High-resolution X-ray spectroscopy of the low and high states of the Seyfert 1 galaxy NGC 4051 with Chandra LETGS

Abstract

Methods. We analyse two observations taken with the Low Energy Transmission Grating Spectrometer of Chandra. We investigated the spectral response to a sudden flux decrease by a factor of 5, which occurred during the second observation. Results. We detect a highly ionised absorption component with an outflow velocity of -4670 km/s, one of the highest outflow velocity components observed in a Seyfert 1 galaxy. The spectra contain a relativistic O VIII Ly alpha line, and four absorption components spanning a range in ionisation parameter xi between 0.07 and 3.19. An emission component producing radiative recombination continua of C VI and C V appears during the low state. The black body temperature decreases with the drop in flux observed in the second observation. Conclusions. For all absorber components we exclude that the ionisation parameter linearly responded to the decrease in flux by a factor of 5. The variability of the absorber suggest that at least three out of four detected components are located in the range 0.02-1 pc. ABRIDGED

Accepted by A&A, 14 pages, 9 figures

Cited by in corpus (9)

• Timing the warm absorber in NGC 4051
• The properties of broad absorption line outflows based on a large sample of quasars
• Radiation Pressure Confinement -- III. The origin of the broad ionization distribution in AGN outflows
• Multiwavelength campaign on Mrk 509 XV. A global modeling of the broad emission lines in the Optical, UV and X-ray bands
• Nature of the Warm Absorber Outflow in NGC 4051
• Warm Absorbers in the Radiation-driven Fountain Model of Low-mass Active Galactic Nuclei
• A deep, multi-epoch Chandra HETG study of the ionized outflow from NGC 4051
• Direct observation of the Broad Line Region in X-rays during the low state of NGC4051
• High Resolution X-ray Spectroscopy of the Seyfert 1, Mrk 1040. Revealing the Failed Nuclear Wind with Chandra