Cookbook for MIPS-944: 70micron Routine Photometry 10second Illumination Correction (IC)

Principal: Almudena Alonso
Deputy: David Frayer
Data Monkey(s): Almudena Alonso, David Frayer, Eiichi Egami
Priority:
Downlink Priority: Normal
Analysis Time: 24-48 hours
Last Updated:

Objective

To obtain a 70micron Routine 10second Photometry IC

Description

We will obtain IOC acceptable routine 70um PHOTOMETRY mode 10second ICs (this task is repeated a number of times in different IOC campaigns) to be used on a regular basis. This activity is a companion to the 70 um routine PHOT and SCAN IC tasks. These activities will allow us to determine the relative efficiency and quality of ICs created using scan and photometry AORs.

Since this task is repeated a number of times during IOC, we will observe different regions of the sky each time. The task will check for possible variations of quality of IC or saturation. This task will also be useful for screening regions of the sky to obtain ICs in SIRTF routine operations.

This task is executed in:

MIPS Campaign X3
MIPS Campaign M001

Data Collected

A 2x2 square dither map (1 cycle) will be obtained at 70microns with 10 second DCEs in a region of the sky chosen to avoid bright point sources. The offsets are 400 arcseconds. The map will require about 20.3 minutes of observing time. This is the AOR file overlaid on the sky:



HEADER: FILE_VERSION=7.0, STATUS = PROPOSAL

      AOT_TYPE:  MIPS Photometry
     AOR_LABEL:  MIPS-944-Nov27-Jan07
    AOR_STATUS:  new

 MOVING_TARGET:  NO
   TARGET_TYPE:  FIXED CLUSTER - OFFSETS
   TARGET_NAME:  zodi_0a
  COORD_SYSTEM:  Equatorial  J2000
     POSITION1:  RA_LON=0h19m54.66s,  DEC_LAT=-4d33m52.3s
     OFFSET_P2:  EAST_ROW_PERP=400.0",  NORTH_COL_PARA=0.0"
     OFFSET_P3:  EAST_ROW_PERP=400.0",  NORTH_COL_PARA=400.0"
     OFFSET_P4:  EAST_ROW_PERP=0.0",    NORTH_COL_PARA=400.0"
OFFSETS_IN_ARRAY:  NO
OBSERVE_OFFSETS_ONLY:  NO
OBJECT_AVOIDANCE:  EARTH = YES, OTHERS = YES
    MICRON_70: IMAGE_SCALE = DEFAULT, FIELD_SIZE = SMALL, EXPOSURE_TIME = 10, N_
CYCLES = 1
SPECIAL: IMPACT = none, LATE_EPHEMERIS = NO,SECOND_LOOK = NO
RESOURCE_EST: TOTAL_DURATION=1217.325, SLEW_TIME=60.6, SETTLE_TIME=88.625, SLEW_
OVERHEAD=180.0, SPECIAL_OVERHEAD=0.0, UPLINK_VOLUME=1590, DOWNLINK_VOLUME=130690
72, VERSION=S8.9.0
INTEGRATION_TIME: MIPS_24=0.0,MIPS_70=125.82912,MIPS_160=0.0

Data Reformatting Requirements

Array Data Desired:

All Arrays

Data Reformatting Option:

NORMAL

1 FITS file per AOR per array.

Special Instructions:

Task Dependencies

CAID and title of Precedent Task #1 (or None)
etc.

Calibration Dependencies

Dark

Output and Deliverable Products

Mosaic of the observed field.

70micron IC obtained in 10second PHOTOMETRY mode.

An IC will be applied to a star observed at different positions across the array to check the quality of the IC. We will provide an array map showing the location dependences -if any- of the photometric sensitivity.

Data Analysis

Standard Pipeline reduction using the DAT and/or SSC Pipeline. If using the DAT, we will run MIPS_SLOPER and then we will do the dark subtraction with MIPS_CALER.
Produce a mosaic of the observed region using MIPS_ENHANCER.
Median combine images (with some rejection algorithm) using the IRAF "imcombine" task to create an IC. Alternatively, once IC DCEs are screened for possible saturation, etc, we can use the MIPS_ENHANCER to create the flatfield frame using an appropriate rejection algorithm.
Apply IC to star observations at different positions across the array (NEED TO DETERMINE IOC TASKS ADEQUATE FOR THIS)
Aperture photometry on star using the IRAF "phot" task to measure flux
Comparison of star aperture photometry at different positions across the array to determine IC accuracy.
Once the task is executed more than once:

we can look for possible IC variations with time/region of sky used
we can determine the number of DCEs necessary to construct a 'super' IC (see J. Stansberry simulations; NEED TO ADD LINK TO FLATFIELD MODEL WEBPAGE).
IMPORTANT NOTE: According to John's simulations we will need approximately 200 DCEs to get an IC with accuracy of 0.5% (rms, over the whole array), so this task needs to be executed at least twice.

We will carry out a detailed comparison between ICs 3second and 10second photometry mode.

Software Requirements

DAT
IRAF
IDL

Actions Following Analysis

If the IC S/N and quality requirements are met, it will be put in the calibration data archive.

Failure Modes and Responses

If region of the sky used is saturated, this region will be removed from the list of flatfield/IC regions (Jeonghee Rho's list of flatfield/IC regions). If regions used are all saturated, we will look for different regions of the sky.