Fitting the young main-sequence; distances, ages and age spreads

Details Fitting the young main-sequence; distances, ages and age spreads Fitting the young main-sequence; distances, ages and age spreads

2008-01-26

arxiv.org/abs/0801.4085v1

Astronomy and Astrophysics

Astrophysics

20 pages, 9 tables and 28 figures. Accepted for publication in MNRAS ref:MN-07-1360-MJ.R3

Scientific paper

10.1111/j.1365-2966.2008.13025.x

We use several main-sequence models to derive distances (and extinctions), with statistically meaningful uncertainties for 11 star-forming-regions and young clusters. The model dependency is shown to be small, allowing us to adopt the distances derived using one model. Using these distances we have revised the age order for some of the clusters of Mayne et al (2007). The new (approximate) nominal ages are: 2 Myrs for NGC6530 and the ONC, 3 Myrs for Lambda Orionis, NGC2264 and Sigma Orionis, 4-5 Myrs for NGC2362, 13 Myrs for h and chi Per, 20 Myrs for NGC1960 and 40 Myrs for NGC2547. In cases of significantly variable extinction we have derived individual extinctions using a revised Q-method (Johnson and Morgan, 1953). These new data show that the largest remaining uncertainty in deriving an age ordering (and necessarily ages) is metallicity. We also discuss the use of a feature we term the R-C gap overlap to provide a diagnostic of isochronal age spreads or varying accretion histories within a given star-formation-region. Finally, recent derivations of the distance to the ONC lie in two groups. Our new more precise distance of 391(+12,-9) pc allows us to decisively reject the further distance, we adopt 400 pc as a convenient value.

Affiliated with

Also associated with

No associations

Rating

Fitting the young main-sequence; distances, ages and age spreads 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 Fitting the young main-sequence; distances, ages and age spreads, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fitting the young main-sequence; distances, ages and age spreads will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-111813