Sigma-D relation

The Sigma-D relation, or Σ-D Relation, is the claimed relation between the radio surface brightness and diameter of a supernova remnant. It is generally regarded as of limited physical use, since it has very large scatter and is dominated by observational selection biases.{{Cite journal |last=Green |first=D. A. |date=1991-02-01 |title=Limitations Imposed on Statistical Studies of Galactic Supernova Remnants by Observational Selection Effects |url=https://ui.adsabs.harvard.edu/abs/1991PASP..103..209G |journal=Publications of the Astronomical Society of the Pacific |volume=103 |pages=209 |doi=10.1086/132810|bibcode=1991PASP..103..209G }}{{Cite journal |last=Green |first=D. A. |date=2005-01-01 |title=Some statistics of Galactic SNRs |url=https://ui.adsabs.harvard.edu/abs/2005MmSAI..76..534G |journal=Memorie della Societa Astronomica Italiana |volume=76 |pages=534–541 |arxiv=astro-ph/0505428|bibcode=2005MmSAI..76..534G }}