Finding radial velocities

I’ve made good progress on a Python code for finding the radial velocity of an object, and expect it to be done soon!  I’m looking forward to finding some radial velocities, and then using the information to determine cluster membership for the brown dwarfs in our sample.

I thought I’d just outline the very basic steps involved in finding radial velocity.

1) Cross correlation: cross correlate two spectra to find how much one is shifted in relation to the other (in pixels).  One of these spectra should be a standard for which the radial velocity is known.

2) Convert this shift in pixels to a shift in velocity.  Note that this is the velocity with respect to the standard object.

3) Subtract the velocity of the standard from the velocity shift to obtain the radial velocity of your object!


Leave a Reply

Your email address will not be published. Required fields are marked *