Hyper-energetic core-collapse supernovae
Not all core-collapse supernovae are the same. Statistics shows a bi-modal distribution with a distinct population of relativistic events evidenced by anomalously large velocities of the ejecta. A fraction of these are hyper-energetic, in having kinetic energies that exceed the maximal spin energy of a proto-neutron star (PNS). These events must be powered by a black hole. While the precise details of how black holes create explosive events remains to be identified, they are generally understood to operate energetically either by accretion or by massive release of angular momentum, if they happen to be rotating rapidly. Black holes hereby offer unique prospects for unification. For instance, if all GRBs are produced by rotating black holes and the durations of short and long GRBs are due to two different modes of accretion, then short GRBs should also feature X-ray afterglows, albeit possibly relatively weak. This prediction (of 2001) was confirmed by HETE II and Swift observations of X-ray afterglows to short GRBs in 2005.
van Putten, M.H.P.M., & Ostriker, E.C., 2001, ApJ 552 L31; van Putten, M.H.P.M., 2011, Della Valle, M., & Levinson, A., A&A Lett., 535, L6
Universality of frame dragging
Frame dragging is a unique feature of general relativity, that recently has become an genuine experimental science with the pioneering measurements by the LAGEOS satellites and Gravity Probe B. By Gravity Probe B, it has become a "tangible" feature, that represents the local interaction of angular momentum with the Riemann tensor, as induced by the angular momentum of the Earth. While extremely weak around the Earth, frame dragging becomes an effect of order unity around rapidly rotating black holes. As a gravitational effect, it acts universally on angular momentum, in particles and fields alike. In particular, it enables the black hole to interact violently with surrounding matter and with charged particles in their radiative Landau states along its spin axis.
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Wave instabilities in forced turbulence
When matter is strongly energized by a central black hole, it tends to develop pressure-induced non-axisymmetric wave-instabilities, not unlike a Hopf bifurcation. In this event, the state of forced turbulence is radiatively stabilized, by a combination of cooling by gravitational wave emission and heating by dissipation in MHD turbulence. For hyper-energetic events, we hereby anticipate a burst in gravitational wave emission accompanying any high-energy emission along the spin axis (that may power a GRB) for the lifetime of rapid spin of the black hole. It is not easy to spindown a black hole. This state can last tens of seconds, effectively accounting for the observed durations of long GRBs.
van Putten, M.H.P.M., 2001, Phys. Rep. 345, 1; 2001, Phys. Rev. Lett. 87, 091101; 2002b, ApJ, 575, L71; van Putten, M.H.P.M., & Levinson, A., 2003, ApJ, 584, 937; van Putten, M.H.P.M., 2003, ApJ, 583, 374; van Putten, M.H.P.M. & Regimbau, T., 2003, 593, L15; van Putten, M.H.P.M., 2004, ApJ, 611, L81; 2008b, ApJ, 685, L63 (buckling stability diagram [Fortran 90], plot routine [Matlab])
Black hole spindown in long GRBs
Following the energetic consideration obtained from some of the hyper-energetic CC-SNe, we recently studied a normalized light curve of all 1491 long GRBs in the BATSE catalogue. The results are remarkably consistent with black hole spindown, disfavoring spindown of PNS. A detailed analysis shows a preference for black hole spindown against matter at the ISCO, rather than further out, consistent with a dominant energy output in gravitational waves, rather than in MeV neutrinos.
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Outlook on long bursts in GWs
These two partial results obtained from some of the hyper-energetic CC-SNe and long GRBs give considerable support for the proposition that long duration bursts in gravitational waves exist and are measurable, provided the event takes place in the local Universe. If true, at least some of the hyper-energetic CC-SNe and long GRBs hereby represent astronomical creation of Bekenstein-Hawking entropy, in the process of viscous spindown of an initially rapidly rotating stellar mass black hole.
van Putten, M.H.P.M., 2008a, ApJ, 684, L91; 2009, MNRAS, 396, L81; van Putten, M.H.P.M., Kanda, N., Tagoshi, H., Tatsumi, D., Masa-Katsu, F., & Della Valle, M., 2011, Phys. Rev. D., 83, 044046; GW model light curve for TSMF [Matlab], GW model light curves on accretion disk instabilities [LIGO Doc T1100093-v1, python]