Featured Science

KIAA Scientists Discover the Most Luminous Quasar with an Ultramassive Black Hole in the Distant Universe

An international team led by Xue-Bing Wu, the associate director of Kavli Institute for Astronomy and Astrophysics (KIAA) and a professor at Department of Astronomy of Peking University, discovered a new quasar with a central black hole mass of 12 billion solar masses and a luminosity of 430 trillion solar luminosity, at a distance of 12.8 billions light years from the Earth. This is the most luminous quasar ever discovered in the early Universe, powered by the most massive black hole yet known at that time. The discovery of this quasar, named SDSS J0100+2802, marks an important step in understanding how quasars, the most powerful objects in the Universe, have evolved from the earliest epoch, only nine hundred million years after the Big Bang. This discovery was published in the top scientific journal Nature on February 26, 2015.

Star cluster evolution not as simple as thought

Using Hubble Space Telescope observations of a 2 billion-year-old Large Magellanic Cloud star cluster, KIAA PhD student Chengyuan Li and his supervisor, Richard de Grijs, showed that the recent paradigm shift from star clusters as single-age stellar populations to complex populations may need a major reverse correction. Morphological features in the cluster's diagnostic Hertzsprung-Russell diagram that are commonly interpreted as evidence of cluster-internal age spreads may instead be owing to the presence of a population of rapidly rotating stars. These latest results resolve nearly a decade of debate among scientists; the resulting paper is published in the 17 December 2014 issue of the journal Nature.

Longstanding Quasar Puzzle Solved

New KIAA faculty member Yue Shen and KIAA Director Luis Ho have solved a two-decade long mystery in quasar research. Namely, what drives the diverse properties of quasars into a well-defined main sequence, known as "Eigenvector 1" (EV1). Shen and Ho showed conclusively that Eddington ratio (the efficiency of BH accretion) is the main driver of EV1. Their work is published in the September 11 issue of the journal Nature.

A New Strategy to Directly Measure the Acceleration of the Universe

The Canadian Hydrogen Intensity Mapping Experiment (CHIME)In a paper recently published in the July 24 issue of Physical Review Letters, KIAA-CITA Joint Postdoctoral Fellow Hao-Ran Yu and his colleagues investigated the potential of using future radio surveys of dense hydrogen clouds to make a direct measurement of the Universe's acceleration.

The 2014 Kavli Prize in Astrophysics

Kavli Prize in Astrophysics 2014 WinnersThe 2014 Kavli Prize in Astrophysics has been awarded to Alan H. Guth, Massachusetts Institute of Technology, USA, Andrei D. Linde, Stanford University, USA, and Alexei A. Starobinsky, Landau Institute for Theoretical Physics, Russian Academy of Sciences, Russia. They receive the prize "for pioneering the theory of cosmic inflation".