相信许多留学生对数学代考都不陌生，国外许多大学都引进了网课的学习模式。网课学业有利有弊，学生不需要到固定的教室学习，只需要登录相应的网站研讨线上课程即可。但也正是其便利性，线上课程的数量往往比正常课程多得多。留学生课业深重，时刻名贵，既要学习知识，又要结束多种类型的课堂作业，physics作业代写，物理代写，论文写作等；网课考试很大程度增加了他们的负担。所以，您要是有这方面的困扰，不要犹疑，订购myassignments-help代考渠道的数学代考服务，价格合理，给你前所未有的学习体会。
我们的数学代考服务适用于那些对课程结束没有掌握，或许没有满足的时刻结束网课的同学。高度匹配专业科目，按需结束您的网课考试、数学代写需求。担保买卖支持，100%退款保证，免费赠送Turnitin检测报告。myassignments-help的Math作业代写服务，是你留学路上忠实可靠的小帮手！
物理代写|高能物理代写High Energy Physics代考|Space-Based Instruments for X-Ray and γ-Ray Detection
The beginning of X-ray Astrophysics (the “softest” photons in the high energy region) had to await the development of space technology. Shortly after the launch of Sputnik in 1957, a group of scientists led by Riccardo Giacconi launched an X-ray detector on board an Aerobee 150 rocket and discovered the first X-ray source outside the Solar System, called Sco X-1. The angular resolution was so poor (worse than $20^{\circ}$ ) that it took time to identify the “spot” in X-rays with the constellation of Scorpius. Today we know that it is a neutron star with a low mass companion (LMXB), the first example showing how the sky is populated with high energy sources. A chronology of the most relevant missions can be found at the website [6].
A few years later in 1970 , the first satellite dedicated to X-ray sky exploration was launched. This was the Uhuru mission (meaning “freedom” in Swahili), with an effective area of only $0.084 \mathrm{~m}^2$ and coverage in the $2-20 \mathrm{keV}$ band, capable of a spatial resolution of about $0.5^{\circ}$. Uhuru identified more than 300 sources, among them Cyg X-1, the first black hole candidate in our galaxy. Over time, several missions have been launched, some of them still in operation, and the exploration of X-ray sources has continued on a sustained basis. Table $3.1$ shows some of the most important space missions in X-ray astrophysics, along with their most important features (collecting area, spatial resolution, and energy band).
As previously mentioned, one must use scintillators to study still higher energies. The Compton effect described above was the basis of the COMPTEL instrument, containing liquid scintillators above a $\mathrm{NaI}$ crystal. The successive interactions of the incident photons until they are finally absorbed can be used to determine the direction of their arrival without having to actually focus them in the conventional sense. The coded mask technique was developed to improve the spatial resolution, which is made much more difficult by the fact that gamma rays cannot be focused. This is an advanced variant of the camera obscura used in the Renaissance.
物理代写|高能物理代写High Energy Physics代考|Stellar Astrophysics
The nature of the observed stars has been a subject of discussion and speculation since the early days of civilization. Atomists Leucippus and Democritus thought that the Milky Way was made of stars, which they considered too small to be distinguished from one another. By the time of the Indian mathematician Aryabhata (5th century A.D.), there existed in the East the notion that stars were, in fact, other suns. It would have been immediately obvious that they would have to be at enormous distances for this hypothesis to make sense. Other important speculations were formulated in the West. For example, in Giordano Bruno’s writings, not only were the stars identified as distant suns, but inhabited planetary systems accompanied them, putting the author on a direct collision course with the Roman Catholic Church. What is certain is that it was only in the early 19th century, with the works of W. Herschel and J. von Fraunhofer, that the star = Sun identification was shown to be correct: the absorption lines of several nearby stars were observed, revealing their kinship with the lines observed in the solar spectrum. This Chapter addesses the construction of stellar models and the important features of Stellar Evolution till the final stages leading to explosions/compact object formation.
Although the nature of stars remained for many centuries on a speculative plane. scientists from Classical Antiquity devoted themselves to their study. The first catalog of stars created in the West was authored by the mathematician and astronomer Hipparchus, and contained some 850 stars observable by naked eye, as reproduced in Ptolemy’s Almagest. Hipparchus and other later astronomers also noticed the differences in brightness of the stars, and especially in their colors (Fig. 4.1). These ancient observations and those recorded after the invention of the telescope in the early 17th century led directly to the basic questions of stellar Astrophysics that will be the subject of our discussion: Are stars “eternal”? What is their internal constitution? How can these questions be linked with available observations? The enormous development of the theory of Stellar Evolution throughout the 20th century and the state of the art in this field will occupy the rest of this chapter and part of the following chapters.
物理代写|高能物理代写高能物理代考|天基x射线和γ射线探测仪器
. x射线探测仪器
x射线天体物理学(高能区域“最柔软”的光子)的开始必须等待空间技术的发展。1957年斯普特尼克发射后不久，由里卡多·贾科尼(Riccardo Giacconi)领导的一组科学家在Aerobee 150火箭上发射了x射线探测器，发现了太阳系外的第一个x射线源，名为Sco X-1。角度分辨率非常差(比$20^{\circ}$还差)，以至于花了很长时间才能在x射线中识别天蝎座的“光点”。今天我们知道它是一颗中子星，伴星质量很低(LMXB)，这是第一个表明天空中充满高能量源的例子。最相关的任务年表可在[6]网站上找到
几年后的1970年，第一颗专门用于x射线天空探测的卫星发射了。这是Uhuru任务(在斯瓦希里语中是“自由”的意思)，有效区域仅为$0.084 \mathrm{~m}^2$，覆盖$2-20 \mathrm{keV}$波段，空间分辨率约为$0.5^{\circ}$。乌胡鲁发现了300多个黑洞源，其中包括Cyg X-1，这是我们星系中第一个黑洞候选星系。随着时间的推移，已经发起了若干次任务，其中一些仍在执行，x射线源的探索一直在持续进行。表$3.1$显示了x射线天体物理学中一些最重要的空间任务，以及它们最重要的特征(收集面积、空间分辨率和能带)
如前所述，人们必须使用闪烁体来研究更高的能量。上面描述的康普顿效应是COMPTEL仪器的基础，在$\mathrm{NaI}$晶体上包含液体闪烁体。入射光子之间的连续相互作用，直到它们最终被吸收，可以用来确定它们到达的方向，而不必像传统意义上那样实际聚焦它们。编码掩模技术是为了提高空间分辨率而开发的，由于伽马射线无法聚焦，这使得空间分辨率变得更加困难。这是文艺复兴时期使用的暗箱的高级改进型。
物理代写|高能物理代写高能物理学代考|恒星天体物理学
自文明早期以来，对观测到的恒星的性质一直是讨论和推测的主题。原子学家琉基普斯和德谟克利特认为银河系是由恒星组成的，他们认为这些恒星太小，无法相互区分。在印度数学家阿雅巴塔(公元5世纪)的时代，东方有一种观念，认为恒星实际上是其他的太阳。很明显，要使这个假设成立，它们必须有巨大的距离。其他重要的推测是在西方提出的。例如，在佐丹诺·布鲁诺的作品中，这些恒星不仅被认为是遥远的太阳，而且还有有人居住的行星系统伴随着它们，这使作者与罗马天主教会直接发生了冲突。可以肯定的是，直到19世纪初，随着赫舍尔和夫琅和费的工作，恒星=太阳的区分才被证明是正确的:观测到几颗附近恒星的吸收线，揭示了它们与太阳光谱中观测到的线的亲缘关系。本章阐述了恒星模型的构建和恒星演化的重要特征，直到最后阶段导致爆炸/致密物体的形成
虽然许多世纪以来，恒星的性质一直停留在一个推测的层面上。古代的科学家们致力于他们的研究。西方最早的恒星目录是由数学家和天文学家希帕尔库斯撰写的，其中包括肉眼可观测到的约850颗恒星，如托勒密的《全集》中所复制的那样。希帕克斯和其他后来的天文学家也注意到了恒星亮度的差异，特别是它们的颜色(图4.1)。这些古老的观测和17世纪早期望远镜发明之后的记录直接导致了恒星天体物理学的基本问题，这将是我们讨论的主题:恒星是“永恒的”吗?它们的内部结构是什么?如何将这些问题与现有的观察结果联系起来?整个20世纪恒星演化理论的巨大发展和这一领域的技术水平将占据本章其余部分和以下几章的部分内容
myassignments-help数学代考价格说明
1、客户需提供物理代考的网址，相关账户，以及课程名称，Textbook等相关资料~客服会根据作业数量和持续时间给您定价~使收费透明，让您清楚的知道您的钱花在什么地方。
2、数学代写一般每篇报价约为600—1000rmb，费用根据持续时间、周作业量、成绩要求有所浮动(持续时间越长约便宜、周作业量越多约贵、成绩要求越高越贵)，报价后价格觉得合适，可以先付一周的款，我们帮你试做，满意后再继续，遇到Fail全额退款。
3、myassignments-help公司所有MATH作业代写服务支持付半款，全款，周付款，周付款一方面方便大家查阅自己的分数，一方面也方便大家资金周转，注意:每周固定周一时先预付下周的定金，不付定金不予继续做。物理代写一次性付清打9.5折。
Math作业代写、数学代写常见问题
留学生代写覆盖学科？
代写学科覆盖Math数学,经济代写，金融,计算机,生物信息，统计Statistics,Financial Engineering，Mathematical Finance，Quantitative Finance，Management Information Systems,Business Analytics,Data Science等。代写编程语言包括Python代写、Physics作业代写、物理代写、R语言代写、R代写、Matlab代写、C++代做、Java代做等。
数学作业代写会暴露客户的私密信息吗？
我们myassignments-help为了客户的信息泄露，采用的软件都是专业的防追踪的软件，保证安全隐私，绝对保密。您在我们平台订购的任何网课服务以及相关收费标准，都是公开透明，不存在任何针对性收费及差异化服务，我们随时欢迎选购的留学生朋友监督我们的服务，提出Math作业代写、数学代写修改建议。我们保障每一位客户的隐私安全。
留学生代写提供什么服务？
我们提供英语国家如美国、加拿大、英国、澳洲、新西兰、新加坡等华人留学生论文作业代写、物理代写、essay润色精修、课业辅导及网课代修代写、Quiz，Exam协助、期刊论文发表等学术服务，myassignments-help拥有的专业Math作业代写写手皆是精英学识修为精湛；实战经验丰富的学哥学姐！为你解决一切学术烦恼！
物理代考靠谱吗？
靠谱的数学代考听起来简单，但实际上不好甄别。我们能做到的靠谱，是把客户的网课当成自己的网课；把客户的作业当成自己的作业；并将这样的理念传达到全职写手和freelancer的日常培养中，坚决辞退糊弄、不守时、抄袭的写手！这就是我们要做的靠谱！
数学代考下单流程
提早与客服交流，处理你心中的顾虑。操作下单，上传你的数学代考/论文代写要求。专家结束论文，准时交给，在此过程中可与专家随时交流。后续互动批改
付款操作：我们数学代考服务正常多种支付方法，包含paypal，visa，mastercard，支付宝，union pay。下单后与专家直接互动。
售后服务：论文结束后保证完美经过turnitin查看，在线客服全天候在线为您服务。如果你觉得有需求批改的当地能够免费批改，直至您对论文满意为止。如果上交给教师后有需求批改的当地，只需求告诉您的批改要求或教师的comments，专家会据此批改。
保密服务：不需求提供真实的数学代考名字和电话号码，请提供其他牢靠的联系方法。我们有自己的工作准则，不会泄露您的个人信息。
myassignments-help擅长领域包含但不是全部:
myassignments-help服务请添加我们官网的客服或者微信/QQ，我们的服务覆盖：Assignment代写、Business商科代写、CS代考、Economics经济学代写、Essay代写、Finance金融代写、Math数学代写、report代写、R语言代考、Statistics统计学代写、物理代考、作业代写、加拿大代考、加拿大统计代写、北美代写、北美作业代写、北美统计代考、商科Essay代写、商科代考、数学代考、数学代写、数学作业代写、physics作业代写、物理代写、数据分析代写、新西兰代写、澳洲Essay代写、澳洲代写、澳洲作业代写、澳洲统计代写、澳洲金融代写、留学生课业指导、经济代写、统计代写、统计作业代写、美国Essay代写、美国代考、美国数学代写、美国统计代写、英国Essay代写、英国代考、英国作业代写、英国数学代写、英国统计代写、英国金融代写、论文代写、金融代考、金融作业代写。