Supernova simulations to date have assumed that during core collapse electron captures occur dominantly on free protons, while captures on heavy nuclei are Pauli-blocked and are ignored. We have ...calculated rates for electron capture on nuclei with mass numbers A=65-112 for the temperatures and densities appropriate for core collapse. We find that these rates are large enough so that, in contrast to previous assumptions, electron capture on nuclei dominates over capture on free protons. This leads to significant changes in core collapse simulations.
Despite more than 30 years of searches, the compact object in Supernova (SN) 1987A has not yet been detected. We present new limits on the compact object in SN 1987A using millimeter, near-infrared, ...optical, ultraviolet, and X-ray observations from ALMA, VLT, HST, and Chandra. The limits are approximately 0.1 mJy (\(0.1\times 10^{-26}\) erg s\(^{-1}\) cm\(^{-2}\) Hz\(^{-1}\)) at 213 GHz, 1 Lsun (\(6\times 10^{-29}\) erg s\(^{-1}\) cm\(^{-2}\) Hz\(^{-1}\)) in optical if our line-of-sight is free of ejecta dust, and \(10^{36}\) erg s\(^{-1}\) (\(2\times 10^{-30}\) erg s\(^{-1}\) cm\(^{-2}\) Hz\(^{-1}\)) in 2-10 keV X-rays. Our X-ray limits are an order of magnitude less constraining than previous limits because we use a more realistic ejecta absorption model based on three-dimensional neutrino-driven SN explosion models (presented in an accompanying article). The allowed bolometric luminosity of the compact object is 22 Lsun if our line-of-sight is free of ejecta dust, or 138 Lsun if dust-obscured. Depending on assumptions, these values limit the effective temperature of a neutron star to <4-8 MK and do not exclude models, which typically are in the range 3-4 MK. For the simplest accretion model, the accretion rate for an efficiency \(\eta\) is limited to \(< 10^{-11} \eta^{-1}\) Msun yr\(^{-1}\), which excludes most predictions. For pulsar activity modeled by a rotating magnetic dipole in vacuum, the limit on the magnetic field strength (\(B\)) for a given spin period (\(P\)) is \(B < 10^{14} P^2\) G s\(^{-2}\). By combining information about radiation reprocessing and geometry, it is likely that the compact object is a dust-obscured thermally-emitting neutron star, which may appear as a region of higher-temperature ejecta dust emission.
Muscle triglycerides and glycogen were measured in biopsy specimens of the vastus lateralis muscle before and after 1 h of ergometric exercise at 50 to 60% of maximal capacity (i. e. at a pulse rate ...during exercise of 180 minus age) in 3 groups of 19 to 35 year old, non-obese male subjects: 10 normals, 10 insulin dependent diabetic patients in relatively good control and 10 poorly controlled insulin dependent diabetic patients in whom insulin was withdrawn 24 h prior to examination. At rest in all subjects muscle triglyceride content was positively correlated with serum triglycerides(p < 0.001) and blood glucose (p < 0.05), resulting in elevated muscle triglyceride stores in the insulin deficient diabetic patients (17.9 +/- 1.8 mumol/g protein vs. 13.4 +/- 1.3 and 9.4 +/- 1.2 in the normal subjects and the well controlled diabetic patients; p < 0.05 and < 0.001). During exercise, utilisation of muscle triglycerides and glycogen were directly related to content at rest (p < 0.001), including the insulin-deprived patients with decreased glycogen. The decrease of muscle fat was associated with a rise in serum glycerol (p < 0.001) and non-esterified fatty acids (p < 0.001) during exercise.
Transporting nu_mu and nu_tau in a supernova (SN) core involves several
processes that have been neglected in traditional simulations. Based on a Monte
Carlo study we find that the flavor-dependent ...spectral differences are much
smaller than is often stated in the literature. A full-scale SN simulation
using a Boltzmann solver and including all relevant neutrino reactions confirms
these results. The flavor-dependent flux differences are largest during the
initial accretion phase.
Transporting nu_mu and nu_tau in a supernova (SN) core involves several processes that have been neglected in traditional simulations. Based on a Monte Carlo study we find that the flavor-dependent ...spectral differences are much smaller than is often stated in the literature. A full-scale SN simulation using a Boltzmann solver and including all relevant neutrino reactions confirms these results. The flavor-dependent flux differences are largest during the initial accretion phase.
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