[daip] velocity dispersion

[Eric Greisen]

On 06/16/2016 03:52 PM, Israa wrote:
> Hi,
>
>
> Is it possible to estimate velocity dispersion by task IRING. I have
> seen that paper is mentioned like that?
>
Normally some tasks like XMOM or MOMNT are used on a transposed image 
cube to fit moments 0 (flux), 1 (velocity), and 2 (dispersion).  Task 
IRING could then be used on the moment 2 image to measure dispersion as 
a function of radius in the galaxy.  Velocity dispersion is found by 
some form of spectral fitting normally - assuming that you are talking 
about the line profiles at various places in your object.  IRING does 
not do spectral fitting.  It simply sums images in elliptical rings.

Eric Greisen