Abbott 2009 LIGO引力波探测器

主要内容:
应该是关于LIGO仪器的最权威的介绍了.

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LIGO: the Laser Interferometer Gravitational-Wave Observatory
B P Abbott,
2009 Rep. Prog. Phys. 72 076901 (25pp)
Abstract: http://www.iop.org/EJ/abstract/-alert=20355/0034-4885/72/7/076901
Full text PDF: http://www.iop.org/EJ/article/-alert=20355/0034-4885/72/7/076901/rpp9_7_076901.pdf

The goal of the Laser Interferometric Gravitational-Wave
Observatory (LIGO) is to detect and study gravitational waves (GWs)
of astrophysical origin. Direct detection of GWs holds the promise
of testing general relativity in the strong-field regime, of
providing a new probe of exotic objects such as black holes and
neutron stars and of uncovering unanticipated new astrophysics.
LIGO, a joint Caltech-MIT project supported by the National Science
Foundation, operates three multi-kilometer interferometers at two
widely separated sites in the United States. These detectors are the
result of decades of worldwide technology development, design,
construction and commissioning. They are now operating at their
design sensitivity, and are sensitive to gravitational wave strains
smaller than one part in 1021. With this unprecedented sensitivity,
the data are being analyzed to detect or place limits on GWs from a
variety of potential astrophysical sources.

Nakar, Ehud 2005 SGR 的giant flare的火球模型

主要内容:
内包含初始罗仑兹因子的推导. 重子loading的推导如下:


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Title:		Pure and Loaded Fireballs in Soft Gamma-Ray Repeater Giant Flares
Authors:		Nakar, Ehud; Piran, Tsvi; Sari, Re'em
Affiliation:		AA(Theoretical Astrophysics, California Institute of Technology, MS 130-33, Pasadena, CA 91125.), AB(Theoretical Astrophysics, California Institute of Technology, MS 130-33, Pasadena, CA 91125.; Racah Institute for Physics, Hebrew University, Jerusalem 91904, Israel.), AC(Theoretical Astrophysics, California Institute of Technology, MS 130-33, Pasadena, CA 91125.)
Publication:		The Astrophysical Journal, Volume 635, Issue 1, pp. 516-521. (ApJ Homepage)
Publication Date:		12/2005
Origin:		UCP
ApJ Keywords:		Gamma Rays: Theory, Stars: Individual: Alphanumeric: SGR 1806-20
Abstract Copyright:		(c) 2005: The American Astronomical Society
DOI:		10.1086/497296
Bibliographic Code:		2005ApJ...635..516N

Abstract

On 2004 December 27, a giant flare from SGR 1806-20 was detected on Earth. Its thermal spectrum and temperature suggest that the flare resulted from an energy release of about 10⁴⁷ ergs s^-1 close to the surface of a neutron star in the form of radiation and/or pairs. This plasma expanded under its own pressure, producing a fireball, and the observed gamma rays escaped once the fireball became optically thin. The giant flare was followed by a bright radio afterglow, with an observable extended size, implying an energetic relativistic outflow. We revisit here the evolution of relativistic fireballs, and we calculate the Lorentz factor and energy remaining in relativistic outflow once the radiation escapes. We show that pairs that arise naturally in a pure pair-radiation fireball do not carry enough energy to account for the observed afterglow. We consider various alternatives and show that if the relativistic outflow that causes the afterglow is related directly to the prompt flare, then the initial fireball must be loaded by baryons or Poynting flux. While we focus on parameters applicable to the giant flare and the radio afterglow of SGR 1806-20, the calculations presented here could be also applicable to gamma-ray bursts (GRBs).

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Nishikawa, K. -I. 相对论激波的磁场扰动辐射

主要内容:
数值模拟

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Title:		Radiation from relativistic shocks with turbulent magnetic fields
Authors:		Nishikawa, K. -I.; Niemiec, J.; Medvedev, M.; Zhang, B.; Hardee, P.; Nordlund, A.; Frederiksen, J.; Mizuno, Y.; Sol, H.; Pohl, M.; Hartmann, D. H.; Oka, M.; Fishman, G. J.
Publication:		eprint arXiv:0906.5018
Publication Date:		06/2009
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		6 pages, 5 figures, Proceeding for Neutron Stars & Gamma Ray Bursts 2009, March 30 - April 4, 2009, eds A. Ibrahim and J. Gridlay
Bibliographic Code:		2009arXiv0906.5018N

Abstract

Using our new 3-D relativistic electromagnetic particle (REMP) code parallelized with MPI, we investigated long-term particle acceleration associated with a relativistic electron-positron jet propagating in an unmagnetized ambient electron-positron plasma. The simulations were performed using a much longer simulation system than our previous simulations in order to investigate the full nonlinear stage of the Weibel instability and its particle acceleration mechanism. Cold jet electrons are thermalized and ambient electrons are accelerated in the resulting shocks. Acceleration of ambient electrons leads to a maximum ambient electron density three times larger than the original value. Behind the bow shock in the jet shock strong electromagnetic fields are generated. These fields may lead to time dependent afterglow emission. We calculated radiation from electrons propagating in a uniform parallel magnetic field to verify the technique. We also used the new technique to calculate emission from electrons based on simulations with a small system. We obtained spectra which are consistent with those generated from electrons propagating in turbulent magnetic fields with red noise. This turbulent magnetic field is similar to the magnetic field generated at an early nonlinear stage of the Weibel instability. A fully developed shock within a larger system generates a jitter/synchrotron spectrum.

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Izzo, L. 2009 超新星+伽玛暴联合做宇宙学

主要内容:
(这不是人家都做过了嘛, 他为什么还说是提出的新方法?)

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Title:		Testing Dark Energy models vs $\Lambda$CDM Cosmology by Supernovae and Gamma Ray Bursts
Authors:		Izzo, L.; Capozziello, S.; Covone, G.; Capaccioli, M.
Publication:		eprint arXiv:0906.4888
Publication Date:		06/2009
Origin:		ARXIV
Keywords:		Astrophysics - Cosmology and Extragalactic Astrophysics
Comment:		8 pages, 9 figures
Bibliographic Code:		2009arXiv0906.4888I

Abstract

A new method to constrain the cosmological equation of state is proposed by using combined samples of gamma-ray bursts (GRBs) and supernovae (SNeIa). The Chevallier-Polarski-Linder parameterization is adopted for the equation of state in order to find out a realistic approach to achieve the deceleration/acceleration transition phase of dark energy models. As results, we find that GRBs, calibrated by SNeIa, could be, at least, good distance indicators capable of discriminating cosmological models with respect to $\Lambda$CDM at high redshift. Besides, GRBs+SNeIa combined redshift-distance diagram puts better in evidence the change of slope around redshift $z\sim 0.5$ which is usually addressed as the "signature" of today observed acceleration. This feature could be interpreted, in more standard way, by the red sequence in galaxy clusters.

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Lazzati, Davide 2009 伽玛暴的X-ray偏振

主要内容:
小综述.

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Title:		X-ray Polarization of Gamma-Ray Bursts
Authors:		Lazzati, Davide
Publication:		eprint arXiv:0906.4346
Publication Date:		06/2009
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Extragalactic Astrophysics
Comment:		Proceedings of the conference "The coming of age of X-ray polarimetry", Rome, Italy, 27-30 April 2009
Bibliographic Code:		2009arXiv0906.4346L

Abstract

The degree and the temporal evolution of linear polarization in the prompt and afterglow emission of gamma-ray bursts is a very robust diagnostic of some key features of gamma-ray bursts jets and their micro and macro physics. In this contribution, I review the current status of the theory of polarized emission from GRB jets during the prompt, optical flash, and afterglow emission. I compare the theoretical predictions to the available observations and discuss the future prospect from both the theoretical and observational standpoints.

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Lazzati, Davide 2009 fragmented fireball的偏振

主要内容:
每个pulse都是由指向不同方向的jet的辐射所构成.

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Title:		Polarization signature of gamma-ray bursts from fragmented fireballs
Authors:		Lazzati, Davide; Begelman, Mitchell
Publication:		eprint arXiv:0906.4337
Publication Date:		06/2009
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Extragalactic Astrophysics
Comment:		ApJL in press
Bibliographic Code:		2009arXiv0906.4337L

Abstract

We study the polarization properties of the prompt emission of gamma-ray bursts produced by fragmented fireballs. Such fireballs, known in the literature under various names, are made by the superposition of many individual blobs, each of which produces a spike in the light curve. The differences between pulses are due both to the intrinsic diversity in the blobs' properties and to their orientation with respect to the line of sight. We show that the peak flux and the polarization of each pulse are connected through the orientation of the blob that produces the pulse, while the position angle fluctuates randomly from one pulse to the next and is constant within an individual pulse. The most polarized pulses are those with approximately one tenth the peak flux of the brightest pulse. These conclusions do not depend on the assumed radiation mechanism nor on the energy and Lorentz factor of the blobs. We compare the prediction of this model to a simulated set of observations, showing that a limited sample of GRBs with time-resolved polarization measurements would provide a crucial test for this model. We finally show that a hint of the predicted correlation may have been already observed.

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Levinson, Amir 2009 对流不稳定性可能是激波磁场的来源

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Title:		Convective Instability of a Relativistic Ejecta Decelerated by a Surrounding Medium: An Origin of Magnetic Fields in GRBs?
Authors:		Levinson, Amir
Publication:		eprint arXiv:0906.4483
Publication Date:		06/2009
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		8 pages 1 fig. A detailed paper will follow
Bibliographic Code:		2009arXiv0906.4483L

Abstract

Global linear stability analysis of a self-similar solution describing a relativistic shell decelerated by an ambient medium is performed. The system is shown to be subject to the convective Rayleigh-Taylor instability, with a rapid growth of eigenmodes having angular scale much smaller than the causality scale. The growth rate appears to be largest at the interface separating the shocked ejecta and shocked ambient gas. The disturbances produced at the contact interface propagate in the shocked media and cause nonlinear oscillations of the forward and reverse shock fronts. It is speculated that such oscillations may affect the emission from the shocked ejecta in the early afterglow phase of GRBs, and may be the origin of the magnetic field in the shocked circum-burst medium.

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Bartolini, C. 2009 GRB 080319B 的瞬时光学辐射

主要内容:
给出了更详细的光学数据, 来自TORTORA.

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Title:		Analysis of the Prompt Optical Emission of the Naked-Eye GRB 080319B
Authors:		Bartolini, C.; Greco, G.; Guarnieri, A.; Piccioni, A.; Beskin, G.; Bondar, S.; Karpov, S.; Molinari, E.
Publication:		eprint arXiv:0906.4144
Publication Date:		06/2009
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		4 pages, 1 figure, proceeding of the "Neutron Stars and Gamma-Ray Burst, Recent Developments and Future Directions" conference, Egypt, March 30 - April 4, 2009
Bibliographic Code:		2009arXiv0906.4144B

Abstract

We present the observed/intrinsic optical parameters and the variability analysis of the Naked-Eye Burst, GRB 080319B, observed by the TORTORA wide-field optical monitoring system. The event is extreme not only in observed properties but also intrinsically: it is the most luminous event ever recorded at optical wavelengths. The temporal properties suggest short-lived periodic activities of the internal engine. This is the fastest optically variable source detected at cosmological distances.

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Götz, D. 2009 中法合作的伽玛暴卫星SVOM

主要内容:
预计2013年上天.

SVOM (Space-based multi-band astronomical Variable Object Monitor)
ECLAIRs , 4–250 keV energy range
XIAO, soft X-ray
the VT, visible telescope
and the GRM units: 50 keV-5 MeV

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Title:		SVOM: a new mission for Gamma-Ray Burst Studies
Authors:		Götz, D.; Paul, J.; Basa, S.; Wei, J.; Zhang, S. N.; Atteia, J.-L.; Barret, D.; Cordier, B.; Claret, A.; Deng, J.; Fan, X.; Hu, J. Y.; Huang, M.; Mandrou, P.; Mereghetti, S.; Qiu, Y.; Wu, B.
Affiliation:		AA(CEA Saclay-DSM/Irfu/Service d'Astrophysique-Orme des Merisiers, F-91191, Gif-sur-Yvette, France), AB(CEA Saclay-DSM/Irfu/Service d'Astrophysique-Orme des Merisiers, F-91191, Gif-sur-Yvette, France; Astroparticules et Cosmologie (APC)-10, rue Alice Domon et Léonie Duquet, F-75205, Paris Cedex 13, France), AC(Laboratoire d'Astrophysique de Marseille/CNRS/Université de Provence, Technopole de l'Etoile, 38 rue Frederic Joliot-Curie, 13388 Marseille Cedex 13, France), AD(National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012, China), AE(Department of Physics and Center for Astrophysics, Tsinghua University, Beijing 100084, China), AF(Laboratoire d'Astrophysique de Toulouse-Tarbes, Université de Toulouse, CNRS, 14 Av. Edouard Belin, 31400 Toulouse, France), AG(Centre d'Etude Spatiale des Rayonnements, Université de Toulouse, Centre Nationale de la Recherche Scientifique, 9 avenue du Colonel Roche, 31028 Toulouse Cedex 04, France), AH(CEA Saclay-DSM/Irfu/Service d'Astrophysique-Orme des Merisiers, F-91191, Gif-sur-Yvette, France), AI(CEA Saclay-DSM/Irfu/Service d'Astrophysique-Orme des Merisiers, F-91191, Gif-sur-Yvette, France), AJ(National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012, China), AK(Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, 17 Xinxi Road, Xi'an, China), AL(National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012, China), AM(National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012, China), AN(Centre d'Etude Spatiale des Rayonnements, Université de Toulouse, Centre Nationale de la Recherche Scientifique, 9 avenue du Colonel Roche, 31028 Toulouse Cedex 04, France), AO(INAF-Istituto di Astrofisica Spaziale e Fisica cosmica (IASF), Via Bassini 23, I-20133, Milano, Italy), AP(National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012, China), AQ(Key Laboratory for particle astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, P.O. Box 918, 100049, China)
Publication:		GAMMA-RAY BURST: Sixth Huntsville Symposium. AIP Conference Proceedings, Volume 1133, pp. 25-30 (2009). (AIPC Homepage)
Publication Date:		05/2009
Origin:		AIP
Keywords:		gamma-ray sources (astronomical), telescopes, galaxies
Abstract Copyright:		(c) 2009: American Institute of Physics
DOI:		10.1063/1.3155898
Bibliographic Code:		2009AIPC.1133...25G

Abstract

We present the SVOM (Space-based multi-band astronomical Variable Object Monitor) mission, that is being developed in cooperation between the Chinese National Space Agency (CNSA), the Chinese Academy of Science (CAS) and the French Space Agency (CNES), and is expected to be launched in 2013. Its scientific objectives include the study of the GRB phenomenon (diversity and unity), GRB physics (particle acceleration, radiation mechanisms), GRB progenitors, cosmology (host galaxies, intervening medium, star formation history, re-ionization, cosmological parameters), and fundamental physics (origin of cosmic rays, Lorentz invariance, gravitational waves sources). SVOM is designed to detect all known types of Gamma-Ray Bursts (GRBs), to provide fast and reliable GRB positions, to measure the broadband spectral characteristics and temporal properties of the GRB prompt emission. This will be obtained in first place thanks to a set of four space flown instruments. A wide field (~2 sr) coded mask telescope (ECLAIRs), operating in the 4-250 keV energy range, will provide the triggers and localizations, while a gamma-ray non-imaging spectrometer (GRM), sensitive in the 50 keV-5 MeV domain, will extend the prompt emission energy coverage. After a satellite slew, in order to place the GRB direction within field of view of the two narrow field instruments-a soft X-ray (XIAO), and a visible telescope (VT)-the GRB position will be refined and the study of the early phases of the GRB afterglow will be possible. A set of three ground based dedicated instruments, two robotic telescopes (GFTs) and a wide angle optical monitor (GWAC), will complement the space borne instruments. Thanks to the low energy trigger threshold (~4 keV) of the ECLAIRs, SVOM is ideally suited for the detection of soft, hence potentially most distant, GRBs. Its observing strategy is optimized to facilitate follow-up observations from the largest ground based facilities.

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Sathyaprakash, B. S. 2009 探测引力波的爱因斯坦卫星

主要内容:
还在设计阶段, 预计可以探测红移2-8的致密双星的并合.

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Title:		Cosmography with the Einstein Telescope
Authors:		Sathyaprakash, B. S.; Schutz, Bernard; Van Den Broeck, Chris
Publication:		eprint arXiv:0906.4151
Publication Date:		06/2009
Origin:		ARXIV
Keywords:		Astrophysics - Cosmology and Extragalactic Astrophysics
Comment:		4 pages, 2 figures
Bibliographic Code:		2009arXiv0906.4151S

Abstract

Einstein Telescope (ET) is a 3rd generation gravitational-wave (GW) detector that is currently undergoing a design study. ET can detect millions of compact binary mergers up to redshifts 2-8. A small fraction of mergers might be observed in coincidence as gamma-ray bursts, helping to measure both the luminosity distance and red-shift to the source. By fitting these measured values to a cosmological model, it should be possible to accurately infer the dark energy equation-of-state, dark matter and dark energy density parameters. ET could, therefore, herald a new era in cosmology.

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Meszaros 2009 短暴不是各向同性的

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Title:		Anisotropy in the sky distributions of the short and intermediate gamma-ray bursts: Breakdown of the cosmological principle?
Authors:		Meszaros, A.; Balazs, L. G.; Bagoly, Z.; Veres, P.
Affiliation:		AA(Charles University, Prague, Czech Republic), AB(Konkoly Observatory, Budapest, Hungary), AC(Eötvös University, Budapest, Hungary), AD(Eötvös University, Budapest, Hungary)
Publication:		GAMMA-RAY BURST: Sixth Huntsville Symposium. AIP Conference Proceedings, Volume 1133, pp. 483-485 (2009). (AIPC Homepage)
Publication Date:		05/2009
Origin:		AIP
Keywords:		gamma-ray sources (astronomical), magnetic anisotropy, cosmology
Abstract Copyright:		(c) 2009: American Institute of Physics
DOI:		10.1063/1.3155958
Bibliographic Code:		2009AIPC.1133..483M

Abstract

After the discovery of the anisotropy in the sky-distribution of intermediate gamma-ray bursts recently also the distribution of the short gamma-ray bursts is proven to be anisotropic. The impact of these behaviors on the validity of the cosmological principle is shortly discussed.

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Suwa 2009 伽玛暴中微子湮灭和磁场所伴随的引力波辐射

主要内容:
(这个东东也会很强? jet甚至双致密星并合的引力波不是强多了?)

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Title:		Probing the central engine of long gamma-ray bursts and hypernovae with gravitational waves
Authors:		Suwa, Yudai; Murase, Kohta
Publication:		eprint arXiv:0906.3833
Publication Date:		06/2009
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Extragalactic Astrophysics, Astrophysics - Solar and Stellar Astrophysics
Comment:		13 pages, 9 figures
Bibliographic Code:		2009arXiv0906.3833S

Abstract

There are the two common candidates as the viable energy source for the central engine of long gamma-ray bursts (GRBs) and hypernovae (HNe), neutrino annihilation and magnetic fields. We investigate gravitational wave (GW) emission accompanied by these two mechanisms. Especially, we focus on GW signals produced by neutrinos from a hyper-accreting disk around a massive black hole. We show that neutrino-induced GWs are detectable for $\sim$1 Mpc events by LISA and $\sim$ 100 Mpc by DECIGO/BBO, if the central engine is powered by neutrinos. Simultaneous neutrino detections are also expected, and helpful for diagnosing the explosion mechanism when later electromagnetic observations enable us to identify the source. GW and neutrino observations are potentially useful for probing choked jets that do not produce prompt emission, as well as successful jets. Even in non-detection cases, observations of GWs and neutrinos could lead to profitable implications for the central engine of GRBs and HNe.

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Amelino-Camelia 2009 Fermi LAT对量子引力的限制

主要内容:
一个好的小综述

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Title:		Prospects for constraining quantum gravity dispersion with near term observations
Authors:		Amelino-Camelia, Giovanni; Smolin, Lee
Publication:		eprint arXiv:0906.3731
Publication Date:		06/2009
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Extragalactic Astrophysics
Comment:		34 pages, LaTex
Bibliographic Code:		2009arXiv0906.3731A

Abstract

We discuss the prospects for bounding and perhaps even measuring quantum gravity effects on the dispersion of light using the highest energy photons produced in gamma ray bursts measured by the Fermi telescope. These prospects are brigher than might have been expected as in the first 10 months of operation Fermi has reported so far eight events with photons over 100 MeV seen by its Large Area Telescope (LAT). We review features of these events which may bear on Planck scale phenomenology and we discuss the possible implications for the alternative scenarios for in-vacua dispersion coming from breaking or deforming of Poincare invariance. Among these are semi-conservative bounds, which rely on some relatively weak assumptions about the sources, on subluminal and superluminal in-vacuo dispersion. We also propose that it may be possible to look for the arrival of still higher energy photons and neutrinos from GRB's with energies in the range 10^14 - 10^17 eV. In some cases the quantum gravity dispersion effect would predict these arrivals to be delayed or advanced by days to months from the GRB, giving a clean separation of astrophysical source and spacetime propagation effects.

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van Eerten 2009 数值模拟结果现实密度跳变不能解释X-ray flare

主要内容:
只能是中央引擎

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Title:		No visible optical variability from a relativistic blast wave encountering a wind-termination shock
Authors:		van Eerten, H. J.; Meliani, Z.; Wijers, R. A. M. J.; Keppens, R.
Publication:		eprint arXiv:0906.3629
Publication Date:		06/2009
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		4 figures, submitted to MNRAS letters
Bibliographic Code:		2009arXiv0906.3629V

Abstract

Gamma-ray burst afterglow flares and rebrightenings of the optical and X-ray light curve have been attributed to both late time inner engine activity and density changes in the medium surrounding the burster. To test the latter, we study the encounter between the relativistic blast wave from a gamma-ray burster and a stellar wind termination shock. The blast wave is simulated using a high performance adaptive mesh relativistic hydrodynamics code, AMRVAC, and the synchrotron emission is analyzed in detail with a separate radiation code. We find no bump in the resulting light curve, not even for very high density jumps. Furthermore, by analyzing the contributions from the different shock wave regions we are able to establish that it is essential to resolve the blast wave structure in order to make qualitatively correct predictions on the observed output and that the contribution from the reverse shock region will not stand out, even when the magnetic field is increased in this region by repeated shocks. This study resolves a controversy in recent literature.

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Capozziello 2009 伽玛暴作为标准烛光

主要内容:
基本上就是把别人的结合一下: 用多个统计关系, 用超新星帮助定标.

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Title:		Cosmography by GRBs : Gamma Ray Bursts as possible distance indicators
Authors:		capozziello, S.; Izzo, L.
Publication:		eprint arXiv:0906.3025
Publication Date:		06/2009
Origin:		ARXIV
Keywords:		Astrophysics - Cosmology and Extragalactic Astrophysics
Comment:		6 pages, 4 figures, Dark Energy Conference, Florence 2009
Bibliographic Code:		2009arXiv0906.3025C

Abstract

A new method to constrain the cosmological equation of state is proposed by using combined samples of gamma-ray bursts (GRBs) and supernovae (SNeIa). The Chevallier-Polarski-Linder parameterization is adopted for the equation of state in order to find out a realistic approach to achieve the deceleration/acceleration transition phase of dark energy models. As results, we find that GRBs, calibrated by SNeIa, could be, at least, good distance indicators capable of discriminating cosmological models with respect to $\Lambda$CDM at high redshift.

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Ukwatta 2009 Swift暴的Variability

主要内容:


精彩摘抄:

From pictures

可以从对光变的FFT得到一个特征时标(在~10Hz处的拐折处)

From pictures

之间有一点关系, 貌似"频率"越高的越亮.

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Title:		Variability in the Prompt Emission of Swift-BAT Gamma-Ray Bursts
Authors:		Ukwatta, T. N.; Dhuga, K. S.; Parke, W. C.; Sakamoto, T.; Markwardt, C. B.; Barthelmy, S. D.; Cioffi, D. F.; Eskandarian, A.; Gehrels, N.; Maximon, L.; Morris, D. C.
Publication:		eprint arXiv:0906.3193
Publication Date:		06/2009
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		4 pages; Submitted to Proceedings of NS-GRB Conference in Egypt 2009 (4 pages, 5 figures)
Bibliographic Code:		2009arXiv0906.3193U

Abstract

We present the results of our study of the variability time scales of a sample of 27 long Swift Gamma-Ray Bursts (GRBs) with known redshifts. The variability time scale can help our understanding of fundamental GRB parameters such as the initial bulk Lorentz factor and the characteristic size associated with the emission region. Fast Fourier Transform (FFT) techniques were used to extract a noise threshold crossing frequency, which we associate with a variability time scale. The threshold frequency appears to show a correlation with the peak isotropic luminosity of GRBs.

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