Berger 2010 短暴的暴周环境对前身星都限制

主要内容:

一共5个相关的暴周环境的观测（不是n，而是宿主星系的大环境），倾向于双中子星并合的模型，而不支持磁星模型。

精彩摘抄:

文章信息:

· Find Similar Abstracts (with default settings below)

· arXiv e-print (arXiv:1005.1068)

· References in the Article

·

· Translate This Page

Title:		The Environments of Short-Duration Gamma-Ray Bursts and Implications for their Progenitors
Authors:		Berger, E.
Publication:		eprint arXiv:1005.1068
Publication Date:		05/2010
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		Solicited review submitted to New Astronomy Reviews; 15 pages, 16 figures
Bibliographic Code:		2010arXiv1005.1068B

Abstract

[Abridged] The study of short-duration gamma-ray bursts (GRBs) experienced a complete revolution in recent years thanks to the discovery of the first afterglows and host galaxies in May 2005. These observations demonstrated that short GRBs are cosmological in origin, reside in both star forming and elliptical galaxies, are not associated with supernovae, and span a wide isotropic-equivalent energy range of ~10^48-10^52 erg. However, a fundamental question remains unanswered: What are the progenitors of short GRBs? The most popular theoretical model invokes the coalescence of compact object binaries with neutron star and/or black hole constituents. However, additional possibilities exist, including magnetars formed through prompt channels (massive star core-collapse) and delayed channels (binary white dwarf mergers, white dwarf accretion-induced collapse), or accretion-induced collapse of neutron stars. In this review I summarize our current knowledge of the galactic and sub-galactic environments of short GRBs, and use these observations to draw inferences about the progenitor population. The most crucial results are: (i) some short GRBs explode in dead elliptical galaxies; (ii) the majority of short GRBs occur in star forming galaxies; (iii) the star forming hosts of short GRBs are distinct from those of long GRBs (lower star formation rates, and higher luminosities and metallicities), and instead appear to be drawn from the general field galaxy population; (iv) the physical offsets of short GRBs relative to their host galaxy centers are significantly larger than for long GRBs; (v) the observed offset distribution is in good agreement with predictions for NS-NS binary mergers; and (vi) short GRBs trace under-luminous locations within their hosts, but appear to be more closely correlated with the rest-frame optical light (old stars) than the UV light (young massive stars).

---

Bibtex entry for this abstract Preferred format for this abstract (see Preferences)

Küpcü 2010 暗暴GRB 020819的宿主星系的消光很大

主要内容:

A_v=1.8-2.6，很大（很大吗？银河系消光多少？也是2-4之间啊）。说是暗暴可能原因就是星系的消光引起的。

精彩摘抄:

文章信息:

· Find Similar Abstracts (with default settings below)

· arXiv e-print (arXiv:1005.1257)

· References in the Article

·

· Translate This Page

Title:		Highly Extinguished Host Galaxy of the Dark GRB 020819
Authors:		Küpcü Yoldaş, A.; Greiner, J.; Klose, S.; Krühler, T.; Savaglio, S.
Publication:		eprint arXiv:1005.1257
Publication Date:		05/2010
Origin:		ARXIV
Keywords:		Astrophysics - Cosmology and Extragalactic Astrophysics
Comment:		Accepted for publication in A&A Letters
Bibliographic Code:		2010arXiv1005.1257K

Abstract

We analyse the properties of the host galaxy of the optically dark gamma-ray burst (GRB) 020819 (z = 0.41) and discuss the possible implications in the context of "dark" GRBs. We present g'r'i'z'JHK photometry of the host galaxy and fit the broad spectral energy distribution including the public Spitzer IRAC data using stellar population models. The broad spectral energy distribution (SED) indicates a high extinction, A_V ~ 1.8 - 2.6 mag, for this relatively massive galaxy. This is the highest global extinction for a GRB host galaxy with a robust spectroscopic redshift. The properties of the host galaxy are indicative of dusty, intense star-formation, which differ from those of the current sample of GRB hosts. This implies that the dust extinction is one of the main reasons for the darkness of low-redshift bursts and that the long GRB host population is far more diverse than previously anticipated.

---

Bibtex entry for this abstract Preferred format for this abstract (see Preferences)

Abdo 2010 用LAT的GeV光子观测限制河外背景光子

主要内容:

高能光子会和河外背景光子湮灭产生正负电子对。如果背景光子足够多，就看不到来自于很远的高能光子了。由于看到了一些高能光子，限制了一些说会有很多背景光子的模型。

精彩摘抄:

· Find Similar Abstracts (with default settings below)

· arXiv e-print (arXiv:1005.0996)

· References in the Article

·

· Translate This Page

Title:		Fermi-LAT Constraints on the Gamma-ray Opacity of the Universe
Authors:		Fermi LAT, The; the GBM Collaboration: A. A. Abdo
Publication:		eprint arXiv:1005.0996
Publication Date:		05/2010
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		39 pages, 11 figures, submitted to ApJ; Corresponding authors: A. Bouvier, A. Chen, S. Raino, S. Razzaque, A. Reimer, L. C. Reyes
Bibliographic Code:		2010arXiv1005.0996F

Abstract

The Extragalactic Background Light (EBL) includes photons with wavelengths from ultraviolet to infrared, which are effective at attenuating gamma rays with energy above ~10 GeV during propagation from sources at cosmological distances. This results in a redshift- and energy-dependent attenuation of the gamma-ray flux of extragalactic sources such as blazars and Gamma-Ray Bursts (GRBs). The Large Area Telescope onboard Fermi detects a sample of gamma-ray blazars with redshift up to z~3, and GRBs with redshift up to z~4.3. Using photons above 10 GeV collected by Fermi over more than one year of observations for these sources, we investigate the effects of the EBL on the gamma-ray flux. We constrain the gamma-ray opacity of the Universe at various energies and redshifts, and compare this with predictions from well-known EBL models. We find that an EBL intensity in the optical-ultraviolet wavelengths as great as predicted by the "fast-evolution" and "baseline" models of Stecker et al (2006) can be ruled out with high confidence.

---

Bibtex entry for this abstract Preferred format for this abstract (see Preferences)

文章信息:

Kubánek 2010 远程操作望远镜的系统RTS2

主要内容:

介绍了一个曾经用来快速余辉跟进的程序RTS2

精彩摘抄:

---

· Find Similar Abstracts (with default settings below)

· arXiv e-print (arXiv:1005.1014)

· References in the Article

·

· Translate This Page

Title:		RTS2 - the Remote Telescope System
Authors:		Kubánek, Petr
Publication:		eprint arXiv:1005.1014
Publication Date:		05/2010
Origin:		ARXIV
Keywords:		Astrophysics - Instrumentation and Methods for Astrophysics
Comment:		9 pages, 3 figures, Workshop on Robotic Autonomous Observatories, M\'alaga, Spain, 18-21 May 2009; Advances in Astronomy, 2010; doi:10.1155/2010/902484
Bibliographic Code:		2010arXiv1005.1014K

Abstract

RTS2 is an open source observatory manager. It was written from scratch in the C++ language, with portability and modularity in mind. Its driving requirements originated from quick follow-ups of Gamma Ray Bursts. After some years of development it is now used to carry tasks it was originally not intended to carry. This article presents the current development status of the RTS2 code. It focuses on describing strategies which worked as well as things which failed to deliver expected results.

---

Bibtex entry for this abstract Preferred format for this abstract (see Preferences)

文章信息:

Neamus 2010 GRB 090510是否可有正向激波解释多波段观测

主要内容:

同步辐射不能解释多波段的拐折，而SSC模型需要星风环境，和它是断暴不符。所以总的说来，可能高能和低能并不都来自于外激波(标准喷流余辉)。

精彩摘抄:

· Find Similar Abstracts (with default settings below)

· arXiv e-print (arXiv:1005.1051)

· References in the Article

·

· Translate This Page

Title:		Can the forward-shock model account for the multiwavelength emission of GRB afterglow 090510 ?
Authors:		Neamus, Ano
Publication:		eprint arXiv:1005.1051
Publication Date:		05/2010
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		9 pages
Bibliographic Code:		2010arXiv1005.1051N

Abstract

GRB 090510 is the first burst whose afterglow emission above 100 MeV was measured by Fermi over two decades in time. Owing to its power-law temporal decay and power-law spectrum, it seems likely that the high-energy emission is from the forward-shock energizing the ambient medium (the standard blast-wave model for GRB afterglows), the GeV flux and its decay rate being consistent with that model's expectations. However, the synchrotron emission from a collimated outflow (the standard jet model) has difficulties in accounting for the lower-energy afterglow emission, where a simultaneous break occurs in the optical and X-ray light-curves at 2 ks, but with the optical flux decay (before and after the break) being much slower than in the X-rays (at same time). The measured X-ray and GeV fluxes are incompatible with the higher-energy afterglow emission being from same spectral component as the lower-energy afterglow emission, which suggests a synchrotron self-Compton model for this afterglow. Cessation of energy injection in the blast-wave can account for the optical and X-ray light-curves provided that the ambient medium has a wind-like n propto r^{-2} density. The latter is incompatible with this short-GRB originating from the merger of two compact stars.

---

Bibtex entry for this abstract Preferred format for this abstract (see Preferences)

文章信息:

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。

精彩摘抄:


文章信息:

· Find Similar Abstracts (with default settings below)

· arXiv e-print (arXiv:1003.0632)

· References in the Article

· Also-Read Articles (Reads History)

·

· Translate This Page

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.

---

Bibtex entry for this abstract Preferred format for this abstract (see Preferences)

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.

精彩摘抄:


文章信息:

· Find Similar Abstracts (with default settings below)

· arXiv e-print (arXiv:1003.0566)

· References in the Article

· Also-Read Articles (Reads History)

·

· Translate This Page

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

Bibtex entry for this abstract Preferred format for this abstract (see Preferences)

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)

精彩摘抄:


文章信息:

· Find Similar Abstracts (with default settings below)

· arXiv e-print (arXiv:1003.1115)

· References in the Article

·

· Translate This Page

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".

---

Bibtex entry for this abstract Preferred format for this abstract (see Preferences)

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。

精彩摘抄:


文章信息:

· Find Similar Abstracts (with default settings below)

· arXiv e-print (arXiv:1003.0710)

· References in the Article

·

· Translate This Page

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.

---

Bibtex entry for this abstract Preferred format for this abstract (see Preferences)

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。

精彩摘抄:


文章信息:

· Find Similar Abstracts (with default settings below)

· arXiv e-print (arXiv:1002.0228)

· References in the Article

·

· Translate This Page

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.

---

Bibtex entry for this abstract Preferred format for this abstract (see Preferences)