collapsar


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collapsar

(kɒˈlæpsɑː)
n
(Astronomy) astronomy a collapsed star, either a white dwarf, neutron star, or black hole
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00] = 0 is the collapse condition, the surface of the collapsar is the mirror separating the spaces with both positive and negative flow of the observable time.
A collapsar is another name for which astronomical phenomenon?
In the popular collapsar model put forth by Woosley and Andrew MacFadyen (now at New York University), the black hole and disk both form quickly, and the wind, made mostly of the radioactive isotope nickel-56, is strong enough to blow apart the star.
Our geometric investigation is based on what seems to be the only time-dependent study of a collapsar, namely that of Oppenheimer and Snyder [6] (OS).
The properties of GRB afterglows at X-ray, visible, and radio wavelengths match predictions of the collapsar model.
According to one theory, known as the collapsar model, gravity rapidly crushes the core of a star at least 20 times as massive as the sun down to a black hole--a superlatively dense cinder whose gravity is so strong not even light can escape its grasp.
In addition we consider the range of angles for which light originating at the surface of such a collapsar crosses the photonsphere, at 1.
In a model developed by Stan Woosley of the University of California, Santa Cruz and his colleagues, this failed supernova, or collapsar, produces a gamma-ray burst that lasts about 20 seconds.
MacFadyen, who helped improve the collapsar model, concedes that the process of jet formation is not yet well understood, though he says it likely involves some combination of rapid rotation and strong magnetic fields.
It was shown above that the Universe considered as a sphere of incompressible liquid is a collapsar.
As these theorists and many others see it, many GRBs occur when a collapsar (the collapsing core of a massive star) ends its life by catastrophically expelling jets that briefly but powerfully emit gamma rays (S&T: February 2001, page 22).