Suren Gourapura

Jadwin Hall Room 253

Washington Road

Princeton, NJ 08544

I am a PhD student in physics at Princeton University, advised by Bill Jones. I work on the SPIDER and Taurus experiments, both of which are balloon-borne CMB polarimeters. SPIDER measured approximately 10% of the sky from Antarctica, using around 2,000 polarization-sensitive detectors over two flights. Taurus plans to measure about 40% of the sky from mid-latitudes, focusing on excellent cross-linking to measure multipoles with ℓ<10.

Summary of work:

SPIDER-1 foreground analysis with a spectral-domain component separation pipeline
SPIDER-2 hardware development, including mechanical design, integration, testing, and calibration
SPIDER-2 low-level analysis, involving the development of data flags and calibration of instrument parameters
SPIDER-2 pointing simulations, implementation, and reconstruction using CMB intensity fluctuations

Before Princeton, I worked on the Askaryan Radio Array and Antarctic Impulsive Transient Antenna (ARA and ANITA) with Amy Connolly at The Ohio State University, focusing on hardware for ARA and antenna simulations for both projects. Outside of work, I am passionate about powerlifting, woodworking, coffee, and metal music!

selected publications

Analysis of Polarized Dust Emission Using Data from the First Flight of SPIDER

P. A. R. Ade, M. Amiri, S. J. Benton, A. S. Bergman, and 66 more authors

The Astrophysical Journal, Jan 2025

Abs DOI

Using data from the first flight of Spider and from the Planck High Frequency Instrument, we probe the properties of polarized emission from interstellar dust in the Spider observing region. Component-separation algorithms operating in both the spatial and harmonic domains are applied to probe their consistency and to quantify modeling errors associated with their assumptions. Analyses of diffuse Galactic dust emission spanning the full Spider region demonstrate (i) a spectral energy distribution that is broadly consistent with a modified-blackbody (MBB) model with a spectral index of β d = 1.45 ± 0.05 (1.47 ± 0.06) for E (B)-mode polarization, slightly lower than that reported by Planck for the full sky; (ii) an angular power spectrum broadly consistent with a power law; and (iii) no significant detection of line-of-sight polarization decorrelation. Tests of several modeling uncertainties find only a modest impact (∼10% in σ r ) on Spider’s sensitivity to the cosmological tensor-to-scalar ratio. The size of the Spider region further allows for a statistically meaningful analysis of the variation in foreground properties within it. Assuming a fixed dust temperature T d = 19.6 K, an analysis of two independent subregions of that field results in inferred values of β d = 1.52 ± 0.06 and β d = 1.09 ± 0.09, which are inconsistent at the 3.9σ level. Furthermore, a joint analysis of Spider and Planck 217 and 353 GHz data within one subregion is inconsistent with a simple MBB at more than 3σ, assuming a common morphology of polarized dust emission over the full range of frequencies. This evidence of variation may inform the component-separation approaches of future cosmic microwave background polarization experiments.
Evolving Antennas for Ultra-High Energy Neutrino Detection

Julie Rolla, Amy Connolly, Kai Staats, Stephanie Wissel, and 15 more authors

Jan 2020