The emission-line knot in the Seyfert 2 galaxy NGC 5347

González Delgado, Rosa M.; Perez, Enrique
Bibliographical reference

Monthly Notices of the Royal Astronomical Society, Volume 280, Issue 1, pp. 53-66.

Advertised on:
5
1996
Number of authors
2
IAC number of authors
1
Citations
14
Refereed citations
13
Description
We report on narrow-band Hα imaging and long-slit spectroscopy at intermediate resolution from [NeV] lambda3425A to [SIII] lambda9532A at PA=25.˚5 through the nucleus of the Seyfert 2 galaxy NGC 5347. The nucleus shows very-high-excitation lines, such as [NeV], HeII, [FeVII] and [FeX]. At 3 arcsec to the north-east there is a high-excitation emission knot which also shows the CaII infrared triplet in absorption, with an equivalent width of 8.2A, indicating the presence of red supergiant stars. We find, however, that the spectrum of this knot has emission-line intensities characteristic of photoionization by a hard AGN-like continuum. This continuum emission seems to be emitted anisotropically by the nucleus. Evidence for the anisotropic radiation field comes from photon deficit arguments, whereby the flux of ionizing photons emitted by the nucleus in the direction of the knot and in the line of sight to the Earth is calculated. The knot is located perpendicular to the stellar bar, and just inside the inner Lindblad resonance.