Progress of research on AGNs at the Urumqi Observatory  

作　　者：T.P.KRICHBAUM L.FUHRMANN N.MARCHILI 

机构地区：[1]Max-Planck-Institut fur Radioastronomie,Auf dem Hugel 69,53121 Bonn,Germany

出　　处：《Science China(Physics,Mechanics & Astronomy)》2010年第S1期244-246,共3页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Basic Research Program of China (Grant No. 2009CB824800);the National Natural Science Foundation of China (Grant No. 10773019)

摘　　要：We report the progress on Very Long Baseline Interferometry(VLBI) observations of Gigahertz Peaked Spectrum(GPS) radio sources,and single-dish observations of active galactic nuclei(AGNs).The GPS sources are a kind of young AGNs observable in radio.From our VLBI observations at 1.6 and 5 GHz with the European VLBI Network(EVN) including the Urumqi and Shanghai stations,most GPS sources show compact doubles with sizes less than 1 kiloparsec.We have classified the sources into double-lobes,core-jets,and complex structures according to the spectral indices as well as images.We also estimated the values of the jet viewing angle for the symmetric objects.In addition,we are monitoring a few samples of AGNs with the Urumqi 25-meter radio telescope,in order to find flux variability.We detected rapid flux variability in quasar 1156+295,and relatively slow variability in a few of the others.The origin of the rapid variability is discussed.Moreover,we launched a radio-optical monitoring program called Fermi-AGN in 2009.We report the progress on Very Long Baseline Interferometry(VLBI) observations of Gigahertz Peaked Spectrum(GPS) radio sources,and single-dish observations of active galactic nuclei(AGNs).The GPS sources are a kind of young AGNs observable in radio.From our VLBI observations at 1.6 and 5 GHz with the European VLBI Network(EVN) including the Urumqi and Shanghai stations,most GPS sources show compact doubles with sizes less than 1 kiloparsec.We have classified the sources into double-lobes,core-jets,and complex structures according to the spectral indices as well as images.We also estimated the values of the jet viewing angle for the symmetric objects.In addition,we are monitoring a few samples of AGNs with the Urumqi 25-meter radio telescope,in order to find flux variability.We detected rapid flux variability in quasar 1156+295,and relatively slow variability in a few of the others.The origin of the rapid variability is discussed.Moreover,we launched a radio-optical monitoring program called Fermi-AGN in 2009.

关 键 词：active GALACTIC NUCLEI VLBI intra-day variability 

分 类 号：P158[天文地球—天文学]