05-13-2011, 08:24 PM
zenmaster, thank you for a nice detailed post on the mental faculties. Much appreciated. Taking up our discussion on Cygnus, the following is from a scientific source and it is very interesting, in my opinion --
Any thoughts?
Quote:New Evidence for a Black Hole in the Compact Binary Cygnus X-3
Shrader, Chris R.; Titarchuk, Lev; Shaposhnikov, Nikolai
The Astrophysical Journal, Volume 718, Issue 1, pp. 488-493 (2010).
The bright and highly variable X-ray and radio source known as Cygnus X-3 was among the first X-ray sources discovered, yet it remains in many ways an enigma. It is known to consist of a massive, Wolf-Rayet primary in an extremely tight orbit with a compact object. However, one of the most basic of parameters—the mass of the compact object—is not known, nor is it even clear whether it is a neutron star or a black hole (BH). In this paper, we present our analysis of the broadband high-energy continua covering a substantial range in luminosity and spectral morphology. We apply these results to a recently identified scaling relationship that has been demonstrated to provide reliable estimates of the compact object mass in a number of accretion powered binaries. This analysis leads us to conclude that the compact object in Cygnus X-3 has a mass greater than 4.2 M sun, thus clearly indicative of a BH and as such, resolves a long-standing issue. The full range of uncertainty in our analysis and from using a range of recently published distance estimates constrain the compact object mass to lie between 4.2 M sun and 14.4 M sun. Our favored estimate, based on a 9.0 kpc distance estimate, is ~10 M sun, with an error margin of 3.2 solar masses. This result may thus pose challenges to shared-envelope evolutionary models of compact binaries, as well as establishing Cygnus X-3 as the first confirmed accretion-powered galactic gamma-ray source.
source: http://adsabs.harvard.edu/abs/2010ApJ...718..488S
Any thoughts?