J/MNRAS/535/2775 Multi-band measurements of AO 0235+164 (Vlasyuk+, 2024)
Multiwavelength variability of the blazar AO 0235+164.
Vlasyuk V.V., Sotnikova Yu.V., Volvach A.E., Mufakharov T.V., Kovalev Yu.A.,
Spiridonova O.I., Khabibullina M.L., Kovalev Y.uYu., Mikhailov A.G.,
Stolyarov V.A., Kudryavtsev D.O., Mingaliev M.G., Razzaque S.,
Semenova T.A., Kudryashova A.K., Bursov N.N., Trushkin S.A., Popkov A.V.,
Erkenov A.K., Rakhimov I.A., Kharinov M.A., Gurwell M.A., Tsybulev P.G.,
Moskvitin A.S., Fatkhullin T.A., Emelianov E.V., Arshinova A.,
Iuzhanina K.V., Andreeva T.S., Volvach L.N., Ghosh A.
<Mon. Not. R. Astron. Soc., 535, 2775-2799 (2024)>
=2024MNRAS.535.2775V 2024MNRAS.535.2775V (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Active gal. nuclei ; Photometry ; Radio continuum ; Optical
Keywords: galaxies: active -
(galaxies:) BL Lacertae objects: individual: AO 0235+164 -
galaxies: jets - radio continuum: galaxies
Abstract:
We present a study of the multiwavelength (MW) variability of the
blazar AO 0235+164 based on the radio-to-gamma-ray data covering a
long time period from 1997 to 2023. The radio data are represented by
the 1-22GHz measurements from the SAO RAS RATAN-600 radio telescope,
the 5 and 8GHz data from the IAA RAS RT-32 telescopes, and the 37GHz
data from the RT-22 telescope of CrAO RAS. The optical measurements in
the R-band were collected with the SAO RAS 1-m Zeiss-1000 and 0.5-m
AS-500/2 telescopes. Additionally, we used the archive data at 230GHz
from the Submillimetre Array and the gamma-ray data in the 0.1-100GeV
band from the Fermi-LAT point source 4FGL-DR2 catalogue. The
variability properties during four epochs containing major flares and
one epoch of relatively low activity were analysed using the
fractional variability indices, discrete correlation functions,
Lomb-Scargle periodograms, and structure functions. A significant
correlation (≥2sigma) between the radio, optical, and gamma-ray bands
is found for all these periods with time delays from 0 to 1.7yr. The
relation between time delay and frequency is described by a linear law
with a negative slope of -10d/GHz. The discovered properties of MW
variability for the low-activity period and for flaring states suggest
that the mechanisms dominating the radio-gamma-ray variations are not
substantially different. The detected quasi-periodic oscillations of
about 6 and 2yr are tentative, as the time span of the observations
includes fewer than four full cycles for the radio and optical data
and only about three cycles for the Fermi-LAT data. These results
should be interpreted with caution, given the limited number of
observed cycles and the influence of red noise. We used cluster
analysis to reliably separate the high and low-activity states and
determined statistical differences in the main properties of AO
0235+164 non- thermal emission. The physical parameters of the radio
jet were obtained using the Hedgehog model applied to the average
radio spectrum of AO 0235+164 in the range 0.1-300GHz. The
effectiveness of replacing electrons with protons in the synchrotron
radio emission of relativistic jets is shown for describing the nature
of blazars and the generation of high-energy neutrinos.
Description:
We present the multi-band (optical and radio) flux density
measurements for the blazar AO 0235+164 obtained at the RATAN-600
radio telescope, 1-m Zeiss-1000 and 0.5-m AS-500/2 optical reflectors
of the Special Astrophysical Observatory of the Russian Academy of
Sciences (SAO RAS), the RT-32 radio telescope of the IAA RAS, and the
RT-22 radio telescope of the CrAO RAS. Tables are numerated as in the
publication.
Objects:
---------------------------------------------------------
RA (2000) DE Designation(s)
---------------------------------------------------------
02 38 38.93 +16 36 59.27 AO 0235+164 = QSO B0235+1624
---------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 86 462 AO 0235+164 radio band flux densities at 1-22GHz
table4.dat 36 370 AO 0235+164 daily radio flux density measurements
at 2 and 5GHz in 2021-2022
table5.dat 26 690 AO 0235+164 radio band flux densities at 37GHz
table6.dat 30 568 AO 0235+164 optical R-band flux densities
--------------------------------------------------------------------------------
See also:
J/A+AS/129/577 : AO 0235+164 BVRI photometry (Takalo+ 1998)
J/ApJ/672/40 : AO 0235+164 outburst in 2006 December (Hagen-Thorn+, 2008)
J/ApJ/837/45 : 2006-2012 Rc-band + 4.8GHz obs. of AO 0235+164 (Fan+, 2017)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 d MJD Observing epoch in modified Julian date
7- 16 A10 "date" Date Observing date in a format YYYY.MM.DD
18- 21 F4.2 Jy S22 ?=- Flux density at 22.3GHz
23- 26 F4.2 Jy e_S22 ?=- Mean error of the flux density at 22.3GHz
28- 31 F4.2 Jy S11 ?=- Flux density at 11.2GHz
33- 36 F4.2 Jy e_S11 ?=- Mean error of the flux density at 11.2GHz
38- 41 F4.2 Jy S8 ?=- Flux density at 8GHz
43- 46 F4.2 Jy e_S8 ?=- Mean error of the flux density at 8GHz
48- 51 F4.2 Jy S5 ?=- Flux density at 4.7GHz
53- 56 F4.2 Jy e_S5 ?=- Mean error of the flux density at 4.7GHz
58- 61 F4.2 Jy S2 ?=- Flux density at 2.3GHz
63- 66 F4.2 Jy e_S2 ?=- Mean error of the flux density at 2.3GHz
68- 71 F4.2 Jy S1 ?=- Flux density at 1.2GHz
73- 76 F4.2 Jy e_S1 ?=- Mean error of the flux density at 1.2GHz
78- 86 A9 --- Tel Observing telescope (RATAN-600 or RT-32)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 d MJD Observing epoch in modified Julian date
7- 16 A10 "date" Date Observing date in a format YYYY.MM.DD
18- 21 F4.2 Jy S5 ?=- Flux density at 5GHz
23- 26 F4.2 Jy e_S5 ?=- Mean error of the flux density at 5GHz
28- 31 F4.2 Jy S2 ?=- Flux density at 2GHz
33- 36 F4.2 Jy e_S2 ?=- Mean error of the flux density at 2GHz
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 d MJD Observing epoch in modified Julian date
7- 16 A10 "date" Date Observing date in a format YYYY.MM.DD
18- 21 F4.2 Jy S37 Flux density at 36.8GHz
23- 26 F4.2 Jy e_S37 Mean error of the flux density at 36.8GHz
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 d MJD Observing epoch in modified Julian date
7- 16 A10 "date" Date Observing date in a format YYYY.MM.DD
18- 20 I3 --- Nobs Number of observations
22- 25 F4.2 mJy SR Flux density at R-band
27- 30 F4.2 mJy e_SR Mean error of the flux density at R-band
--------------------------------------------------------------------------------
Acknowledgements:
Timur Mufakharov, timur.mufakharov(at)gmail.com
(End) Patricia Vannier [CDS] 22-Jan-2025