Principal: Chad Engelbracht
Deputy: Dean Hines, Dave Frayer, Susan Stolovy, Jeonghee Rho
Data Monkey(s): Kate Su, Eiichi Egami
Priority: Necessary
Downlink Priority: Normal
Analysis Time: 1 week
Last Updated:
This tasks compares flux standards of differing brightness on similar backgrounds to check for flux-dependent calibration changes and to begin to screen our sample of potential calibration stars.
Three standards will be observed in each of the 24, 70, and 160µm bands. The standards in each band will be of different brightness but observed against a similar background. The observations will be made using the standard photometry AOR (plus the 24µm stim IER, mips-ier-120), using 3-second DCEs. The 24µm stim IER should be executed before and after the observation of the routine 24µm standard (i.e., the star used in mips-920 and marked with a * in the table here).
For each array, I have included the star selected for the routine calibration tasks MIPS-92[0,2,4]. This will allow us to directly compare the new standards observed in this task to the same standards observed routinely throughout IOC. The other two stars for each band were selected to be a few times brighter or fainter (1 of each, if possible) than the routine calibration standard. I have also tried to create some overlap by observing 1 star at 24µm/70µm and 1 at 70µm/160µm, to aid in cross-calibration of the MIPS bands. Finally, I have attempted to segregate spectral type in the 3 flux-calibration tasks 350, 351, and 352, by observing mostly late-type giants in one task, A stars in another, and solar analogs in another. This should aid us in looking for systematic differences between the calibrator types.
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Candidate Stars |
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| ID | type | RA | DEC | Band | flux | bkgd. | visibility |
| |
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(2000) | (2000) | (um) | (mJy) | MJy/sr | |
| HD39608 | K5III | 05:49:36.5 | -60:40:35 | 24 | 252 | 15.6 | 2003/08/24-2006/05/01 |
| *HD159330 | K2III | 17:30:43.6 | 57:52:37 | 24 | 515 | 15.3 | 2003/08/24-2006/05/01 |
| HD53501 | K3III | 06:59:50.5 | -67:54:59 | 24 | 1178 | 15.7 | 2003/08/24-2006/05/01 |
| HD53501 | K3III | 06:59:50.5 | -67:54:59 | 70 | 140 | 6.0 | 2003/08/24-2006/05/01 |
| *HD50310 | K1III | 06:49:56.2 | -50:36:52 | 70 | 700 | 5.7 | 2003/09/17-2004/06/02 |
| HD211416 | K3III | 22:18:30.1 | -60:15:35 | 70 | 1200 | 6.0 | 2003/09/16-2003/11/17 |
| HD211416 | K3III | 22:18:30.1 | -60:15:35 | 160 | 220 | 5.2 | 2003/09/16-2003/11/17 |
| HD062509 | K0IIIb | 07:45:19.0 | 28:01:34 | 160 | 470 | 8.2 | 2003/10/07-2003/11/18 |
| *HD131873 | K4III | 14:50:42.3 | 74:09:20 | 160 | 610 | 4.6 | 2003/09/27-2004/06/10 |
All observations for this task use the photometry AOT. 2 cycles are performed at 24µm, 3 at 70µm, and 2 at 160µm in superresolution mode, for a total of 6 cycles at 160µm. The number of images of each source is 30 at 24µm, 30 at 70µm, and 12 at 160µm. The AORs take 1.1 hours to execute. Even with the 24µm stim IER (mips-ier-120) added in (which will only add about 2 minutes), this still takes less time than the 1.38 hours allocated for this task.
Array Data Desired:
All Arrays
Data Reformatting Option:
Special Instructions:
The data will be analyzed in a manner identical to the individual flux calibration tasks MIPS-920, MIPS-922, and MIPS-924. This will generate flux conversion factors for the 7 stars. The conversion factors will be compared to assess the effects of flux levels on the measurements. As we are only measuring 3 stars per band, the report will not go into great detail on linearity effects. We will also be able to screen out any targets with obvious debris disks or other factors that make them unsuitable as calibrators.
If the test fails, it should be repeated.