(click to enlarge)To calibrate the ISOPHOT polarimetry, we will use a point about 3 arcmin north of BN wherethe polarization vectors are very nearly parallel and in a direction thatdoes not change with wavelength. The calibration will then be insensitiveto pointing errors, beam size, and passband.
Here is the coordinate for a pointing center north of KL, which we havecalled OMC-1N. It is a submillimeter (350um) peak)
RA +5:32:50.1 Dec -5:21:23.8
At 100um the flux is 5000 Jy in a 1' Beam.
The polarization should be between 4 and 5% and the position angle between 35 and 45 degrees, as shown here:
This information was contributed by David Schleuning and Roger Hildebrand, and compiled by Alyssa Goodman. See Schleuning 1998 for the whole story on Orion.
IRAS 100-micron Map and estimated fluxes:
Fluxes and positions at crosses (1 is at center; 2 is at upper right):
1. Calib (ON): RA = 83.200190 DEC = -5.351859 brightness = 2.428e+04 MJY/SR band = 100 RA = 5h32m48.04560s DEC = -5d21m06.6924s (B1950)
2. Calib (OFF): RA = 82.672960 DEC = -4.982425 brightness = 110.8 MJY/SR band = 100 RA = 5h30m41.51040s DEC = -4d58m56.7300s (B1950)
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