MMTPol

A Brief Description:

MMTPol (Temporarily unavailable): NOTE: MMTPol is being upgraded while the MMT AO system is also undergoing an upgrade. The AO system will be available sometime in 2019.MMTPol is a 1-5 µm diffraction-limited imaging polarimeter fed by the f/15 AO beam with negligible instrumental polarization. It was built at the Universities of Minnesota & Florida and commissioned at the MMT in November 2011. It is a PI instrument. Contacts are Terry Jones and Chris Packham.

The Fundamental Capabilities:

	Basics
FOV	20″ x 40″
Instrumental Polarization	0.05% +/-0.03%
FWHM at 2.2 µm with AO	0.17″
SB Sensitivity	At 2.2 µm 18.1 mag/arcsec^2, S/N=3/1 in 2 hrs
SB Sensitivity	At 3.1 µm 15.9 mag/arcsec^2, S/N=3/1 in 2 hrs
Point Source Polarimetry	At 2.2 µm m=14.6, P=+/-1% in 2 hrs
Point Source Polarimetry	At 3.1 µm m=12.2, P=+/-1% in 2 hrs

Filters available:

1.32 µm 3%
2.20 µm 5%
3.12 µm 4%
3.50 µm 8%
3.80 µm L’
4.70 µm M

Further Information:

MMTPol is an adaptive optics optimized imaging polarimeter for use at the 6.5m MMT. By taking full advantage of the adaptive optics secondary mirror of the MMT, this polarimeter offers diffraction-limited polarimetry with very low instrumental polarization. The advent of AO secondary mirrors (e.g., Brusa et al. 2003) offers the chance to observe at the diffraction limit of large telescopes but with negligible increased instrumental polarization. The combination of a large collecting area, an AO system with no off-axis reflections, and an optical design approach to offer precision polarimetry, will permit polarimetric images in the 1-5μm region at higher precision at the diffraction limit than any other polarimeter.