银河系的旋转方向

是顺着旋臂还是逆着？

等离子云、原子云、分子云

from：http://www.cnbeta.com/articles/251244.htm
研究人员解释说，根据温度和密度，宇宙气体可以分为三类：等离子云（粒子数密度：0.01/立方厘米，几百万摄氏度）、原子云（10/立方厘米，-160摄氏度）和分子云（10000/立方厘米，-260摄氏度）。原子云密度增加会变成分子云，分子云密度增加会变成恒星“温床”。反过来，如果受到高强度紫外线照射，构成分子云的分子也会分散变成原子。

Basak, Rupal 2013 高能GeV和MeV的幂律成分相关

主要内容:
他们把MeV的分成两种成分：黑体（双温）+幂律；然后发现幂律成分的光变和GeV瞬时阶段的光变一致（注意不是晚期的，他们还是同意晚期的还是外激波的同步辐射）(另外注意，这一点不是他们文章的主要内容，而是进一步的目标，他们发现的仅仅是：对于有很多GeV光子的暴，幂律的MeV光子和LAT的GeV光子一样，也有延迟，见下图)，以此说明瞬时阶段的辐射和瞬时阶段的幂律的MeV是同源的。

那么这么说的话，一共就有如下这些成分：瞬时的两个黑体成分，可能是来自光球辐射（为什么是两个呢？） ；瞬时幂律成分，来自内激波，这个延伸到了GeV；外激波余辉，延伸到了GeV。

于是紧接着可以做的一件事情：分析幂律MeV光子和瞬时阶段的GeV光子的光变曲线的关联程度（但是估计很难，因为不知道怎么在光变上区分幂律和非幂律的光子）。

嗯，也许把MeV的分出几个不同的成分是解释GeV以及MeV自身的一个办法。

精彩摘抄:
幂律部分的MeV光子应该和GeV的track

文章信息:

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Title:		A lingering non-thermal component in the GRB prompt emission: predicting GeV emission from the MeV spectrum
Authors:		Basak, Rupal; Rao, A. R.
Publication:		eprint arXiv:1308.2819
Publication Date:		08/2013
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		9 Pages, 2 Figures, ApJ Accepted
Bibliographic Code:		2013arXiv1308.2819B

Abstract

The high energy GeV emission of gamma-ray bursts (GRBs), detected by \emph{Fermi}/LAT, has a significantly different morphology compared to the lower energy MeV emission, detected by \emph{Fermi}/GBM. Though the late time GeV emission is believed to be synchrotron radiation produced via an external shock, this emission as early as the prompt phase is puzzling. Meaningful connection between these two emissions can be drawn only by an accurate description of the prompt MeV spectrum. We perform a time-resolved spectroscopy of the GBM data of long GRBs having significant GeV emission, using a model consisting of 2 blackbodies and a power-law. We examine in detail the evolution of the spectral components and found that GRBs having high GeV emission (GRB 090902B and GRB 090926A) have a delayed onset of the power-law component, in the GBM spectrum, which lingers at the later part of the prompt emission. This behaviour mimics the flux evolution in LAT. In contrast, bright GBM GRBs with an order of magnitude lower GeV emission (GRB 100724B and GRB 091003) show a coupled variability of the total and the power-law flux. Further, by analyzing the data for a set of 17 GRBs, we find a strong correlation between the power-law fluence in the MeV and the LAT fluence (Pearson correlation: r=0.88 and Spearman correlation: $\rho=0.81$). We demonstrate that this correlation is not influenced by the correlation between the total and the power-law fluences at a confidence level of 2.3$\sigma$. We speculate the possible radiation mechanisms responsible for the correlation.

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Sanchez 2013 一个python写的LAT的简化数据分析软件

主要内容:
叫Enrico

精彩摘抄:


文章信息:

arXiv:1307.4534 [pdf, other]

Enrico : a Python package to simplify Fermi-LAT analysis

D.A. Sanchez, C. Deil

Comments: In Proceedings of the 33rd International Cosmic Ray Conference (ICRC2013), Rio de Janeiro (Brazil)

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Instrumentation and Methods for Astrophysics (astro-ph.IM)

With the advent of the Large Array Telescope (LAT) on board the Fermi satellite, a new window on the Universe has been opened. Publicly available, the Fermi-LAT data come together with an analysis software named ScienceTools (ST, this http URL) which can be run through a Python interface. Nevertheless, for the user, the ST can be hard to run and imply several steps. Users already contributed with scripts for a specific task but no tool allowing a complete analysis is currently available.
We present a Python package called {\tt Enrico}, designed to facilitate the data analysis. Using only configuration files and front end tools from the command line, the user can easily perform/reproduce an entire Fermi analysis and make plots for publications. It also include new features like debug plots, pipeline execution on one or several CPUs, downloading of the Fermi data or the generation of a sky model from the Fermi catalogue.
{\tt Enrico} is an open-source project currently available for download at \url{https://github.com/gammapy/enrico}

快速射电暴

主要内容:
最近出现一种新的现象：射电暴。上了science，
 http://www.sciencemag.org/content/341/6141/40.summary?sid=674f043f-2e4d-4ec4-8cfd-86939a6cd1aa
http://www.sciencemag.org/content/341/6141/53.abstract?sid=674f043f-2e4d-4ec4-8cfd-86939a6cd1aa
http://www.sciencemag.org/content/341/6141/9.11.full?sid=674f043f-2e4d-4ec4-8cfd-86939a6cd1aa
上了新闻，
 http://www.cnbeta.com/articles/243668.htm
模型也跟进了。
 http://arxiv.org/abs/1307.1409

它持续时间特短，没有已知的东西成协，爆发率还很高，每天上万个。估计会火一段时间。

精彩摘抄:


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宇宙邪恶轴心

居然还存在“宇宙邪恶轴心”！axis of evil。国内有好几篇这个的科普文章。
2010年的
http://songshuhui.net/archives/36055
2013年Planck出了结果后的
http://www.guokr.com/article/436853/

就是微博背景辐射存在一个特殊的方向，神奇的是这个方向和黄道（地球轨道平面） 一致！WMAP的数据里有，最近的Planck的数据里也有，应该就是一个比较确定的事了。
不过学术上叫preferred axis或者anisotropy，虽然用axis of evil在ADS上也能搜出几十篇文章出来。
有一篇比较著名的在PRL上说如何检验这个邪恶轴心的文章，被引用了288次：
http://adsabs.harvard.edu/abs/2005PhRvL..95g1301L

如果确实存在这个轴心的话，CMB有，那别的源也应该有啊，比如GRB。


另外一个神奇的事情是南方还有个大窟窿，叫做大暗斑。

Ade 2013 Planck 2013年的结果

主要内容:
Planck卫星的观测放出了一大批结果，20多篇的系列文章，可能没有别的这么大的手笔了吧。都投到了A＆A。这是它们的Overview。

总体上来说就像Planck发射的目标一样，得到了更加精细的结果。偏振数据还没放出来。

宇宙学参数有所改动（WMAP每次出新结果也改动了的）：宇宙年龄比137长了点儿 138.2亿年，哈伯常数小了点儿H0 = (67+- 1.2) km s^-1Mpc^-1，暗能量的比例少了些，Omega_lambda:
 0.67+0.027-0.023 (68 % CL).

精彩摘抄:

所有文章的概述，那些文章干了啥。本文就主要是概述，列举了主要结果：frequency map， component map， power spectra， parameters

全天图，包括银河系等所有的源。

各波段的全天图

仅有微波背景辐射的全天图，可见比COBE和WMAP都更精细。

角向功率谱

功率密度谱

功率密度谱，和别的结果放在一张图上

宇宙学参数的结果

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Title:		Planck 2013 results. I. Overview of products and scientific results
Authors:		Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartelmann, M.; Bartlett, J. G.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bobin, J.; Bock, J. J.; Bonaldi, A.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Bowyer, J. W.; Bridges, M.; Bucher, M.; Burigana, C.; Butler, R. C.; Cappellini, B.; Cardoso, J.-F.; Carr, R.; Casale, M.;Catalano, A.; Challinor, A.; Chamballu, A.; Chary, R.-R.; Chen, X.; Chiang, L.-Y; Chiang, H. C.; Christensen, P. R.; Church, S.; Clements, D. L.; Colombi, S.; Colombo, L. P. L.; Couchot, F.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.;Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Dunkley, J.; Dupac, X.; Efstathiou, G.; Enßlin, T. A.; Eriksen, H. K.;Falgarone, E.; Finelli, F.; Foley, S.; Forni, O.; Frailis, M.; Franceschi, E.; Freschi, M.; Fromenteau, S.; Gaier, T. C.; Galeotta, S.; Gallegos, J.; Gandolfo, B.; Ganga, K.; Giard, M.; Giardino, G.; Giraud-Héraud, Y.; González-Nuevo, J.; Górski, K. M.; Gratton, S.;Gregorio, A.; Gruppuso, A.; Haissinski, J.; Hansen, F. K.; Hanson, D.; Harrison, D.; Helou, G.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.;Huffenberger, K. M.; Jaffe, T. R.; Jaffe, A. H.; Jewell, J.; Jones, W. C.; Juvela, M.; Kangaslahti, P.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.;Lasenby, A.; Laureijs, R. J.; Lawrence, C. R.; Le Jeune, M.; Leach, S.; Leahy, J. P.; Leonardi, R.; León-Tavares, J.; Leroy, C.; Lesgourgues, J.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lowe, S.; Lubin, P. M.; Macías-Pérez, J. F.;Maffei, B.; Maino, D.; Mandolesi, N.; Maris, M.; Marshall, D. J.; Martin, P. G.; Martínez-González, E.; Masi, S.; Matarrese, S.; Matthai, F.; Mazzotta, P.; McDonald, A.; McGehee, P.; Meinhold, P. R.; Melchiorri, A.; Melin, J.-B.; Mendes, L.; Mennella, A.;Migliaccio, M.; Miniscalco, R.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; North, C.; Noviello, F.;Novikov, D.; Novikov, I.; O'Dwyer, I. J.; Osborne, S.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Paladini, R.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Pearson, D.; Pearson, T. J.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.;Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Platania, P.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reach, W. T.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.;Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rossetti, M.; Roudier, G.; Rowan-Robinson, M.; Rubiño-Martín, J. A.; Rusholme, B.; Salerno, E.; Sandri, M.; Santos, D.; Savini, G.; Scott, D.; Seiffert, M. D.; Shellard, E. P. S.; Smoot, G. F.;Spencer, L. D.; Starck, J.-L.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sureau, F.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Tavagnacco, D.; Taylor, D.; Terenzi, L.; Texier, D.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.;Tuovinen, J.; Türler, M.; Tuttlebee, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Varis, J.; Vibert, L.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L. A.; Wandelt, B. D.; Watson, R.; Watson, C.; White, M.; White, S. D. M.; Wilkinson, A.; Yvon, D.;Zacchei, A.; Zonca, A.
Publication:		eprint arXiv:1303.5062
Publication Date:		03/2013
Origin:		ARXIV
Keywords:		Astrophysics - Cosmology and Extragalactic Astrophysics
Bibliographic Code:		2013arXiv1303.5062P

Abstract

The ESA's Planck satellite, dedicated to studying the early universe, was launched on May 2009 and has been surveying the microwave and submillimetre sky since August 2009. In March 2013, ESA and the Planck Collaboration publicly released the initial cosmology products based on the first 15.5 months of Planck operations, along with a set of scientific and technical papers and a web-based explanatory supplement. This paper describes the mission and its performance, and gives an overview of the processing and analysis of the data, the characteristics of the data, the main scientific results, and the science data products and papers in the release. Scientific results include robust support for the standard, six parameter LCDM model of cosmology and improved measurements for the parameters that define this model, including a highly significant deviation from scale invariance of the primordial power spectrum. The Planck values for some of these parameters and others derived from them are significantly different from those previously determined. Several large scale anomalies in the CMB temperature distribution detected earlier by WMAP are confirmed with higher confidence. Planck sets new limits on the number and mass of neutrinos, and has measured gravitational lensing of CMB anisotropies at 25 sigma. Planck finds no evidence for non-Gaussian statistics of the CMB anisotropies. There is some tension between Planck and WMAP results; this is evident in the power spectrum and results for some of the cosmology parameters. In general, Planck results agree well with results from the measurements of baryon acoustic oscillations. Because the analysis of Planck polarization data is not yet as mature as the analysis of temperature data, polarization results are not released. We do, however, illustrate the robust detection of the E-mode polarization signal around CMB hot- and cold-spots.

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Bibtex entry for this abstract   Preferred format for this abstract (see Preferences) 在宇宙学方面的结果（还在别的领域也有结果的）

With the Planck data, we: (a) firmly establish a deviation from scale invariance for primordial matter perturbations, a key indicator of cosmic inflation; (b) detect with high significance lensing of the CMB by intervening matter, providing evidence for dark energy from the CMB alone; (c) find no evidence for significant deviations from Gaussianity in the statistics of CMB anisotropies; (d) find a low value of the Hubble constant, in tension with the value derived from the standard distance ladder; (e) find a deficit of power at low-`s with respect to our best-fit model; (f) confirm the anomalies at large angular scales first detected by WMAP; and (g) establish the number of neutrino species at three.

Cepheid variable star为什么被翻译成造父变星

昨天彭老师给我们上完课，一起走在回宾馆的路上，我就问到一直奇怪的问题：Cepheid variable star为什么被翻译成造父变星？
我还没问完呢，他就说是戴文赛先生翻译的，因为我们古代命名了一颗星叫造父星，而它是一个典型的Cepheid variable star，于是这种星就叫造父变星。
彭老师真是天文活字典啊，还包括八卦。。。

Remillard 2006 黑洞双星的X射线辐射

主要内容:


精彩摘抄:

一些黑洞双星的大小

20个确认了的黑洞

Q形图

其中某个的光变和谱

高频QPO

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Title:		X-Ray Properties of Black-Hole Binaries
Authors:		Remillard, Ronald A.; McClintock, Jeffrey E.
Publication:		Annual Review of Astronomy & Astrophysics, vol. 44, Issue 1, pp.49-92 (Annual Reviews Homepage)
Publication Date:		09/2006
Origin:		ARAA
DOI:		10.1146/annurev.astro.44.051905.092532
Bibliographic Code:		2006ARA&A..44...49R

Abstract

We review the properties and behavior of 20 X-ray binaries that contain a dynamically-confirmed black hole, 17 of which are transient systems. During the past decade, many of these transient sources were observed daily throughout the course of their typically year-long outburst cycles using the large-area timing detector aboard the Rossi X-Ray Timing Explorer. The evolution of these transient sources is complex. Nevertheless, there are behavior patterns common to all of them as we show in a comprehensive comparison of six selected systems. Central to this comparison are three X-ray states of accretion, which are reviewed and defined quantitatively. We discuss phenomena that arise in strong gravitational fields, including relativistically-broadened Fe lines, high-frequency quasi-periodic oscillations (100 450 Hz), and relativistic radio and X-ray jets. Such phenomena show us how a black hole interacts with its environment, thereby complementing the picture of black holes that gravitational wave detectors will provide. We sketch a scenario for the potential impact of timing/spectral studies of accreting black holes on physics and discuss a current frontier topic, namely, the measurement of black hole spin.

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Mirabel 1998 银河系中的微类星体

主要内容:


精彩摘抄:

看到了视超光速运动  GRS1915+105

著名的图就是来自这篇文章

文章信息:

Progress

Nature 392, 673-676 (16 April 1998) | doi:10.1038/33603

Microquasars in our Galaxy

I. F. Mirabel¹ & L. F. Rodríguez²

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Abstract

Microquasars are stellar-mass black holes in our Galaxy that mimic, on a smaller scale, many of the phenomena seen in quasars. Their discovery opens the way for a new understanding of the connection between the accretion of matter onto black holes and the origin of the relativistic jets observed in remote quasars.

Discovered more than 30 years ago, quasars remain some of the most mysterious objects in the Universe. It is widely believed that they are powered by black holes of several million solar masses or more that lie at the centres of remote galaxies. Their luminosities are much larger than ordinary galaxies like the Milky Way, yet originate from regions smaller than the size of the Solar System. Occasionally, quasars spout jets of gas that appear to move on the plane of the sky with velocities exceeding that of light (that is, with superluminal velocities). The extreme distance of quasars introduces many uncertainties into the interpretation of the source of energy and the nature of the ejecta that appear to be moving with superluminal speeds.

The recent finding in our own Galaxy of microquasars^{1, 2, 3, 4}, a class of objects that mimics — on scales millions of times smaller — the properties of quasars, has opened new perspectives for the astrophysics of black holes (seeFig. 1). These scaled-down versions of quasars are believed to be powered by spinning black holes⁵ but with masses of up to a few tens times that of the Sun. The word microquasar was chosen to suggest that the analogy with quasars is more than morphological, and that there is an underlying unity in the physics of accreting black holes over an enormous range of scales, from stellar-mass black holes in binary stellar systems, to supermassive black holes at the centre of distant galaxies. As the characteristic times in the flow of matter onto a black hole are proportional to its mass, variations with intervals of minutes in a microquasar correspond to analogous phenomena with durations of thousands of years in a quasar of 10⁹ solar masses, which is much longer than a human lifetime. Therefore, variations with minutes of duration in microquasars could be sampling phenomena that we have not been able to study in quasars.