Horvath 2010 伽马暴还是分三类

主要内容:
长暴、短暴和中间类型。这次是增加了样本。

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Title:		Detailed Classification of Swift's Gamma-Ray Bursts
Authors:		Horvath, I; Bagoly, Z; Balazs, LG; de Ugarte Postigo, A; Veres, P; Meszaros, A
Publication:		eprint arXiv:1003.0632
Publication Date:		03/2010
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Extragalactic Astrophysics
Comment:		Accepted for publication in The Astrophysical Journal
Bibliographic Code:		2010arXiv1003.0632H

Abstract

Earlier classification analyses found three types of gamma-ray bursts (short, long and intermediate in duration) in the BATSE sample. Recent works have shown that these three groups are also present in the RHESSI and the BeppoSAX databases. The duration distribution analysis of the bursts observed by the Swift satellite also favors the three-component model. In this paper, we extend the analysis of the Swift data with spectral information. We show, using the spectral hardness and the duration simultaneously, that the maximum likelihood method favors the three-component against the two-component model. The likelihood also shows that a fourth component is not needed.

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Guetta 2010 长暴GeV辐射对伽马暴的限制

主要内容:
高能GeV的观测发现没有想象的多，这给高能辐射一个限制，至少大部分暴不是由高能辐射主导，也说明MeV的高能部分不是一个幂律延伸到GeV。如果这个没有高能辐射来自于GeV光子的广深的话，对Lorentz因子也给出了限制小于300.

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Title:		FERMI constraints on the high energy, ~1 GeV, emission of long GRBs
Authors:		Guetta, Dafne; Pian, Elena; Waxman, Eli
Publication:		eprint arXiv:1003.0566
Publication Date:		03/2010
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		9 pages, 6 figures. Submitted to A&A
Bibliographic Code:		2010arXiv1003.0566G

Abstract

We investigate the constraints imposed on the luminosity function (LF) of long duration Gamma Ray Bursts (LGRBs) by the flux distribution of bursts detected by the GBM at ~1 MeV, and the implications of the non detection of the vast majority, ~95%, of the LGRBs at higher energy, ~1 GeV, by the LAT detector. We find a LF that is consistent with those determined by BATSE and Swift. The non detections by LAT set upper limits on the ratio R of the prompt fluence at ~1 GeV to that at ~1 MeV. The upper limits are more stringent for brighter bursts, with R<{0.1,0.3,1} for {5,30,60}% of the bursts. This implies that for most bursts the prompt ~1 GeV emission may be comparable to the ~1 MeV emission, but can not dominate it. The value of R is not universal, with a spread of (at least) an order of magnitude around R~10^(-1). For several bright bursts with reliable determination of the photon spectral index at ~1 MeV, the LAT non detection implies an upper limit to the ~100 MeV flux which is 0.1

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Uhm 2010 相对论激波的产生

主要内容:
在给定能量后利用压力平衡计算了激波的产生，发现在这个过程中与绝热过程的能量守恒不一致（？）

(原文当天无法获得)

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Title:		Formulation for the Relativistic Blast Waves
Authors:		Uhm, Z. Lucas
Publication:		eprint arXiv:1003.1115
Publication Date:		03/2010
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		28 pages, 7 figures, submitted to ApJ
Bibliographic Code:		2010arXiv1003.1115U

Abstract

We present a detailed description of the blast-wave modeling technique for a very general class of explosions. Providing a simple method of evaluating the blast energy, we demonstrate that a common approximation of pressure balance for the blast wave violates the energy-conservation law significantly for adiabatic blast waves. We show that the energy-violation problem is successfully resolved by the "mechanical model".

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Zalamea 2010 黑洞超吸积下的中微子碰撞

主要内容:
在Kerr度规下计算中微子流量和散射，看是否能产生伽马暴所需的能量。公式（22）给出了所能产生的能量，（23）给出了效率(中微子转换为喷流的效率)，都在可行范围内。

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Title:		Neutrino heating near hyper-accreting black holes
Authors:		Zalamea, Ivan; Beloborodov, Andrei M.
Publication:		eprint arXiv:1003.0710
Publication Date:		03/2010
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		8 pages, submitted to MNRAS
Bibliographic Code:		2010arXiv1003.0710Z

Abstract

Hyper-accretion discs around black holes emit copious neutrinos and anti-neutrinos. A fraction of the emitted neutrinos convert to electron-positron plasma above the disc through the annihilation reaction $\nu\bar\nu\to e^+e^-$. This process may drive relativistic jets associated with GRB explosions. We calculate the efficiency of energy deposition by neutrinos. Our calculation is fully relativistic and based on a geodesic-tracing method. We find that the efficiency of neutrino heating is a well-defined function of (i) accretion rate and (ii) spin of the black hole. It is practically independent of the details of neutrino transport in the opaque zone of the disc. The results help identify accretion discs whose neutrino emission can power GRBs.

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Ohno 2010 几个Fermi-LAT观测的暴

主要内容:
会议文集，随便列举了几个暴的观测：GRB 080825C and GRB 090217和短暴 GRB 081024B。

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Title:		Fermi-LAT observations of GRBs with weak LAT emission
Authors:		Ohno, Masanori; for the Fermi-LAT/GBM collaborations
Publication:		eprint arXiv:1002.0228
Publication Date:		02/2010
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Extragalactic Astrophysics
Comment:		2009 Fermi Symposium. eConf Proceedings C091122
Bibliographic Code:		2010arXiv1002.0228O

Abstract

We present the analysis results of three Gamma-Ray Bursts (GRBs) detected by the Gamma-ray Burst Monitor (GBM) and the Large Area Telescope (LAT) onboard Fermi: the two long GRB 080825C and GRB 090217, and the first short burst with GeV photons GRB 081024B. The emission from GRB 081024B observed by the LAT above 100 MeV is delayed with respect to the GBM trigger, and significantly extends after the low-energy episode. Some hints for spectral hardening was observed in this burst as well as in GRB 080825C, possibly related to a separate and harder component showing up at late times. Conversely, GRB 090217 does not exhibit any noticeable feature. Together with the other bright LAT detected bursts (e.g. GRB 080916C and GRB 090510), these observations help to classify the GRB properties and give new insight on the acceleration mechanisms responsible for their emission at the highest energies.

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Kizivat 2010 伽玛暴黑洞吸积盘附近的VP过程

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Title:		Gamma-Ray Bursts Black hole accretion disks as a site for the vp-process
Authors:		Kizivat, L. -T.; Martinez-Pinedo, G.; Langanke, K.; Surman, R.; McLaughlin, G. C.
Publication:		eprint arXiv:1001.3009
Publication Date:		01/2010
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics
Comment:		9 pages, 16 figures, accepted for publication in Phys. Rev. C
Bibliographic Code:		2010arXiv1001.3009K

Abstract

We study proton rich nucleosynthesis in windlike outflows from gamma-ray bursts accretion disks with the aim to determine if such outflows are a site of the vp-process. The efficacy of this vp-process depends on thermodynamic and hydrodynamic factors. We discuss the importance of the entropy of the material, the outflow rate, the initial ejection point and accretion rate of the disk. In some cases the vp-process pushes the nucleosynthesis out to A~100 and produces light p-nuclei. However, even when these nuclei are not produced, neutrino induced interactions can significantly alter the abundance pattern and cannot be neglected.

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Gorecki 2010 超高能伽玛射线与红外背景光子的作用定Hubble参数

主要内容:
也可以用伽玛暴的超高能辐射的缺失来做。

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Title:		Very high energy gamma-rays and the Hubble parameter
Authors:		Gorecki, A.; Barrau, A.; Grain, J.; Memola, E.
Publication:		eprint arXiv:1001.2973
Publication Date:		01/2010
Origin:		ARXIV
Keywords:		Astrophysics - Cosmology and Extragalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Comment:		Proc. of the 12th Marcel Grossmann meeting on general relativity. 3 pages, 1 figure
Bibliographic Code:		2010arXiv1001.2973G

Abstract

A new method, based on the absorption of very high-energy gamma-rays by the cosmic infrared background, is proposed to constrain the value of the Hubble constant. As this value is both fundamental for cosmology and still not very well measured, it is worth developing such alternative methods. Our lower limit at the 68% confidence level is H0 > 74 km/s/Mpc, leading, when combined with the HST results, to H0 ~ 76 km/s/Mpc. Interestingly, this value, which is significantly higher than the usually considered one, is in exact agreement with other independent approaches based on baryonic acoustic oscillations and X-ray measurements. Forthcoming data from the experiments HESS-2 and CTA should help improving those results. Finally, we briefly mention a plausible correlation between absorption by the extragalactic background light and the absence of observation of gamma-ray bursts (GRBs) at very high energies.

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Lopez-Camara 2010 在吸积盘系统中由于critical角动量导致的喷流宁静期

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Title:		Quiescence and late time activity in collapsars due to critical angular momentum distributions
Authors:		Lopez-Camara, D.
Publication:		eprint arXiv:1001.4770
Publication Date:		01/2010
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		Proceedings for "The shocking Universe: Gamma-Ray Bursts and High Energy Shock Phenomena in the Universe", Venice 2009
Bibliographic Code:		2010arXiv1001.4770L

Abstract

Even thought a large amount of long gamma ray bursts (LGRBs) present quiescent periods, their origin remains unclear. In this talk, it is shown how different angular momentum distributions, as a function of the stellar radius), can lead to neutrino luminosity variability and the possibility of quiescent epochs in LGRBs.

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Raikov 2010 伽玛暴的空间分布的不均匀性

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伽玛暴的红移分布和距离分布。

和伽玛暴关联的类星体的红移分布。

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Title:		Non-homogeneities in the spatial distribution of gamma-ray bursts
Authors:		Raikov, A. A.; Orlov, V. V.; Beketov, O. B.
Publication:		eprint arXiv:1001.4592
Publication Date:		01/2010
Origin:		ARXIV
Keywords:		Astrophysics - Cosmology and Extragalactic Astrophysics
Comment:		12 pages, 8 figures
Bibliographic Code:		2010arXiv1001.4592R

Abstract

In order to reveal possible non-homogeneities in the spatial distribution of long (T_90 > 2^s) gamma-ray bursts we have examined 201 of them with known redshifts z. For different functional forms of metric distance r(z)we use the distribution function f(l)of separations between objects. Asymptotically, for small l this function behaves like f(l)~l^{D-1} for fractal sets whose fractal dimension is D. It is revealed that for all of the considered forms of r(z) the spatial distribution of gamma-ray burst sources shows signs of fractality with D=2.2-2.5. A few spatially isolated groups of gamma-ray burst sources have been found, one of which has equatorial coordinates alpha extending from 23^h 56^m to 0^h 49^m and delta from +19^o to +23^o its redshifts being within the range of 0.81 to 0.94.

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Sidoli 2010 EXIST可能对超亮快X射线变源的观测

主要内容:

Supergiant Fast X-ray Transients (SFXTs) 是 High Mass X-ray Binaries involving about 20 sources to date, with 8 firmly identified SFXTs and many candidates.

the bright flares (peaking at 1E36-1E37erg/s)

EXIST是 Energetic X-ray Imaging Survey Telescope (EXIST)

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Title:		EXIST perspective for Supergiant Fast X-ray Transients
Authors:		Sidoli, L.; Sguera, V.; Bazzano, A.; Ubertini, P.
Publication:		eprint arXiv:1001.3234
Publication Date:		01/2010
Origin:		ARXIV
Keywords:		Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Comment:		Accepted for publication on PoS, Proceedings of "The Extreme sky: Sampling the Universe above 10 keV", held in Otranto (Italy) in October 2009
Bibliographic Code:		2010arXiv1001.3234S

Abstract

Supergiant Fast X-ray Transients (SFXTs) are one of the most intriguing (and unexpected) results of the INTEGRAL mission. They are a new class of High Mass X-ray Binaries involving about 20 sources to date, with 8 firmly identified SFXTs and many candidates. They are composed by a massive OB supergiant star as companion donor and a compact object. At least four SFXTs host a neutron star, because X-ray pulsations have been discovered, while for the others a black hole cannot be excluded. SFXTs display short X-ray outbursts (compared with Be/X-ray transients) characterized by fast flares on brief timescales of hours and large flux variability typically in the range 1,000-100,000. The INTEGRAL/IBIS sensitivity allowed to catch only the bright flares (peaking at 1E36-1E37erg/s), without persistent or quiescent emission. The investigation of their properties, in particular the rapid variability time scales of their flaring activity, will greatly benefit from observations with the Energetic X-ray Imaging Survey Telescope (EXIST), with the possibility to perform a long term and continuous as possible monitoring of the hard X-ray sky.

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