SIMBAD references

2009ApJ...700..654E - Astrophys. J., 700, 654-678 (2009/July-3)

Keck HIRES spectroscopy of extragalactic H II regions: C and O abundances from recombination lines.


Abstract (from CDS):

We present very deep spectrophotometry of 14 bright extragalactic H II regions belonging to spiral, irregular, and blue compact galaxies. The data for 13 objects were taken with the High Resolution Echelle Spectrometer on the Keck I telescope. We have measured C II recombination lines in 10 of the objects and O II recombination lines in eight of them. We have determined electron temperatures from line ratios of several ions, especially those of low ionization potential. We have found a rather tight linear empirical relation between Te([N II]) and Te([O III]). We have found that O II lines give always larger abundances than [O III] lines. Moreover, the difference of both O++ abundance determinations–the so-called abundance discrepancy factor–is very similar in all the objects, with a mean value of 0.26±0.09 dex, independent of the properties of the H II region and of the parent galaxy. Using the observed recombination lines, we have determined the O, C, and C/O radial abundance gradients for three spiral galaxies: M33, M101, and NGC 2403, finding that C abundance gradients are always steeper than those of O, producing negative C/O gradients across the galactic disks. This result is similar to that found in the Milky Way and has important implications for chemical evolution models and the nucleosynthesis of C.

Abstract Copyright:

Journal keyword(s): galaxies: abundances - galaxies: individual (M31, M33, M83, M101, NGC 1741, NGC 2366, NGC 2403, NGC 4395, NGC 4861) - galaxies: ISM - galaxies: spiral - H II regions

VizieR on-line data: <Available at CDS (J/ApJ/700/654): sources.dat tab234.dat>

CDS comments: K932 is [WB92a] 932 and H1013 is HGGK 1013 in Simbad.

Simbad objects: 35

goto Full paper

goto View the references in ADS

To bookmark this query, right click on this link: simbad:2009ApJ...700..654E and select 'bookmark this link' or equivalent in the popup menu


© Université de Strasbourg/CNRS

    • Contact