We analyze the radio spectral index of blazars from the University of Michigan Radio Astronomy Observatory database,and find that there exists quasiperiodic activity in 2251＋158.The long-term periodicity analysis is ...We analyze the radio spectral index of blazars from the University of Michigan Radio Astronomy Observatory database,and find that there exists quasiperiodic activity in 2251＋158.The long-term periodicity analysis is accomplished by three methods,which are the Jurkevich method（Jurkevich）,the discrete correlation function（DCF）,and the Periodogram method（P）.The results show that 2251＋158 has two strong periodicities,which are P1=6.3±1.1 yr and P2=3.8±1.2 yr.展开更多
We report results of our optical photometric observations of ten gamma-ray loud blazers, namely: 0219+428 (3C66A), PKS 0420-014 (OA 129), S5 0716+714, 0754+100 (OI 090.4), 0827+243 (OJ248), 1652+398 (Mrk 501), 2200+42...We report results of our optical photometric observations of ten gamma-ray loud blazers, namely: 0219+428 (3C66A), PKS 0420-014 (OA 129), S5 0716+714, 0754+100 (OI 090.4), 0827+243 (OJ248), 1652+398 (Mrk 501), 2200+420 (BL Lacertae), 2230+114 (CTA 102), 2251+158 (3C 454.3) and 2344+514. The observations were carried out in September-October, 2000 using the 70 cm optical telescope at Abstumani Observatory, Georgia. We found intra-day variations in 0420-014, S5 0716+714, BL Lacertae and CTA 102. A variation of 0.3 magnitude over a time scale of about 3 hours was observed in the R passband in BL Lacertae on JD 2451827. We did not detect any variation in 3C 66A, Mrk 501, or 3C 454.3 during our observations. Nor did we detect any clear evidence of variation in 1ES 2344+514 during our two weeks' observing run of the TeV gamma-ray source.展开更多
基金supported by the National Natural Science Foundation of China (Grant No.10633010)the University of Michigan Radio Astronomy Observatory,which has been supported by the University of Michigan and the Nationa Science Foundation
文摘We analyze the radio spectral index of blazars from the University of Michigan Radio Astronomy Observatory database,and find that there exists quasiperiodic activity in 2251＋158.The long-term periodicity analysis is accomplished by three methods,which are the Jurkevich method（Jurkevich）,the discrete correlation function（DCF）,and the Periodogram method（P）.The results show that 2251＋158 has two strong periodicities,which are P1=6.3±1.1 yr and P2=3.8±1.2 yr.
基金Supported by the National Natural Science Foundation of China
文摘We report results of our optical photometric observations of ten gamma-ray loud blazers, namely: 0219+428 (3C66A), PKS 0420-014 (OA 129), S5 0716+714, 0754+100 (OI 090.4), 0827+243 (OJ248), 1652+398 (Mrk 501), 2200+420 (BL Lacertae), 2230+114 (CTA 102), 2251+158 (3C 454.3) and 2344+514. The observations were carried out in September-October, 2000 using the 70 cm optical telescope at Abstumani Observatory, Georgia. We found intra-day variations in 0420-014, S5 0716+714, BL Lacertae and CTA 102. A variation of 0.3 magnitude over a time scale of about 3 hours was observed in the R passband in BL Lacertae on JD 2451827. We did not detect any variation in 3C 66A, Mrk 501, or 3C 454.3 during our observations. Nor did we detect any clear evidence of variation in 1ES 2344+514 during our two weeks' observing run of the TeV gamma-ray source.
