VOSA. Help and Documentation

Version 6.0, Apr 2018

1. Introduction
2. Input files
2.1. Upload files
2.2. VOSA file format
2.3. Single object
2.4. Manage files
2.5. Archiving
2.6. Filters
3. Objects
3.1. Coordinates
3.2. Distances
3.3. Extinction
4. Build SEDs
4.1. VO photometry
4.2. SED
4.3. Excess
5. Analysis
5.1. Model Fit
5.2. Bayes analysis
5.3. Template Fit
5.4. Templates Bayes
5.5. HR diagram
5.6. Upper Limits
5.7. Statistics
6. Save results
6.1. Download
6.2. SAMP
6.3. References
6.4. Log file
6.5. Plots
7. VOSA Architecture
8. Phys. Constants
9. FAQ
10. Use Case
11. Quality
11.1. Stellar libraries
11.2. VO photometry
12. Credits
13. Helpdesk
14. About

Use Case: From SED fitting to Age estimation. The case of Collinder 69

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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
LOri00140005.00.01.913e-10 ± 3.314e-120.9541 ± 0.016530.0009 - 0.00110.5988 - 0.6976
LOri00237502.00.22.056e-10 ± 2.799e-121.025 ± 0.013960.0008 - 0.00100.4042 - 0.5932
LOri00339004.50.01.715e-10 ± 3.015e-120.8553 ± 0.015040.0009 - 0.00100.5056 - 0.5999
LOri00436005.50.01.551e-10 ± 2.804e-120.7732 ± 0.01399? - 0.0005?
LOri00537502.50.51.733e-10 ± 1.402e-110.864 ± 0.069930.0009 - 0.00160.4042 - 0.5949
LOri00639005.00.01.493e-10 ± 2.991e-120.7448 ± 0.014910.0010 - 0.00130.5135 - 0.6011
LOri00738005.50.01.244e-10 ± 6.919e-120.6203 ± 0.03450.0010 - 0.00140.4786 - 0.5410
LOri00840005.50.01.489e-10 ± 5.718e-120.7424 ± 0.028520.0011 - 0.00200.6002 - 0.7014
LOri00941004.50.01.176e-10 ± 3.771e-120.5867 ± 0.01880.0025 - 0.00390.7138 - 0.8329
LOri01041005.00.01.111e-10 ± 6.831e-120.5541 ± 0.034060.0027 - 0.00430.7183 - 0.8499

 

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