X-ray time delays in the narrow line Seyfert 1 galaxy PG 1244+026

Alston, W.N.; Done, C.; Vaughan, S.

doi:10.1093/mnras/stu005

X-ray time delays in the narrow line Seyfert 1 galaxy PG 1244+026

Alston, W.N.; Done, C.; Vaughan, S.

Authors

W.N. Alston

Professor Christine Done chris.done@durham.ac.uk
Professor

S. Vaughan

Abstract

We analyse the X-ray time-lags in the narrow line Seyfert 1 (NLS1) galaxy PG 1244+026 (MBH ∼ 107 M⊙, L/LEdd ∼ 1). The time delay between the soft (0.3–0.7 keV) and harder (1.2–4.0 keV) variations shows the well-established switch from hard lags at low frequencies to soft lags at high frequencies. The low-frequency hard lags are qualitatively consistent with the propagation of fluctuations model, with some long-time-scale response of the reflection component. The high-frequency soft lag appears to extend over a wide frequency band, that we divide this into two narrow frequency ranges, and examine the lag as a function of energy for each of these. At high frequencies the soft excess emission is delayed with respect to the harder energy bands, without any corresponding strong, hard X-ray reflection signature. At even higher frequencies a soft lag is seen at the softest energies, as well as tentative evidence for an iron Kα reverberation signal. These results point to the importance of reprocessing as well as reflection in determining the lags in NLS1s.

Citation

Alston, W., Done, C., & Vaughan, S. (2014). X-ray time delays in the narrow line Seyfert 1 galaxy PG 1244+026. Monthly Notices of the Royal Astronomical Society, 439(2), 1548-1555. https://doi.org/10.1093/mnras/stu005

Journal Article Type	Article
Acceptance Date	Jan 1, 2014
Online Publication Date	Feb 7, 2014
Publication Date	Apr 1, 2014
Deposit Date	Mar 16, 2016
Publicly Available Date	Mar 18, 2016
Journal	Monthly Notices of the Royal Astronomical Society
Print ISSN	0035-8711
Electronic ISSN	1365-2966
Publisher	Royal Astronomical Society
Peer Reviewed	Peer Reviewed
Volume	439
Issue	2
Pages	1548-1555
DOI	https://doi.org/10.1093/mnras/stu005
Related Public URLs	http://adsabs.harvard.edu/abs/2014MNRAS.439.1548A

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This article has been accepted for publication in Monthly notices of the Royal Astronomical Society ©: 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.