Looking for a math inputer
After searching the web, I find it is impossible to find a method, just add something like:
mathMATH ... MATHmath
then you can input latex in it.
Impossible.
星期二, 一月 08, 2008
Mao 2008 stochastic acceleration for the shellow decay phase
主要内容:
Using a micro-physical process to explain the shallow decay phase. In fact, is the variation of micro parameters.
I fear that 1. why it stops to a normal decay; 2. if it stops, it should come to a steep and than normal, because of that the E_0.
精彩摘抄:
文章信息:
A New Scenario on X-ray Shallow Decay of Gamma-ray Bursts
(Submitted on 6 Jan 2008)
Abstract: In this Letter, we propose that a microphysical process takes a vital role in the shocked region in which the prompt emission of GRBs is emitted. The turbulent energy is included in the internal energy transferred by the kinetic energy of the shock. It dissipates through stochastic acceleration for the electrons to supply the early X-ray emission in the phase of shallow decay. We put the constraints on the time evolution of microphysical parameters. The early X-ray fluxes can be obtained by this scenario and these results are consistent with the Swift observation
Natalucci 2008 CZT gamma-camera for EDGE mission
主要内容:
CZT
精彩摘抄:
working in the range 8-200 keV, having a sensitivity of 0.4 ph cm-2 s-1 in 1s (15-150 keV) and arcmin location accuracy over a sky region as wide as 3sr.
文章信息:
Design of a CZT Gamma-Camera for GRB and Fast Transient Follow-up: a Wide-Field-Monitor for the EDGE Mission
(Submitted on 7 Jan 2008)
Abstract: The success of the SWIFT/BAT and INTEGRAL missions has definitely opened a new window for follow-up and deep study of the transient gamma-ray sky. This now appears as the access key to important progresses in the area of cosmological research and deep understanding of the physics of compact objects. To detect in near real-time explosive events like Gamma-Ray bursts, thermonuclear flashes from Neutron Stars and other types of X-ray outbursts we have developed a concept for a wide-field gamma-ray coded mask instrument working in the range 8-200 keV, having a sensitivity of 0.4 ph cm-2 s-1 in 1s (15-150 keV) and arcmin location accuracy over a sky region as wide as 3sr. This scientific requirement can be achieved by means of two large area, high spatial resolution CZT detection planes made of arrays of relatively large (~1cm2) crystals, which are in turn read out as matrices of smaller pixels. To achieve such a wide Field-Of-View the two units can be placed at the sides of a S/C platform serving a payload with a complex of powerful X-ray instruments, as designed for the EDGE mission. The two units will be equipped with powerful signal read out system and data handling electronics, providing accurate on-board reconstruction of the source positions for fast, autonomous target acquisition by the X-ray telescopes.
星期一, 一月 07, 2008
Maeda 2008 Asymmetry SN explosion analysis by Spectroscopy
主要内容:
From the emission line of (mainly) OI, one can derive the velocity in the different part of the explosion, and derive the asymmetric explosion.
精彩摘抄:
Spectra for different SNe for OI emission line.
the line and the relation of velocity.
文章信息: Asymmetry in Supernova Explosions from Late-Time Spectroscopy
(Submitted on 7 Jan 2008)
Abstract: Core-collapse supernovae (CC-SNe) are the explosion following the death of massive stars. Some of them are linked to long-duration gamma-ray bursts (GRBs). One important question is whether all CC-SNe share common features in their explosion mechanism. Here we present late-time spectra for a number of stripped-envelope CC-SNe, and use them to explore any asphericity generated in the inner part of the exploding star, near the site of collapse. A variety of oxygen emission-line profiles is observed, including a high incidence of double-peaked profiles, a distinct signature of an aspherical explosion. Our results suggest that all stripped-envelope CC-SNe are aspherical, perhaps jet-driven explosions, and that SNe accompanied by GRBs exhibit the highest degree of asphericity.
Song 2008 The Distance of GRB is Independent from the Redshift
主要内容:
Main reason: Host galaxies may not host, but background galaxies.
精彩摘抄:
文章信息:
The Distance of GRB is Independent from the Redshift
(Submitted on 5 Jan 2008)
Abstract: Although it is acknowledged that the host galaxy of GRB is the source of GRB at present, but it is in fact not obtained a reliable confirmation. However, the fact is still unclear because the host is possibly a background galaxy that has no physical affiliation to the GRB. Here, I show a series of evidences, including three methods, to identify the status of hosts. The correlation analysis shows that there is no correlation between the distance of GRBs and the redshift of hosts although there is a significant correlation between the apparent magnitude of hosts and the redshift; the deductive reasoning shows that many wrong conclusions that violate to the basic principle of physics would inevitably be obtained if the redshift indicates the distance; and the variables separation test proves directly that, however, the distance is independent from the redshift and the values of the fluence and the photon flux can be accurately forecasted for the GRB with higher redshift. On the other hand, the three statistical laws of GRBs have been deduced theoretically based on the observed fact; and a precise background galaxy theory can explain all the observed laws of GRBs and provides a new method with the least uncertain factors for determining the deceleration parameter that contains the contribution of the dark matter, and obtain q0 = 0.148.
星期日, 一月 06, 2008
Starling 2008 GRB 070616 prompt spectral evolution
主要内容:
The spectral index in the prompt era evolves very violently.
This may be an evidence that the internal shocks model for GRB 050904, whose spectral was also evolving.
精彩摘抄:
spectral evolution, alpha is the spectral index for low-energy in Band spectra.
light curve
文章信息:
Strong spectral evolution during the prompt emission of GRB 070616
(Submitted on 4 Jan 2008)
Abstract: Swift has revealed features in GRB early light curves, such as steep decays and X-ray flares, whose properties are consistent with an internal origin though they are far from understood. The steep X-ray decay is often explained using the curvature effect; however a significant number of GRBs display strong spectral evolution during this phase, and a new mechanism must be invoked to explain this. Of particular interest are the longest duration GRBs in which the early emission can be studied in most detail. Here we present data for GRB 070616, in which the prompt emission shows a complex multipeaked structure, leading to one of the longest prompt emission durations ever recorded. We take advantage of extensive coverage of such a long burst by all Swift instruments. Combining data from Swift and Suzaku we study the evolution of the prompt emission spectrum, following the temporal variability of the peak energy and spectral slope.
Complete version: 0711.3753
http://grblogscn.blogspot.com/2007/11/starling-2007-spectral-evolution-of-grb.html
Brown 2008 LMC X-3 May Be a Relic of a GRB Similar to Cosmological GRBs
主要内容:
Correct on Fruchter et al. (2006).
精彩摘抄:
文章信息:
LMC X-3 May Be a Relic of a GRB Similar to Cosmological GRBs
Authors: G.E. Brown, C.-H. Lee, E. Moreno Mendez
(Submitted on 3 Jan 2008)
Abstract: The present scenario for high-luminosity long gamma-ray bursts is strongly influenced by the paper of Fruchter et al. (2006). Whereas the main contention of this paper that these GRBs occur in low-metallicity irregular galaxies is based on a considerable collection of observational results and although the main thesis is doubtless correct, the paper does not explain the dynamics that produces such GRBs and much of the discussion not directly concerning the main thesis is wrong. We propose a dynamics and elucidate how the Fruchter et al. (2006) results may be tested, in our neighborhood in the LMC, suggesting that LMC X-3 is a relic of a high luminosity explosion, probably accompanied by a GRB and hypernova explosion. The way to test our suggestion is to measure the system velocity of the present black hole. We correct errors of the Fruchter et al. paper in stellar evolution, so that the study of GRBs is consistent with it. We show that the subluminous GRB 060218 had a low-mass black hole as central engine.
星期三, 一月 02, 2008
De Rujula 2007 XRF 060218 and its associated supernova
主要内容:
精彩摘抄:
文章信息:
- arXiv:0801.0397 [ps, pdf, other]
美国科学家证实宇宙尘埃来自超新星
| [发布时间:20071227] [来源:http://www.sciencenet.cn/sbhtmlnews/2007122713024603197808.html?id=197808 中国科学技术信息研究所加工整理] |
科学时报2007年12月27日消息：新华社电 尽管科学家认为，宇宙尘埃来自于超新星，但一直没有找到有关证据。美国喷气推进实验室的科学家日前宣布，他们借助斯皮策太空望远镜找到了宇宙尘埃产生于超新星的“确凿证据”。 该实验室科学家在最新出版的美国《天体物理学杂志》上发表报告说，借助斯皮策太空望远镜上的超敏感红外线探测仪，科学家发现了距离人类所处星系1.1万光年的仙后座A星系的一个超新星在爆炸后遗留下来的尘埃，这些尘埃质量是地球的1万倍。 报告说，尽管仙后座Ａ并非是宇宙最早的星系，但它却离地球比较近，对它的观察能让科学家掌握许多宇宙形成发展的证据。 报告说，当宇宙年轻时，处于发展阶段的类似太阳的恒星尚没有到死亡的时间，所以不能产生尘埃。随着时间推移，这些恒星在死亡坍塌时转变成超新星爆发，并产生大量的尘埃。仙后座A星系的这颗超新星发生的一切说明了这一点。 宇宙尘埃是宇宙中各种星系、星球甚至生命的主要成分。 |
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