We present the methodology and results of the on-sky responsivity calibration of the South Pole Telescope Shirokoff Line Intensity Mapper (SPT-SLIM). SPT-SLIM is a pathfinder line intensity mapping experiment utilizing the on-chip spectrometer technology, and was first deployed during the 2024-2025 Austral Summer season on the South Pole Telescope. During the two-week on-sky operation of SPT-SLIM, we performed periodic measurements of the detector response as a function of the telescope elevation angle. Combining these data with atmospheric opacity measurements from an on-site atmospheric tipping radiometer, simulated South Pole atmospheric spectra, and measured detector spectral responses, we construct estimates for the responsivity of SPT-SLIM detectors to sky loading. We then use this model to calibrate observations of the moon taken by SPT-SLIM, cross-checking the result against the known brightness temperature of the Moon as a function of its phase.
@article{arxiv.2510.14220,
title = {An On-Sky Atmospheric Calibration of SPT-SLIM},
author = {K. R. Dibert and M. Adamic and A. J. Anderson and P. S. Barry and B. A. Benson and C. S. Benson and E. Brooks and J. E. Carlstrom and T. Cecil and C. L. Chang and M. Dobbs and K. Fichman and K. S. Karkare and G. K. Keating and A. M. Lapuente and M. Lisovenko and D. P. Marrone and J. Montgomery and T. Natoli and Z. Pan and A. Rahlin and G. Robson and M. Rouble and G. Smecher and V. Yefremenko and M. R. Young and C. Yu and J. A. Zebrowski and C. Zhang},
journal= {arXiv preprint arXiv:2510.14220},
year = {2025}
}
Comments
7 pages, 7 figures, submitted to the 2025 International Workshop on Low Temperature Detectors (LTD 2025) proceedings