Day 142

Thursday.  Adventmarkt had roasted chestnuts.  Saw Eric from afar, smoking outside of James Joyce on the way back.  


1111.5329
Basic properties of MHD turbulence in the inertial range
Beresnyak


MHD turbulence in the inertial range: numerics favor Goldreich-Sridhar -5/3 slope.  Full description of MHD cascade spectral quantities.


1111.5341
The 2010 very high energy gamma-ray flare & 10 years of multi-wavelength observations of M87
The H.E.S.S. collaboration


M87, an giant elliptical galaxies with a single jet, is a VHE (>100GeV) gamma-ray emitter.


1111.5424
Photon trapping enables super-Eddington growth of BH seeds in galaxies at high redshift
Wyithe, Loeb


* Bondi accretion: spherical acretion onto an object.  \dot{M} = pi R^2 rho v


Find: density at the center of typical high redshift galaxies was at a level where the Bondi accretion rate implies a diffusion speed of photons that was slower than the gravitational infall velocity, resulting in photons being trapped within the accretion flow and advected into the the BH.  Range of BH masses (M_bh~1e3 to 1e5 Msun) has accretion flow trapping radiation, corresponding to BHs that were massive enough to generate a photon trapping accretion flow, but small enough that their Bondi radii did not exceed the isothermal scale height of self-gravitating gas.  Under these conditions, the accretion reaches levels in excess of Eddington rate.  Predict: X-ray number counts of AGN at z>6 exhibit a cutoff at the low luminosities corresponding to BH masses below 1e5 Msun.  At low z, find photon trapping to be unimportant because it could only occur in rare low spin halos, and would require BH masses in excess of expectations from the observed BH-halo mass relation.  The super-Eddington growth of 1e5 solar mass seed BHs at high z may have provided a natural acceleration towards the growth of super-massive BHs at z~6-7, less than a billion years after the BB.


1111.5427
Spectral energy distributions of a set of HII regions in M33 (HerM33es)
Relano et al


HerM33es is a Key Project for Herschel.  Study SED of a set of HII regions of M33 [3rd largest in the local group].  Perform classification of selected HII region sample in morphology (filled/ mixed shell and clear shell objects); study SED for each and for each morphology type.  Study emission distribution of each band within the region.  Find different trends in the SEDs for each morphological type that are related to properties of the dust and their associated stellar cluster.  Emission distribution of each band within the region is different for each morphological type of object.  


1111.5449
Stellar population models in the UV:  I. Characterisation of the new generation stellar library
Koleva, Vazdekis


UV and optical domain spectral predictions not accurate in stellar population models, because the lack of high-quality stellar libraries.  NGSL represent at significant step towards the improvement of this situation.


1111.5461
UHE neutrinos from PopIII stars: concept and constraints
Berezinsky, Blasi


Cosmogenic UHE neutrinos in SNe explosions that accompany the death of Pop III stars.  Accelerated protons produce neutrinos in collisions with CMB photons.  Simplify: Pop III star death at fixed redshift (z_b=10-20).  Discuss formation of collisionless shocks and particle acceleration in the early universe.  Composition of accelerated particles is expected to be proton dominated.  Diffuse neutrino flux from the "bright phase" burst is concentrated in a relatively narrow range around 7.5e15 (20/z_b)^2 eV.  The mu neutrino flux may be detectable by IceCube .  Possible signature of the neutrino production from Pop II stars may be the detection of resonant neutrino events--10 events in 5 years of observations, at E=6.3e15 eV, in the form of e-m cascades.  Large uncertainties in the existing predictions of UHE cosmogenic neutrino fluxes--those from the first stars might be the best bet.


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