Simultaneous EUV and X-ray variability of NGC 4051

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.

8 pages, accepted for publication in MNRAS

References in corpus (2)

• Central Masses and Broad-Line Region Sizes of Active Galactic Nuclei: I. Comparing the Photoionization and Reverberation Techniques
• The swansong in context: long-timescale X-ray variability of NGC 4051

Cited by in corpus (20)

• Combined Long and Short Timescale X-ray Variability of NGC4051 with RXTE and XMM-Newton
• X-Ray and Optical Variability in NGC 4051 and the Nature of Narrow-Line Seyfert 1 Galaxies
• High-Resolution X-ray and Ultraviolet Spectroscopy of the Complex Intrinsic Absorption in NGC 4051 with Chandra and HST
• The Origin of the X-ray and Ultraviolet Emission in NGC 7469
• Twelve years of X-ray and optical variability in the Seyfert galaxy NGC 4051
• Complex Optical-X-ray Correlations in the Narrow-Line Seyfert 1 Galaxy NGC 4051
• The Sloan Digital Sky Survey Reverberation Mapping Project: Ensemble Spectroscopic Variability of Quasar Broad Emission Lines
• Temporal characteristics of the X-ray emission of NGC 7469
• A simple test for the existence of two accretion modes in Active Galactic Nuclei
• Multiwavelength spectral and high time resolution observations of SWIFT J1753.5-0127: new activity?
• Complex X-ray spectral behaviour of NGC 4051 in the low flux state
• Catching NGC 4051 in the low state with Chandra
• An Extreme Ultraviolet Explorer Atlas of Seyfert Galaxy Light Curves: Search for Periodicity
• A Jet Model for the Broadband Spectrum of the Seyfert-1 Galaxy NGC 4051
• X-ray variability of AGN and correlations with spectral properties
• Far Ultraviolet Spectroscopic Explorer Spectroscopy of Absorption and Emission Lines from the Narrow-Line Seyfert 1 Galaxy NGC 4051
• Multiwavelength Monitoring of the Dwarf Seyfert 1 Galaxy NGC 4395. II. X-ray and Ultraviolet Continuum Variability
• Detection of X-ray/UV delay in NGC 4051 using AstroSat observations
• The Broad Line Region in NGC 4051: An Inflow Illuminated by a 10^5 K Accretion Disk
• Multiwavelength Monitoring of the Dwarf Seyfert 1 Galaxy NGC 4395. IV. The Variable UV Absorption Lines