Lü, Hou-Jun 2014 磁星作为伽马暴的中心引擎

主要内容:
用closure relation和磁星的预言对比，发现一致。

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Title:		A test of the millisecond magnetar central engine model of GRBs with Swift data
Authors:		Lü, Hou-Jun; Zhang, Bing
Publication:		eprint arXiv:1401.1562
Publication Date:		01/2014
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		19 pages, 35 figures, 3 Tables. comments are welcome
Bibliographic Code:		2014arXiv1401.1562L

Abstract

A rapidly spinning, strongly magnetized neutron star (magnetar) has been proposed as one possible candidate of the central engine of gamma-ray bursts (GRBs). In this paper, we systematically analyze the Swift/XRT light curves of long GRBs detected before 2013 August, and characterize them into four categories based on how likely they may harbor a magnetar central engine: "Gold", "Silver", "Aluminum" and "Non-magnetar". We also independently analyze the data of short GRBs with a putative magnetar central engine. We then perform a statistical study of various properties of the magnetar samples and the non-magnetar sample, and investigate whether the data are consistent with the hypothesis that there exist two types of central engines. By deriving the physical parameters of the putative magnetars, we find that the observations of the Gold and Silver samples are generally consistent with the predictions of the magnetar model. For a reasonable beaming factor for long GRBs, the derived magnetar surface magnetic field $B_p$ and initial spin period $P_0$ fall into the reasonable range. Magnetar winds in short GRBs, on the other hand, are consistent with being isotropic. No GRB in the magnetar sample has a beam-corrected total energy exceeding the maximum energy budget defined by the initial spin energy of the magnetar ($E_{\rm rot}\sim 2\times 10^{52}$ erg), while some non-magnetar GRBs do violate such a limit. With beaming correction, on average the non-magnetar sample (probably powered by a black hole) is more energetic and luminous than the magnetar samples. Our analysis hints that millisecond magnetars are likely operating in a good fraction, but probably not all, GRBs.

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Ghirlanda 2013 Swift亮暴的射电余辉统计

主要内容:


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不同波段的峰值时间和峰值流量

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Title:		Radio afterglows of a complete sample of bright Swift GRBs: predictions from present days to the SKA era
Authors:		Ghirlanda, G.; Salvaterra, R.; Burlon, D.; Campana, S.; Melandri, A.; Bernardini, M. G.; Covino, S.; D'Avanzo, P.; D'Elia, V.; Ghisellini, G.; Nava, L.; Prandoni, I.; Sironi, L.; Tagliaferri, G.; Vergani, S. D.; Wolter, A.
Affiliation:		AA(INAF - Osservatorio Astronomico di Brera, via E. Bianchi 46, I-23807 Merate, Italy; giancarlo.ghirlanda@brera.inaf.it), AB(INAF - IASF Milano, via E. Bassini 15, I-20133 Milano, Italy), AC(Sydney Institute for Astronomy, School of Physics, The University of Sydney, NSW 2006, Australia; ARC Centre of Excellence for All-sky Astrophysics (CAASTRO), The University of Sydney, NSW 2006, Australia), AD(INAF - Osservatorio Astronomico di Brera, via E. Bianchi 46, I-23807 Merate, Italy), AE(INAF - Osservatorio Astronomico di Brera, via E. Bianchi 46, I-23807 Merate, Italy), AF(INAF - Osservatorio Astronomico di Brera, via E. Bianchi 46, I-23807 Merate, Italy), AG(INAF - Osservatorio Astronomico di Brera, via E. Bianchi 46, I-23807 Merate, Italy), AH(INAF - Osservatorio Astronomico di Brera, via E. Bianchi 46, I-23807 Merate, Italy), AI(ASI - Science Data Center, via Galileo Galilei, I-00044 Frascati, Italy; INAF-OAR Via Frascati 33, I-00040 Monteporzio Catone, Italy), AJ(INAF - Osservatorio Astronomico di Brera, via E. Bianchi 46, I-23807 Merate, Italy), AK(APC Université Paris Diderot, 10 rue Alice Domon et Leonie Duquet, F-75205 Paris Cedex 13, France; INAF - Osservatorio Astronomico di Brera, via E. Bianchi 46, I-23807 Merate, Italy), AL(INAF - Istituto di Radioastronomia, via P. Gobetti, 101, I-40129 Bologna, Italy), AM(Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA), AN(INAF - Osservatorio Astronomico di Brera, via E. Bianchi 46, I-23807 Merate, Italy), AO(GEPI, Observatoire de Paris, CNRS, Univ. Paris Diderot, 5 place Jules Janssen, F-92190 Meudon, France; INAF - Osservatorio Astronomico di Brera, via E. Bianchi 46, I-23807 Merate, Italy), AP(INAF - Osservatorio Astronomico di Brera, via E. Bianchi 46, I-23807 Merate, Italy)
Publication:		Monthly Notices of the Royal Astronomical Society, Volume 435, Issue 3, p.2543-2551 (MNRAS Homepage)
Publication Date:		11/2013
Origin:		OUP
Astronomy Keywords:		radiation mechanisms: non thermal, radio continuum: general
Abstract Copyright:		2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society
DOI:		10.1093/mnras/stt1466
Bibliographic Code:		2013MNRAS.435.2543G

Abstract

Radio observations of Gamma-Ray Bursts (GRBs) afterglows are fundamental in providing insights into their physics and environment, and in constraining the true energetics of these sources. Nonetheless, radio observations of GRB afterglows are presently sparse in the time/frequency domain. Starting from a complete sample of 58 bright Swift long bursts (BAT6), we constructed a homogeneous sub-sample of 38 radio detections/upper limits which preserves all the properties of the parent sample. One half of the bursts have detections between 1 and 5 d after the explosion with typical fluxes F ≳ 100 μJy at 8.4 GHz. Through a Population SYnthesis Code coupled with the standard afterglow Hydrodynamical Emission model, we reproduce the radio flux distribution of the radio sub-sample. Based on these results, we study the detectability in the time/frequency domain of the entire long GRB population by present and future radio facilities. We find that the GRBs that typically trigger Swift can be detected at 8.4 GHz by Jansky Very Large Array within few days with modest exposures even at high redshifts. The final Square Kilometre Array (SKA) can potentially observe the whole GRB population provided that there will be a dedicated GRB gamma-ray detector more sensitive than Swift. For a sizeable fraction (50 per cent) of these bursts, SKA will allow us to perform radio calorimetry, after the trans-relativistic transition (occurring ˜100 d), providing an estimate of the true (collimation corrected) energetics of GRBs.

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Chandra, Poonam 2011 1997-2011所有的射电余辉的总结

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Title:		A Radio-Selected Sample of Gamma Ray Burst Afterglows
Authors:		Chandra, Poonam; Frail, Dale A.
Publication:		eprint arXiv:1110.4124
Publication Date:		10/2011
Origin:		ARXIV
Keywords:		Astrophysics - Cosmology and Extragalactic Astrophysics
Comment:		To appear in 20th Jan 2012 issue of ApJ, 26 pages in ApJ format, 48 figures, 6 tables
Bibliographic Code:		2011arXiv1110.4124C

Abstract

We present a catalog of radio afterglow observations of gamma-ray bursts (GRBs) over a 14 year period from 1997 to 2011. Our sample of 304 afterglows consists of 2995 flux density measurements (including upper limits) at frequencies between 0.6 GHz and 660 GHz, with the majority of data taken at 8.5 GHz frequency band (1539 measurements). We use this dataset to carry out a statistical analysis of the radio-selected sample. The detection rate of radio afterglows has stayed unchanged almost at 31% before and after the launch of the {\em Swift} satellite. The canonical long-duration GRB radio light curve at 8.5 GHz peaks at 3-6 days in the source rest frame, with a median peak luminosity of $10^{31}$ erg s$^{-1}$ Hz$^{-1}$. The peak radio luminosities for short-hard bursts, X-ray flashes and the supernova-GRB classes are an order of magnitude or more fainter than this value. There are clear relationships between the detectability of a radio afterglow and the fluence or energy of a GRB, and the X-ray or optical brightness of the afterglow. However, we find few significant correlations between these same GRB and afterglow properties and the peak radio flux density. We also produce synthetic light curves at centimeter (cm) and millimeter (mm) bands using a range of blastwave and microphysics parameters derived from multiwavelength afterglow modeling, and we use them to compare to the radio sample. Finding agreement, we extrapolate this behavior to predict the cm and mm behavior of GRBs observed by the Expanded Very Large Array and the Atacama Large Millimeter Array.

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de Ugarte Postigo 2011 ALMA之前的红外观测

主要内容:
也就是目前的红外余辉的所有观测的总结。一共77个暴。将来ALMA可以观测到98%的暴的余辉！

ALMA座落在智利南的Llano de Chajnantor，有5000m的海拔。2011年末它就可以开始用了。

ALMA的能段

Band Frequency range Wavelength range
(GHz) (mm)
Band 1 31 – 45 6.66 – 9.67
Band 2 67 – 90 3.33 – 4.47
Band 3 84 – 116 2.58 – 3.56
Band 4 125 –163 1.84 – 2.40
Band 5 162 – 211 1.42 – 1.85
Band 6 211 – 275 1.09 – 1.42
Band 7 275 – 373 0.80 – 1.09
Band 8 385 – 500 0.60 – 0.78
Band 9 602 – 720 0.42 – 0.50
Band 10 787 – 950 0.32 – 0.38


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Title:		Pre-ALMA observations of GRBs in the mm/submm range
Authors:		de Ugarte Postigo, A.; Lundgren, A.; Martín, S.; Garcia-Appadoo, D.; de Gregorio Monsalvo, I.;Michałowski, M. J.; Thöne, C. C.; Campana, S.; Gorosabel, J.; Tanvir, N. R.; Wiersema, K.; Castro-Tirado, A. J.; Schulze, S.; De Breuck, C.; Petitpas, G.; Hjorth, J.; Jakobsson, P.; Covino, S.;Fynbo, J. P. U.; Winters, J. M.; Bremer, M.; Levan, A. J.; Salvaterra, R.
Publication:		eprint arXiv:1108.1797
Publication Date:		08/2011
Origin:		ARXIV
Keywords:		Astrophysics - Cosmology and Extragalactic Astrophysics
Comment:		21 pages, 12 figures, 5 tables (one big one!), submitted to A&A. Comments welcome, including any possible overlooked datasets
Bibliographic Code:		2011arXiv1108.1797D

Abstract

It is well known that GRBs generate an afterglow emission that can be detected from radio to X-rays during days, or even weeks after the initial explosion. The peak of this emission crosses the mm/submm range during the first hours to days, making their study in this range crucial for constraining the models. Observations have been limited until now due to the low sensitivity of the observatories in this range. We present observations of 10 GRB afterglows obtained from APEX and SMA at 230 and 345GHz and put them into context with a catalogue of all the observations that have been published until now in the spectral range that will be covered by ALMA. The catalogue of mm/submm observations collected here is the largest to date and is composed of 77 GRBs, of which 65 had afterglow observations, whereas the rest are host galaxy searches. With our programmes, we contributed with data of 10 GRBs and the discovery of 2 submm counterparts. In total, the full sample, including data from the literature, has 19 afterglow detections with redshift ranging from 0.168 to 8.2. GRBs have been detected in mm/submm wavelengths with peak luminosities spanning 2.5 orders of magnitude, the most luminous reaching 10^33erg s^-1 Hz^-1. We observe a correlation between the X-ray brightness at 0.5 days and the mm/submm peak brightness. Finally we give a rough estimate of the distribution of peak flux densities of GRB afterglows, based on the current mm/submm sample. Observations in the mm/submm bands have been shown to be crucial for our understanding of the physics of GRBs, but have until now been limited by the sensitivity of the observatories. With the start of the operations at ALMA, the sensitivity will be increased by more than an order of magnitude. Our estimates predict that, once completed, ALMA will detect up to 98% of the afterglows if observed during the passage of the peak synchrotron emission.

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Racusin 2011 Fermi和Swift暴的余辉统计

主要内容:
把这些暴拿过来一起统计，有多个量。

精彩摘抄:

统计的暴的来源数

上面是长暴，下面是短暴。 左边是X射线的，右边是u波段的光变曲线。

不同来源的暴的几率分布，可见BAT短暴明显分布于红移低的地方。

1天的时候x射线的光变指数和谱指数的分布

1天的时候光学波段的光变指数和谱指数的分布

不同时间不同来源的长暴的光度分布

对短暴（太少）

长暴和短暴各向同性能量的分布

各个量之间的关联的KS检验，值越小表明两个数据之间的差别越明显

（应该最大值是1，表明量数据完全相同）

暴的张角分布（不确定度很大），以及从而到处的实际光子能量

利用 11小时的时候X射线的光度所导出的动能（依赖于很多参数的方法）

和各向同性能量之间的统计关系

各参数值的范围

初始Lorentz因子的范围，采用了：gamma-gamma,t_peak,

ZP10, 2 zone-gamma gamma这四种方法

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Title:		Fermi and Swift Gamma-Ray Burst Afterglow Population Studies
Authors:		Racusin, J. L.; Oates, S. R.; Schady, P.; Burrows, D. N.; de Pasquale, M.; Donato, D.; Gehrels, N.;Koch, S.; McEnery, J.; Piran, T.; Roming, P.; Sakamoto, T.; Swenson, C.; Troja, E.; Vasileiou, V.;Virgili, F.; Wanderman, D.; Zhang, B.
Publication:		eprint arXiv:1106.2469
Publication Date:		06/2011
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		13 pages, 11 figures, Accepted for publication in ApJ
Bibliographic Code:		2011arXiv1106.2469R

Abstract

The new and extreme population of GRBs detected by Fermi-LAT shows several new features in high energy gamma-rays that are providing interesting and unexpected clues into GRB prompt and afterglow emission mechanisms. Over the last 6 years, it has been Swift that has provided the robust dataset of UV/optical and X-ray afterglow observations that opened many windows into components of GRB emission structure. The relationship between the LAT detected GRBs and the well studied, fainter, less energetic GRBs detected by Swift-BAT is only beginning to be explored by multi-wavelength studies. We explore the large sample of GRBs detected by BAT only, BAT and Fermi-GBM, and GBM and LAT, focusing on these samples separately in order to search for statistically significant differences between the populations, using only those GRBs with measured redshifts in order to physically characterize these objects. We disentangle which differences are instrumental selection effects versus intrinsic properties, in order to better understand the nature of the special characteristics of the LAT bursts.

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Panaitescu, A. 2010 光学余辉的峰和平台

主要内容:
列出了光学余辉的主要两种：一种有峰值，一种是平台。并试图解释原因。
还列出一些光学和X射线余辉的对比。

精彩摘抄:

还有一个统计关系：

有X和光学一致的光变

Add caption

也有不一致的：

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Title:		Optical afterglows of Gamma-Ray Bursts: peaks, plateaus, and possibilities
Authors:		Panaitescu, A.; Vestrand, W. T.
Publication:		eprint arXiv:1009.3947
Publication Date:		09/2010
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		10 pages, submitted to MNRAS
Bibliographic Code:		2010arXiv1009.3947P

Abstract

The optical light-curves of GRB afterglows display either peaks or plateaus. We identify 15 afterglows of the former type and 20 of the latter. Their optical energy release is similar and is correlated to the GRB output, the correlation being stronger for peaky afterglows. That suggests that the prompt (burst) and delayed emissions of peaky afterglows are from the same relativistic ejecta and that the optical emission of plateau afterglows arises more often from ejecta that did not produce the burst emission. Consequently, we propose that peaky optical afterglows are from impulsive ejecta releases and that plateau optical afterglows originate from long-lived engines, the break in the optical light-curve (peak or plateau end) marking the onset of the entire outflow deceleration. In the peak luminosity--peak time plane, the distribution of peaky afterglows displays an edge with L_p propto t_p^{-3}, which is more likely to arise from variations (among afterglows) in the ambient medium density. The fluxes and epochs of optical plateau breaks follow a L_b propto t_b^{-0.5} anticorrelation which arises, perhaps, from an upper limit to the afterglow output. Sixty percent of 25 afterglows that were well monitored in both the optical and X-ray show coupled decays at these frequencies, with comparable decays indices and achromatic light-curve breaks. The other 40 percent display three types of decoupled light-curves: i) chromatic optical light-curve breaks (that could be due to the peak of the synchrotron spectrum crossing the optical), ii) X-ray flux decays faster than in the optical (suggesting that the X-ray emission is from local inverse-Compton scattering), and iii) chromatic X-ray light-curve breaks (which suggest that the X-ray emission is from external up-scattering).

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Chincarini 2010 X射线耀发的一些特性

主要内容:
分析了很多XRFs，得到了很多数据，以及如下的结论：
1. 宽度越宽，能量越低， w～E^-1/2.可以理解，原因是越宽的越晚，自然能量比较低。
2. 耀发的形状比较不对称，t_rise/t_decay~0.5；
3. 对同一个暴，多个耀发的时标是随时间变长的，但2中的比例不变；
4. 时标w～0.2t_peak（这个值应该比较有价值）;
5. 峰值光度随时间降低（这个太明显了）；
6. 各向同性能1e51erg，比暴本身低，谱比暴本身软（也是可预期的）；
7. 多个flares也是越来越软（不奇怪）。

精彩摘抄:

他们的拟合过程

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Title:		Unveiling the origin of X-ray flares in gamma-ray bursts
Authors:		Chincarini, G.; Mao, J.; Margutti, R.; Bernardini, M. G.; Guidorzi, C.; Pasotti, F.; Giannios, D.; Valle, M. Della; Moretti, A.; Romano, P.; D'Avanzo, P.; Cusumano, G.; Giommi, P.
Affiliation:		AA(INAF - Osservatorio Astronomico di Brera, via Bianchi 46, I-23807 Merate (LC), Italy; Physics Department, University of Milano Bicocca, Piazza della Scienza 3, Milano 20126, Italy), ...
Publication:		Monthly Notices of the Royal Astronomical Society, Volume 406, Issue 4, pp. 2113-2148. (MNRAS Homepage)
Publication Date:		08/2010
Origin:		WILEY
MNRAS Keywords:		radiation mechanisms: non-thermal, gamma-ray burst: general, X-rays: bursts
Abstract Copyright:		(c) Journal compilation © 2010 RAS
DOI:		10.1111/j.1365-2966.2010.17037.x
Bibliographic Code:		2010MNRAS.406.2113C

Abstract

ABSTRACT We present an updated catalogue of 113 X-ray flares detected by Swift in the ~33 per cent of the X-ray afterglows of gamma-ray burst (GRB). 43 flares have a measured redshift. For the first time the analysis is performed in four different X-ray energy bands, allowing us to constrain the evolution of the flare temporal properties with energy. We find that flares are narrower at higher energies: their width follows a power-law relation w ~ E^-0.5 reminiscent of the prompt emission. Flares are asymmetric structures, with a decay time which is twice the rise time on average. Both time-scales linearly evolve with time, giving rise to a constant rise-to-decay ratio: this implies that both time-scales are stretched by the same factor. As a consequence, the flare width linearly evolves with time to larger values: this is a key point that clearly distinguishes the flare from the GRB prompt emission. The flare 0.3-10keV peak luminosity decreases with time, following a power-law behaviour with large scatter: L_pk ~ t^-2.7+/-0.5_pk. When multiple flares are present, a global softening trend is established: each flare is on average softer than the previous one. The 0.3-10 keV isotropic energy distribution is a lognormal peaked at 10⁵¹erg, with a possible excess at low energies. The flare average spectral energy distribution is found to be a power law with spectral energy index β ~ 1.1. These results confirmed that the flares are tightly linked to the prompt emission. However, after considering various models we conclude that no model is currently able to account for the entire set of observations.

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