What is the origin of the X-ray emission in young stars?
• Focus in a star formation region, Orion Nebula Search for X-ray sources and retrieve their flux
• Search for their infrared counterparts and retrieve J band magnitude, then observe the correlation of X-ray flux and J magnitude
• Compare to known relation Lx ~ Lbol in star formation regions indicating that X-ray emission is due to magnetic fields on the starsʼ surface
• Search the Chandra Catalog for sources in a 1 arcmin box in the Orion Nebula and retrieve their flux
• Search for sources in the twomass catalog with a 1 arcsec radius from each found Chandra source and retrieve their magnitude
• Plot the two magnitudes and observe a correlation
Step by Step
1. Download and start seleste
Click on Launch
Allow the application to access the computer
2. The application starts in the Guide mode
Click on the Form icon to start building a query
3. Click on Services and select Chandra Source Catalog
Open the master_source table in the Contents area on the left.
Select ra, dec, flux_aper90_b and add in the Output Columns area.
Select err_ellipse_r0, add in the Column Criteria and set < 3 to select on-axis sources
Add the following Column Criteria for 1 arcmin area in Orion
(ra < 83.82) AND ra > 83.8) AND (dec < -5.3) AND dec > -5.5)
4. In the Jobs window, once the job status shows as Pending hit Run
When the status becomes Completed view the results and hit Save to save them in a file e.g. csc_orion.xml
5. Return to the Query form and under services select GAVO Data Center TAP Service
Hit Upload and upload the table of previously saved Chandra sources e.g. csc_orion.xml, it will appear
as TAP_UPLOAD.user_table in Contents.
Select user_table and add in Output Columns
From twomass select raj2000, dej2000, jmag and add in Output Columns
6. Add a Position Search
Select twomass.data from drop down menu
Select Center around: Other table and Select Table TAP_UPLOAD.user_table
Set Radius 1.0 arcsec
7. In the Jobs window hit run
When job is completed send results to Topcat
Scatter plot log(flux_aper90_b) vs jmag and observe the correlation