1H 0323＋342 is a γ-ray-loud narrow-line Seyfert 1 galaxy（NLS1）. The variability mechanism of γ-ray-loud NLS1 s remains unclear. We have observed 1H 0323＋342 photometrically from 2006 to2010 with a total of 41 ni...1H 0323＋342 is a γ-ray-loud narrow-line Seyfert 1 galaxy（NLS1）. The variability mechanism of γ-ray-loud NLS1 s remains unclear. We have observed 1H 0323＋342 photometrically from 2006 to2010 with a total of 41 nights of observations in order to constrain the variability mechanism. Intraday variabilities（IDVs） are detected on four nights. When considering the nights with time spans 〉 2 hours,the duty cycle is 28.3%. The average variability amplitude is 10.8% for IDVs and possibly variable nights. In the color-magnitude diagram, there are bluer-when-brighter chromatic trends for intraday and long-term timescales, which could be explained by the shock-in-jet model, and also could possibly be due to two distinct components or an accretion disk model.展开更多
Near-Eddington accretion rates onto low-mass black holes are thought to be a prime driver of the multi-wavelength properties of the narrow-line Seyfert 1 （NLS1） population of active galactic nuclei （AGNs）. Orienta...Near-Eddington accretion rates onto low-mass black holes are thought to be a prime driver of the multi-wavelength properties of the narrow-line Seyfert 1 （NLS1） population of active galactic nuclei （AGNs）. Orientation effects have repeatedly been considered as another important factor involved, but detailed studies have been hampered by the lack of measured viewing angles towards this type of AGN. Here we present multi-epoch, 15 GHz VLBA images （MOJAVE program） of the radio-loud and Fermi/LAT- detected NLS 1 galaxy 1H 0323＋342. These are combined with single-dish, multi-frequency radio monitoring of the source＇s variability, obtained with the Effelsberg 100-m and IRAM 30-m telescopes, in the course of the F-GAMMA program. The VLBA images reveal six components with apparent speeds of 1 - 7 c, and one quasi-stationary feature. Combining the obtained apparent jet speed （βapp） and variability Doppler factor （Dvar） estimates together with other methods, we constrain the viewing angle 0 towards 1H 0323＋342 to 0 ≤ 4°-13°. Using literature values of βapp and Dvar, we also deduce a viewing angle of 〈8°-9° towards another radio- and γ-ray-loud NLS1, namely SBS 0846＋513.展开更多
基金provided by the National Key Program for Science and Technology Research and Development (Grant 2016YFA0400701)the Key Research Program of the CAS (Grant No. KJZD-EW-M06)+3 种基金the National Natural Science Foundation of China (NSFC, Grant Nos. 11133006, 11433004 and 11303085)the Western Light Youth Projectsupport from Chinese Western Young Scholars Program‘Light of West China’ Program provided by CAS
文摘1H 0323＋342 is a γ-ray-loud narrow-line Seyfert 1 galaxy（NLS1）. The variability mechanism of γ-ray-loud NLS1 s remains unclear. We have observed 1H 0323＋342 photometrically from 2006 to2010 with a total of 41 nights of observations in order to constrain the variability mechanism. Intraday variabilities（IDVs） are detected on four nights. When considering the nights with time spans 〉 2 hours,the duty cycle is 28.3%. The average variability amplitude is 10.8% for IDVs and possibly variable nights. In the color-magnitude diagram, there are bluer-when-brighter chromatic trends for intraday and long-term timescales, which could be explained by the shock-in-jet model, and also could possibly be due to two distinct components or an accretion disk model.
基金a stipend from the International Max Planck Research School (IMPRS) for Astronomy and Astrophysics at the Universities of Bonn and Colognesupported by the Deutsche Forschungsgemeinschaft grant WI 1860/10-1+1 种基金partial support by the the Spanish MINECO project AYA2012-38491-C02-01by the Generalitat Valenciana project PROMETEOII/2014/057
文摘Near-Eddington accretion rates onto low-mass black holes are thought to be a prime driver of the multi-wavelength properties of the narrow-line Seyfert 1 （NLS1） population of active galactic nuclei （AGNs）. Orientation effects have repeatedly been considered as another important factor involved, but detailed studies have been hampered by the lack of measured viewing angles towards this type of AGN. Here we present multi-epoch, 15 GHz VLBA images （MOJAVE program） of the radio-loud and Fermi/LAT- detected NLS 1 galaxy 1H 0323＋342. These are combined with single-dish, multi-frequency radio monitoring of the source＇s variability, obtained with the Effelsberg 100-m and IRAM 30-m telescopes, in the course of the F-GAMMA program. The VLBA images reveal six components with apparent speeds of 1 - 7 c, and one quasi-stationary feature. Combining the obtained apparent jet speed （βapp） and variability Doppler factor （Dvar） estimates together with other methods, we constrain the viewing angle 0 towards 1H 0323＋342 to 0 ≤ 4°-13°. Using literature values of βapp and Dvar, we also deduce a viewing angle of 〈8°-9° towards another radio- and γ-ray-loud NLS1, namely SBS 0846＋513.
