Maps of the Magellanic clouds from combined South Pole Telescope and Planck data

• Published in: The Astrophysical Journal Supplement Series
• Main Authors: Crawford, T. M., Chown, R., Holder, G. P., Aird, K. A., Benson, B. A., Bleem, L. E., Carlstrom, J. E., Chang, C. L., Cho, H-M., Crites, A. T., Haan, T. de, Dobbs, M. A., George, E. M., Halverson, N. W., Harrington, N. L., Holzapfel, W. L., Hou, Z., Hrubes, J. D., Keisler, R., Knox, L., Lee, A. T., Leitch, E. M., Luong-Van, D., Marrone, D. P., McMahon, J. J., Meyer, S. S., Mocanu, L. M., Mohr, J. J., Natoli, T., Padin, S., Pryke, C., Reichardt, C. L., Ruhl, J. E., Sayre, J. T., Schaffer, K. K., Shirokoff, E., Staniszewski, Z., Stark, A. A., Story, K. T., Vanderlinde, K., Vieira, J. D., Williamson, R.
• Language: unknown
• Published: 2021
• Subjects: 79 ASTRONOMY AND ASTROPHYSICS; South Pole; South pole
• Online Access: http://www.osti.gov/servlets/purl/1594619; https://www.osti.gov/biblio/1594619; https://doi.org/10.3847/1538-4365/227/2/23

Here, we present maps of the Large and Small Magellanic Clouds from combined South Pole Telescope (SPT) and Planck data. Both instruments are designed to make measurements of the cosmic microwave background but are sensitive to any source of millimeter-wave (mm-wave) emission. The Planck satellite observes in nine mm-wave bands, while the SPT data used in this work were taken with the three-band SPT-SZ camera. The SPT-SZ bands correspond closely to three of the nine Planck bands, namely those centered at 1.4, 2.1, and 3.0 mm. The angular resolution of the Planck data in these bands ranges from 5 to 10 arcmin, while the SPT resolution in these bands ranges from 1.0 to 1.7 arcmin. The combined maps take advantage of the high resolution of the SPT data and the long-timescale stability of the space-based Planck observations to deliver high signal-to-noise and robust brightness measurements on scales from the size of the maps down to ~1 arcmin. In each of the three bands, we first calibrate and color-correct the SPT data to match the Planck data, then we use noise estimates from each instrument and knowledge of each instrument's beam, or point-spread function, to make the inverse-variance-weighted combination of the two instruments' data as a function of angular scale. Furthermore, we create maps assuming a range of underlying emission spectra (for the color correction) and at a range of final resolutions. We perform several consistency tests on the combined maps and estimate the expected noise in measurements of features in the maps. Finally, we compare the maps of the Large Magellanic Cloud (LMC) from this work to maps from the Herschel HERITAGE survey, finding general consistency between the datasets. Furthermore, the broad wavelength coverage provides evidence of different emission mechanisms at work in different environments in the LMC.