The Most Distant BL Lacertae Object Discovered by NCU’s Astronomy Team

Posted on: 2022-06-08    

Photo by Chen Yi-An

Professor Hwang Chorng-Yuan and Assistant Research Scholar Ekaterina Koptelova at the Graduate Institute of Astronomy discovered a BL Lacertae (BL Lac) object at a redshift of around 6.5. This newly discovered BL Lac object has currently become the most distant one among other BL Lac objects known to the world, setting a new record in the astronomy field. The research outcome was also published in The Astrophysical Journal Letters, bringing new insights into the knowledge of models of active galactic nuclei and the origin and evolution of supermassive black holes.


Dr. Hwang and Dr. Koptelova chose high-redshift quasars as their research objects among a large amount of observational data. In 2020, they discovered this celestial object through spectrum observation and analysis, hoping to realize its redshift. After more than two years of investigation, this research target, originally considered a quasi-stellar object, turned out to be a BL Lacertae object with a redshift of 6.5 identified through the wave and spectrum analysis and the characteristic of rapid change observed by the United Kingdom Infra-Red Telescope (UKIRT). This celestial object was strange to the astronomy field. Dr. Hwang and Dr. Koptelova’s discovery of the BL Lacertae object has shaken the current theories of the formation and evolution of supermassive black holes and galaxies.


Currently, Dr. Hwang and Dr. Koptelova are working closely with some international research teams and are further investigating this BL Lac object with a redshift of 6.5 to find out its difference from other neighboring celestial objects by using very-long-baseline interferometry (VLBI). They expect to search for more distant BL Lac objects and discover more unknown mysteries of the universe.

The solid red star is the most distant object in the constellation Scorpius discovered by this study. Photo by the Institute of Astronomy.

Last updated: 2022-11-24 Posted by: Headlines Visit counts: 20