About
Contact
Help
Sending publications
How to publish
Advanced Search
View Item 
  •   Home
  • Facultad de Ciencias Físicas y Matemáticas
  • Artículos de revistas
  • View Item
  •   Home
  • Facultad de Ciencias Físicas y Matemáticas
  • Artículos de revistas
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

Browse byCommunities and CollectionsDateAuthorsTitlesSubjectsThis CollectionDateAuthorsTitlesSubjects

My Account

Login to my accountRegister
Biblioteca Digital - Universidad de Chile
Revistas Chilenas
Repositorios Latinoamericanos
Tesis LatinoAmericanas
Tesis chilenas
Related linksRegistry of Open Access RepositoriesOpenDOARGoogle scholarCOREBASE
My Account
Login to my accountRegister

Correlated X-ray/ultraviolet/optical variability in the very low mass AGN NGC 4395

Artículo
Thumbnail
Open/Download
IconCameron_DT.pdf (988.8Kb)
Publication date
2012-05
Metadata
Show full item record
Cómo citar
Cameron, D. T.
Cómo citar
Correlated X-ray/ultraviolet/optical variability in the very low mass AGN NGC 4395
.
Copiar
Cerrar

Author
  • Cameron, D. T.;
  • McHardy, I.;
  • Dwelly, T.;
  • Breedt, E.;
  • Uttley, P.;
  • Lira Teillery, Paulina;
  • Arévalo, P.;
Abstract
We report the results of a 1-yr Swift X-ray/ultraviolet (UV)/optical programme monitoring the dwarf Seyfert nucleus in NGC4395 in 2008–2009. The UV/optical flux from the nucleus was found to vary dramatically over the monitoring period, with a similar pattern of variation in each of the observed UV/optical bands (spanning 1900–5500 Å). In particular, the luminosity ofNGC4395 in the 1900Åband changed by more than a factor of 8 over the monitoring period. The fractional variability was smaller in the UV/optical bands than that seen in the X-rays, with the X-ray/optical ratio increasing with increasing flux. Pseudo-instantaneous flux measurements in the X-ray and each UV/optical band were well correlated, with cross-correlation coefficients of ≥0.7, significant at 99.9 per cent confidence. Archival Swift observations from 2006 sample the intra-day X-ray/optical variability on NGC4395. These archival data show a very strong correlation between the X-ray and b bands, with a cross-correlation coefficient of 0.84 (significant at >99 per cent confidence). The peak in the cross-correlation function is marginally resolved and asymmetric, suggesting that X-rays lead the b band, but by ≤1 h. In response to recent (2011 August) very high X-ray flux levels from NGC4395 we triggered Swift target of opportunity observations, which sample the intra-hour X-ray/UV variability. These observations indicate, albeit with large uncertainties, a lag of the 1900 Å band behind the X-ray flux of ∼400 s. The tight correlation between the X-ray and UV/optical lightcurves, together with the constraints we place on the lag time-scale, is consistent with the UV/optical variability of NGC4395 being primarily due to reprocessing of X-ray photons by the accretion disc.
General note
Artículo de publicación ISI
Patrocinador
School of Physics and Astronomy, Southampton University STFC Fondecyt 1110049
Identifier
URI: https://repositorio.uchile.cl/handle/2250/125783
DOI: DOI: 10.1111/j.1365-2966.2012.20677.x
ISSN: 0035-8711
Quote Item
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY Volume: 422 Issue: 1 Pages: 902-912 Published: MAY 2012
Collections
  • Artículos de revistas
xmlui.footer.title
31 participating institutions
More than 73,000 publications
More than 110,000 topics
More than 75,000 authors
Published in the repository
  • How to publish
  • Definitions
  • Copyright
  • Frequent questions
Documents
  • Dating Guide
  • Thesis authorization
  • Document authorization
  • How to prepare a thesis (PDF)
Services
  • Digital library
  • Chilean academic journals portal
  • Latin American Repository Network
  • Latin American theses
  • Chilean theses
Dirección de Servicios de Información y Bibliotecas (SISIB)
Universidad de Chile

© 2020 DSpace
  • Access my account