grows

Hubble Space Telescope gives astronomers a rare look at a Jupiter-sized, still-forming planet that is feeding off material surrounding a young star.

Most Distant Quasar Discovered Sheds Light on How Black Holes Grow

A team of astronomers led by the University of Arizona has observed a luminous quasar 13.03 billion light-years from Earth – the most distant quasar discovered to date. Two KIAA astronomers, Linhua Jiang and Xue-Bing Wu, joined the research team.

New 3D view of the dense interstellar gas in Milky Way

An international research team of more than 50 astronomers (including KIAA faculty Ke Wang) led by the Max Planck Institute for Radio Astronomy in Bonn, Germany, used the APEX submillimeter telescope at 5100 m altitude in Chile to look deep into the galactic plane and measure the interstellar medium.

Spectroscopic confirmation of the most distant galaxy at redshift 10.957

An international team of astronomers, led by Professor Linhua Jiang at KIAA, obtained near-infrared spectra and successfully measured the redshift of a very faint galaxy 13.4 billion light-years away, the most distant astrophysical object known to date. Meanwhile, the team also detected a burst signal with a duration of minutes from the galaxy, which can be explained as an ultraviolet flash associated with a gamma-ray burst (GRB). These results are important to understand the formation of stars and galaxies in the very early Universe). Two papers based on the results were recently published in Nature Astronomy.

Elliptical accretion disk as a model for tidal disruption events: A Jerusalem bagel from ...

When a star passing closely enough by a supermassive black hole is disrupted by tidal forces, the stellar debris falls onto the black hole triggering a tidal disruption event (TDE). It is commonly assumed that the accretion disk that forms circularizes efficiently, because of the relativistic apsidal precession and interactions between the crossing streams of matter. This picture is challenged by observations of the optical/UV spectra and the total bolometric output of the TDEs. If the circularization is inefficient, which is suggested by some numerical simulations, such low angular momentum accretion flow should result in a formation of an elliptical accretion disk. Such a model, with radiation originating from the shocks at the self-intersection of streams and being called self-crossing shock model in the community, was proposed by Tsvi Piran and colleagues.