Multiband optical variability of 3C 279 on diverse time-scales

Agarwal A., Cellone S. A., Andruchow I., Mammana L., Singh M., Anupama G. C., ...Daha Fazla

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, cilt.488, sa.3, ss.4093-4105, 2019 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 488 Sayı: 3
  • Basım Tarihi: 2019
  • Doi Numarası: 10.1093/mnras/stz1981
  • Dergi Adı: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.4093-4105
  • Anahtar Kelimeler: galaxies: active, BL Lacertae objects: general, BL Lacertae objects: individual: 3C 279, quasars: individual, ACTIVE GALACTIC NUCLEI, NEAR-INFRARED INTRADAY, OBJECT S5 0716+714, BL-LACERTAE, RELATIVISTIC JETS, MICROVARIABILITY OBSERVATIONS, RAPID VARIABILITY, INTERNAL SHOCKS, RADIO-SOURCES, LIGHT CURVES
  • İstanbul Üniversitesi Adresli: Hayır

Özet

We have monitored the flat spectrum radio quasar, 3C 279, in the optical B, V, R, and I passbands from 2018 February to 2018 July for 24 nights, with a total of 716 frames, to study flux, colour, and spectral variability on diverse time-scales. 3C 279 was observed using seven different telescopes: two in India, two in Argentina, two in Bulgaria, and one in Turkey to understand the nature of the source in optical regime. The source was found to be active during the whole monitoring period and displayed significant flux variations in B, V, R, and I passbands. Variability amplitudes on intraday basis varied from 5.20 to 17.9 per cent. A close inspection of variability patterns during our observation cycle reveals simultaneity among optical emissions from all passbands. During the complete monitoring period, progressive increase in the amplitude of variability with frequency was detected for our target. The amplitudes of variability in B, V, R, and I passbands have been estimated to be 177 per cent, 172 per cent, 171 per cent, and 158 per cent, respectively. Using the structure function technique, we found intraday time-scales ranging from similar to 23 min to about 115 min. We also studied colour-magnitude relationship and found indications of mild bluer-when-brighter trend on shorter time-scales. Spectral indices ranged from 2.3 to 3.0 with no clear trend on long-term basis. We have also generated spectral energy distributions for 3C 279 in optical B, V, R, and I passbands for 17 nights. Finally, possible emission mechanisms causing variability in blazars are discussed briefly.