Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

The Simons Observatory: Beam characterization for the small aperture telescopes

Dachlythra, Nadia, Duivenvoorden, Adriaan J., Gudmundsson, Jon E., Hasselfield, Matthew, Coppi, Gabriele, Adler, Alexandre E., Alonso, David, Azzoni, Susanna, Chesmore, Grace E., Fabbian, Giulio ORCID:, Ganga, Ken, Gerras, Remington G., Jaffe, Andrew H., Johnson, Bradley R., Keating, Brian, Keskitalo, Reijo, Kisner, Theodore S., Krachmalnicoff, Nicoletta, Lungu, Marius, Matsuda, Frederick, Naess, Sigurd, Page, Lyman, Puddu, Roberto, Puglisi, Giuseppe, Simon, Sara M., Teply, Grant, Tsan, Tran, Wollack, Edward J., Wolz, Kevin and Xu, Zhilei 2024. The Simons Observatory: Beam characterization for the small aperture telescopes. Astrophysical Journal 961 (1) , 138. 10.3847/1538-4357/ad0969

[thumbnail of pdf.pdf] PDF - Published Version
Download (5MB)


We use time-domain simulations of Jupiter observations to test and develop a beam reconstruction pipeline for the Simons Observatory Small Aperture Telescopes. The method relies on a mapmaker that estimates and subtracts correlated atmospheric noise and a beam fitting code designed to compensate for the bias caused by the mapmaker. We test our reconstruction performance for four different frequency bands against various algorithmic parameters, atmospheric conditions, and input beams. We additionally show the reconstruction quality as a function of the number of available observations and investigate how different calibration strategies affect the beam uncertainty. For all of the cases considered, we find good agreement between the fitted results and the input beam model within an ∼1.5% error for a multipole range ℓ = 30–700 and an ∼0.5% error for a multipole range ℓ = 50–200. We conclude by using a harmonic-domain component separation algorithm to verify that the beam reconstruction errors and biases observed in our analysis do not significantly bias the Simons Observatory r-measurement

Item Type: Article
Date Type: Published Online
Status: Published
Schools: Physics and Astronomy
Additional Information: License information from Publisher: LICENSE 1: URL:, Type: cc-by
Publisher: American Astronomical Society
ISSN: 0004-637X
Date of First Compliant Deposit: 22 January 2024
Date of Acceptance: 1 November 2023
Last Modified: 24 Jan 2024 15:14

Actions (repository staff only)

Edit Item Edit Item


Downloads per month over past year

View more statistics