J/A+A/618/A92 Radio-loud NLSy1 galaxies optical polarisation (Angelakis+, 2018)
Optical polarisation variability of radio-loud narrow-line Seyfert 1 galaxies.
Search for long rotations of the polarisation plane.
Angelakis E., Kiehlmann S., Myserlis I., Blinov D., Eggen J., Itoh R.,
Marchili N., Zensus J.A.
<Astron. Astrophys. 618, A92 (2018)>
=2018A&A...618A..92A 2018A&A...618A..92A (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Galaxies, optical ; Polarization
Keywords: galaxies: active - galaxies: Seyfert - polarization -
techniques: polarimetric - methods: numerical - methods: statistical
Abstract:
We quantify the temporal behaviour of the optical polarisation
fraction and angle for a selected sample of radio-loud NLSy1s. We also
search for rotations of the polarisation plane similar to those
commonly observed in blazars. The dataset was obtained with the
RoboPol polarimeter of the Skinakas observatory as well as the KANATA,
Perkins, and Steward observatories. We carried out numerical
simulations to assess the probability that long rotations of the
polarisation plane were caused by intrinsically evolving electric
vector position angles (EVPAs) instead of observational noise. We
conclude that it is much more likely that intrinsic rotations are
responsible for the observed phenomenology.
Description:
Polarisation fraction p and adjusted EVPA as a function of time for
the ten radio-loud narrow-line Seyfert 1 galaxies presented in the
paper. The polarisation fraction and EVPA measurements as well as the
corresponding uncertainties have been corrected for the Rice bias as
shown in Section 3 of the paper. Due to the inherent n-pi ambiguity,
the EVPA measurements have been adjusted to minimize the the
variability between adjacent data points. As discussed in Section 4 of
the paper, we choose the EVPA values for which the difference from the
previous data point is smaller than 90 degrees. The data correspond to
Table 2 and Figures 1, 8 and 14 of the paper, as well as Figure 12
which shows a portion of Figure 8. The data are sorted first with the
source identifier and then with the Julian date of the measurements.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
sources.dat 76 10 List of studied sources
pol.dat 60 203 Optical polarisation data (full table2)
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Byte-by-byte Description of file: sources.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- ID Source identifier
12- 34 A23 --- SurveyID Survey identifier
37- 38 I2 h RAh Right ascension (J2000)
40- 41 I2 min RAm Right ascension (J2000)
43- 48 F6.3 s RAs Right ascension (J2000)
50 A1 --- DE- Declination sign (J2000)
51- 52 I2 deg DEd Declination (J2000)
54- 55 I2 arcmin DEm Declination (J2000)
57- 61 F5.2 arcsec DEs Declination (J2000)
63- 65 I3 --- N Number of available measurements in
pol.dat table
67- 74 F8.6 --- z Redshift
76 I1 --- r_z [1/4] Redshift reference (1)
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Note (1): Redshift references as follows:
1 = Zhou et al. (2007ApJ...658L..13Z 2007ApJ...658L..13Z)
2 = Hewett & Wild (2010, Cat. J/MNRAS/405/2302)
3 = Foschini et al. (2015A&A...575A..13F 2015A&A...575A..13F)
4 = Oh et al. (2015, Cat. J/ApJS/219/1)
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Byte-by-byte Description of file: pol.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- ID Source identifier
12- 22 F11.3 d JD Julian date
25- 29 F5.3 --- p Debiased polarisation fraction
32- 36 F5.3 --- e_p 1-sigma uncertainty on p
40- 44 F5.1 deg EVPA Polarisation angle (EVPA)
47- 51 F5.1 deg e_EVPA 1-sigma uncertainty on EVPA
54- 60 A7 --- Tel Used optopolarimetric instrument (1)
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Note (1): The Telescope identifiers are as follows:
RoboPol = Optical polarization data from the RoboPol instrument of the
Skinakas observatory
Kanata = Optical polarization data from the KANATA instrument of the
Higashi-Hiroshima Observatory
Perkins = Optical polarization data from the PRISM instrument of the
Lowell Observatory
Steward = Optical polarization data from the Steward Observatory
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Acknowledgements:
Emmanouil Angelakis, eangelakis(at)mpifr-bonn.mpg.de,
agele(at)physics.auth.gr
Ioannis Myserlis, imyserlis(at)mpifr-bonn.mpg.de
The RoboPol project is a collaboration between Caltech in the USA, MPIfR
in Germany, the Torun Centre for Astronomy in Poland, the University of
Crete/FORTH in Greece, and IUCAA in India. Data acquired with the Perkins
telescope was funded by the PEGA RPE grant at Georgia State University.
Data from the Steward Observatory spectropolarimetric monitoring project
were used. This program is supported by Fermi Guest Investigator grants
NNX08AW56G, NNX09AU10G, NNX12AO93G, and NNX15AU81G.
(End) Ioannis Myserlis [MPIfR, Germany], Patricia Vannier [CDS] 03-Sep-2018