[AZ-Observing] Re: NGC2403 - Enhanced Hydrogen Comparison
- From: Brian Skiff <bas@xxxxxxxxxx>
- To: az-observing@xxxxxxxxxxxxx
- Date: Wed, 3 Jan 2007 11:35:44 -0700 (MST)
Presumably you'd have to adjust the subtraction to correspond
at least roughly to the relative bandpasses of the two filters
and also to the relative exposures. Basically try to answer the
question of how much of the red continuum from cool stars appears
in the H-alpha bandpass and subtract that out, so you're left with
only the emission. The other suggestion (red only) would attempt
to remove the clumpiness in the appearance of the galaxy caused
by the emission regions, and show just the light from the stars
glowing at the H-alpha wavelength. Obviously this involves
subtracting rather little of the total 'red' signal from the
narrow slice of H-alpha. What you should get for typical spirals
is a rather smooth diaphanous galaxy with the spiral structure
smeared out---which will be in stark contrast to the H-alpha-only
image. There will be additional features brought out that tells
you something about how the star-formation proceeds and where.
\Brian
--
See message header for info on list archives or unsubscribing, and please
send personal replies to the author, not the list.
Other related posts:
