The Sigma-D relation, or Σ-D Relation, is the radio
surface brightness
In astronomy, surface brightness (SB) quantifies the apparent brightness or flux density per unit angular area of a spatially extended object such as a galaxy or nebula, or of the night sky background. An object's surface brightness depends on ...
to
diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle. It can also be defined as the longest chord of the circle. Both definitions are also valid fo ...
relation of a
supernova remnant
A supernova remnant (SNR) is the structure resulting from the explosion of a star in a supernova. The supernova remnant is bounded by an expanding shock wave, and consists of ejected material expanding from the explosion, and the interstellar ma ...
.
[Urošević, D. et al. (2009]
Sigma-D relation for supernova remnants and its dependent on the density of the interstellar medium
''Astronomy and Astrophysics'', 495, 537-546
See also
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Cosmic distance ladder
The cosmic distance ladder (also known as the extragalactic distance scale) is the succession of methods by which astronomers determine the distances to celestial objects. A ''direct'' distance measurement of an astronomical object is possible ...
*
Faber–Jackson relation
*
M–sigma relation
The M–sigma (or ''M''–''σ'') relation is an empirical correlation between the stellar velocity dispersion ''σ'' of a galaxy bulge and the mass M of the supermassive black hole at its center.
The ''M''–''σ'' relation was first presented ...
References
Physical cosmology
Astrophysics
Equations of astronomy
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