J/A+A/703/A259 Multiband optical variability of blazar Ton 599 (Vince+, 2025)
Multiband optical variability on diverse timescales of the blazar Ton 599
during 2011-2023.
Vince O., Raiteri C.M., Villata M., Gupta A.C., Kovacevic-Dojcinovic J.,
Lakicevic M., Popovic L.C., Kushwaha P., Mirzaqulov D.O., Ehgamberdiev S.A.,
Carosati D., Jorstad S.G., Marscher A.P., Weaver Z.R., Webb J.R.,
Smith P.S., Chen W., Tsai A., Lin H., Borman G.A., Grishina T.S.,
Hagen-Thorn V.A., Kopatskaya E.N., Larionova E.G., Larionov V.M.,
Larionova L.V., Morozova D.A., Savchenko S., Troitskiy I.S.,
Troitskaya Y.V., Vasilyev A., Zhovtan A.V., Shishkina E.V., Kurtanidze O.M.,
Nikolashvili M.G., Kurtanidze S.O., Ivanidze R., Acosta-Pulido J.A.,
Carnerero M.I., Damljanovic G., Stojanovic M., Jovanovic M.D., Vlasyuk V.,
Spiridonova O.I., Moskvitin A.S., Pursimo T., Elsasser D., Feige M.,
Kunkel L., Ledermann J., Reinhart D., Scherbantin A., Schoch K.,
Steineke R., Lorey C., Agudo I., Escudero Pedrosa J., Aceituno F.J.,
Bonnoli G., Casanova V., Morcuende D., Sota A., Bozhilov V., Valcheva A.,
Zaharieva E., Minev M., Strigachev A., Bachev R., Mihov B.,
Slavcheva-Mihova L., Sadun A.C., Takey A., Shokry A., El-Sadek M.A.,
Marchini A., Verna G.
<Astron. Astrophys. 703, A259 (2025)>
=2025A&A...703A.259V 2025A&A...703A.259V (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Photometry ; Optical
Keywords: galaxies: active - quasars: individual: Ton 599
Abstract:
We analyze the optical variability of the flat-spectrum radio quasar
(FSRQ) Ton 599 using BVRI photometry from the WEBT Collaboration
(2011-2023), complemented by Steward Observatory monitoring. The study
characterizes flux distributions, intranight changes, color evolution,
and spectra to constrain physical parameters and processes in the
central engine. We test flux distributions against normal and
log-normal models, derive power spectral densities (PSDs), quantify
intranight variability, and estimate emitting region sizes and
magnetic fields from variability timescales. Long-term behavior is
investigated by segmenting the light curves into 12 intervals, and
color evolution is traced through color-magnitude and color-time
diagrams. MgII line properties from low-flux spectra provide a black
hole mass estimate. Ton 599 shows strong optical variability with
log-normal flux distributions, red-noise PSDs, positive rms-flux
relations, intranight variability, and a redder-when-brighter to
bluer-when-brighter evolution depending on flux state. The peak R-band
flux reaches 23.5mJy (logνLν=48.48[erg/s]). The estimated black
hole mass is of order 108M☉, consistent with previous studies.
Description:
We present multiband (B, V, R, I) optical photometry of the
flat-spectrum radio quasar Ton 599 obtained during 2011-2023 as part
of the WEBT campaign. The tables contain observed magnitudes (not
corrected for Galactic extinction), together with Julian Date,
measurement error, and observatory code. These data underlie the light
curves shown in the paper.
Objects:
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RA (2000) DE Designation(s)
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11 59 31.83 +29 14 43.8 Ton 599 = QSO J1159+2915
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
phot.dat 53 12054 Ton 599 BRVI photometry
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Byte-by-byte Description of file: phot.dat
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Bytes Format Units Label Explanations
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1 A1 --- Band [BVRI] Band
3- 15 F13.5 d JD Julian Date
17- 22 F6.3 mag mag Magnitude in Band (1)
24- 28 F5.3 mag e_mag Error in magnitude in Band
30- 53 A24 --- Observ Observatory code (2)
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Note (1): Magnitudes are given as observed values (not corrected for Galactic
extinction).
For scientific use, Galactic extinction corrections (e.g. Schlafly &
Finkbeiner, 2011ApJ...737..103S 2011ApJ...737..103S) may be applied if required.
Flux densities used in the analysis were derived from extinction-corrected
magnitudes using standard zero-points, but are not tabulated here.
Note (2): Observatories are identified by short codes (e.g., St.Petersburg,
Lulin(SLT), Teide(IAC80), etc.). Full names and telescope details are
provided in the paper (Appendix, Table of observatories).
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Acknowledgements:
From Oliver Vince, ovince(at)aob.rs
The WEBT collaboration and all participating observatories are
acknowledged.
(End) Patricia Vannier [CDS] 13-Sep-2025