A highly-ionized region surrounding SN Refsdal revealed by MUSE

Supernova (SN) Refsdal is the first multiply-imaged, highly-magnified, and spatially-resolved SN ever observed. The SN exploded in a highly-magnified spiral galaxy at z=1.49 behind the Frontier Fields Cluster MACS1149, and provides a unique opportunity to study the environment of SNe at high z. We exploit the time delay between multiple images to determine the properties of the SN and its environment, before, during, and after the SN exploded. We use the integral-field spectrograph MUSE on the VLT to simultaneously target all observed and model-predicted positions of SN Refsdal. We find MgII emission at all positions of SN Refsdal, accompanied by weak FeII* emission at two positions. The measured ratios of [OII] to MgII emission of 10-20 indicate a high degree of ionization with low metallicity. Because the same high degree of ionization is found in all images, and our spatial resolution is too coarse to resolve the region of influence of SN Refsdal, we conclude that this high degree of ionization has been produced by previous SNe or a young and hot stellar population. We find no variability of the [OII] line over a period of 57 days. This suggests that there is no variation in the [OII] luminosity of the SN over this period, or that the SN has a small contribution to the integrated [OII] emission over the scale resolved by our observations.Comment: 5 pages, 4 figures, accepted for publication in A&

The final fate of spherical inhomogeneous dust collapse II: Initial data and causal structure of singularity

Further to results in [9], pointing out the role of initial density and velocity distributions towards determining the final outcome of spherical dust collapse, the causal structure of singularity is examined here in terms of evolution of the apparent horizon. We also bring out several related features which throw some useful light towards understanding the nature of this singularity, including the behaviour of geodesic families coming out and some aspects related to the stability of singularity.Comment: Latex file, uses epsf.sty, 15 pages and 3 eps figures. Paragraph on role of smooth functions rewritten. Four references added. To appear in Classical & Quantum Gravit

The story of supernova 'Refsdal' told by MUSE

We present MUSE observations in the core of the HFF galaxy cluster MACS J1149.5+2223, where the first magnified and spatially-resolved multiple images of SN 'Refsdal' at redshift 1.489 were detected. Thanks to a DDT program with the VLT and the extraordinary efficiency of MUSE, we measure 117 secure redshifts with just 4.8 hours of total integration time on a single target pointing. We spectroscopically confirm 68 galaxy cluster members, with redshift values ranging from 0.5272 to 0.5660, and 18 multiple images belonging to 7 background, lensed sources distributed in redshifts between 1.240 and 3.703. Starting from the combination of our catalog with those obtained from extensive spectroscopic and photometric campaigns using the HST, we select a sample of 300 (164 spectroscopic and 136 photometric) cluster members, within approximately 500 kpc from the BCG, and a set of 88 reliable multiple images associated to 10 different background source galaxies and 18 distinct knots in the spiral galaxy hosting SN 'Refsdal'. We exploit this valuable information to build 6 detailed strong lensing models, the best of which reproduces the observed positions of the multiple images with a rms offset of only 0.26". We use these models to quantify the statistical and systematic errors on the predicted values of magnification and time delay of the next emerging image of SN 'Refsdal'. We find that its peak luminosity should should occur between March and June 2016, and should be approximately 20% fainter than the dimmest (S4) of the previously detected images but above the detection limit of the planned HST/WFC3 follow-up. We present our two-dimensional reconstruction of the cluster mass density distribution and of the SN 'Refsdal' host galaxy surface brightness distribution. We outline the roadmap towards even better strong lensing models with a synergetic MUSE and HST effort.Comment: 21 pages, 9 figures, 6 tables; accepted for publication in the Astrophysical Journal - extra information on data analysis added, all model predictions and results unchange

The influence of the Lande gg-factor in the classical general relativistic description of atomic and subatomic systems

We study the electromagnetic and gravitational fields of the proton and electron in terms of the Einstenian gravity via the introduction of an arbitrary Lande $g$-factor in the Kerr-Newman solution. We show that at length scales of the order of the reduced Compton wavelength, corrections from different values of the $g$-factor are not negligible and discuss the presence of general relativistic effects in highly ionized heavy atoms. On the other hand, since at the Compton-wavelength scale the gravitational field becomes spin dominated rather than mass dominated, we also point out the necessity of including angular momentum as a source of corrections to Newtonian gravity in the quantum description of gravity at this scale.Comment: 11 pages, 2 figure

How Efficient Is The Langacker-Pi Mechanism of Monopole Annihilation?

We investigate the dynamics of monopole annihilation by the Langacker-Pi mechanism. We find taht considerations of causality, flux-tube energetics and the friction from Aharonov-Bohm scatteering suggest that the monopole annihilation is most efficient if electromagnetism is spontaneously broken at the lowest temperature ($T_{em} \approx 10^6 GeV$) consistent with not having the monopoles dominate the energy density of the universe.Comment: 10 page

Quantum Radiation from Black Holes and Naked Singularities in Spherical Dust Collapse

A sufficiently massive collapsing star will end its life as a spacetime singularity. The nature of the Hawking radiation emitted during collapse depends critically on whether the star's boundary conditions are such as would lead to the eventual formation of a black hole or, alternatively, to the formation of a naked singularity. This latter possibility is not excluded by the singularity theorems. We discuss the nature of the Hawking radiation emitted in each case. We justify the use of Bogoliubov transforms in the presence of a Cauchy horizon and show that if spacetime is assumed to terminate at the Cauchy horizon, the resulting spectrum is thermal, but with a temperature different from the Hawking temperature.Comment: PHYZZX macros, 27 pages, 3 figure

Toward a Midisuperspace Quantization of LeMaitre-Tolman-Bondi Collapse Models

LeMa\^\i tre-Tolman-Bondi models of spherical dust collapse have been used and continue to be used extensively to study various stellar collapse scenarios. It is by now well-known that these models lead to the formation of black holes and naked singularities from regular initial data. The final outcome of the collapse, particularly in the event of naked singularity formation, depends very heavily on quantum effects during the final stages. These quantum effects cannot generally be treated semi-classically as quantum fluctuations of the gravitational field are expected to dominate before the final state is reached. We present a canonical reduction of LeMa\^\i tre-Tolman-Bondi space-times describing the marginally bound collapse of inhomogeneous dust, in which the physical radius, $R$, the proper time of the collapsing dust, $\tau$, and the mass function, $F$, are the canonical coordinates, $R(r)$, $\tau(r)$ and $F(r)$ on the phase space. Dirac's constraint quantization leads to a simple functional (Wheeler-DeWitt) equation. The equation is solved and the solution can be employed to study some of the effects of quantum gravity during gravitational collapse with different initial conditions.Comment: 9 pages, 1 figure, Latex file. Minor corrections made. A general solution of the constraints is presented. Revised version to appear in Phys. Rev.

INTERFERÊNCIA DA NUTRIÇÃO NA RESISTÊNCIA MECÂNICA DO CÓLON E COMPARAÇÃO ENTRE DUAS TÉCNICAS DE SUTURA PARA A SÍNTESE DE COLOTOMIA EM RATOS

Trinta ratos, linhagem Wistar, fêmeas, com peso inicial médio de 150 gramas, foram divididos em seis grupos de cinco animais, sendo o grupo I - dieta controle (ração comercial), grupo II - dieta controle + colotomia e síntese com sutura contínua simples; grupo III - dieta controle + colotomia e síntese com sutura tipo Cushing, grupo IV - dieta não balanceada, grupo V - dieta não balanceada + colotomia e síntese com sutura contínua simples, grupo VI - dieta não balanceada + colotomia e síntese com sutura tipo Cushing. A colotomia foi executada no cólon descendente e no quinto dia do pós-operatório os animais foram sacrificados para estudo da tensão de ruptura, pelo método de explosão, nos cólons transverso e descendente. A média do ganho de peso com a dieta não balanceada foi aproximadamente a metade da controle. Não houve diferença estatística entre os tipos de sutura, nem entre o estado nutricional e técnicas de sutura. Em geral, os valores da tensão de ruptura no cólon transverso intacto e no cólon descendente dos animais operados (dieta controle e não balanceada), foram inferiores ao dos não operados com dieta controle. O epíplon dos ratos dos grupos V e VI apresentou-se menos volumoso e adelgaçado, o que promoveu aderências graves de outros órgãos sobre a região da colotomia. Essas adesões podem ter interferido na avaliação da tensão de ruptura do cólon descendente. Foi possível concluir que o método de força de explosão não permitiu estabelecer diferenças entre os padrões de sutura utilizados e o grau de nutrição. Nutrition interference on mechanic resistance of colon and comparison of two suture techniques for colotomy closure in rats Abstract Thirty female Wistar rats with initial average weight of 150 g, were divided in six experimental groups as follows: group 1 - control diet (commercial rat food); group II - control diet and colostomy with simple continuous suture; group III - control diet and colostomy with Cushings pattern suture; group IV - unbalanced diet; group V - unbalanced diet and colostomy with simple continuous suture; group VI - unbalanced diet and colostomy with Cushings pattern suture. Colostomy was carried out in descending colon. At the fifth day after surgery, the animals underwent euthanasia in order to measure the bursting strength of the transverse and descending colon. The gain of weight in the unbalanced diet was almost half of the control diet. here were no statistic differences between the sutures patterns, neither in regard to the nutritional conditions and suture techniques. Generally, the bursting strength values measured in both colons of the animals under either control and unbalanced diets, that underwent surgery, were lower than the ones found for rats under control diet that did not underwent surgery. The omentum of the rats from groups V and VI was less voluminous and thin causing serious adhesions to other organs at the colostomy area. These adherences might have interfered in the evaluation of the bursting strength in the descending colon. According to the results found, it was possible to conclude that evaluation of the bursting strength did not allow to establish differences between the suture patterns and the nutritional conditions of the experimental animals