Galaxies Selected from the SDSS by Forbidden High-Ionization Emission Lines

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Scientific paper

We have defined the largest and most homogenous sample of galaxies with strong forbidden high-ionization emission lines (FHILs). These lines, with ionization potentials $\gtrsim 100$ eV respond to a portion of the spectrum that is often difficult to observe directly, thereby providing constraints on the EUV--soft X-ray continuum. We combine measurements of [Fe VII] 6087, [Fe X] 6374, and [Fe XI] 7892 Å line fluxes and profiles with models of lower-ionization lines (both narrow and broad) and with X-ray data (available for about half of our sample). We demonstrate many correlations, including the close relationship between the highest-ionization lines and soft X-ray flux. We use these data to make numerous inferences about the structure of the FHIL-emitting region and discuss what information these lines may convey about the high-energy continuum. Among our conclusions, we find evidence for a stratified outflow of FHIL-emitting clouds, in which the [Fe X] and [Fe XI] clouds are sufficiently close to the central engine that they can be obscured by the torus and the [Fe VII]-emitting clouds are extended on much larger scales; that the flux of [Fe X] is directly correlated with the 250 eV continuum and the [Fe X]/[Fe VII] and [Fe X]/[O III] flux ratios provide evidence of an X-ray soft excess; and that prominent FHIL emission is much more common amongst narrow-lined Seyfert 1s than amongst other Seyfert types (NLS1s comprise nearly 20\% of our sample). It is clear that the FHILs are sensitive diagnostics of the geometry on scales between the broad and traditional narrow line regions, and also of the ionizing continuum in the soft X-ray band to which they respond most strongly.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Galaxies Selected from the SDSS by Forbidden High-Ionization Emission Lines does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Galaxies Selected from the SDSS by Forbidden High-Ionization Emission Lines, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Galaxies Selected from the SDSS by Forbidden High-Ionization Emission Lines will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1704424

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.