Task Outcome Summary

• DATA STATUS: Nominal
• TASK OUTCOME: Nominal

Abstract

Analysis

The data were reduced with version 2.32 of the MIPS DAT. The non-default parameters used included turning off the correction for electronic nonlinearity, specifying the dark and illumination correction for this campaign, and specifying the 70µm parameter file. The data were combined using a custom IDL routine which includes the following steps:

• Throw out the first DCE after each stim DCE to reduce the effect of the stim latent.
• Throw out all DCEs in which the source is located on side B.
• Measure the median background level in the good part of side A, and subtract it from the whole image (this is a simplified way of removing the stim latent from the image).
• Apply integer pixel shifts (determined using the WCS) to align the images.
• Apply sigma-clipping (typically 3 sigma) and average the remaining pixels.

The mosaicked image (a combination of 13 DCEs) is shown in Figure 1. The disparity between the noise properties of side A (the "good" side, on which the source is located) and side B is readily apparent.

Figure 1: 70µm image of HD 50310.

Photometry was performed on the mosaicked image with a private IDL program, and its results were often checked against the APPHOT program in IRAF. The parameters used were an aperture radius of 3 pixels and a sky annulus of 4-8 pixels. Sky values that deviated by more than 3 sigma from the median were rejected. The aperture correction was determined to be 1.27 based on a STinyTim PSF. Noise measurements include only the standard deviation of the pixels in the sky annulus.

Results

The measured photometry can be found in the table below. Note that the measurements are made on data calibrated by dividing by a stimflash, and so the "MIPS₇₀ Unit" refers to a ratio of the sky image to the stimflash. Due to the median-subtraction process described above, the residual background should be close to 0, which accounts for the small value of and large error on the background measurement in the table.

Photometry
Target	Predicted Flux	Predicted Sky	Measured Flux	Measured Sky	Calibration Factor	Integration Time
	(Jy)	(MJy/sr)	(MIPS70 Unit)	(MIPS70 Unit)	(MIPS70/Jy)	(MIPS s)
HD50310	0.690	5.7	0.28±0.01	0.0024±0.0012	0.40±0.01	39

Conclusions

The target was observed successfully and good S/N obtained. A calibration factor was successfully measured.

Output and Deliverable Products

The calibration factor is delivered in this report.

Actions Following Analysis

• 70um photometry should be modified to use the good side (side A) of the array only. (I'm cheating - by the time this report was written, the photometry AOT was already modified for later campaigns.)