Portal de Periódicos da CAPES

[ITAL]Chandra[/ITAL] Observations of the X-Ray Narrow-Line Region in NGC 4151

2000; IOP Publishing; Volume: 545; Issue: 2 Linguagem: Inglês

10.1086/317890

1538-4357

Patrick Ogle, Herman L. Marshall, J. C. Lee, C. R. Canizares,

Gamma-ray bursts and supernovae

We present the first high-resolution X-ray spectrum of the Seyfert 1.5 galaxy NGC 4151. Observations with the Chandra High-Energy Transmission Grating Spectrometer reveal a spectrum dominated by narrow emission lines from a spatially resolved (1.6 kpc), highly ionized nebula. The X-ray narrow-line region is composite, consisting of both photoionized and collisionally ionized components. The X-ray emission lines have similar velocities, widths, and spatial extent to the optical emission lines, showing that they arise in the same region. The clouds in the narrow-line region must contain a large range of ionization states in order to explain both the optical and X-ray photoionized emission. Chandra data give the first direct evidence of X-ray line emission from a hot plasma (T ~ 107 K) that may provide pressure confinement for the cooler (T = 3 × 104 K) photoionized clouds.