Thursday, June 3, 2010

M31 Distance Calculation

Today I spent the day working on a calculation to determine the distances from the Andromeda satellites to the center of the Andromeda galaxy. The morning consisted of a complicated method to get this distance. Upon working at this for quite some time, I realized I should just convert this into Cartesian coordinates. After lunch, Beth helped me get on track with this. I spent the afternoon doing a few sample calculations, and then entering the functions into our FITS binary table. As of now, I have the values for the x, y, and z coordinates, along with the distance and distance error values (all converted into radians) in neat columns in a new file. Surprisingly, when the distance was calculated, some dwarfs other than the And satellites had values up to 1.9 (MW satellites should have a value of 0)...gotta take a closer look at that. Also.....

Complications to work out:
- format when name of dwarf is included in table
- the distance error for the last two values (check and see if error is that large, or if it is a calculation flaw)
- where command (know that it is different from regular old code, but needs tweaking)

Hopefully by tomorrow, this table will be in good form. Maybe add it to big data table (or subset of it)...? We'll see. Next week, I hope to make a plot or two using these distances -- any blatant errors should pop up then.

Also for tomorrow:
- Look up central surface brightness values (turn to Mateo and Martin for majority of them)
- Finish up readings

No comments:

Post a Comment