研究亮点与新闻

  首页/研究/研究亮点与新闻

New insight into Jupiter’s diluted core

Jupiter was smacked head-on by a massive planetary embryo about 4.5 billion years ago in the early solar system, according to a new study published in the journal Nature on August 15, 2019. An international collaboration team including two astronomers from Tsinghua University, Dr. Xiaochen Zheng from Department of Astronomy and Department of Physics and Prof. Doug Lin from Institute for Advanced Study, demonstrate their giant impact scenario can explain Jupiter’s large diluted core inferred from Jupiter’s gravity field measurement by the Juno mission. The study was led by Dr. Shangfei Liu from Sun Yat-Sen University. The paper can be found at https://www.nature.com/articles/s41586-019-1470-2

阅读更多...

Wandering Earth

The 25th “New Worlds, New Horizons” Public Astronomy Lecture took place in the Xijie lecture hall of Tsinghua University on Apr. 17th, 2019. It was delivered by Dr. GOU Lijun from the National Astronomical Observatory, Dr. YU Jun (Steed) from GuoKr.com, and Prof. MAO Shude from the Tsinghua University. It attracted a large amount of audience on site and over one hundred fifty thousand online viewers via the Tencent News live broadcast.

阅读更多...

THCA Annual Report 2018

On 14th of March, 2019, the Tsinghua Center for Astrophysics (THCA) released its Annual Report for the year 2018, which is publicly available at the THCA website.

阅读更多...

Environmental dependence of alpha abundance for nearby galaxies

The alpha-to-iron ratio ([alpha/Fe]) is an important indicator for star formation histories because alpha-elements (such as O, Ne, Mg, Si, Ca, Ti) are mostly produced in core-collapse supernovae, whose progenitors are high-mass stars, while irons (Fe) are mostly produced by Type Ia supernovae, whose progenitors are low-mass compact stars. High-mass stars generally have a very short lifetime (~ 1 Million year), whilst low-mass compact stars almost all have ages larger than 1 Giga year. So a galaxy formed in a single burst or experienced fast quenching will be enhanced in [alpha/Fe] in comparison with a galaxy formed with an extended star formation history.

阅读更多...

PolarLight detects first light events

On December 18, PolarLight, an X-ray polarimeter onboard a CubeSat, was powered on for in-orbit test, and detected the first events triggered by cosmic X-rays and charged particles. This is the first time that the new technique for X-ray polarimetry is demonstrated in space, implying that a new window in X-ray astronomy can be opened in the future.

阅读更多...

X-rays Reveal Supercritically Accreting Compact Objects

Accretion onto compact objects has a critical rate when the radiation balances the gravity. The physics for supercritical accretion is still an unsolved problem. It is suggested that, because of the presence of strong radiation pressure, supercritical accretion will power a massive wind that is optically thick and Eddington-limited. Based on Chandra observations of nearby galaxies, Zhou et al. found a list of very soft X-ray sources, which are argued to be good candidates for compact objects under supercritical accretion. The results will be published in the Astrophysical Journal.

阅读更多...