A comparative analysis of the long-term optical variability characteristics of narrow and broad-line Seyfert 1 galaxies at z > 0.8

@misc{dey2026comparative,
  title = {{A comparative analysis of the long-term optical variability characteristics of narrow and broad-line Seyfert 1 galaxies at z > 0.8}},
  author = {Aratrika Dey and Stalin C. S. and Akshith S. and Suvendu Rakshit},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.15127},
  eprint = {2609.15127},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.15127},
  note = {CC0},
}

TY  - UNPB
TI  - A comparative analysis of the long-term optical variability characteristics of narrow and broad-line Seyfert 1 galaxies at z > 0.8
AU  - Aratrika Dey
AU  - Stalin C. S.
AU  - Akshith S.
AU  - Suvendu Rakshit
PY  - 2026
DA  - 2026/09/14
PB  - arXiv
DO  - 10.48550/arxiv.2609.15127
UR  - https://arxiv.org/abs/2609.15127
AB  - We present the results on a comparative analysis of the long-term optical variability characteristics of high-redshift narrow-line Seyfert 1 (NLSy1) galaxies and broad-line Seyfert 1 (BLSy1) galaxies. Our sample spanning the redshift range of 0.8 < z < 2.6, comprises 2490 NLSy1 and 2490 BLSy1 galaxies matched in the optical brightness−redshift plane. We used V-band data from the Catalina Real-Time Transient Survey covering a baseline of 5−9 years, and g, r, and i-band data from the Zwicky Transient Facility spanning 5 to 6 years. To characterise variability we estimated the amplitude of variability (σ_m). We found that NLSy1 galaxies generally exhibit lower σ_m compared to BLSy1 galaxies. In both the NLSy1 and BLSy1 galaxy samples, we observed a wavelength dependent variability using data from Zwicky Transient Facility, with σ_m gradually increasing towards shorter wavelengths. We found an anti-correlation between σ_m and Eddington ratio in the g, r, and i bands for BLSy1 galaxies, whereas this anti-correlation is observed only in the r and i bands for NLSy1 galaxies. For both NLSy1 and BLSy1 galaxies, we found no correlation between σ_m in g, r, and i bands and black hole mass. In both the samples, we found that ∼90\% of the sources showed a bluer when brighter trend. We found no significant time lag between variations in g and r bands in both BLSy1 and NLSy1 galaxies. The observed long-term trends in the optical light curves of our high redshift sample of BLSy1 and NLSy1 galaxies could be driven by variations in the accretion disk.
ER  -