Subject: GRIM II Modifications


Submitted: Thu, 22 Feb 1996 15:06:54 -0700

Message number: 5 (previous: 4, next: 6 up: Index)

Please direct comments regarding the following to the GRIM II mailing list.

> From: cgarasi@NMSU.Edu
> Date: Thu, 22 Feb 1996 14:39:16 -0700
> To:
> 	Currently, I am developing a dissertation thesis and am very interested
> in creating an observational portion which will involve GRIM Spectroscopy.
> Specifically, I am interested in using GRIM to observe the CO Absorption
> band at 2.3 microns within cooling flow clusters. Because of the redshifted
> light from these clusters, we will have to observe the spectra out to the
> atmospheric water absorption at 2.45-2.5 microns. 
> 	It has been brought to my attention by Jon Holtzman here at NMSU that
> there are 2 problems which will hamper this type of analysis:
> _________________________
> 1) the read noise of the GRIM detector is very high, and will not allow
>    for the sensitivity needed for this type of spectroscopy
> 2) The slit disperses the IR spectrum to a red cutoff around 2.4 microns.
> _________________________
> 	Dr. Holtzman feels that the 1st problem can be fixed by performing
> mulitple reads from the GRIM chip. This will allow us to average out the
> read noise by performing a software change.
> 	The second problem will entail relocating the slit so that we can
> observe out to the H20 atmosphere. Currently we are not sure how far the
> slit would have to move, but if this was done, CO spectroscopy would
> be openend up to all ARC users.
> 	I would appreciate your input on these matters in regards to their
> feasibility and who I should contact. Currently, I am going to contact
> Bob Lowenstein to see if the multiple read changes can be made in the 
> GRIM software. The second item is more serious in that it will involve
> opening up GRIM. Plerase let me know what your thoughts are and whether
> this is a possibility.
> Thanks,
> Chris Garasi
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