Use Case: From SED fitting to Age estimation. The case of Collinder 69 HR diagram.
In order to estimate values for the mass and age of our objects, we use collections of isochrones and evolutionary tracks to build a HR diagram.
First, we access the HR diagram tab.
In order to build an HR diagram VOSA uses the available collection of isochrones and evolutionary tracks more adequate for the best model fit for each object.
In this case, the best fit model is Kurucz for some objects and BT-Settl-CIFIST for some others. For the objects with a Kurucz best fit, we will use the Siess isochrones and tracks. For those with a BT-Settl-CIFIST we will use the BHAC15 ones.
When we click the "See list of objects" link, we can see the list of objects that will correspond to each collection of models.
When we click in the Make HR diagram button VOSA builds and HR diagram (one for each model collection) and, interpolating among the isochrones and evolutionary tracks, estimates values for both the age and the mass of our objects.
If you click in one of the object names VOSA will locate it in the corresponding plot. If you click in some point of one of the plots, VOSA will identify the closer object. You can play with the plots in a number of ways.
Interpolating the isochrones and tracks VOSA has estimated values for the age and mass of most of our objects. We have now more physical properties for them:
Object |
Teff |
Log(G) |
Meta. |
Ftot |
Lbol/Lsun |
Age (Gyr) |
Mass/Msun |
LOri001 | 4000 | 5.0 | 0.0 | 1.913e-10 ± 3.314e-12 | 0.9541 ± 0.01653 | 0.0009 - 0.0011 | 0.5988 - 0.6976 |
LOri002 | 3750 | 2.0 | 0.2 | 2.056e-10 ± 2.799e-12 | 1.025 ± 0.01396 | 0.0008 - 0.0010 | 0.4042 - 0.5932 |
LOri003 | 3900 | 4.5 | 0.0 | 1.715e-10 ± 3.015e-12 | 0.8553 ± 0.01504 | 0.0009 - 0.0010 | 0.5056 - 0.5999 |
LOri004 | 3600 | 5.5 | 0.0 | 1.551e-10 ± 2.804e-12 | 0.7732 ± 0.01399 | ? - 0.0005 | ? |
LOri005 | 3750 | 2.5 | 0.5 | 1.733e-10 ± 1.402e-11 | 0.864 ± 0.06993 | 0.0009 - 0.0016 | 0.4042 - 0.5949 |
LOri006 | 3900 | 5.0 | 0.0 | 1.493e-10 ± 2.991e-12 | 0.7448 ± 0.01491 | 0.0010 - 0.0013 | 0.5135 - 0.6011 |
LOri007 | 3800 | 5.5 | 0.0 | 1.244e-10 ± 6.919e-12 | 0.6203 ± 0.0345 | 0.0010 - 0.0014 | 0.4786 - 0.5410 |
LOri008 | 4000 | 5.5 | 0.0 | 1.489e-10 ± 5.718e-12 | 0.7424 ± 0.02852 | 0.0011 - 0.0020 | 0.6002 - 0.7014 |
LOri009 | 4100 | 4.5 | 0.0 | 1.176e-10 ± 3.771e-12 | 0.5867 ± 0.0188 | 0.0025 - 0.0039 | 0.7138 - 0.8329 |
LOri010 | 4100 | 5.0 | 0.0 | 1.111e-10 ± 6.831e-12 | 0.5541 ± 0.03406 | 0.0027 - 0.0043 | 0.7183 - 0.8499 |
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