SED Mode Wavelength Calibration

Principal: psmith
Deputy: jstansberry, dfrayer, nanyao
Data Monkey(s):
Priority: Critical
Downlink Priority: Normal
Analysis Time: 48 hours
Last Updated:

Objective

To confirm the wavelength calibration of the MIPS SED mode.

Description

Two cycles of the SED AOT will be executed on at least two of four targets, 1 each of planetary nebulae (bright line at 63 microns) and HII regions (bright line at 88 microns). This will confirm both the zero point and the dispersion of the SED mode. Two different wavelengths are necessary to check the dispersion, and posable alternative targets are required to guard against poor (or no) detections in one source. Ideally, the sources for this observation should be extended by at least a few arcminutes on the sky. For the current luanch date of April 18, 2003, the targets will be 30 Dor (HII region) and the planetary nebulae NGC6826, NGC6891, and NGC7009.

Data Collected

Spectra for at least 1 PN and 1 H II region will be obtained. These data will be flat fielded and the background will be subtracted. Data will be obtained using the standard SED AOT. 

The AOR file can be found here

Data Reformatting Requirements

Array Data Desired:

70 µm

Data Reformatting Option:

Special Instructions:

Task Dependencies

Calibration Dependencies

Output and Deliverable Products

The zero point of the dispersion solution and the dispersion (microns/pixel) will be determined.

Data Analysis

  1. Data is processed using MIPS_sloper and MIPS_caler.
  2. Sky offset images subtracted from target images (IDL or IRAF "imarith").
  3. If necessary, PN image added to H II region image to give us multiple lines (IRAF imsum). Dithered images of targets can also be added together if spectral features do not extend over the entire length of the slit.
  4. IRAF task twodspec.longslit.identify used to assign wavelengths to observed lines and solve for a dispersion solution for a column or columns with the brightest spectral features.
  5. IRAF task twodspec.longslit.reidentify used to identify emission lines and assign a dispersion solution for other columns of the array. This will map the changes in the dispersion solution as a function of array column. Results can be used as input to MIPS_enhancer as part of the distortion correction for SED data.

Software Requirements

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