Spartan Observing Guide
Spartan is the new Infra-Red camera (1 - 2.5 micron) on the SOAR 4-m telescope. For 2010A, it is being offered on a shared-risk basis, pending complete characterization.
Focal plane:
Spartan's focal plane has four "Hawaii-II" 2048 x 2048 pixel HgCdTe detectors,
with two plate scales: angular resolution of 68 mas per pixel
(roughly 5 x 5 arcmin FOV) in the low-res and 43 mas and 2.5 x 2.5 arcmin in
the high-res configuration. 3 of the 4 detectors are science grade while one
is an engineering grade array (named d2 below).
Filters:
In addition to broadband Y,J,H and K, line and continuum filters covering
Br-gamma, FeII, H2, CO, HeI and CIV are available. See the Observing.pdf
document hosted at the Michigan State Spartan site, Inst. parameters Section
for details.
Sensitivity:
Spartan has not been fully characterised yet with all 4 detectors: for now an Integration Time Calculator is not available. The following notes should serve to roughly scale the required integration times in broadband J and K. These numbers are for faint point sources in the field from ~1 hr integrations in mostly moderate conditions, in the low-res mode on detector d3, which is one of the science grade arrays. The performance of the other arrays is comparable.
Zero-mag fluxes used for the estimates below are from Bessel, Castelli and Plez (1998).
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J Band, d3
22 minutes integration. (120 s frames).
Flux of detection: 2.60100E-17 W/m2/um (25 pix rad aperture)
= 20.3 J mags
Sky noise in same aperture: 3.826594E-19
Roughly 2 sigma detection.
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K band, d3
1 hr integration (120 s frames).
Flux of detection: 1.88E-18 W/m2/um (15 pix aperture)
= 20.8 K mags
Roughly 3 sigma detection
Sample images:
Reduced (100 s exposure) and raw frames on all 4 detectors (named d0 through d3) of 20 s x 5 dither pattern in H band of a Persson standard. The raw frames (20 s exposure) show patterned bias and other cosmetics which are fairly well removed with standard reduction.
