T-ReCS Photometric Standards

Starting in Semester 2005B Phase II Science Programs must specify two flux standards, one that would match the airmass of the target if observed before it and one that would match it if observed after. The Gemini Staff member at the telescope will select one of these for baseline calibration, which will not be charged to the science program. If the PI desires both flux standards or any additional flux standards to be observed, these additional standards will be charged to the science program. The PI should factor into their choice of flux standards the amount of time to be spent observing the science target. If, for example, the science target requires two hours, ideally the first standard would have an RA 1 hr less and a Dec equal to the science target. If the time on the target is very short (i.e. less than 30 minutes of real time), then one flux standard at a similar airmass to the science target will be sufficient.

A short list of very bright mid-infrared standards in the Southern Hemisphere that are commonly used by the T-ReCS Team is available.

A list of 422 "Cohen standards" containing coordinates and approximate flux densities (courtesy Keck Obs.) at several wavelengths is available. A gzip-compressed tar file containing Cohen's model template spectra of these stars also is available. The reference is Cohen et al. 1999 AJ, 117, 1864.

Additional discussion of mid-infrared flux calibration is available here .

Last update June 7, 2005; J.M. De Buizer