[1401.3711] A Be-type star with a black hole companion

[1401.3711] A Be-type star with a black hole companion:



Stellar-mass black holes have all been discovered through X-ray emission, which arises from the accretion of gas from their binary companions (this gas is either stripped from low-mass stars or supplied as winds from massive ones). Binary evolution models also predict the existence of black holes accreting from the equatorial envelope of rapidly spinning Be-type stars (stars of the Be type are hot blue irregular variables showing characteristic spectral emission lines of hydrogen). Of the ~80 Be X-ray binaries known in the Galaxy, however, only pulsating neutron stars have been found as companions. A black hole was formally allowed as a solution for the companion to the Be star MWC 656 (also known as HD 215227), although that was based on a single radial velocity curve of the Be star, a mistaken spectral classification and rough estimates of the inclination angle. Here we report observations of an accretion disk line mirroring the orbit of the Be star. This, together with an improved radial velocity curve of the Be star through fitting sharp Fe II profiles from the equatorial disk, and a refined Be classification (to that of a B1.5-B2 III star), reveals a black hole of 3.8 to 6.9 solar masses orbiting MWC 656, the candidate counterpart of the gamma-ray source AGL J2241+4454. The black hole is X-ray quiescent and fed by a radiatively inefficient accretion flow giving a luminosity less than 1.6 x 10-7 times the Eddington luminosity. This implies that Be binaries with black-hole companions are difficult to detect by conventional X-ray surveys.



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[astro-ph/0701358] Dark Matter in an n-Space Expanding Universe

[astro-ph/0701358] Dark Matter in an n-Space Expanding Universe:



The total number of degrees of freedom of a d-dimensional body in n-space is derived so that equipartition of energy may be applied to a possibly n-dimensional early universe. A comparison is made of a range of proposals to include free and bound black holes as either a small component or the dominant constituent of dark matter in the universe. The hypothesis that dark matter consists in part of atomic gravitationally bound primordial black holes is closely examined in 3-space, as well as in n-space; and the Chavda and Chavda holeum hypothesis is found to be flawed. Blackbody and Hawking radiation are generalized to n-space, and Hawking radiation is shown to be simply proportional to the black hole density. The importance of quantum gravity in understanding the role of early universe dark matter is undermined because present approaches to a theory of quantum gravity violate the equivalence principle. A general heuristic proof for geodesics on an expanding hypersphere is presented. Classical limits of Einstein's General Relativity are considered. A novel approach to the accelerated expansion of the universe is discussed. An anomalous surprising aspect of 4-space is demonstrated.



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Gravity

This note is NOT about Alfonso Cuaron's movie. Go see it though, it is good. It is about the difference between this force and the other three known forces, nuclear-strong, nuclear-weak, and electromagnetic. I posted a video on the possibility that atoms are black-holes.

There is a puzzle in Physics right now, the atomic nucleus of Hydrogen, seems to have two different sizes, if we measure it with electrons, or with its weak cousin, the muon. So far no differences had been found between these two particles, leading the great physicist Isidor Rabi to ask, who ordered that? The new puzzle may answer this old question.

According to Roberto Onofrio, there is a way to test if muons, and electrons interact differently with the proton, due to a new component of Gravity.

That'll be neat.

The black hole bit, though, is another story altogether.

Black Holes

[1301.3808] Formation of Regular Satellites from Ancient Massive Rings in the Solar System

[1301.3808] Formation of Regular Satellites from Ancient Massive Rings in the Solar System:

"When a planetary tidal disk -like Saturn's rings- spreads beyond the Roche radius (inside which planetary tides prevent aggregation), satellites form and migrate away. Here, we show that most regular satellites in the solar system probably formed in this way. According to our analytical model, when the spreading is slow, a retinue of satellites appear with masses increasing with distance to the Roche radius, in excellent agreement with Saturn's, Uranus', and Neptune's satellite systems. This suggests that Uranus and Neptune used to have massive rings that disappeared to give birth to most of their regular satellites. When the spreading is fast, only one large satellite forms, as was the case for Pluto and Earth. This conceptually bridges the gap between terrestrial and giant planet systems."

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[astro-ph/0209276] Dynamical derivation of Bode's law

[astro-ph/0209276] Dynamical derivation of Bode's law:

"In a planetary or satellite system, idealized as n small bodies in initially coplanar, concentric orbits around a large central body, obeying Newtonian point-particle mechanics, resonant perturbations will cause dynamical evolution of the orbital radii except under highly specific mutual relationships, here derived analytically apparently for the first time. In particular, the most stable situation is achieved (in this idealized model) only when each planetary orbit is roughly twice as far from the Sun as the preceding one, as observed empirically already by Titius (1766) and Bode (1778) and used in both the discoveries of Uranus (1781) and the Asteroid Belt (1801). ETC."

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Paradigm Shifts

Nevertheless the opportunity was utterly blocked by the scientific paradigm of Laplacian determinism.

From Ivan I. Shevchenko