A Theoretical Recalibration of the Extragalactic H II Region Sequence

Details A Theoretical Recalibration of the Extragalactic H II Region Sequence A Theoretical Recalibration of the Extragalactic H II Region Sequence

Oct 2000

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000apj...542..224d&link_type=abstract

The Astrophysical Journal, Volume 542, Issue 1, pp. 224-234.

Astronomy and Astrophysics

Astronomy

114

Galaxies: Abundances, Galaxies: Evolution, Ism: H Ii Regions, Ism: Abundances

Scientific paper

We have theoretically recalibrated the extragalactic H II region sequence and defined the theoretical boundary between objects excited by stars, and those exited by active galactic nuclei. We used both the PEGASE and STARBURST99 codes to generate the SED of the young star clusters, and MAPPINGS 3 to compute photoionization models which include a self-consistent treatment of dust physics and chemical depletion. We find that the two stellar spectral synthesis codes are in excellent agreement with each other for zero-age instantaneous age models. Also, the extragalactic H II region sequence is reproduced remarkably well by our models, provided that the clusters which excite them are all rather young (<2 Myr). This is most likely an observational selection effect. The line ratio usually used for measuring the ionization parameter, [O III] λ5007/[O II] λλ3726, 3729, is indeed a good diagnostic. Amongst other easily observed line ratios we found that the [N II] λλ6548, 6584/[O II] λλ3726, 3729 ratio gives the best diagnostic of abundance, as it is monotonic between 0.1 and over 3.0 times solar metallicity. The extragalactic H II regions are characterized by abundances 0.1-2.5 solar and ionization parameters in the range 107

Affiliated with

Also associated with

No associations

Rating

A Theoretical Recalibration of the Extragalactic H II Region Sequence 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 A Theoretical Recalibration of the Extragalactic H II Region Sequence, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Theoretical Recalibration of the Extragalactic H II Region Sequence will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1768795