The highest resolution chandra view of photoionization and jet-cloud interaction in the nuclear region of ngc 4151

Junfeng Wang, G. Fabbiano, M. Karovska, M. Elvis, G. Risaliti, A. Zezas, C. G. Mundell

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

We report high resolution imaging of the nucleus of the Seyfert 1 galaxy NGC 4151 obtained with a 50 ks Chandra High Resolution Camera (HRC) observation. The HRC image resolves the emission on spatial scales of 0.5, ∼30 pc, showing an extended X-ray morphology overall consistent with the narrow-line region (NLR) seen in optical line emission. Removal of the bright point-like nuclear source and image deconvolution techniques both reveal X-ray enhancements that closely match the substructures seen in the Hubble Space Telescope [O III] image and prominent knots in the radio jet. We find that most of the NLR clouds in NGC 4151 have [O III]/soft X-ray ratio ∼10, despite the distance of the clouds from the nucleus. This ratio is consistent with the values observed in NLRs of some Seyfert 2 galaxies, which indicates a uniform ionization parameter even at large radii and a density decreasing as r-2 as expected for a nuclear wind scenario. The [O III]/X-ray ratios at the location of radio knots show an excess of X-ray emission, suggesting shock heating in addition to photoionization. We examine various mechanisms for the X-ray emission and find that, in contrast to jetrelated X-ray emission in more powerful active galactic nucleus, the observed jet parameters in NGC 4151 are inconsistent with synchrotron emission, synchrotron self-Compton, inverse Compton of cosmic microwave background photons or galaxy optical light. Instead, our results favor thermal emission from the interaction between radio outflow and NLR gas clouds as the origin for the X-ray emission associated with the jet. This supports previous claims that frequent jet-interstellar medium interaction may explain why jets in Seyfert galaxies appear small, slow, and thermally dominated, distinct from those kpc-scale jets in the radio galaxies.

Original languageEnglish
Pages (from-to)1195-1203
Number of pages9
JournalAstrophysical Journal
Volume704
Issue number2
DOIs
Publication statusPublished - 30 Sep 2009

Fingerprint

photoionization
high resolution
x rays
interactions
radio
galaxies
synchrotrons
cameras
shock heating
nuclei
Seyfert galaxies
radio galaxies
deconvolution
thermal emission
substructures
Hubble Space Telescope
active galactic nuclei
ionization
outflow
heating

Keywords

  • Galaxies
  • Individual (ngc 4151) - Galaxies
  • Jets - Galaxies
  • Seyfert - X-rays

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

The highest resolution chandra view of photoionization and jet-cloud interaction in the nuclear region of ngc 4151. / Wang, Junfeng; Fabbiano, G.; Karovska, M.; Elvis, M.; Risaliti, G.; Zezas, A.; Mundell, C. G.

In: Astrophysical Journal, Vol. 704, No. 2, 30.09.2009, p. 1195-1203.

Research output: Contribution to journalArticle

Wang, Junfeng ; Fabbiano, G. ; Karovska, M. ; Elvis, M. ; Risaliti, G. ; Zezas, A. ; Mundell, C. G. / The highest resolution chandra view of photoionization and jet-cloud interaction in the nuclear region of ngc 4151. In: Astrophysical Journal. 2009 ; Vol. 704, No. 2. pp. 1195-1203.
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