Howell 2010 瞬变体的峰值流量和观测时间的关系

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Title:		Using temporal distributions of transient events to characterize cosmological source populations
Authors:		Howell, E.; Coward, D.; Burman, R.; Blair, D.
Affiliation:		AA(School of Physics, the University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia ejhowellatphysics.uwa.edu.au)
Publication:		FRONTIERS OF FUNDAMENTAL AND COMPUTATIONAL PHYSICS: 10th International Symposium. AIP Conference Proceedings, Volume 1246, pp. 203-206 (2010). (AIPC Homepage)
Publication Date:		06/2010
Origin:		AIP
Keywords:		gravitational waves, gamma-rays, cosmology, brightness, integral equations
PACS Keywords:		Gravitational waves: theory, gamma-ray sources; gamma-ray bursts, Particle-theory and field-theory models of the early Universe, Magnitudes and colors; luminosities, Integral equations
Abstract Copyright:		(c) 2010: American Institute of Physics
DOI:		10.1063/1.3460205
Bibliographic Code:		2010AIPC.1246..203H

Abstract

The brightest events in a time series of cosmological transients obey an observation time dependence which is often overlooked. This dependence can be exploited to probe the global properties of electromagnetic and gravitational wave transients [1, 2]. We describe a new relation based on a peak flux-observation time distribution and show that it is invariant to the luminosity distribution of the sources [3]. Applying this relation, in combination with a new data analysis filter, to Swift gamma-ray burst data, we demonstrate that it can constrain their rate density.

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Foucart 2010 黑洞-中子星并和的数值模拟

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采用全广义相对论的框架。

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Title:		Black hole-neutron star mergers: effects of the orientation of the black hole spin
Authors:		Foucart, Francois; Duez, Matthew D.; Kidder, Lawrence E.; Teukolsky, Saul A.
Publication:		eprint arXiv:1007.4203
Publication Date:		07/2010
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena, General Relativity and Quantum Cosmology
Comment:		14 pages, 12 figures; Submitted to Phys. Rev. D
Bibliographic Code:		2010arXiv1007.4203F

Abstract

The spin of black holes in black hole-neutron star (BHNS) binaries can have a strong influence on the merger dynamics and the postmerger state; a wide variety of spin magnitudes and orientations are expected to occur in nature. In this paper, we report the first simulations in full general relativity of BHNS mergers with misaligned black hole spin. We vary the spin magnitude from a/m=0 to a/m=0.9 for aligned cases, and we vary the misalignment angle from 0 to 80 degrees for a/m=0.5. We restrict our study to 3:1 mass ratio systems and use a simple Gamma-law equation of state. We find that the misalignment angle has a strong effect on the mass of the postmerger accretion disk, but only for angles greater than ~ 40 degrees. Although the disk mass varies significantly with spin magnitude and misalignment angle, we find that all disks have very similar lifetimes ~ 100ms. Their thermal and rotational profiles are also very similar. For a misaligned merger, the disk is tilted with respect to the final black hole's spin axis. This will cause the disk to precess, but on a timescale longer than the accretion time. In all cases, we find promising setups for gamma-ray burst production: the disks are hot, thick, and hyperaccreting, and a baryon-clear region exists above the black hole.

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Vink 2010 对麦哲伦云的WR星的观测

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可能对伽马暴的前身星的研究提供帮助。

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一个旋转大质量恒星的示意结构图

星风损失率和宿主星系金属丰度的关系

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Title:		Spectropolarimetry of Wolf–Rayet Stars in the Magellanic Clouds: Constraining the Progenitors of Gamma-ray Bursts
Authors:		Vink, J.
Affiliation:		AA(Armagh Observatory, College Hill, Northern Ireland, United Kingdom)
Publication:		The Messenger, vol. 140, p. 46-49 (Msngr Homepage)
Publication Date:		06/2010
Origin:		ESO
Bibliographic Code:		2010Msngr.140...46V

Abstract

Wolf–Rayet stars have been identified as objects in their final phase of massive star evolution. It has been suggested that Wolf–Rayet stars are the progenitors of long-duration gamma-ray bursts in low-metallicity environments. However, this deduction has yet to be proven. Here we report on our initial results from a VLT/FORS linear spectropolarimetry survey of Wolf–Rayet stars in the Magellanic Clouds, which is intended to constrain the physical criteria — such as weaker stellar winds, rapid rotation, and associated asymmetry — of the collapsar model. Finally, we provide an outlook for polarisation studies with an extremely large telescope.

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Fan, X. L. 2010 长暴宿主星系均为不规则星系

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来自化学元素丰度和丰度比的观测。

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Title:		The nature of Long-GRB host galaxies from chemical abundances
Authors:		Fan, X. L.; Yin, J.; Matteucci, F.
Publication:		eprint arXiv:1007.4435
Publication Date:		07/2010
Origin:		ARXIV
Keywords:		Astrophysics - Cosmology and Extragalactic Astrophysics
Comment:		8 pages, 8 figures, A&A accepted
Bibliographic Code:		2010arXiv1007.4435F

Abstract

Gamma-ray bursts (GRBs) are the most energetic events after the Big Bang and they have been observed up to very high redshift. By means of measures of chemical abundances now available for the galaxies hosting such events,thought to originate from the explosion of very powerful supernovae (Type Ib/c), we have the opportunity to study the nature of these host galaxies. The aim of this paper is to identify the hosts of Long GRBs (LGRBs) observed both at low and high redshift to see whether the hosts can be galaxies of the same type observed at different cosmic epochs. We adopt detailed chemical evolution models for galaxies of different morphological type (ellipticals, spirals, irregulars) which follow the time evolution of the abundances of several chemical elements (H, He, $\alpha$-elements, Fe), and compare the results with the observed abundances and abundance ratios in galaxies hosting LGRBs. We find that the abundances and abundance ratios predicted by models devised for typical irregular galaxies can well fit the abundances in the hosts both at high and low redshift. We also find that the predicted Type Ib/c supernova rate for irregulars is in good agreement with observations. Models for spirals and particularly ellipticals do not fit the high-redshift hosts of LGRBs (DLA systems) nor the low redshift hosts: in particular, ellipticals cannot possibly be the hosts of gamma-ray-bursts at low redshift since they do not show any star formation, and therefore no supernovae Ib/c. We conclude that the observed abundance and abundance ratios in LGRBs hosts suggest that these hosts are irregular galaxies both at high and low redshift thus showing that the host galaxies belong to in an evolutionary sequence.

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Sahu 2010 失败的伽马暴的中微子振荡

主要内容:
如果前身星的包层太厚，伽马暴的jet冲不出来，就可能形成choked GRB。
文中分析了所产生的中微子振荡，比例不是1：1：1

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Title:		Effect of Resonant Neutrino Oscillation on TeV Neutrino Flavor Ratio from Choked GRBs
Authors:		Sahu, Sarira; Zhang, Bing
Publication:		eprint arXiv:1007.4582
Publication Date:		07/2010
Origin:		ARXIV
Keywords:		High Energy Physics - Phenomenology, Astrophysics - High Energy Astrophysical Phenomena
Comment:		5 pages, two column, revtex style, to be published in Research in Astronomy and Astrophysics (RAA)
Bibliographic Code:		2010arXiv1007.4582S

Abstract

In the collapsar scenario of the long duration Gamma-Ray Bursts (GRBs), multi-TeV neutrino emission is predicted as the jet makes its way through the stellar envelope. Such a neutrino signal is also expected for more general ``failed'' GRBs in which a putative jet is ``choked'' by a heavy envelope. If the \nu_e \rightarrow \nu_\mu neutrino oscillation parameters are in the atmospheric neutrino oscillation range, we show that the resonant oscillation of \nu_e\leftrightarrow\nu_{\mu,\tau} can take place within the inner high density region of the choked jet progenitor with a heavy envelope, altering the neutrino flavor ratio on its surface to \Phi^s_{\nu_e}:\Phi^s_{\nu_\mu}:\Phi^s_{\nu_\tau}=5:11:2. Considering vacuum oscillation of these neutrinos on their way to Earth, the final flavor ratio detected on Earth is further modified to either $1:1.095:1.095$ for the large mixing angle solution to the solar neutrino data, or 1:1.3:1.3 for maximal mixing among the muon and tau neutrinos in vacuum.

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Kappes 2010 IceCube所能对伽马暴中微子的观测

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小综述，目前的现状是还没有观测到。

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Title:		IceCube: Neutrino Messages from GRBs
Authors:		A. Kappes for the IceCube Collaboration
Publication:		eprint arXiv:1007.4629
Publication Date:		07/2010
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		8 pages, 5 figures, proceedings for workshop on "Deciphering the Ancient Universe with Gamma-Ray Bursts", Kyoto, April 2010, to be published by AIP
Bibliographic Code:		2010arXiv1007.4629A

Abstract

The mystery of where and how Nature accelerates the cosmic rays is still unresolved a century after their discovery. Gamma ray bursts (GRBs) have been proposed as one of the more plausible sources of extragalactic cosmic rays. A positive observation of neutrinos in coincidence with a GRB would identify these objects as sources of the highest-energy cosmic rays and provide invaluable information about the processes occurring inside these phenomena. Calculations show that a kilometer-scale neutrino telescope is necessary for this task. The idea of such a detector is now becoming reality as IceCube at the South Pole nears completion. The contribution reviews the status of the construction and operation of IceCube and summarize the results from searches for neutrinos from GRBs and similar phenomena with IceCube and its predecessor, AMANDA. At the end, an outline of future plans and perspectives for IceCube is given.

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Covino 2010 GRB 060908的多波段观测

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有全波段的观测的暴还是比较少。

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Title:		Challenging GRB models through the broadband dataset of GRB060908
Authors:		Covino, S.; Campana, S.; Conciatore, M. L.; D'Elia, V.; Palazzi, E.; Thöne, C. C.; Vergani, S. D.; Wiersema, K.; Brusasca, M.; Cucchiara, A.; Cobb, B. E.; Fernandez-Soto, A.; Kann, D. A.; Malesani, D.; Tanvir, N. R.; Antonelli, L. A.; Bremer, M.; Castro-Tirado, A. J.; de Ugarte Postigo, A.; Molinari, E.; Nicastro, L.; Stefanon, M.; Testa, V.; Tosti, G.; Vitali, F.; Amati, L.; Chapman, R.; Conconi, P.; Cutispoto, G.; Fynbo, J. P. U.; Goldoni, P.; Henriksen, C.; Horne, K. D.; Malaspina, G.; Meurs, E. J. A.; Pian, E.; Stella, L.; Tagliaferri, G.; Ward, P.; Zerbi, F. M.
Publication:		eprint arXiv:1007.4769
Publication Date:		07/2010
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		A&A, in press. 11 pages, 5 figures
Bibliographic Code:		2010arXiv1007.4769C

Abstract

Context: Multiwavelength observations of gamma-ray burst prompt and afterglow emission are a key tool to disentangle the various possible emission processes and scenarios proposed to interpret the complex gamma-ray burst phenomenology. Aims: We collected a large dataset on GRB060908 in order to carry out a comprehensive analysis of the prompt emission as well as the early and late afterglow.
Methods: Data from Swift-BAT, -XRT and -UVOT together with data from a number of different ground-based optical/NIR and millimeter telescopes allowed us to follow the afterglow evolution from about a minute from the high-energy event down to the host galaxy limit. We discuss the physical parameters required to model these emissions. Results: The prompt emission of GRB060908 was characterized by two main periods of activity, spaced by a few seconds of low intensity, with a tight correlation between activity and spectral hardness. Observations of the afterglow began less than one minute after the high-energy event, when it was already in a decaying phase, and it was characterized by a rather flat optical/NIR spectrum which can be interpreted as due to a hard energy-distribution of the emitting electrons. On the other hand, the X-ray spectrum of the afterglow could be fit by a rather soft electron distribution.
Conclusions: GRB060908 is a good example of a gamma-ray burst with a rich multi-wavelength set of observations. The availability of this dataset, built thanks to the joint efforts of many different teams, allowed us to carry out stringent tests for various interpretative scenarios showing that a satisfactorily modeling of this event is challenging. In the future, similar efforts will enable us to obtain optical/NIR coverage comparable in quality and quantity to the X-ray data for more events, therefore opening new avenues to progress gamma-ray burst research.

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Xu, Lixin 2010 检测伽马暴和超新星做标准烛光

主要内容:
用Amati关系，和超新星放一起，看他们是否一致。结论是基本一致的。不过他们貌似就5个暴，选择效应太大，再说Amati关系都不能做标准烛光的。

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Title:		Testing the Consistence of Gamma Ray Burst Data-set and Supernovae Union2
Authors:		Xu, Lixin; Wang, Yuting
Publication:		eprint arXiv:1007.4734
Publication Date:		07/2010
Origin:		ARXIV
Keywords:		Astrophysics - Cosmology and Extragalactic Astrophysics
Comment:		5 pages, 0 figure
Bibliographic Code:		2010arXiv1007.4734X

Abstract

In this paper, we test the consistence of Gamma Ray Bursts (GRBs) Data-set and Supernovae Union2 (SNU2) via the so-called {\it multi-dimensional consistence test} under the assumption that $\Lambda$CDM model is a potentially correct cosmological model. We find that the probes are inconsistent with $1.456\sigma$.

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Bolmont, J. 2010 Lorentz 违背的综述

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Title:		Lorentz Symmetry Breaking studies with photons from Astrophysical Observations
Authors:		Bolmont, J.; Jacholkowska, A.
Publication:		eprint arXiv:1007.4954
Publication Date:		07/2010
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena, General Relativity and Quantum Cosmology
Comment:		22 pages, 9 figures. Invited review talk to the 2nd International Colloquium "Scientific and Fundamental Aspects of the Galileo Programme", 14-16 october 2009, Padua, Italy
Bibliographic Code:		2010arXiv1007.4954B

Abstract

Lorentz Invariance Violation (LIV) may be a good observational window on Quantum Gravity physics. Within last few years, all major Gamma-ray experiments have published results from the search for LIV with variable astrophysical sources: Gamma-ray Bursts with detectors on-board satellites and Active Galactic Nuclei with ground-based experiments. In this paper, the recent time-of-flight studies with unpolarized photons published from the space and ground based observations are reviewed. Various methods used in the time delay searches are described, and their performance discussed. Since no significant time-lag value was found within experimental precision of the measurements, the present results consist of 95% Confidence Level limits on the Quantum Gravity scale on the linear and quadratic terms in the standard photon dispersion relations.

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