English

Simultaneous EUV and X-ray variability of NGC 4051

Astrophysics 2009-10-31 v1

Abstract

We present a flux variability study of simultaneous RXTE and EUVE observations of the highly variable Seyfert galaxy NGC4051. We find a strong correlation between variability in the EUV and medium energy X-ray bands,indicating that both are sampling the same power-law continuum. The lag between the two bands is less than 20 ks and, depending on model assumptions, may be <1 ks. We examine the consequences of such a small lag in the context of simple Comptonisation models for the production of the power-law continuum. A lag of <1 ks implies that the size of the Comptonising region is less than 20 Schwarzschild radii for a black hole of mass >1E6 solar masses.

Keywords

Cite

@article{arxiv.astro-ph/9912103,
  title  = {Simultaneous EUV and X-ray variability of NGC 4051},
  author = {P. Uttley and I. M. McHardy and I. E. Papadakis and I. Cagnoni and A. Fruscione},
  journal= {arXiv preprint arXiv:astro-ph/9912103},
  year   = {2009}
}

Comments

8 pages, accepted for publication in MNRAS