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Thursday, October 27, 2011

Comparing methods

I went through a couple of ROSAT catalogs and gathered the CORRECT band of xray data. I took the raw count rates and the hardness ratios and fed them into equations (1) and (2) from the Mamajek paper to get an age out. I now have:

Age (R'HK) - 231 (84 %)
Age (Lxbol) - 78 (28%)
Age (period) - 34 (12%)
Age (isochrones) - 195 (71%)
Age (mamajek paper) - 61 (22%)

There is plenty of overlap, however, so I have SOME kind of age for 248 stars. (and I haven't finished gathering cluster data yet). The problem is knowing which age to choose. I have about 20 stars with 4 different ages available from the various methods. My personal feelings are that the ages should be trusted in the following order:

1. mamajek ages
2. period ages
3. rhk ages
4. lxbol ages
5. isochrone ages


Since I trust the mamajek ages the most, I can choose between the other age determination methods using a 3-d comparison between two methods and the mamajek ages. for example;


So for this plot, ages derived from rhk seem to agree better with the gyro ages from mamajek, so I trust rhk ages over lxbol ages. Likewise, I can compare my own gyro ages to my rhk ages:


This is a little harder to interpret, since gyro ages generally agree with activity ages. I would use the two points at (6,1) or so to decide that my gyro process determined the correct age for these stars, and should be trusted over my rhk ages.

For younger stars, I will do the same thing but use cluster age instead of mamajek ages.

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