aalto1 untyped-item.component.html
The awakening of the γ-ray narrow-line Seyfert 1 galaxy PKS 1502+036
Loading...
Files
Access rights
openAccess
publishedVersion
URL
Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
This publication is imported from Aalto University research portal.
View publication in the Research portal (opens in new window)
View/Open full text file from the Research portal (opens in new window)
Other link related to publication (opens in new window)
View publication in the Research portal (opens in new window)
View/Open full text file from the Research portal (opens in new window)
Other link related to publication (opens in new window)
Unless otherwise stated, all rights belong to the author. You may download, display and print this publication for Your own personal use. Commercial use is prohibited.
Date
Department
Major/Subject
Mcode
Degree programme
Language
en
Pages
12
Series
Monthly Notices of the Royal Astronomical Society, Volume 463, issue 4, pp. 4469-4480
Abstract
After a long low-activity period, a γ-ray flare from the narrow-line Seyfert 1 PKS 1502+036 (z = 0.4089) was detected by the Large Area Telescope (LAT) on board Fermi in 2015. On 2015 December 20, the source reached a daily peak flux, in the 0.1-300 GeV band, of (93 ± 19) × 10-8 ph cm-2 s-1, attaining a flux of (237 ± 71) × 10-8 ph cm-2 s-1 on 3-h time-scales, which corresponds to an isotropic luminosity of (7.3 ± 2.1) × 1047 erg s-1. The γ-ray flare was not accompanied by significant spectral changes. We report on multiwavelength radio-to-γ-ray observations of PKS 1502+036 during 2008 August-2016 March by Fermi-LAT, Swift, XMM-Newton, Catalina Real-Time Transient Survey and the Owens Valley Radio Observatory (OVRO). An increase in activity was observed on 2015 December 22 by Swift in optical, UV and X-rays. The OVRO 15 GHz light curve reached the highest flux density observed from this source on 2016 January 12, indicating a delay of about three weeks between the γ-ray and 15 GHz emission peaks. This suggests that the γ-ray-emitting region is located beyond the broad-line region. We compared the spectral energy distribution (SED) of an average activity state with that of the flaring state. The two SED, with the high-energy bump modelled as an external Compton component with seed photons from a dust torus, could be fitted by changing the electron distribution parameters as well as the magnetic field. The fit of the disc emission during the average state constrains the black hole mass to values lower than 108 M⊙. The SED, high-energy emission mechanisms and γ-ray properties of the source resemble those of a flat spectrum radio quasar.
Description
Other note
Citation
D'Ammando, F, Orienti, M, Finke, J, Hovatta, T, Giroletti, M, Max-Moerbeck, W, Pearson, T J, Readhead, A C S, Reeves, R A & Richards, J L 2016, 'The awakening of the γ-ray narrow-line Seyfert 1 galaxy PKS 1502+036', Monthly Notices of the Royal Astronomical Society, vol. 463, no. 4, pp. 4469-4480. https://doi.org/10.1093/mnras/stw2325