The High-Altitude Water Cherenkov, or HAWC, experiment is a TeV-energy-scale gamma-rayobservatory located at high altitude (4100 meters above sea level) in Mexico. Its primary goal is to survey the Northern Hemisphere sky for steady and transient high-energy gamma rays and thereby determine the sources of Galactic cosmic rays. The instrument’s construction was completed in January 2015. The Southern Wide-field Gamma-ray Observatory (SWGO) is a Southern Hemisphere counterpart of HAWC that is currently in the research and development phase.

Research Topics

  • Determine origins of cosmic rays
  • Measure diffuse gamma-ray spectrum
  • Precision measurements of cosmic-ray anisotropy
  • Gamma-ray astronomy 

Senior Personnel

Stefan Westerhoff, institutional lead, professor
Michael DuVernois, senior scientist 
Tom Weisgarber, postdoctoral researcher 

Complete list of HAWC personnel at WIPAC

WIPAC Contributions

UW–Madison scientists involved with HAWC work on a broad range of topics including trigger design, analysis of cosmic-ray anisotropy, fast searches for flaring activity in astrophysical sources, energy estimation, and map making. Their cosmic ray anisotropy results show patterns in the TeV region in agreement with previous measurements in the Northern Hemisphere.

During construction, the WIPAC team contributed to detector monitoring, tank construction and commissioning, and detector design.  

Select Publications

Search for TeV Gamma-Ray Emission from Point-like Sources in the Inner Galactic Plane with a Partial Configuration of the HAWC Observatory
HAWC Collaboration: A. U. Abeysekara et al
(Journal Article) submitted to Astrophys. J., e-print archive: arXiv: 1509.05401 [astro-ph.HE], September 2015

Milagro Limits and HAWC Sensitivity for the Rate-Density of Evaporating Primordial Black Holes
Milagro collaboration: A. A. Abdo et al. and HAWC Collaboration: A. U. Abeysekara et al
(Journal Article) Astropart. Phys. 64 (2015) 4-12; e-print: arXiv:1407.1686 [astro-ph.HE]

Search for Gamma Rays from the Unusually Bright GRB 130427A with the HAWC Gamma-Ray Observatory
HAWC Collaboration: A.U. Abeysekara et al
(Journal Article) Astrophys. J.800 (2015) 78; DOI: 10.1088 0004-637X 800 2 78; e-print: arXiv: 1410.1536 [astro-ph.HE]

The Sensitivity of HAWC to High-Mass Dark Matter Annihilations
HAWC Collaboration: A. U. Abeysekara et al
(Journal Article) Phys .Rev. D90 (2014) 122002; DOI: 10.1103/PhysRevD.90.122002; e-print: arXiv:1405.1730 [astro-ph.HE]

Observation of Small-scale Anisotropy in the Arrival Direction Distribution of TeV Cosmic Rays with HAWC
HAWC Collaboration: A. U. Abeysekara et al
(Journal Article) Astrophys. J. 796 (2014) 108; DOI: 10.1088/0004-637X/796/2/108; e-print: arXiv:1408.4805 [astro-ph.HE]

Sensitivity of the High-Altitude Water Cherenkov Detector to Sources of Multi-TeV Gamma Rays
HAWC Collaboration: A. U. Abeysekara et al
(Journal Article) Astropart. Phys. 50-52 (2013) 26-32; DOI: 10.1016/j.astropartphys.2013.08.002; e-print archive arXiv:1306.5800 [astro-ph.HE]

On the Sensitivity of the HAWC Observatory to Gamma-Ray Bursts
HAWC Collaboration: A. U. Abeysekara et al
(Journal Article) Astropart. Phys. 35 (2012) 641-650; DOI: 10.1016/j.astropartphys.2012.02.001; e-print archive arXiv:1108.6034 [astro-ph.HE]