Chemical Evolution of Galaxies and Quasar Metallicities

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

74

Galaxies: Abundances, Galaxies: Elliptical And Lenticular, Cd, Galaxies: Evolution, Galaxies: Quasars: General

Scientific paper

As part of a continuing investigation of the connection between observational properties of active galactic nuclei and their host galaxies, we study the evolution of the chemical composition of the gas lost by stars in elliptical galaxies and bulges of spirals by means of a self-consistent model of galactic evolution. It is found that with Salpeter-like, or flatter, initial mass functions, solar abundances are reached in a few 108 yr, thereby explaining in a natural way the standard emission lines observed in high-redshift quasars. Furthermore, after the first Gyr, the same mass functions give rise to overabundances of N, Si, and Fe, and roughly solar abundances of C, Ne, O, and Mg, only weakly time-dependent. These results are consistent with the (few) available abundance estimates for the gas emitting the broad lines observed in quasar spectra and, in particular, they could solve the puzzle of the quasi-similarity of quasar spectra at different redshifts Finally, the metal overabundances inferred in high-redshift quasars are inconsistent with the association of these objects with newly formed galaxies as prescribed, for example, by the starburst model of active galactic nuclei, since in this case quasars should have abundance ratios very different from the estimated ones as well as lower absolute abundances. A criterion for distinguishing between the early burst and other hypothesis is given on the basis of the predicted abundance ratios.

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

Chemical Evolution of Galaxies and Quasar Metallicities 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 Chemical Evolution of Galaxies and Quasar Metallicities, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Chemical Evolution of Galaxies and Quasar Metallicities will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-785090

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