Evidence for an Abundance Spread in the Outer Disk Open Cluster Tombaugh 2

Details Evidence for an Abundance Spread in the Outer Disk Open Cluster Tombaugh 2 Evidence for an Abundance Spread in the Outer Disk Open Cluster Tombaugh 2

Dec 2007

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007aas...211.5836f&link_type=abstract

American Astronomical Society, AAS Meeting #211, #58.36; Bulletin of the American Astronomical Society, Vol. 39, p.840

Astronomy and Astrophysics

Astrophysics

Scientific paper

We present new high-resolution spectroscopy for the old open cluster Tombaugh 2, which has been suggested to be one of a group of clusters previously identified with the Galactic Anticenter Stellar Structure (also known as the Monoceros stream). We derive abundances and radial velocities for stars in the field of Tombaugh 2 using VLT/FLAMES with the UVES and GIRAFFE spectrographs. We find a radial velocity of 121 ± 0.4 km/s, in agreement with previous studies, but at higher precision. We also make the first measurement of Tombaugh 2's velocity dispersion, which is σ = 1.8 ± 0.3 km/s. Abundance analysis of radial-velocity-selected members finds that Tombaugh 2 is more metal-rich than found by previous studies ([Fe/H] -0.14). Our large sample also reveals that RV member stars show a relatively large spread in chemical properties (Δ[Fe/H] > 0.2). This is the first evidence suggesting a significant abundance spread within an open star cluster. The distribution of abundances of these RV members shows a possible division into two subsamples with different mean chemical characteristics having ([Fe/H], [α/Fe]) (-0.06, +0.02) and (-0.28, +0.36). We explore the possible explanations for the spread in abundances and origins for the two possible sub-populations are presented. Based on position and kinematics Tombaugh 2 is a likely member of the GASS/Monoceros stream, which makes Tombaugh 2 the second star cluster, after NGC 2808, that shows internal abundance variations within the proposed GASS/Monoceros family.
PMF is supported by an NSF Astronomy and Astrophysics Postdoctoral Fellowship under award AST-0602221. D.G. gratefully acknowledges support from the Chilean Centro de Astrofisica FONDAP No. 15010003.

Affiliated with

Also associated with

No associations

Rating

Evidence for an Abundance Spread in the Outer Disk Open Cluster Tombaugh 2 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 Evidence for an Abundance Spread in the Outer Disk Open Cluster Tombaugh 2, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evidence for an Abundance Spread in the Outer Disk Open Cluster Tombaugh 2 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1478086