[daip] RMS flux density per pixel

[Eric Greisen]

Modhurita Mitra wrote:
> Hi,
> 
> I need to know the RMS flux density per pixel in an off-source region of 
> an image. IMSTAT reports the RMS in Jy/beam, and also reports the 
> beamsize in pixels. To calculate the RMS flux density per pixel, do I 
> divide the RMS reported in Jy/beam by the beamsize in pixels? If not, 
> how do I calculate it?

Yes that will do it.  Be sure to be off source.

IMEAN provides another way which fits the peak in the histogram.
What I do is

blc=0; trc=0; imstat
pixstd=pixstd/10
go imean

But that will also be in Jy/beam.  To get Jy/pixel divide by the beam 
area in pixels.  Do be aware that the noise in each pixel is not 
independent of the noise in adjacent pixels.

Eric Greisen