Intra-night optical variability characteristics of different classes of narrow line Seyfert 1 galaxies

Abstract

In a first systematic effort to characterize the intra-night optical variability (INOV) of different classes of narrow line Seyfert 1 (NLSy1) galaxies, we have carried out observations on a sample of radio-loud (RL) and radio-quiet (RQ) NLSy1 galaxies. The RL-NLSy1 galaxies are further divided into γ-ray loud (GL) and γ-ray quiet (GQ) NLSy1 galaxies. Our sample consists of four sets, each set consisting of a RQ-NLSy1, a GQ-NLSy1 and a GL-NLSy1 galaxy, closely matched in redshift and optical luminosity. Our observations on both RQ and GQ-NLSy1 galaxies consist of a total of 19 nights, whereas the data for GL-NLSy1 galaxies (18 nights) were taken from literature published earlier by us. This enabled us to do a comparison of the duty cycle (DC) of different classes of NLSy1 galaxies. Using power-enhanced F-test, with a variability threshold of 1%, we find DCs of about 55%, 39% and 0% for GL, GQ and RQ-NLSy1 galaxies respectively. The high DC and large amplitude of INOV (24.0 +/- 13.7%) shown by GL-NLSy1 galaxies relative to the other two classes might be due to their inner aligned relativistic jets having large bulk Lorentz factors. The null DC of RQ-NLSy1 galaxies could mean the presence of low power and/or largely misaligned jets in them. However, dividing RL-NLSy1 galaxies into low and high optical polarization sources, we find that sources with large polarization show somewhat higher DCs (69%) and amplitudes (29%) compared to those with low polarization. This points to a possible link between INOV and optical polarization.

11 pages, 9 figures, 5 tables, Accepted for publication in MNRAS

References in corpus (11)

• A Comprehensive Study of 2 000 Narrow Line Seyfert 1 Galaxies from the Sloan Digital Sky Survey: I. The Sample
• Radio-loud Narrow-Line Type 1 Quasars
• The FIRST-2MASS Red Quasar Survey
• RoboPol: The optical polarization of gamma-ray--loud and gamma-ray--quiet blazars
• The Peculiar Radio-Loud Narrow Line Seyfert 1 Galaxy 1H 0323+342
• The first gamma-ray detection of the narrow-line Seyfert 1 FBQS J1644+2619
• On the reliability of microvariability tests in quasars
• Violent Intranight Optical Variability of a Radio-Loud Narrow-Line Seyfert 1 Galaxy: SDSS J094857.3+002225
• Discovery of a pseudobulge galaxy launching powerful relativistic jets
• Looking for blazars in a sample of unidentified high-energy emitting Fermi sources
• Variable optical polarization during high state in gamma-ray loud narrow line Seyfert 1 galaxy 1H 0323+342

Cited by in corpus (12)

• Optical Flux and Spectral Variability of the TeV blazar PG 1553+113
• A comparison of X-ray photon indices among the narrow and broad-line Seyfert 1 galaxies
• Optical Variability of the TeV Blazar 1ES 0806+524 on Diverse Timescales
• Intra-night optical variability of $\gamma -$ray detected narrow-line Seyfert 1 galaxies
• Multi-band Optical Variability of the TeV Blazar PG 1553+113 in 2019
• Multiband Optical Variability of the Blazar 3C 454.3 on Diverse Timescales
• The Variability of the Narrow-line Seyfert 1 Galaxies from the PanSTARRS's View
• Solid Identification of Extragalactic Gamma-Ray Source Using High-Resolution Radio Interferometric Observation
• Multi-band optical variability of the blazar OP 313 in the outburst state during 2024-2025
• Intranight optical monitoring of the rare quasar J0950+5128, the brightest known candidate for transition from radio-quiet to radio-loud state
• Intra-night optical variability study of a non-jetted narrow-line Seyfert 1 galaxy: SDSS J163401.94+480940.1
• Evidence of jet induced optical microvariability in radio-loud Narrow Line Seyfert 1 Galaxies