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Updated: Aug 6, 2026
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Bringing the Visible Universe into Focus with Robo-AO
Published on: February 12, 2013
Shared cloud interactions unveil a candidate binary-system supernova pair with no known analogue
Miltiadis Michailidis1,2,3, Marianne Lemoine-Goumard4, Reinhold Willcox5
1W. W. Hansen Experimental Physics Laboratory, Stanford, CA, USA. milmicha@stanford.edu.
Nature Communications
|July 21, 2026
Summary
Fermi-LAT observations reveal extended gigaelectronvolt gamma-ray emission from G189.6+3.3, a supernova remnant near IC 443. Distinct hadronic and leptonic components suggest spatial segregation of emission mechanisms and support a binary system hypothesis.
Area of Science:
- High-energy astrophysics
- Gamma-ray astronomy
- Supernova remnants
Background:
- IC 443 is a well-studied supernova remnant, but its surroundings are poorly understood.
- G189.6+3.3 is a gamma-ray source previously obscured by the brighter IC 443.
Purpose of the Study:
- To investigate the nature of the gamma-ray emission from G189.6+3.3.
- To spatially resolve different gamma-ray emission mechanisms.
- To explore the relationship between G189.6+3.3 and IC 443.
Main Methods:
- Analysis of 16 years of Fermi-LAT gamma-ray observations.
- Morphological and spectral analysis of gamma-ray emission.
- Comparison with eROSITA X-ray data and molecular gas distribution.
- Crushed-cloud modeling and ultraviolet observations.
Main Results:
- Detection of extended gigaelectronvolt gamma-ray emission from G189.6+3.3.
- Identification of distinct hadronic and leptonic gamma-ray components, spatially segregated based on molecular gas presence.
- Hadronic emission in the north correlates with an Hα filament and S249 cloud, suggesting proton re-acceleration.
- G189.6+3.3 and IC 443 are at a similar distance, supporting a binary supernova remnant hypothesis.
Conclusions:
- The study reveals spatially segregated hadronic and leptonic gamma-ray emission mechanisms in G189.6+3.3.
- Proton re-acceleration in compressed post-shock gas is a likely source of hadronic gamma rays.
- The findings support the hypothesis that G189.6+3.3 and IC 443 are a binary system of supernova remnants.
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