The ordinary life of the γ-ray emitting narrow-line Seyfert 1 galaxy PKS 1502+036
We report on multifrequency observations of the γ-ray emitting narrow-line Seyfert 1 galaxy PKS 1502+036 performed from radio to γ-rays during 2008 August–2012 November by Fermi-Large Area Telescope (LAT), Swift (X-ray Telescope and Ultraviolet/Optical Telescope), Owens Valley Radio Observatory, Very Long Baseline Array (VLBA) and Very Large Array. No significant variability has been observed in γ-rays, with 0.1–100 GeV flux that ranged between (3–7) × 10^−8 ph cm^−2 s^−1 using 3-month time bins. The photon index of the LAT spectrum (Γ = 2.60 ± 0.06) and the apparent isotropic γ-ray luminosity (L_0.1-100 GeV = 7.8 × 10^45 erg s^−1) over 51 months are typical of a flat spectrum radio quasar. The radio spectral variability and the one-sided structure, in addition to the observed γ-ray luminosity, suggest a relativistic jet with a high Doppler factor. In contrast to SBS 0846+513, the VLBA at 15 GHz did not observe superluminal motion for PKS 1502+036. Despite having the optical characteristics typical of a narrow-line Seyfert 1 galaxy, radio and γ-ray properties of PKS 1502+036 are found to be similar to those of a blazar at the low end of the black hole mass distribution for blazars. This is in agreement with what has been found in the case of the other γ-ray emitting narrow-line Seyfert 1 SBS 0846+513.
Additional Information© 2013 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2013 May 2; Received 2013 April 18; in original form 2013 March 14. First published online: June 3, 2013. The Fermi-LAT Collaboration acknowledges generous ongoing support from a number of agencies and institutes that have supported both the development and the operation of the LAT as well as scientific data analysis. These include the National Aeronautics and Space Administration and the Department of Energy in the United States, the Commissariat à l'Energie Atomique and the Centre National de la Recherche Scientifique/Institut National de Physique Nucléaire et de Physique des Particules in France, the Agenzia Spaziale Italiana and the Istituto Nazionale di Fisica Nucleare in Italy, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), High Energy Accelerator Research Organization (KEK) and Japan Aerospace Exploration Agency (JAXA) in Japan, and the K. A. Wallenberg Foundation, the Swedish Research Council and the Swedish National Space Board in Sweden. Additional support for science analysis during the operations phase is gratefully acknowledged from the Istituto Nazionale di Astrofisica in Italy and the Centre National d'Études Spatiales in France. Part of this work was done with the contribution of the Italian Ministry of Foreign Affairs and Research for the collaboration project between Italy and Japan. We thank the Swift team for making these observations possible, the duty scientists, and science planners. The OVRO 40 m monitoring programme is supported in part by NASA grants NNX08AW31G and NNX11A043G, and NSF grantsAST-0808050 and AST-1109911. The CSS survey is funded by the National Aeronautics and Space Administration under Grant No. NNG05GF22G issued through the Science Mission Directorate Near-Earth Objects Observations Programme. The CRTS survey is supported by the US National Science Foundation under grants AST-0909182. The VLA and VLBA are operated by the National Radio Astronomy Observatory. The NRAO is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. FD, MO, MG acknowledge financial contribution from grant PRIN-INAF-2011. We thank the referee, Dr. Dirk Grupe and F. Schinzel for helpful comments and suggestions.
Published - MNRAS-2013-D'Ammando-952-61.pdf
Published - MNRAS-2013-D=0027Ammando-952-61.pdf
Submitted - 1305.0572v2.pdf