Posted by Esther Hu on July 14, 1999 at 21:59:20:
In Reply to: Medium-band IR filters posted by Sam Pascarelle on July 13, 1999 at 11:40:22:
I'd like to follow up on Sam Pascarelle's comments on the issue of red filter selection, which is arguably the area which requires the most rethinking in the light of both very recent scientific discoveries (e.g., methane brown dwarfs, and new varieties of low-mass stars from IR surveys; very high redshift (z>5) galaxies; Kuiper Belt Objects and other outer Solar System bodies; etc.) and new instrumentation capabilities (IR detector side). For these programs a combination of medium bandpass filters spanning the far red wavelengths (from ~9000 Ang onwards) are important, and can be selected along with the J1, J2 filters to provide good general color discriminants, while also covering spectral diagnostic features (e.g., Alex Storrs' suggestion for 1.05 micron silicate feature in a medium bandpass filter). One can also include a filter placed in a region which is inaccessible or difficult to study from the ground due to a combination of strong night sky emission and telluric absorption (following Peter Eisenhardt's suggestion). This would be an effective combination for a variety of programs. I would also favor a very broad JH filter for deep coverage.