Abstract:
We studied the optical variability
(
OV
)
of a large sample of narrow-line Seyfert 1
(
NLSy1
)
and broad-line Seyfert
1
(
BLSy1
)
galaxies with
z
<
0.8 to investigate any differences in their OV properties. Using archival optical
V
-band light curves from the Catalina Real Time Transient Survey that span 5
–
9 years and modeling them using
damped random walk, we estimated the amplitude of variability. We found that NLSy1 galaxies as a class show
lower amplitude of variability than their broad-line counterparts. In the sample of both NLSy1 and BLSy1 galaxies,
radio-loud sources are found to have higher variability amplitude than radio-quiet sources. Considering only
sources that are detected in the X-ray band, NLSy1 galaxies are less optically variable than BLSy1 galaxies. The
amplitude of variability in the sample of both NLSy1 and BLSy1 galaxies is found to be anti-correlated with Fe
II
strength but correlated with the width of the H
β
line. The well-known anti-correlation of variability
–
luminosity and
the variability
–
Eddington ratio is present in our data. Among the radio-loud sample, variability amplitude is found
to be correlated with radio-loudness and radio-power, suggesting that jets also play an important role in the OV in
radio-loud objects, in addition to the Eddington ratio, which is the main driving factor of OV in radio-quiet sources.
