The chemical abundances in the Galactic Centre from the atmospheres of Red Supergiants

Details The chemical abundances in the Galactic Centre from the atmospheres of Red Supergiants The chemical abundances in the Galactic Centre from the atmospheres of Red Supergiants

2008-11-19

arxiv.org/abs/0811.3179v1

Astrophys.J.694:46-55,2009

Astronomy and Astrophysics

Astrophysics

23 pages, 5 figs. Accepted for publication in ApJ

Scientific paper

10.1088/0004-637X/694/1/46

The Galactic Centre (GC) has experienced a high degree of recent star-forming activity, as evidenced by the large number of massive stars currently residing there. The relative abundances of chemical elements in the GC may provide insights into the origins of this activity. Here, we present high-resolution $H$-band spectra of two Red Supergiants in the GC (IRS~7 and VR~5-7), and in combination with spectral synthesis we derive abundances for Fe and C, as well as other $\alpha$-elements Ca, Si, Mg Ti and O. We find that the C-depletion in VR~5-7 is consistent with the predictions of evolutionary models of RSGs, while the heavy depletion of C and O in IRS~7's atmosphere is indicative of deep mixing, possibly due to fast initial rotation and/or enhanced mass-loss. Our results indicate that the {\it current} surface Fe/H content of each star is slightly above Solar. However, comparisons to evolutionary models indicate that the {\it initial} Fe/H ratio was likely closer to Solar, and has been driven higher by H-depletion at the stars' surface. Overall, we find $\alpha$/Fe ratios for both stars which are consistent with the thin Galactic disk. These results are consistent with other chemical studies of the GC, given the precision to which abundances can currently be determined. We argue that the GC abundances are consistent with a scenario in which the recent star-forming activity in the GC was fuelled by either material travelling down the Bar from the inner disk, or from the winds of stars in the inner Bulge -- with no need to invoke top-heavy stellar Initial Mass Functions to explain anomalous abundance ratios.

Affiliated with

Also associated with

No associations

Rating

The chemical abundances in the Galactic Centre from the atmospheres of Red Supergiants 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 The chemical abundances in the Galactic Centre from the atmospheres of Red Supergiants, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The chemical abundances in the Galactic Centre from the atmospheres of Red Supergiants will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-429554