St Andrews Research Repository

St Andrews University Home
View Item 
  •   St Andrews Research Repository
  • University of St Andrews Research
  • University of St Andrews Research
  • University of St Andrews Research
  • View Item
  •   St Andrews Research Repository
  • University of St Andrews Research
  • University of St Andrews Research
  • University of St Andrews Research
  • View Item
  •   St Andrews Research Repository
  • University of St Andrews Research
  • University of St Andrews Research
  • University of St Andrews Research
  • View Item
  • Login
JavaScript is disabled for your browser. Some features of this site may not work without it.

X-ray/UV/optical variability of NGC 4593 with Swift : reprocessing of X-rays by an extended reprocessor

Thumbnail
View/Open
McHardy_2018_X_ray_UV_MNRAS_2881.pdf (1.615Mb)
Date
11/2018
Author
McHardy, I. M.
Connolly, S. D.
Horne , K
Cackett, E. M.
Gelbord, J.
Peterson, B. M.
Pahari, M.
Gehrels, N.
Goad, M.
Lira, P.
Arevalo, P.
Baldi, R. D.
Brandt, N.
Breedt, E.
Chand, H.
Dewangan, G.
Done, C.
Elvis, M.
Emmanoulopoulos, D.
Fausnaugh, M. M.
Kaspi, S.
Kochanek, C. S.
Korista, K.
Papadakis, I. E.
Rao, A. R.
Uttley, P.
Vestergaard, M.
Ward, M. J.
Keywords
Galaxies: active
Galaxies: individual: NGC4593
Galaxies: Seyfert
Ultraviolet: galaxies
X-rays: galaxies
QB Astronomy
QC Physics
3rd-DAS
Metadata
Show full item record
Altmetrics Handle Statistics
Altmetrics DOI Statistics
Abstract
We report the results of intensive X-ray, UV, and optical monitoring of the Seyfert 1 galaxy NGC 4593 with Swift. There is no intrinsic flux-related spectral change in any variable component with small apparent variations being due to contamination by a constant hard (reflection) component in the X-rays and the red host galaxy in the UV/optical. Relative to the shortest wavelength band, UVW2, the lags of the other UV/optical bands mostly agree with the predictions of reprocessing of high energy emission by an accretion disc. The U-band lag is, however, larger than expected, probably because of reprocessed Balmer continuum emission from the distant broad line region (BLR). The UVW2 band is well correlated with the X-rays but lags by ∼6× more than expected if the UVW2 results only from reprocessing of X-rays by the disc. However, if the light curves are filtered to remove variations on time-scales >5 d, the lag approaches the expectation from disc reprocessing. memecho analysis shows that direct X-rays can be the driver of most of the UV/optical variations if the response functions have tails up to 10 d, from BLR reprocessing, together with strong peaks at short lag (<1 d) from disc reprocessing. For the 5 AGN monitored so far, the observed UVW2 to V-band lags are ∼<2 of disc reprocessing expectations and vary little between AGN. However, the X-ray to UVW2 lags greatly exceed disc reprocessing expectations and differ between AGN. The two most absorbed AGN have the largest excesses, so absorption and scattering may affect these lags, but there is no simple relationship between excess and absorption.
Citation
McHardy , I M , Connolly , S D , Horne , K , Cackett , E M , Gelbord , J , Peterson , B M , Pahari , M , Gehrels , N , Goad , M , Lira , P , Arevalo , P , Baldi , R D , Brandt , N , Breedt , E , Chand , H , Dewangan , G , Done , C , Elvis , M , Emmanoulopoulos , D , Fausnaugh , M M , Kaspi , S , Kochanek , C S , Korista , K , Papadakis , I E , Rao , A R , Uttley , P , Vestergaard , M & Ward , M J 2018 , ' X-ray/UV/optical variability of NGC 4593 with Swift : reprocessing of X-rays by an extended reprocessor ' , Monthly Notices of the Royal Astronomical Society , vol. 480 , no. 3 , pp. 2881–2897 . https://doi.org/10.1093/mnras/sty1983
Publication
Monthly Notices of the Royal Astronomical Society
Status
Peer reviewed
DOI
https://doi.org/10.1093/mnras/sty1983
ISSN
0035-8711
Type
Journal article
Rights
© 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. This work has been made available online in accordance with the publisher's policies. This is the final published version of the work, which was originally published at https://doi.org/10.1093/mnras/sty1983
Description
Funding: UK STFC grant ST/M001296/1 (KH).
Collections
  • University of St Andrews Research
URL
http://arxiv.org/abs/1712.04852v1
URI
http://hdl.handle.net/10023/17510

Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.

Related items

Showing items related by title, author, creator and subject.

  • SDSS-IV MaNGA: How the stellar populations of passive central galaxies depend on stellar and halo mass 

    Oyarzún, Grecco A.; Bundy, Kevin; Westfall, Kyle B.; Tinker, Jeremy L.; Belfiore, Francesco; Argudo-Fernández, Maria; Zheng, Zheng; Conroy, Charlie; Masters, Karen L.; Wake, David; Law, David R.; McDermid, Richard M.; Aragón-Salamanca, Alfonso; Parikh, Taniya; Yan, Renbin; Bershady, Matthew; Sánchez, Sebastián F.; Andrews, Brett H.; Fernández-Trincado, José G.; Lane, Richard R.; Bizyaev, D.; Boardman, Nicholas Fraser; Lacerna, Ivan; Brownstein, J. R.; Drory, Niv; Zhang, Kai (2022-07-06) - Journal article
    We analyze spatially resolved and co-added SDSS-IV MaNGA spectra with signal-to-noise ratio ∼100 from 2200 passive central galaxies (z ∼ 0.05) to understand how central galaxy assembly depends on stellar mass (M*) and halo ...
  • Secular-and merger-built bulges in barred galaxies 

    Mendez Abreu, Jairo; Debattista, V. P.; Corsini, E. M.; Aguerri, J. A. L. (2014-12) - Journal article
    Context. Historically, galaxy bulges were thought to be single-component objects at the center of galaxies. However, this picture is now questioned since different bulge types with different formation paths, namely classical ...
  • Galaxy And Mass Assembly (GAMA) : galaxy close pairs, mergers and the future fate of stellar mass 

    Robotham, A. S. G.; Driver, S. P.; Davies, L. J. M.; Hopkins, A. M.; Baldry, I. K.; Agius, N. K.; Bauer, A. E.; Bland-Hawthorn, J.; Brough, S.; Brown, M. J. I.; Cluver, M.; De Propris, R.; Drinkwater, M. J.; Holwerda, B. W.; Kelvin, L. S.; Lara-Lopez, M. A.; Liske, J.; Lopez-Sanchez, A. R.; Loveday, J.; Mahajan, S.; McNaught-Roberts, T.; Moffett, A.; Norberg, P.; Obreschkow, D.; Owers, M. S.; Penny, S. J.; Pimbblet, K.; Prescott, M.; Taylor, E. N.; van Kampen, E.; Wilkins, S. M. (2014-11-11) - Journal article
    We use a highly complete subset of the Galaxy And Mass Assembly II (GAMA-II) redshift sample to fully describe the stellar mass dependence of close pairs and mergers between 10(8) and 10(12)M(circle dot). Using the analytic ...
Advanced Search

Browse

All of RepositoryCommunities & CollectionsBy Issue DateNamesTitlesSubjectsClassificationTypeFunderThis CollectionBy Issue DateNamesTitlesSubjectsClassificationTypeFunder

My Account

Login

Open Access

To find out how you can benefit from open access to research, see our library web pages and Open Access blog. For open access help contact: openaccess@st-andrews.ac.uk.

Accessibility

Read our Accessibility statement.

How to submit research papers

The full text of research papers can be submitted to the repository via Pure, the University's research information system. For help see our guide: How to deposit in Pure.

Electronic thesis deposit

Help with deposit.

Repository help

For repository help contact: Digital-Repository@st-andrews.ac.uk.

Give Feedback

Cookie policy

This site may use cookies. Please see Terms and Conditions.

Usage statistics

COUNTER-compliant statistics on downloads from the repository are available from the IRUS-UK Service. Contact us for information.

© University of St Andrews Library

University of St Andrews is a charity registered in Scotland, No SC013532.

  • Facebook
  • Twitter