McGlynn 2009 GRB 061122的高能和偏振观测

主要内容:
有8MeV以上的辐射, 偏振的上限是60%

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Title:		High energy emission and polarisation limits for the INTEGRAL burst GRB 061122
Authors:		McGlynn, S.; Foley, S.; McBreen, B.; Hanlon, L.; McBreen, S.; Clark, D. J.; Dean, A. J.; Martin-Carrillo, A.; O'Connor, R.
Publication:		eprint arXiv:0903.5218
Publication Date:		03/2009
Origin:		ARXIV
Keywords:		Astrophysics - Cosmology and Extragalactic Astrophysics
Comment:		9 pages, 6 figures, accepted for publication in Astronomy & Astrophysics
Bibliographic Code:		2009arXiv0903.5218M

Abstract

(Abridged) GRB 061122 is one of the brightest GRBs detected within INTEGRAL's field of view to date. The two gamma-ray detectors on INTEGRAL were used to investigate the spectral characteristics of GRB 061122. A search for linear polarisation in the prompt emission was carried out using the SPI multiple event data in the energy range 100 keV-1 MeV. The prompt spectrum was best fit by a combination of a blackbody and a power--law model (the quasithermal model), with evidence for high energy emission continuing above 8 MeV. A pseudo-redshift value of pz = 0.95 +/- 0.18 was determined using the spectral fit parameters. The isotropic energy at this pseudo-redshift is 8.5 x 10^{52} erg. The jet opening angle was estimated to be smaller than 2.8 deg or larger than 11.9 deg from the X-ray lightcurve. An upper limit of 60% polarisation was determined for the prompt emission of GRB 061122, using the multiple event data. The high energy emission observed in the spectrum may be due to the reverse shock interacting with the GRB ejecta when it is decelerated by the circumburst medium. This behaviour has been observed in a small fraction of GRBs to date, but is expected to be more commonly observed by the Fermi Gamma-ray Space Telescope. The conditions for polarisation are met if the jet opening angle is less than 2.8 deg, but further constraints on the level of polarisation are not possible.

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Balazs 2009 光学亮暴和暗暴在伽玛和X射线的表现是有区别的

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Title:		Observational difference between gamma and X-ray properties of optically dark and bright GRBs
Authors:		Balazs, L. G.; Horvath, I.; Bagoly, Z.; Meszaros, A.; Veres, P.
Publication:		eprint arXiv:0903.5275
Publication Date:		03/2009
Origin:		ARXIV
Keywords:		Astrophysics - Cosmology and Extragalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Comment:		Santa Fe proc
Bibliographic Code:		2009arXiv0903.5275B

Abstract

Using the discriminant analysis of the multivariate statistical analysis we compared the distribution of the physical quantities of the optically dark and bright GRBs, detected by the BAT and XRT on board of the Swift Satellite. We found that the GRBs having detected optical transients (OT) have systematically higher peak fluxes and lower HI column densities than those without OT.

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Thomas 2009 近处可能的伽玛暴(kpc)可能对地球的危害

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Title:		Gamma-Ray Bursts as a Threat to Life on Earth
Authors:		Thomas, Brian C.
Publication:		eprint arXiv:0903.4710
Publication Date:		03/2009
Origin:		ARXIV
Keywords:		Astrophysics - Earth and Planetary Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Comment:		8 pages; submitted as part of proceedings of the ESLAB Symposium on 'Cosmic Cataclysms and Life', November 2008; to be published in a special issue of the International Journal of Astrobiology
Bibliographic Code:		2009arXiv0903.4710T

Abstract

Gamma-ray bursts (GRBs) are likely to have made a number of significant impacts on the Earth during the last billion years. The gamma radiation from a burst within a few kiloparsecs would quickly deplete much of the Earth's protective ozone layer, allowing an increase in solar ultraviolet radiation reaching the surface. This radiation is harmful to life, damaging DNA and causing sunburn. In addition, NO2 produced in the atmosphere would cause a decrease in visible sunlight reaching the surface and could cause global cooling. Nitric acid rain could stress portions of the biosphere, but the increased nitrate deposition could be helpful to land plants. We have used a two-dimensional atmospheric model to investigate the effects on the Earth's atmosphere of GRBs delivering a range of fluences, at various latitudes, at the equinoxes and solstices, and at different times of day. We have estimated DNA damage levels caused by increased solar UVB radiation, reduction in solar visible light due to NO2 opacity, and deposition of nitrates through rainout of HNO3. In this paper I give a concise review of this work and discuss current and future work on extending and improving our estimates of the terrestrial impact of a GRB.

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Gupta 2009 伽玛暴的EeV极高能辐射

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Title:		On the Gamma Ray Burst Origin of Extremely Energetic Cosmic Rays
Authors:		Gupta, Nayantara
Publication:		eprint arXiv:0903.4733
Publication Date:		03/2009
Origin:		ARXIV
Keywords:		Astrophysics - Cosmology and Extragalactic Astrophysics
Comment:		16pages,8figures. version accepted in Astroparticle Physics
Bibliographic Code:		2009arXiv0903.4733G

Abstract

Air shower experiments have detected cosmic ray events of energies upto 300 EeV. Most likely these cosmic rays have originated from compact objects. Their exact sources are yet to be identified. It has been suggested before that gamma ray bursts are possible sources of ultra-high energy cosmic rays. The two models of gamma ray burst emissions most often discussed are the internal and external shock models. We have calculated the proton spectrum above 60EeV from all gamma ray bursts distributed upto a redshift of 0.02 in the internal shock model assuming redshift and luminosity distributions consistent with observations, log normal distributions for their values of Lorentz factors, variability times and duration of bursts. Within the external shock model we have calculated the proton flux above 60EeV from all nearby gamma ray bursts assuming log normal distributions in their values of total energies, Lorentz factors at the deceleration epoch and compared with the observed data. We find that gamma ray bursts can produce cosmic ray proton flux comparable to the flux observed by the Pierre Auger experiment both within the internal and external shock models. We have also studied the dependence of the maximum proton energies and the cooling breaks in the proton spectrum on the various parameters like Lorentz factor, energy of the GRB fireball, variability time (in case of internal shocks), ambient particle density (in case of external shocks). Our results are important to understand how the various observable parameters determine which mechanism e.g. $p\gamma$ interactions, synchrotron cooling of protons will dominate over one another inside these sources.

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Jin 2009 GRB 081109A的wind+ISM 拟合

主要内容:
认为它的外部介质是先wind, 然后在1e17cm左右变为均匀介质(还不是星际介质).

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Title:		The X-ray afterglow of GRB 081109A: clue to the wind bubble structure
Authors:		Jin, Zhi-Ping; Xu, Dong; Fan, Yi-Zhong; Wei, Da-Ming
Publication:		eprint arXiv:0903.4476
Publication Date:		03/2009
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Extragalactic Astrophysics
Comment:		6 pages, 4 figures, MNRAS submitted
Bibliographic Code:		2009arXiv0903.4476J

Abstract

We present the prompt BAT and afterglow XRT data of Swift-discovered GRB081109A up to ~5\times10^5 sec after the trigger. The ground-based optical afterglow follow-ups are rare for this event. The temporal and spectral indices of the X-ray afterglow emission change remarkably, which are interpreted as the GRB outflow firstly expands into the stellar-wind-like (WIND) medium surrounding the progenitor (for t\lesssim 300 sec after the burst), and lately expands into the homogeneous interstellar-medium like (ISM) medium. Numerical fit of the afterglow data indicates that for this burst the parameter of the WIND medium, $A_*$, is ~0.01, the particle density, $n$, of the ISM-like medium is ~0.1 cm^-3, and the WIND-ISM transition radius, $R_t$, occurs at ~3.3\times10^17 cm.

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Hartnett 2009 光度距离, 角直径距离和表面光度的计算

主要内容:
这个不错, 给了一些基本量的计算方法, 而且又是很近的文章.

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Luminosity Distance, Angular Size and Surface Brightness in Cosmological General Relativity Journal Foundations of Physics Publisher Springer Netherlands ISSN 0015-9018 (Print) 1572-9516 (Online) Issue Volume 37, Number 3 / March, 2007 DOI 10.1007/s10701-007-9108-x Pages 446-454 Subject Collection Physics and Astronomy SpringerLink Date Friday, February 23, 2007

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Luminosity Distance, Angular Size and Surface Brightness in Cosmological General Relativity

John G. Hartnett¹ and Firmin J. Oliveira²

(1)	School of Physics, The University of Western Australia, 35 Stirling Hwy, Crawley, 6009, WA, Australia

(2)	Joint Astronomy Centre Hilo, Hilo, HI 96720, USA

Received: 17 March 2006 Revised: 7 December 2006 Published online: 22 February 2007

This paper corrects the explanation given by Oliveira and Hartnett, Found. Phys. Lett. 19(6), 519–535, 2006 for the luminosity distance in Cosmological General Relativity. The mathematical expression for the luminosity distance used in that paper is correct but the explanation in Eqs. (22) and (23) is flawed. Expressions for the angular size and surface brightness of sources are also derived. Finally some comment is made about the calculations of χ² values in that paper compared with an earlier paper, Found. Phys. 36(6), 839–861, 2006.

Keywords Carmeli’s cosmology - luminosity distance - angular size - surface brightness

also:

http://arxiv.org/abs/astro-ph/0603500

为什么f_nu的表达式里有个nu

就是这个式子啊:
f_nu=(1+z)L_nu/(4pi d_L^2)
来源是
f=L/(4pi d_L^2), 这是定义式
在对nu求导的时候有观测者和当地系的区别
df/dnu=dL/dnu /(4pi d_L^2)=dL/(dnu'/(1+z)) /(4pi d_L^2)
于是多了个(1+z)

Sivaram 2009 黑洞产生相对论喷流

主要内容:
文中公式比较混乱, 不知道是不是对的.

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Title:		Relativistic Jets from Black Holes: A Unified Picture
Authors:		Sivaram, C; Arun, Kenath
Publication:		eprint arXiv:0903.4005
Publication Date:		03/2009
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		15 pages, 53 equations
Bibliographic Code:		2009arXiv0903.4005S

Abstract

The current understanding of the formation of powerful bi-directional jets in systems such as radio galaxies and quasars is that the process involves a supermassive black hole that is being fed with magnetized gas through an orbiting accretion disc. In this paper we discuss the dynamics of the jet powered by rotating black holes, in the presence of a magnetic field, including the scaling of the jet length and their typical time scales. We consider a unified picture covering all phenomena involving jets and rotating black holes ranging from gamma ray bursts to extragalactic jets and discuss the relevant scaling laws. We have also discussed the acceleration of the particles in jets and consequent synchrotron and inverse Compton radiations. Accelerated protons from jets as possible sources of high energy cosmic rays are also discussed.

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Bloom 1998 GRB 980425的瞬时光变曲线

主要内容:
找了好久的这个暴的光变曲线, 居然藏在一个不以980425为标题的文章里.

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Title:		Expected Characteristics of the Subclass of Supernova Gamma-Ray Bursts
Authors:		Bloom, J. S.; Kulkarni, S. R.; Harrison, F.; Prince, T.; Phinney, E. S.; Frail, D. A.
Publication:		The Astrophysical Journal, Volume 506, Issue 2, pp. L105-L108. (ApJ Homepage)
Publication Date:		10/1998
Origin:		APJ
ApJ Keywords:		GAMMA RAYS: BURSTS, STARS: SUPERNOVAE: GENERAL, STARS: SUPERNOVAE: INDIVIDUAL: ALPHANUMERIC: SN 1998BW
Abstract Copyright:		(c) 1998: The American Astronomical Society
DOI:		10.1086/311655
Bibliographic Code:		1998ApJ...506L.105B

Abstract

The spatial and temporal coincidence of gamma-ray burst (GRB) 980425 and supernova (SN) 1998bw has prompted speculation that there exists a subclass of GRBs produced by SNe (``S-GRBs''). A physical model motivated by radio observations lead us to propose the following characteristics of S-GRBs: (1) prompt radio emission and an implied high brightness temperature close to the inverse Compton limit, (2) high expansion velocity (>~50,000 km s^-1) of the optical photosphere as derived from lines widths and energy release larger than usual, (3) no long-lived X-ray afterglow, and (4) a single-pulse GRB profile. Radio studies of previous SNe show that only (but not all) Type Ib and Ic SNe potentially satisfy the first condition. We investigate the proposed associations of GRBs and SNe within the context of these proposed criteria and suggest that ~1% of GRBs detected by BATSE may be members of this subclass.

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Savchenko 2009 Swift暴的死线去哪里了?

主要内容:
其实HETE的也几乎没有(Barraud et al. 2003)

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死线是在同步模型下, 低能段的谱指数 f_nu~ nu^alpha, 应该是1/3, 如果掺上了-1/2或者-(p-1)/2的高能段, 则可能在观测上小于1/3(如果谱指数比1/3大, 则在同步谱上不可能, 如果不考虑同步自吸收导致的谱指数为2的贡献的话). 换成光子谱指数就是小于-2/3, 在上图上就是大于2/3(因为他把指数的负号去掉了). 其中蓝线是batse的, 红线是swift的. 可见在2/3的附近, swift的暴很少.

虽然死线可以用黑体成份来解释. 但是如果看到这个图, 则很可能说明但是BATSE的谱测量不够精确才导致这些死线的出现的.

图中在纵坐标上, 谱的个数居然也有error bar, 搞不懂.

文章信息:

arXiv:0903.3556 [ps, pdf, other]

Title: Where are Swift Gamma-ray bursts beyond the "synchrotron deathline"?

Authors: V.Savchenko, A.Neronov

Comments: 11 pages, 20 figures, accepted for publication in MNRAS

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

We study time-resolved spectra of the prompt emission of Swift Gamma-ray bursts (GRB). Our goal is to see if previous BATSE claims of the existence of a large amount of spectra with the low energy photon indices harder than 2/3 are consistent with Swift data. We perform a systematic search of the episodes of the spectral hardening down to the photon indices below 2/3 in the prompt emission spectra of Swift GRBs. We show that the data of the BAT instrument on board of Swift are consistent with BATSE data, if one takes into account differences between the two instruments. Much lower statistics of the very hard spectra in Swift GRBs is explained by the smaller field of view and narrower energy band of the BAT telescope.

Peng 2009 在pulse下降阶段的E_p的演化

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arXiv:0903.3457 [ps, pdf, other]

Title: The $E_{p}$ Evolutionary Slope within the Decay Phase of "FRED" Gamma-ray Burst Pulses

Authors: Z. Y. Peng, L. Ma, X. H. Zhao, Y. Yin, L. M. Fang, Y. Y. Bao

Comments: 25 pages, 9 figures, accepted for publication in The Astrophysical Journal

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

Employing two samples containing of 56 and 59 well-separated FRED (fast rise and exponential decay) gamma-ray burst (GRB) pulses whose spectra are fitted by the Band spectrum and Compton model, respectively, we have investigated the evolutionary slope of $E_{p}$ (where $E_{p}$ is the peak energy in the $\nu F\nu$ spectrum) with time during the pulse decay phase. The bursts in the samples were observed by the Burst and Transient Source Experiment (BATSE) on the Compton Gamma-Ray Observatory. We first test the $E_{p}$ evolutionary slope during the pulse decay phase predicted by Lu et al. (2007) based on the model of highly symmetric expanding fireballs in which the curvature effect of the expanding fireball surface is the key factor concerned. It is found that the evolutionary slopes are normally distributed for both samples and concentrated around the values of 0.73 and 0.76 for Band and Compton model, respectively, which is in good agreement with the theoretical expectation of Lu et al. (2007). However, the inconsistence with their results is that the intrinsic spectra of most of bursts may bear the Comptonized or thermal synchrotron spectrum, rather than the Band spectrum. The relationships between the evolutionary slope and the spectral parameters are also checked. We show the slope is correlated with $E_{p}$ of time-integrated spectra as well as the photon flux but anticorrelated with the lower energy index $\alpha$. In addition, a correlation between the slope and the intrinsic $E_{p}$ derived by using the pseudo-redshift is also identified. The mechanisms of these correlations are unclear currently and the theoretical interpretations are required.

Lipunova 2009 用spinar解释伽玛暴的前兆

主要内容:
预言高红移的前兆可以在1000s以前发生.

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Title:		Population synthesis of gamma-ray bursts with precursor activity and the spinar paradigm
Authors:		Lipunova, G. V.; Gorbovskoy, E. S.; Bogomazov, A. I.; Lipunov, V. M.
Publication:		eprint arXiv:0903.3169
Publication Date:		03/2009
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Extragalactic Astrophysics
Comment:		11 pages, 9 figures. Submitted to MNRAS
Bibliographic Code:		2009arXiv0903.3169L

Abstract

We study statistical properties of long gamma-ray bursts (GRBs) produced by the collapsing cores of WR stars in binary systems. Fast rotation of the cores enables a two-stage collapse scenario, implying the formation of a spinar-like object. A burst produced by such a collapse consists of two pulses, whose energy budget is enough to explain observed GRBs. We calculate models of spinar evolution using results from a population synthesis of binary systems (done by the `Scenario Machine') as initial parameters for the rotating massive cores. Among the resulting bursts, events with precursor are identified, and the precursor-to-main-pulse time separations fully agree with the range of the observed values. The calculated fraction of long GRBs with precursor (about 10 per cent) and the durations of the main pulses are also consistent with observations. Precursors with lead times greater by up to one order of magnitude than those observed so far are expected to be about twice less numerous. Independently of a GRB model assumed, we predict the detection of precursors that arrive up to >~ 10^3 s in advance of the main events of GRBs occured at high redshifts.

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Wang 2009 后退的那个喷流的余辉

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虚线是后退喷流的贡献. 如果参数不同, 贡献可以更大.


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Title:		On the afterglow from the receding jet of gamma-ray burst
Authors:		Wang, Xin; Huang, Y. F.; Kong, Si-Wei
Publication:		eprint arXiv:0903.3119
Publication Date:		03/2009
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		Submitted to A&A on 2009-01-06; 10 pages, 7 figures
Bibliographic Code:		2009arXiv0903.3119W

Abstract

According to popular progenitor models of gamma-ray bursts, twin jets should be launched by the central engine, with a preceding jet moving toward the observer and a receding jet moving backwardly. However, in calculating the afterglows, usually only the emission from the preceding jet is considered. Here we present a detailed numerical study on the afterglow from the receding jet. Our calculation is based on a generic dynamical description, and includes some delicate ingredients such as the effect of the equal arrival time surface. It is found that the emission from the receding jet is generally rather weak. In radio bands, it usually peaks at a time of $t \geq 1000$ d, with the peak flux nearly 4 magnitudes lower than the peak flux of the preceding jet. Also, it usually manifests as a short plateau in the total afterglow light curve, but not as an obvious rebrightening as once expected. In optical bands, the contribution from the receding jet is even weaker, with the peak flux being $\sim 8$ magnitudes lower than the peak flux of the preceding jet. We thus argue that the emission from the receding jet is very difficult to detect. However, in some special cases, i.e., when the circum-burst medium density is very high, or if the parameters of the receding jet is quite different from those of the preceding jet, the emission from the receding jet can be significantly enhanced and may still emerge as a marked rebrightening. We suggest that the search for receding jet emission should mostly concentrate on nearby gamma-ray bursts, and the observation campaign should last for at least several hundred days for each event.

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Nakar 2009 同步和SSC的Klein-Nishina效应

主要内容:
本文只考虑了KN区不会有正负电子对产生的情况(光深小). (对伽玛暴来说可能性比较小.)

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这是文中弱KN效应的图: 黑线是同步和SSC的谱(红线是数值结果), 虚线是不考虑KN应该出现的谱. SSC部分容易理解, 同步部分, 可能原因是由于较高频率处的光子被KN抑制了, 所以比不考虑KN的时候多一些. (可是我印象中这点差别很小的, 特别是光深也很小的时候, 只有\tau的光子被IC, 而这里确相差有几倍的样子, 不知道什么原因. 也没仔细看文中的解释.)

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Title:		Klein-Nishina effects on Synchrotron and Synchrotron self-Compton spectrum
Authors:		Nakar, Ehud; Ando, Shin'ichiro; Sari, Re'em
Publication:		eprint arXiv:0903.2557
Publication Date:		03/2009
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Bibliographic Code:		2009arXiv0903.2557N

Abstract

We present analytic approximations to the optically thin synchrotron and synchrotron self-Compton (SSC) spectra when Klien-Nishina (KN) effects are important and pair production and external radiation fields can be neglected. This theory is useful for analytical treatment of radiation from astrophysical sources, such as gamma-ray bursts (GRBs), active galactic nuclei and pulsar wind nebula, where KN effects may be important. We consider a source with a continuous injection of relativistic electrons with a power-law energy distribution above some typical injection energy. We find that the synchrotron-SSC spectra can be described by a broken power-law, and provide analytical estimates for the break frequencies and power-law indices. In general, we show that the dependence of the KN cross-section on the energy of the upscattering electron results in a hardening of the energy distribution of fast cooling electrons and therefore in a hardening of the observed synchrotron spectrum. As a result, for example, the synchrotron spectrum of fast cooling electrons, below the typical injection energy, can be as hard as $F_\nu \propto \nu^0$, instead of the classical $\nu^{-1/2}$ when KN effects are neglected. Another example is that the synchrotron energy output can be dominated by electrons with energy above the typical injection energy. We solve self-consistently for the cooling frequency and find that the transition between synchrotron and SSC cooling can result in a discontinuous variations of the cooling frequency and the synchrotron and SSC spectra. We demonstrate the application of our results to theory by applying them to prompt and afterglow emission models of GRBs.

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Guidorzi 2009 GRB/XRF 080330的观测

主要内容:
说可能是一个偏轴的伽玛暴

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Title:		Rise and fall of the X-ray flash 080330: an off-axis jet?
Authors:		Guidorzi, C.; Clemens, C.; Kobayashi, S.; Granot, J.; Melandri, A.; D'Avanzo, P.; Kuin, N. P. M.; Klotz, A.; Fynbo, J. P. U.; Covino, S.; Greiner, J.; Malesani, D.; Mao, J.; Mundell, C. G.; Steele, I. A.; Jakobsson, P.; Margutti, R.; Bersier, D.; Campana, S.; Chincarini, G.; D'Elia, V.; Fugazza, D.; Genet, F.; Gomboc, A.; Kruehler, T.; Kupcu Yoldacs, A.; Moretti, A.; Mottram, C. J.; O'Brien, P. T.; Smith, R. J.; Szokoly, G.; Tagliaferri, G.; Tanvir, N. R.; Gehrels, N.
Publication:		eprint arXiv:0903.2958
Publication Date:		03/2009
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		accepted to A&A, 19 pages, 11 figures
Bibliographic Code:		2009arXiv0903.2958G

Abstract

X-ray flashes (XRFs) are a class of gamma-ray bursts (GRBs) with the peak energy of the time-integrated spectrum, Ep, below 30 keV, whereas classical GRBs have Ep of a few hundreds keV. Apart from Ep and the lower luminosity, the properties of XRFs are typical of the classical GRBs. Yet, the nature of XRFs and the differences from that of GRBs are not understood. In addition, there is no consensus on the interpretation of the shallow decay phase observed in most X-ray afterglows of both XRFs and GRBs. We examine in detail the case of XRF 080330 discovered by Swift at the redshift of 1.51. This burst is representative of the XRF class and exhibits an X-ray shallow decay. The rich and broadband (from NIR to UV) photometric data set we collected across this phase makes it an ideal candidate to test the off-axis jet interpretation proposed to explain both the softness of XRFs and the shallow decay phase. We present prompt gamma-ray, early and late IR/visible/UV and X-ray observations of the XRF 080330. We derive a SED from NIR to X-ray bands across the plateau phase with a power-law index of 0.79 +- 0.01 and negligible rest-frame dust extinction. The multi-wavelength evolution of the afterglow is achromatic from ~10^2 s out to ~8x10^4 s. We describe the temporal evolution of the multi-wavelength afterglow within the context of the standard afterglow model and show that a single-component jet viewed off-axis explains the observations (abriged).

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Sokolowski 2009 用"Pi of the Sky"观测暴本身期间的光学辐射

主要内容:
由于偶然看到了080319B, 所以想向这个方向倾斜.

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Title:		Prompt optical observations of GRBs with "Pi of the Sky" system
Authors:		Sokolowski, M.; Cwiok, M.; Dominik, W.; Juchniewicz, J.; Kasprowicz, G.; Majcher, A.; Majczyna, A.; Malek, K.; Mankiewicz, L.; Nawrocki, K.; Pietrzak, R.; Piotrowski, L. W.; Rybka, D.; Uzycki, J.; Wawrzaszek, R.; Wrochna, G.; Zaremba, M.; Zarnecki, A. F.
Publication:		eprint arXiv:0903.2998
Publication Date:		03/2009
Origin:		ARXIV
Keywords:		Astrophysics - Cosmology and Extragalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Comment:		6 pages, 3 figures, to appear in Proc. of the 6th Huntsville Gamma-Ray Burst Symposium, eds. C. A. Meegan, N. Gehrels, and C. Kouveliotou (AIP Conf. Proc., New York)
Bibliographic Code:		2009arXiv0903.2998S

Abstract

The "Pi of the Sky" prototype apparatus observed prompt optical emission from extremely bright GRB080319B since the very beginning of the gamma emission. The burst occurred at redshift z=0.937 and set the record of optical luminosity reaching 5.3 mag. The position of the burst was observed before, during and after the explosion by several telescopes and unprecedented coverage of optical light curve has been achieved. The combination of these unique optical data with simultaneous gamma-ray observations provides a powerful diagnostic tool for the physics of the GRB explosion within seconds of its start. The "Pi of the Sky" prototype, working since 2004 in Las Campanas Observatory in Chile, consists of 2 cameras observing same 20x20 deg^2 fields in the sky with time resolution of 10 seconds. The prototype reacts to GCN alerts, but it has also its own algorithm for identification of optical flashes. The final system covering field of view of Swift or Fermi satellite will consist of 2 arrays of 16 cameras installed in a distance of about 100 km. The system is currently under construction. It will be a powerful tool for early optical observations of GRBs, allowing for optical observation of GRBs before, during and after the gamma emission. With the on-line data analysis in real time, it will identify short optical flashes autonomously and will be able to distribute this information among the community. In this contribution the general idea of the final version of the experiment and the most interesting results from the prototype are presented.

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