Investigating powerful jets in radio-loud narrow-line Seyfert 1s
2015 (English)In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 453, no 4, 4037-4050 p.Article in journal (Refereed) Published
We report results on multiband observations from radio to gamma-rays of the two radio-loud narrow-line Seyfert 1 (NLSy1) galaxies PKS 2004-447 and J1548+3511. Both sources show a core-jet structure on parsec scale, while they are unresolved at the arcsecond scale. The high core dominance and the high variability brightness temperature make these NLSy1 galaxies good gamma-ray source candidates. Fermi-Large Area Telescope detected gamma-ray emission only from PKS 2004-447, with a gamma-ray luminosity comparable to that observed in blazars. No gamma-ray emission is observed for J1548+ 3511. Both sources are variable in X-rays. J1548+ 3511 shows a hardening of the spectrum during high activity states, while PKS 2004-447 has no spectral variability. A spectral steepening likely related to the soft excess is hinted below 2 keV for J1548+ 3511, while the X-ray spectra of PKS 2004-447 collected by XMM-Newton in 2012 are described by a single power law without significant soft excess. No additional absorption above the Galactic column density or the presence of an Fe line is detected in the X-ray spectra of both sources.
Place, publisher, year, edition, pages
2015. Vol. 453, no 4, 4037-4050 p.
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:kth:diva-177408DOI: 10.1093/mnras/stv1845ISI: 000363651600050OAI: oai:DiVA.org:kth-177408DiVA: diva2:874560
QC 201511272015-11-272015-11-202015-11-27Bibliographically approved