Multiwavelength observations of the gamma-ray-emitting narrow-line Seyfert 1 PMN J0948+0022 in 2011
2014 (English)In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 438, no 4, 3521-3534 p.Article in journal (Refereed) Published
We report on radio-to-gamma-ray observations during 2011 May-September of PMN J0948+0022, the first narrow-line Seyfert 1 (NLSy1) galaxy detected in gamma-rays by Fermi-Large Area Telescope. Strong variability was observed in gamma-rays, with two flaring periods peaking on 2011 June 20 and July 28. The variability observed in optical and near-infrared seems to have no counterpart in gamma-rays. This different behaviour could be related to a bending and inhomogeneous jet or a turbulent extreme multicell scenario. The radio spectra showed a variability pattern typical of relativistic jets. The XMM spectrum shows that the emission from the jet dominates above similar to 2 keV, while a soft X-ray excess is evident in the low-energy part of the X-ray spectrum. Models where the soft emission is partly produced by blurred reflection or Comptonization of the thermal disc emission provide good fits to the data. The X-ray spectral slope is similar to that found in radio-quiet NLSy1, suggesting that a standard accretion disc is present, as expected from the high accretion rate. Except for the soft X-ray excess, unusual in jet-dominated active galactic nuclei, PMN J0948+0022, shows all characteristics of the blazar class.
Place, publisher, year, edition, pages
2014. Vol. 438, no 4, 3521-3534 p.
galaxies: active, galaxies: individual: (PMN J0948+0022), galaxies: nuclei, galaxies: Seyfert, gamma-rays: galaxies, gamma-rays: general
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:kth:diva-143983DOI: 10.1093/mnras/stt2464ISI: 000332038000064ScopusID: 2-s2.0-84894344824OAI: oai:DiVA.org:kth-143983DiVA: diva2:710328
QC 201404072014-04-072014-04-042014-04-07Bibliographically approved