2018/11/28 by Suvendu Rakshit, Ansu Johnson, C. S. Stalin +4 · 25 citations
Physics and Astronomy · #Active galactic nucleus #Amplitude #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Blazar #Galaxies: Formation, Evolution, Phenomena #Galaxy #Infrared #Luminosity #Luminous infrared galaxy #Physics #Radio Astronomy Observations and Technology #Radio galaxy #astro-ph.GA #astro-ph.HE
paper · pdf · open access · doi:10.1093/mnras/sty3261
published in Monthly Notices of the Royal Astronomical Society 483(2), 2362-2370 (Oxford University Press) · 10 pages; Accepted for publication in MNRAS
arxiv created 2018/11/28 · openalex publication_date 2018/11/29 · openalex created_date 2018/12/11 · arxiv updated 2018/12/12 · openalex updated_date 2026/08/05
We present the colour and flux variability analysis at 3.4 μm (W1 band) and 4.6 μm (W2 band) of 492 narrow-line Seyfert 1 (NLSy1) galaxies using archival data from the Wide-field Infrared Survey Explorer (WISE). In the WISE colour–colour, (W1 − W2) versus (W2 − W3) diagram, |∼ 58 \rm per cent| of the NLSy1 galaxies of our sample lie in the region occupied by the blazar category of active galactic nuclei (AGNs). The mean W1 − W2 colour of candidate variable NLSy1 galaxies is 0.99 ± 0.18 mag. The average amplitude of variability is 0.11 ± 0.07 mag in long term (multiyear) with no difference in variability between W1 and W2 bands. The W1 − W2 colour of NLSy1 galaxies is anticorrelated with the relative strength of [O iii] to Hβ, strongly correlated with continuum luminosity, black hole mass, and Eddington ratio. The long-term amplitude of variability shows weak anticorrelation with the Fe ii strength, continuum luminosity and Eddington ratio. A positive correlation between colour as well as the amplitude of variability with the radio power at 1.4 GHz was found for the radio-detected NLSy1 galaxies. This suggests non-thermal synchrotron contribution to the mid-infrared colour and flux variability in radio-detected NLSy1 galaxies.