J/ApJ/672/40 AO 0235+164 outburst in 2006 December (Hagen-Thorn+, 2008)
The outburst of the blazar AO 0235+164 in 2006 December:
Shock-in-Jet interpretation.
Hagen-Thorn T.A., Larionov V.M., Jorstad S.G., Arkharov A.A.,
Hagen-Thorn E.I., Efimova N.V., Larionova L.V., Marscher A.P.
<Astrophys. J., 672, 40-47 (2008)>
=2008ApJ...672...40H 2008ApJ...672...40H
ADC_Keywords: BL Lac objects ; Photometry, UBVRI ; Photometry, infrared ;
Polarization
Keywords: BL Lacertae objects: individual (AO 0235+164) -
galaxies: active - galaxies: jets - polarization
Abstract:
We present the results of polarimetric (R-band) and multicolor
photometric (BVRIJHK) observations of the blazar AO 0235+16 during an
outburst in 2006 December. The data reveal a short timescale of
variability (several hours), which increases from optical to near-IR
wavelengths; even shorter variations are detected in polarization. The
flux density correlates with the degree of polarization, and at the
maximum degree of polarization the electric vector tends to align with
the parsec-scale jet direction. We find that a variable component with
a steady power-law spectral energy distribution and very high optical
polarization (30%-50%) is responsible for the variability. We
interpret these properties of the blazar within a model of a
transverse shock propagating down the jet. In this case a small change
in the viewing angle of the jet, by ~<1°, and a decrease in the
shocked plasma compression by a factor of ∼1.5 are sufficient to
account for the variability.
Description:
Observational data at optical wavelengths (BVRI bands) were obtained
at the 70cm reflector of the Crimean Astrophysical Observatory with
the photometer-polarimeter of the Astronomical Institute at St.
Petersburg State University based on an ST-7 CCD.
Observations at near-IR wavelengths (JHK bands) were carried out at
the 1.1m telescope of the Main (Pulkovo) Astronomical Observatory of
the Russian Academy of Sciences located at Campo Imperatore (Italy)
and equipped with the SWIRCAM camera.
Objects:
-----------------------------------------------------
RA (2000) DE Designation(s)
-----------------------------------------------------
02 38 38.9 +16 36 59 AO 0235+164 = QSO B0235+1624
-----------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 95 62 Optical data
table2.dat 71 55 Near-IR data
table3.dat 32 51 Polarization data in R band
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 F12.4 d JDB ? Julian Date of B band observation
14- 18 F5.2 mag Bmag ? The B band magnitude
20- 23 F4.2 mag e_Bmag ? Uncertainty in Bmag
25- 36 F12.4 d JDV ? Julian Date of V band observation
38- 42 F5.2 mag Vmag ? The V band magnitude
44- 47 F4.2 mag e_Vmag ? Uncertainty in Vmag
49- 60 F12.4 d JDR Julian Date of R band observation
62- 66 F5.2 mag Rmag The R band magnitude
68- 71 F4.2 mag e_Rmag Uncertainty in Rmag
73- 84 F12.4 d JDI ? Julian Date of I band observation
86- 90 F5.2 mag Imag ? The I band magnitude
92- 95 F4.2 mag e_Imag ? Uncertainty in Imag
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 F12.4 d JDJ Julian Date of J band observation
14- 18 F5.2 mag Jmag The J band magnitude
20- 23 F4.2 mag e_Jmag Uncertainty in Jmag
25- 36 F12.4 d JDH Julian Date of H band observation
38- 42 F5.2 mag Hmag The H band magnitude
44- 47 F4.2 mag e_Hmag Uncertainty in Hmag
49- 60 F12.4 d JDK ? Julian Date of K band observation
62- 66 F5.2 mag Kmag ? The K band magnitude
68- 71 F4.2 mag e_Kmag ? Uncertainty in Kmag
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 F12.4 d JD Julian Date
14- 17 F4.1 % pol Degree of polarization
19- 21 F3.1 % e_pol Uncertainty in Pol
23- 27 F5.1 deg theta Polarization position angle
29- 32 F4.1 deg e_theta Uncertainty in Theta
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 05-Apr-2010