Remnant, The

How do interstellar absorption affects the classification of a supernova remnant of a type 1a or type II supernova rest?

absorption interstellar absorption of starlight by dust and gas in space between the stars.

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Type 1a supernovae are standard candles, because their light curves are still very similar. This measures the distance of two independent ways:
- The total scale of light as 1/distance ^ 2
- The redshift

Absorption by the interstellar medium affect both of these measures. It absorbs the light so the total decrease in intensity, and it absorbs more blue light than red, which is the object appears redder.

http://en.wikipedia.org/wiki/Extinction_ ...
Extinction is a term used in astronomy to describe the absorption and scattering of electromagnetic radiation emitted by astronomical objects by matter (dust and gas) emissions between the object and the observer.
http://en.wikipedia.org/wiki/Interstella ...
In astronomy, the interstellar reddening is a phenomenon associated with the interstellar extinction, where the spectrum of electromagnetic radiation from the characteristics of a radiation source changes from that which has been issued. Blushing is caused by light scattering dust and other materials in the interstellar medium, not to be confused with redshifts are proportional frequency shifts of the spectra without distortion. Flushing removes preferentially shorter wavelength photons from a radiation spectrum, while leaving the photon wavelength (in optics, light is red), leaving unchanged the spectroscopic lines.
http://en.wikipedia.org/wiki/Supernova_r ...
A supernova remnant (SNR) is the structure resulting from the gigantic explosion of a supernova star. The supernova remnant is bounded by an expanding shock wave, and consists of ejected material expanding from the explosion and the interstellar material it sweeps and bumps en route.
a supernova explosion expels much or all stellar material with velocities as much as 1% of the speed of light, about 3000 km / s. When the subject comes up against this with the gas surrounding circumstellar or interstellar, it forms a shock wave that can heat the gas to temperatures as high as 10 million K, forming a plasma.