remember we are not really so much taking about mass separation as we are seeing differences in ionization potential.
the wavelength of the [SII] line is the longest of the three lines used for the image so the ionization potential is the lowest for the singly ionized sulfur and the doubly ionized oxygen has the highest ionization potential.
I have a bit of a flat field problem so I will probably re-shoot the [OIII] flat and reprocess today or tomorrow.
stay tuned
rdc
----- Original Message -----
From: Philip Terzian
To: The Astronomy Connection
Sent: Wednesday, March 09, 2005 2:25 AM
Subject: Re: [TAC] Thor's Helmet from Castro Valley
Very cool shot. Man, Looooooots of data collection time.
Interesting distribution of elements. I wonder if the Hydrogen is mostly in the distant background. The Oxygen core with Sulphur fringe seems counterintuitive to me since the sulphur is twice as heavy as the oxygen. I would have expected the sulphur in the center of this remnant.
Phil
Richard Crisp <rdcrisp@No-Spam> wrote:
tonight i finished gathering data for a tricolor version of Thor's Helmet.
I shot 45 minute exposures using an IMG6303 and AP180EDT f/9 with 0.75x telecompressor
the final count was 5 x 45 min for Ha, 5 x 45 minutes for [OIII] and 6 x 45 minutes for [SII]
All together that was 12 hours exposure
I used the wavelength ordered or so called Hubble Palette: [SII] = Red, Ha = Green and [OIII] = blue.
I recently heard Thor's Helmet called an "octopus", well this is really it.
http://www.narrowbandimaging.com/ngc2359_thor_6303_s2hao3_page.htm
"El Pulpo"
Received on Wed Mar 9 07:56:28 2005