APOD090709 费米卫星发现的γ射线脉冲星

今天的APOD是费米卫星眼中的γ射线天空，更确切的说，γ射线脉冲星。
http://apod.nasa.gov/apod/ap090709.html
2009 July 9
Fermi's Gamma-ray Pulsars

                               
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NASA, DOE, Fermi LAT Collaboration
美国宇航局、美国能源部、费米卫星大区域望远镜协同工作组（从后文看我猜LAT是 Large Area Telescope）
Explanation:
Born in supernovae, pulsars are spinning neutron stars, collapsed stellar cores left from the death explosions of massive stars. Traditionally identified and studied by observing their regular radio pulsations, two dozen pulsars have now been detected at extreme gamma-ray energies by the Fermi Gamma-ray Space Telescope. The detections include 16 pulsars identified by their pulsed gamma-ray emission alone. This gamma-ray all-sky map, aligned with the plane of our Milky Way Galaxy, shows the pulsar positions, with the 16 new Fermi pulsars circled in yellow (8 previously known radio pulsars are in magenta). Bizarre stellar corpses, the Vela, Crab, and Geminga pulsars on the right are the brightest ones in the gamma-ray sky. Pulsars Taz, Eel, and Rabbit are named for the nebulae they are now known to power. The Gamma Cygni and CTA 1 pulsars at the left also reside within expanding supernova remnants of the same name.
脉冲星是诞生于超新星爆发的高速旋转的中子星，是大质量恒星晚期剧烈爆发后的残余核心，传统上通过有规律的射电脉冲辐射辨识和研究它们。现在，费米γ射线空间望远镜已经发现了2打发出高能γ射线的脉冲星，其中的16个已经通过它们独立的γ射线脉冲辐射被（新）确认为脉冲星。
本图是γ射线的全天区图，图中横亘的亮区是我们银河系的银道面。图中用黄圈标出了费米卫星新发现的16个脉冲星（8个早先辨认出的用品红色圈标识）。图中右边的几个亮γ射线源是：船帆座γ射线源(Vela)、蟹状星云（Crab）和双子座γ射线源。另外几个脉冲星以被它们所激发的遗迹星云命名——小胡子、鳗鱼和兔子。（不好意思，我不知道这几个星云，但英文应该是这个意思——gohomeman1译注） 图左，天鹅座γ射线源和CTA 1脉冲星也位于同名的超新星遗迹中。

今天的APOD大图比较大，2048X1103
http://apod.nasa.gov/apod/image/0907/Fermi_pulsar_map_labels_2048.jpg

                               
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今天两家都没有翻译，如果晚上他们还不提供翻译，我自己做吧。
先说明一下图中的文字：黄圈中是新发现的γ射线脉冲星，blind search直译是盲目搜索，当然我们一般称为地毯式搜索。玫瑰红圈中的是毫秒级脉冲星。

APOD曾经多次提到费米卫星，这是其中之一，就在今年的3月份：
http://antwrp.gsfc.nasa.gov/apod/ap090321.html

2009 March 21
Fermi's Gamma-Ray Sky

                               
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Credit: NASA, DOE, Fermi LAT Collaboration
Explanation:
Scanning the entire sky in gamma-rays, photons with over 50 million times the energy of visible light, the Fermi mission's Large Area Telescope (LAT) explores the high-energy universe. This all-sky map constructed from 3 months of LAT observations (August 4 to October 30, 2008) represents a deeper, better-resolved view of the gamma-ray sky than any previous space mission. What shines in Fermi's gamma-ray sky? A new paper describes the 205 brightest gamma-ray sources, but this map highlights a Fermi "top ten" list of five sources within, and five sources that lie beyond our Milky Way Galaxy. Within our galaxy: the Sun traces a faint arc across the map between the observation dates, LSI +61 303 is an X-ray binary star about 6,500 light-years away, PSR J1836+5925 is a type of pulsar (spinning neutron star) that is only seen to pulse at gamma-ray energies, and 47 Tuc is a globular star cluster some 15,000 light-years away. A fifth galactic source (unidentified), just above the center of the galactic plane, is intriguing because it is a variable source and has no clear counterpart at other wavelengths. Beyond our galaxy: NGC 1275 is a large galaxy at the heart of the Perseus galaxy cluster some 233 million light-years away, while 3C 454.3, PKS 1502+106, and PKS 0727-115 are active galaxies billions of light-years distant. Another unidentified source, seen below the galactic plane, is likely beyond the boundaries of the Milky Way. Its nature remains a mystery.

本文翻译来自成大 http://www.phys.ncku.edu.tw/~astrolab/mirrors/apod/ap090321.html  ，北馆当日无翻译。
費米太空望遠鏡的伽瑪射線巡天圖
圖像提供: NASA, DOE, Fermi LAT Collaboration
說明: 在比可見光能量要高上五千萬倍的伽瑪射線波段巡天，費米太空望遠鏡的大面積相機 (LAT)正探索著高能波段宇宙。上面這張全天圖，是用大面積相機在2008年8月4日到10月30日所取得的數據建構出來的。和以往類似的太空觀測任務比較，這是一幅更深、解析度更高的伽瑪射線全天圖。費米望遠鏡的伽瑪射線天空有那些明亮光源？最近一篇論文描述了其中最亮的205個伽瑪射線源，而上面影像呈現了其中最亮的十顆：五顆位在我們銀河系內，另五顆在銀河系外。在我們銀河系內有：在觀測期間拖曳出一道弧線的太陽、離我們約6,500光年的X射線雙星LSI +61 303，在伽瑪射線才能見到閃爍的波霎PSR J1836+5925、離我們約15,000光年遠的球狀星團杜鵑座47 (47 Tuc)、及一顆位在銀河盤面中心點上方的未知伽瑪射線源。這個未知光源很有趣，因為它是個變光源，而且在其他波段都找不到和它對應的天體。在我們銀河系外的亮源有：離我們約二億三百萬光年遠英仙座星系團中心的大型星系NGC 1275、和3C 454.3、PKS 1502+107、PKS 0727-115等三個離我們有數十億光年遠的活躍星系，第五個則是一個位在銀河盤面下方的未知光源，它的本質為何仍是個待解之謎團。

这是另外一次http://antwrp.gsfc.nasa.gov/apod/ap080828.html

2008 August 28

                               
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Fermi's First Light
Credit: NASA, DOE, International LAT Team
Explanation:
Launched on June 11 to explore the universe at extreme energies, the Gamma-ray Large Area Space Telescope has been officially renamed the Fermi Gamma-ray Space Telescope, in honor of Nobel Laureate Enrico Fermi (1901-1954), pioneer in high-energy physics. After testing, Fermi's two instruments, the Gamma-ray Burst Monitor (GBM) and the Large Area Telescope (LAT), are now regularly returning data. Fermi's first map of the gamma-ray sky from the LAT is shown in this false-color image, an all-sky view that looks toward the center of our Milky Way Galaxy with the galactic plane projected across the middle. What shines in the gamma-ray sky? Along the galactic plane, energetic cosmic rays collide with gas and dust to produce the diffuse gamma-ray glow. Strong emission from spinning neutron stars or pulsars, and distant active galaxies known as blazars, can be identified by placing your cursor over the map. A prelude to future discoveries, the remarkable result combines only 4 days of observations, equivalent to a year of observations with the Compton Gamma-ray Observatory mission of the 1990s. In addition to the ability to monitor gamma-ray bursts, the greatly improved sensitivity will allow Fermi to look deeper into the high-energy Universe.

本文翻译来自北京天文馆 http://www.bjp.org.cn/apod/2008-08/28/content_8718.htm
费尔米的第一光
影像提供：NASA, DOE, International LAT Team
说明：
伽马射线大视场太空望远镜被官方命名为费尔米伽马射线太空望远镜，是在6月11日发射升空，目的为了探索高能宇宙。该望远镜的命名也是为了纪念诺贝尔得主恩里克.费尔米（1901-1954），高能物理的先驱者。经过测试后，费尔米的两个设备--伽马射线暴监测器（GBM）和大视场望远镜（LAT）正有规律地发回数据。费尔米上LAT拍摄的第一张伽马射线天空影像就是这张假色影像，朝我们银河系中心拍摄到的全天域影像，银道面投影在影像的中央。在伽马射线下，天空中是什么在闪光？沿着银道面，高能宇宙射线与气体和尘埃发生碰撞，产生了散漫的伽马射线光。将你得鼠标放在这张影像上就能分辨出从高速旋转中的中子星或脉冲星，以及遥远活动星系（通常被称为耀变体）发出的强烈射线。作为未来发现的前奏，这一显著的影像仅仅集合了4天的观测结果，相当于20世纪90年代康普顿伽玛射线观测仪一年的成果。除了监测伽马射线爆的能力外，改进巨大的敏锐性也让费尔米望远镜能更深入地拍摄高能宇宙。

把文章翻译了，方便大家阅读。我对脉冲星的了解不是特别深，尤其是对费米卫星工作组不大了解，翻译中不足之处，请大家多多指正。

稍稍查了一下资料，船帆座γ射线源和双子座γ射线源与蟹状星云中心星一样都是脉冲星，而且蟹状星云、船帆座γ射线源在γ射线辐射上的能量比射电波段多了100万倍以上；图中可见，它们是周天最亮的γ射线源之一。

好在离我们远！