Emission line taxonomy and the nature of AGN-looking galaxies in the SDSS

Details Emission line taxonomy and the nature of AGN-looking galaxies in the SDSS Emission line taxonomy and the nature of AGN-looking galaxies in the SDSS

2009-12-08

arxiv.org/abs/0912.1376v1

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

8 pages, 4 figures, Proceedings of IAU Symposium 267, Co-Evolution of Central Black Holes and Galaxies

Scientific paper

Massive spectroscopic surveys like the SDSS have revolutionized the way we study AGN and their relations to the galaxies they live in. A first step in any such study is to define samples of different types of AGN on the basis of emission line ratios. This deceivingly simple step involves decisions on which classification scheme to use and data quality censorship. Galaxies with weak emission lines are often left aside or dealt with separately because one cannot fully classify them onto the standard Star-Forming, Seyfert of LINER categories. This contribution summarizes alternative classification schemes which include this very numerous population. We then study how star-formation histories and physical properties of the hosts vary from class to class, and present compelling evidence that the emission lines in the majority of LINER-like systems in the SDSS are not powered by black-hole accretion. The data are fully consistent with them being galaxies whose old stars provide all the ionizing power needed to explain their line ratios and luminosities. Such retired galaxies deserve a place in the emission line taxonomy.

Affiliated with

Also associated with

No associations

Rating

Emission line taxonomy and the nature of AGN-looking galaxies in the SDSS 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 Emission line taxonomy and the nature of AGN-looking galaxies in the SDSS, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Emission line taxonomy and the nature of AGN-looking galaxies in the SDSS will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-385221