Damp Mergers Recent Gaseous Mergers without Significant Globular Cluster Formation
8星系与宇宙的大尺度结构
~45x109太阳质量
•根据质光关系定M33中发光物质的质量 •太阳的绝对光度：4.8；M33绝对光度：-19.5
•光度差：2.51224.3=~5.2x109
•M33中发光物质的质量： =~5.2x109 太阳质量， 只有动力学质量的1/10! •进一步的改正：不发光的气体和尘埃，恒星质光 关系的改正，银河系的质光关系：1.5
宽发射线区
Gas clouds moving at several thousand km/sec These appear to be orbital motions (gravity) Gas is photoionized by radiation from the accretion disk and its corona
z
0 0.158 0
活动星系核：高光度
在可见光波段，活动星系核比它的寄主星系要亮 几千倍！
活动星系核：宽的发射谱
Comparable power emitted across ~seven orders of magnitude in photon energy
发射区域：尺度小！
Reverberation Mapping
Measure the time lag in response of BLR clouds to changing ionizing flux from the accretion disk Implied sizes range from light weeks in low power AGN to light years in powerful ones Size plus velocity yield black hole mass
【英语单词记忆】天文术语 D F
【英语单词记忆】天文术语 D F 【英语单词记忆】天文术语d-fdabundance氘丰度dactyl艾卫darkhalo暗晕dataacquisition数据采集declinephase下降阶段deep-fieldobservation浅天区观测densityarm密度臂densityprofile密度轮廓dereddening红化改正desdemona天卫十destabiliizingeffect去稳效应dewshield露罩diagonalmirror对角镜diagnosticdiagram确诊图differentialreddening较差红化diffusedensityEnergetic密度diffusedwarf弥漫矮星系diffusex-ray弥漫着x射线diffusionapproximation扩散近似digitalopticalskysurvey数字光学巡天digitalskysurvey数字巡天disappearance掩始cisconnectionevent断尾事件dish碟形天线diskglobularcluster盘族球状星团dispersionmeasure频散量度dissector析象管distanceestimator估距关系distributionparameter分布参数disturbedgalaxy告以星系disturbinggalaxy扰动星系dobsonianmounting多布森装置dobsonianreflector多布森反射望远镜dobsoniantelescope多布森望远镜dominantgalaxy主星系double-modecepheid双锻铁父变星double-modepulsator双模脉动星double-moderrlyraestar双模天琴rr型星 double-ringgalaxy双环星系dqherculisstar武仙dq型星dredge-up上翻driftscanning飘移读取drivingsystem驱动系统dumbbellradiogalaxy哑铃状射电星系duponttelescope杜邦望远镜dustring尘环dwarfcarbonstar碳矮星dwarfspheroidal狼球状星系dwarfspheroidalgalaxy矮球状星系 dwarfspiral狼旋涡星系dwarfspiralgalaxy矮旋涡星系dynamicalage动力学年龄dynamicalastronomy动力天文dynamicalevolution动力学进化eaglenebula(m16)鹰状星云eartycluster晚型星系团earlyearth早期地球。
暗物质简介
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暗物质粒子的脱耦
在运动学脱耦之后，暗物质粒子不再与背景等离子体有动量交换， 因此暗物质粒子的质量扰动开始随时间对数增长，逐渐形成结构。
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非重子暗物质的脱耦时间比重子的脱耦时间更早！
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Hale Waihona Puke • 不过，标量多重态的情况没这么简单。标量多重态
存在多种自相互作用，以及与 Higgs 场的相互作用。
• 最近有研究[Hamada, et al., arXiv:1505.01721]表明 ，
七重态标量的四次自相互作用耦合常数在 108 GeV
能标处就会遇到朗道极点。
• 我们进一步研究了在什么情况下可以将朗道极点提升
费米子：n ≥ 5 标量：n ≥ 7 这是一种偶然对称性 (accidental symmetry)，比 人为地引入 Z2 对称性的一般方法显得更加自然
• 多重态的引入会影响弱耦合常数 g2 的跑动。如果要求 g2 能够一直到普朗克能标都不遇到朗道极点，可以给 出 n 的上限。
Majorana费米子：n ≤ 5 实标量： n ≤ 8
我们发现，y 的跑动与 g2 的跑动强烈相关。当 y 的取
值为
时，可得
。否则
y 的朗道极点将早于 g2 的朗道极点出现。若允许精细
调节初值，至多可将朗道极点能标推迟到
。
精细调节 y 的初值，将耦合常数演化至 1014 GeV（略 低于朗道极点能标），则可用真空稳定性和微扰性条件
限制七重态的耦合常数
生活大爆炸 第四季第二集中英文剧本
生活大爆炸第四季第二集在干嘛呢\Whatcha doin' there?研究抓哔哔鸟的新方法吗\Working on a new plan to catch the roadrunner?你这个幽默暗指我是大笨狼怀尔吗\The humorous implication being that I am Wile E. Coyote?没错\Yes.而板上画的捕鸟设备\And this is a schematic for a bird-trapping device最终只会适得其反让我受伤吗\that will ultimately backfire and cause me physical injury?没错\Yes.我正在做的\What I'm doing here是想计算出我的死亡时间\is trying to determine when I'm going to die.很多人都在做这方面的研究\A lot of people are working on that research.那这些是什么\So what is all this?我家人的寿命长短\My family history factoring in longevity疾病倾向等信息\propensity for disease, et cetera.有意思\Interesting.卡尔叔叔的死因是KBB\Cause of death for Uncle Carl was KBB.KBB是什么\What's "KBB"?被獾所杀\"Killed by badger."怎么回事\How's that?那是感恩节\It was Thanksgiving.卡尔叔叔说"我觉得有只獾住在咱家烟囱里"\Uncle Carl said, "I think there's a badger living in our chimney. ""把手电筒给我"\"Hand me that flashlight."那是他对我们说的最后几句话\Those were the last words he ever spoke to us.我觉得\I don't think you need你没必要担心被獾所杀会遗传\to worry about death by badgers being hereditary.不对\Not true.战斗或逃跑的本能受基因控制\The fight or flight instinct is coded genetically.他没选择逃跑反而赤手空拳\Instead of fleeing, he chose to fight barehanded跟鼬类动物中强壮的一员战斗\against a brawny member of the weasel family.谁能肯定我没遗传这种有缺陷的基因\Who's to say that I don't share that flawed DNA?你反正可以找只獾来验证的\You can always get a badger and find out.说实在的\But seriously即使我忽略卡尔叔叔这个因素\even if I disregard the Uncle Carl factor我最多也只剩60年寿命\at best I have 60 years left.还有那么长啊\That long, huh?60年我只能活到这里\60 only takes me to here.我要活到这里\I need to get to here.那里有什么\What's there?据预计奇点最早出现的时间\The earliest estimate of the singularity人们能将自己的意识\when man will be able to transfer his consciousness转移进机器而获得永生\into machines and achieve immortality.这么说你不高兴自己会错失\So, you're upset about missing out变成某种怪异的有自我意识的机器人的机会\on becoming some sort of freakish self-aware robot?就差这么一点啊\By this much.真可惜你要吃鸡蛋吗\Tough break. You want eggs?你不明白莱纳德\You don't get it, Leonard.我会错过很多东西\I'm going to miss so much.统一场论冷聚变还有章狗\the unified field theory, cold fusion, the dogapus.章狗是什么\What's a dogapus?狗和章鱼的杂交动物\The hybrid dog and octopus.人类在水下的忠实朋友\Man's underwater best friend.有人研究这个吗\Is somebody working on that?我打算过研究的\I was going to.我想把它作为我三百岁的生日礼物\I planned on giving it to myself on my 300th birthday.等等你讨厌狗\Wait a minute. You hate dogs.章狗玩接球时能接八个球\A dogapus can play fetch with eight balls.没有人能讨厌这个\No one can hate that.我们欠你多少钱\What do we owe you?一共是28.17美元\It came to $28.17.每人就六美元吧\Let's say six bucks apiece.给你\Here you go.谢谢\Thank you.干嘛\What?算了我请了\Never mind. I got it.你要我给钱啊\Oh, you wanted me to pay.-不用了-不不不你是对的\- It's no big deal. - No, no, no, no. You're right.我们已经分手了我应该自己付钱\We're not going out anymore; I should pay for myself.笑什么\What?他说"如果他有女人身子"\He said, "If he had woman parts"他后半辈子就不愁吃了"\"he'd eat for free the rest of his life"是啊可你也没办法跟自己说话了\Yeah, but you wouldn't be able to talk to yourself.我现金有点紧张啊\I'm a little low on cash.-你有多少-没有\- How much you got? - Nothing.你不带钱怎么出门啊\How can you walk around with no money?我漂亮别人请客\I'm cute. I get by.没事欠着吧\It's okay, you can owe me.-谢谢-谢尔顿六美元\- Thank you. - Sheldon, six bucks.不了谢谢我今晚不吃披萨\No, thank you. I'm not eating pizza tonight.可今天是星期四\But it's Thursday.星期四是披萨之夜\Thursday's pizza night.对我来说不是\Not for me.现在改成十字花科蔬菜之夜了\Thursday is now Cruciferous Vegetable Night.今晚的特选小包菜\Tonight's selection: Brussels sprouts.真的吗\Really?你要改谢尔顿日程表\You're changing the Sheldonian calendar?-这只是个小小的代价-为啥\- It's a small price to pay. - For what?-不别问啊-对不起\- No, no, don't ask. - Sorry, sorry, sorry, sorry, sorry.为了把我的寿命延长到能把意识\In order to live long enough to fuse my consciousness转移到人造大脑上我要改变饮食\with cybernetics, I need to change my diet.等等人造大脑是机器人之类的吧\Wait. Cybernetics is robot stuff, right?没错\Correct.这么说你想把自己变成某种机器人\So you want to turn yourself into some sort of robot?本质上是这样\Essentially, yes.我想问个问题\Okay, here's my question.你不是已经变成机器人了吗\Didn't you already do that?虽然我受宠若惊可惜还没有\Flattering, but sadly, no.我还打算开始一种运动养生法\I'm also planning to begin an exercise regimen加强我的心血管系统\designed to strengthen my cardiovascular system.也就是慢跑\AKA jogging.等等亲爱的你以前跑过步吗\Wait. Honey, have you ever run before?当然跑过\Certainly.我被恶霸狗和暴走的鸡追过\I've run from bullies, dogs, angry chickens...还有个锲而不舍执意要给我做\and one particularly persistent P.E. teacher脊柱侧弯测试的体育老师\determined to bend me over and give me a scoliosis test.你说得对佩妮经常跑步\You're right. Penny jogs.你们可以一起跑的\Maybe you guys can run together.这主意太棒了\That's an excellent idea.如果我们边跑边聊\Yeah, if we chat就会感觉时间流逝得更快了\it will create the illusion of time going faster.绝对不可能\No, it won't.他怎么知道我跑步的\Um, how does he know I jog?因为他在车里用高倍望远镜尾行你\Oh, he watches you from his car with high-powered binoculars. 我的天呐这太猥琐了\Oh, my God, that is so creepy!我就说嘛\I know!他说他要坚持发扬下去\And he says he's not gonna stop.那找心理医生解决怎么和女人说话的问题啊\Then see a shrink and figure out how to talk to women.什么玩意儿\What the hell?怎么了\What's the matter?疼痛以我的肚脐为起点\I have pain radiating from my navel延伸到我的右下腹\to my lower right abdomen.我感到恶心和发热\I'm nauseated and feverish.我觉得我得霍乱了\I believe I may have cholera.帕萨迪纳才没霍乱呢\There's no cholera in Pasadena.就跟去年夏天帕萨迪纳也没有疟疾一样\Just like last summer, when there was no malaria in Pasadena. 好吧如果那不是霍乱\Well, if it's not cholera根据搜索结果\then based on a quick Internet search由相似度递减排列的其他解释分别是\the other explanations in decreasing order of likelihood先天性巨结肠肉毒杆菌中毒一条30英尺长的绦虫\are Hirschsprung's Disease, botulism, a 30-foot tapeworm或者是不小心摄入菊花\or accidental ingestion of chrysanthemum blossoms.你什么时候会不小心摄入菊花的\When would you have accidentally eaten chrysanthemum blossoms? 这是包括了梦游\It's part of an unlikely scenario和24小时营业的花店\that involves sleepwalking and a 24-hour flower mart以及不靠谱的经营者的不可能场景\with a less-than- vigilant proprietor.噢老天我的肚子\Oh, Lord, my belly!你切除过阑尾吗\Ever had your appendix out?没有\I haven't.我想来着但谁有那时间啊\I've been meaning to, but who has the time?我送你去医院吧\Let's get you to the hospital.于是乎就此了结\So this is how it ends...真是无比残酷的讽刺\with cruel irony.正当我保证要保护爱惜自己的身体之时\Just as I make the commitment to preserving my body我被自己的阑尾所背叛就一退化的器官\I am betrayed by my appendix, a vestigial organ.你知道阑尾原本的作用是什么吗莱纳德\Do you know the original purpose of the appendix, Leonard? 不知道\No.我知道而知道太多的却灭亡而你却能继续活下去\I do. And yet I'm doomed while you live on.结局很出乎意料是不是\Funny how things work out, isn't it?噢天呐我感觉要爆炸了\Oh, Lord, I think it's about to burst!还有种可能\On the other hand也许都是小包菜的错\it might have been the Brussels sprouts.晚安您呐\Good night.晚安\Good night.阑尾炎\Appendicitis.自己紧张个甚啊\What a nervous Nelly.佩妮佩妮佩妮\Penny! Penny! Penny!来啦来啦\Coming, coming.嘿跑鞋不错嘛\Hey, nice knees.谢谢\Thank you.这是我娘的\They're my mother's.闪电侠T恤是什么意思\Oh. And the Flash shirt is what?你要跑的飞快吗\Because, what, you're gonna run really fast?不是穿闪电侠衫是因为今天是星期五\No, the Flash shirt is because it's Friday但要是真能有效就更好了\but it's nice when things work out.-你的心率监测器在哪儿-没有\- Where's your heart rate monitor? - I don't have one.-计步器呢-没有\- What about your pedometer? - Don't have one.那你鞋子里有传感器连接到iPod吗\Do you have telematics in your shoes connected to an iPod?-没-那你干嘛呢\- Uh, no. - What do you do就出去像兔子一样随便蹦蹦跳跳一下吗\You just go out there and gambol about like a bunny?不也就跑到饿了然后买个熊爪包吃\No. I just run till I'm hungry, then I stop for a bear claw.为什么要这么做\Why are you doing that?在跑步前最好拉伸下肌肉\It's good to stretch your muscles before you run.好吧\All right.先来摸个脚趾\Let's start with a toe touch.你来做一个\Okay, you do it.我正做着呢\I <i>am</i> doing it.哇哦不错\Oh. Wow. Good job.你能做这个么\Can you do this?我们永远也不会知道的\We'll never know.好吧那边跑边热身吧\Okay, let's just warm up on the run.-好的-那出发吧\- Okay. - Okay, let's go.我最近一直在读生物力学的书\I've been reading up on biomechanics.我认为你会惊讶于我的...\I think you'll be surprised at my...我的天呐你还好吗\Oh, my God, are you okay?应该吧\I think so.-我来拉你一把吧-谢谢\- Oh, let me help you up. - Thank you.噢谢尔顿\Oh, Sheldon!如果这能让你觉得好些的话\If it makes you feel any better星期四不再是十字花科蔬菜之夜了\Thursday is no longer Cruciferous Vegetable Night.这是我的咖喱鸡\Here's my chicken curry.霍华德的鲜虾菜饭\Howard, your shrimp biryani.-谢谢您-菠菜奶豆腐是佩妮的\- Thank you, sir. - Palak paneer, that's Penny.-谢谢-而拉杰·库萨帕里的\- Thanks. - And for Rajesh Koothrappali家乡发明出这些美味佳肴的人\from whose homeland these tasty dishes originate一个大份的麦乐鸡\one large order of chicken McNuggets.-我的这份多少钱-12刀\- Hey, what's my share? - Uh... 12 bucks.-我能周五付工资以后再还你吗-没问题\- Okay, can I get you after Friday when I get paid? - Sure. 我欠你多少了\What am I up to now?呃算上印度菜比萨\Well, okay, with the Indian food, the pizza泰国菜一箱油\the Thai food, the tank of gas冷冻酸奶\the frozen yogurt外带你的房租嗯...\and your rent, uh...一千四百多一点吧\a little over $1,400.又怎么了\What now?他只是表示膜拜\He's just expressing his admiration that你不用献身也能蹭吃蹭喝\you don't even have to put out to get free stuff.我这不是蹭我会还钱的\It's not free-- I'm gonna pay him back.给我停\Shut up!谢尔顿你不来吗\Sheldon, are you gonna join us?就来\Coming!你们好伙计们\Greetings, friends.你好你个天知道是什么的鬼东西\Greetings, whatever the hell you are.我是一个移动虚拟化身设备\I am a mobile virtual presence device.鉴于近来发生的事\Recent events我意识到我的肉身太过脆弱\have demonstrated to me that my body is too fragile承受不了大千世界的种种\to endure the vicissitudes of the world.因此在我能够\Until such time as I am able转移意识之前\to transfer my consciousness我的肉身将保存在一个安全地点\I shall remain in a secure location并借此方式同外界联系\and interact with the world in this manner.没搞错吧你就想问这个--\Really? That's your question--他啥时搞来的那个斜坡\when did he put a ramp in?你占了我的专属座位\You're in my spot.可能一开始感觉会有点怪\This may seem a little odd at first但时间久了你们就会渐渐习惯\but over time, you'll grow accustomed和这样的我打交道\to dealing with me in this configuration.是咩说实话我觉得没什么不同\Yeah, to be honest, I don't see much difference.谢谢\Thank you.这也是我的目的\That's what I was going for.那个莱纳德明天我们去上班时\Now, Leonard, tomorrow, when we go to work你得腾出点时间来\you'll need to allow some extra time把我搬下楼梯\to get me down the stairs.为了让你省力我会分解成四个部分\For your convenience, I disassemble into four pieces.这太荒唐了\This is ridiculous.我要去找你谈谈\I'm coming to talk to you.你不知道我在哪儿\You don't know where I am.我的肉身现被安置在\My physical body is safely ensconced一个安全保密的场所\in a secure, undisclosed location.你不就在你卧室里么\You're in your bedroom.不我不在\No, I'm not.我都能听到你说话的声音从卧室传出来\I can hear your voice coming from your bedroom.不你听不到\No, you can't.你给我等着\Wait.回来\Come back.站住\Halt.未经授权人员禁止入内\Authorized personnel only!好吧你们两个变态\So, either one of you weirdos有谁想买我的内衣么只要一千四百块哦\want to buy my underwear? Only 1,400 bucks.谢尔顿这太荒唐了\Sheldon, this is ridiculous.我在你后面\I'm behind you.和我说话时请看着我\Please look at me when you're talking to me.我正看着你呢\I am looking at you.不你没有\No, you're not.无视床上的那个人\Pay no attention to that man in the bed.你不能以这种方式存在于这世上\You cannot exist as a virtual presence.这儿不行工作时就更不行了\Not here and certainly not at work.我的娘咧\Oh, good God.你知不知道我这年纪的人\At my age, do you know统计数字上最可能怎么死吗\how I'm statistically most likely to die?被你室友做掉吗\At the hands of your roommate?死于一场意外\An accident.我就准备弄成像是一场意外\That's how I'm going to make it look.在我将自己的智慧\Until I can transfer my intellect转移到一个更持久的容器内之前\to a more durable container我的肉身将被安全安置在我的床上\my body will remain safely ensconced in my bed.随你但别指望我会帮你\Fine, but don't expect my help.你必须帮我室友协议里写了\You have to help-- it's in the roommate agreement.不才没有\No, it's not.74条C款\Section 74.C.两人间若有人成了机器人\The various obligations and duties of the parties另一人所应尽的各项义务和责任\in the event one of them becomes a robot.让我一头撞死好了\I'll be damned.这种感觉太赞了\This is delightful.哼哼\Uh-huh.不用担心死于车祸\It's much easier to enjoy这样在上班路中欣赏美景\the picturesque route we travel to work就更加怡然自得了\when you remove the specter of fiery vehicular death.提醒我下\Refresh my memory.我干嘛不直接把你塞进后备箱呢\Why didn't I just put you in the trunk?因为我先抢了前排座位记得不\Because I called shotgun. Remember?好吧\Right.你看着压力很大\You seem tense.这样会不会感到放松\Perhaps this will relax you.我不想听音乐谢尔顿\I don't want to listen to music, Sheldon.好吧\Very well.真不明白你为什么不喜欢这样\I don't understand why you're not enjoying this.你和增强功能的我一起在车里\Together, in this car, with my enhanced capabilities这就好比霹雳游侠嘛\we're like Knight Rider.\an8\fn方正黑体简体\fs18\b1\bord1\shad1\3c&H2F2F2F&同名电视剧男主角和他的人工智能车那里面的车可不是括约肌吱吱响的废柴\Except in Knight Rider, the car isn't a yammering sphincter.你居然嘲笑括约肌\You mock the sphincter括约肌可是人体的一组肌肉\but the sphincter is a class of muscle没有的话人类没法存活的哦\without which human beings couldn't survive.人体内共有超过50种\There are over 50 different sphincters不同的括约肌\in the human body.你能叫出多少\How many can you name?我错了这就是一霹雳游侠没说的\I was wrong-- this is exactly like Knight Rider.你大概会对另一个游戏感兴趣\Perhaps you'd be interested in a different game.没兴趣\No.这张照片是在1911年\This is a photograph of the 1911召开的辐射和量子理论索尔瓦会议\Solvay Conference on the theory of radiation and quanta.我PS了几处不该存在的东西\Using Photoshop, I've introduced a few anachronisms.看看你能不能找出所有24处\See if you can spot all 24.我先给你第一个提示好了\I'll give you the first one.居里夫人不该带着电子表\Madame Curie should not be wearing a digital watch.你继续吧\And go.\an8益智游戏节目《冒险》的主题曲够了拜拜\That's it. Bye-bye.吓死你\Bazinga.我有更高权限的开关\I have an override switch.我差点被你害死了\I almost died!而我仍安然无恙地坐在床上\And I'm safe and sound in bed.现在再看谁是疯子\Who's crazy now?我还是会说你\I'm still going to go with you.你好霍斯金斯教授\Hello, Professor Hoskins.很高兴见到你敏迪\Nice to see you, Mindy.早上好[日语] 中村博士\And <i>konnichiwa, Dr. Nakamura.</i>很遗憾那帮瑞典佬推翻了你的理论\Sorry the Swedes disproved your theory.莱纳德我的门\Leonard, my door.你的门怎么了\What about it?乖给哥开个门\Be a lamb and open it for me.为嘛有啥问题吗\Why? What's the problem?你以为你难住我了对吗\You think you have me stymied, don't you?没有啊我觉得难住你的是门把手\No, I think a doorknob has you stymied.哦看啊莱纳德和R2-D-Bag[代指《星战》里的R2-D2机器人]\Oh, look, it's Leonard and R2-D-Bag. \an8《星战》里R2-D2机器人这里D-bag是douchebag[蠢货]的缩写这笑话是我想出来的我昨晚给你讲的\That's my joke. I told it last night.你不能随便剽窃好吧\You can't just use it.拉杰乖替哥开下门\Raj, be a lamb and open the door for me.好的\Oh, sure.他真乖\He's a lamb.你不乖\You're not.我好乖哦\I'm a lamb.这一切多美好啊\Isn't this nice?在享受同伴感情的同时\The pleasures of fellowship and camaraderie又不必忍受你们污浊呼吸对我皮肤的伤害\without having to tolerate your germy breath on my skin. 要我说咱们把他送到塔图因星球上\I say we just take him to Tatooine把他卖给爪哇人吧[《星战》情节]\and sell him to some Jawas.第二次了老兄\That's two, dude.写你自己的笑话去\Write your own jokes.哎呦欸\Oh, great.嗨我叫佩妮今晚为你们服务\Hi, I'm Penny, I'll be your waitress.你干嘛还要作自我介绍啊\Why are you introducing yourself?不管怎么样我宁愿\I'd rather people not know大家都不知道我跟你们之前有任何联系\I have any prior connection to you whatsoever.你能介绍一下今晚有什么特色菜吗\Can you tell me the specials this evening?谢尔顿我不为你服务\Sheldon, I'm not waiting on you.当然了\Obviously.你还没给我倒水呢\I don't even have water yet.因为你不在这里\Because you're not here.你这是对远程遥控人员的歧视\That's discrimination against the otherwise located.我要去找你的领导[也有比你高的意思]\I'm going to have to go over your head.经理经理在吗\Manager... manager.天啊快看那是谁\Oh, Lord, look who it is.那是斯蒂夫·沃兹尼亚克吗[苹果公司创始人之一]\Is that Steve Wozniak?我猜没错\I think it is.神奇而伟大的沃兹啊\The Great and Powerful Woz.佩妮斯蒂夫·沃兹尼亚克\Penny, Steve Wozniak was可是苹果电脑公司的创始人之一呢\one of the cofounders of Apple Computer.-他和斯蒂夫·乔布斯一起创办了... -没错\- He and Steve Jobs started it... - Yeah我知道他是谁我看过《与星共舞》\I know who he is. I watch <i>Dancing with the Stars.</i>\an8斯蒂夫·沃兹尼亚克曾参加过该节目我得去和他聊聊\I must speak to him.你当然得去了\Of course you must.这条街上还有家橄榄园[意大利连锁餐馆]\You know, there's an Olive Garden down the street.你们有空应该去尝尝\You guys should try it sometime.打扰了沃兹尼亚克先生\Excuse me, Mr. Wozniak?嘿\Oh, hey.很不错的虚拟化身仪器\Nice virtual presence device.谢谢夸奖\Thank you.我想说我是你的忠实粉丝\I just want to say I'm a big fan.你在我最爱的科技远见卓识者排行榜上排第15\You're my 15th favorite technological visionary.才第15啊\Only 15th?那也比斯蒂夫·乔布斯高6名呢\It's still six spots above Steve Jobs.我既不喜欢高翻衣领也不喜爱炫舞技的人\I care neither for turtlenecks nor showmanship.嗯我从来不穿高翻领的衣服\Yeah, I never got that turtleneck thing.我最得意的收藏就是一台1977年产的苹果Ⅱ\One of my proudest possessions is a vintage 1977 Apple Two.如果不考虑苹果DOS 3.3版文件系统的局限性\Despite the file system limitations of Apple DOS 3.3它确实算个一流的小成就\it was a pretty nifty little achievement.多谢"一流"这个词让我受宠若惊\Thanks, we were shooting for "nifty."如果你能把它带过来的话\You know, if you had it here我可以在上面签个名\I'd autograph it for you.别走开等我15到30分钟\Don't move for 15 to 30 minutes具体情况得看公交车的运营情况\depending on how the buses are running.书呆子\Nerds.我来了沃兹我来了\I'm coming, Woz, I'm coming.佩妮佩妮佩妮\Penny... Penny... Penny.怎么了谢童木\What up, Shel-Bot?我下不了床\I can't get out of bed.脚扭了\I hurt my ankle.你想让我干嘛啊\What do you want me to do?给我唱"乖乖猫"吧\Sing me "Soft Kitty."你真的想让我对着个电脑显示器唱\Really, you want me to sing "Soft Kitty""乖乖猫"吗\to a computer monitor?你想过来当面对我唱吗\Would you rather come over and sing it to me in person?乖乖猫暖暖猫\Soft kitty, warm kitty小小毛绒球\Little ball of fur...离麦克风近点儿\Closer to the microphone.快乐猫瞌睡...\Happy kitty, sleepy...打住\No.从头开始\You have to start over.乖乖猫暖暖猫\Soft kitty, warm kitty小小毛绒球\Little ball of fur快乐猫瞌睡猫\Happy kitty, sleepy kitty呜呜呜[猫叫声]\Purr, purr, purr.。
原子核衰变率是否与太阳事件-中国科学院大科学装置理论物理研究中心
一个引起争论的问题：原子核衰变率是 否与太阳耀斑和地球-太阳距离相关？
白 希 祥
中国原子能科学研究院
历史背景
自1896年Becquerel发现放射性以来，核物理学家一直在探讨原 子核衰变率是否会受到温度、压力、化学状态、浓度和磁场等外 在条件的影响。1930年Rutherford，Chadwick和Ellis等曾断言在 所有条件下衰变率都保持不变(除K-俘获或强电磁场环境中b-衰 变外，因为这两种情况略显复杂一些)，但后来的研究表明他们 的论断过于绝对化。若干裸核和高剥离态原子的b衰变实验结果 就是最有力的反面证据之一。例如,163Dy中性原子是稳定的，但 其裸核163Dy66+的半衰期变成47±5年；187Re中性原子的半衰期为 43.5×109年，其裸核187Re75+的缩短为32.9±2.0年。关于各种外 部条件对原子核衰变影响的有无和程度至今仍是一个引起争论的 问题。无论如何，不稳定核素的寿命不应看作是绝对恒定不变的， 因为衰变率并非完全决定于原子核的内秉特性。
2006.12.2-2007.1.2期间Purdue大学实验室利用1mCi的54Mn紧贴在NaI闪 烁计数器上、具有良好铅屏蔽的装臵，在19.5℃的恒温条件下连续测量了 54Mn K-俘获过程54Mn+e-→54Cr+n 形成的54Cr退激产生的834.8 keVg-射 e 线。2006年12.12-12.17期间在与地球相对位臵不变的多个军用同步环境卫 星(GOES)上均观测到了与两次太阳耀斑相伴随的X-射线和带电粒子通 量的尖峰, Purdue大学实验室同时探测到54Mn衰变率的显著下降。这些 观测支持核衰变率可能随太阳耀斑或地球-太阳距离改变的猜想。
引力波观测原文PhysRevLett.116.061102
Observation of Gravitational Waves from a Binary Black Hole MergerB.P.Abbott et al.*(LIGO Scientific Collaboration and Virgo Collaboration)(Received21January2016;published11February2016)On September14,2015at09:50:45UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal.The signal sweeps upwards in frequency from35to250Hz with a peak gravitational-wave strain of1.0×10−21.It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole.The signal was observed with a matched-filter signal-to-noise ratio of24and a false alarm rate estimated to be less than1event per203000years,equivalent to a significance greaterthan5.1σ.The source lies at a luminosity distance of410þ160−180Mpc corresponding to a redshift z¼0.09þ0.03−0.04.In the source frame,the initial black hole masses are36þ5−4M⊙and29þ4−4M⊙,and the final black hole mass is62þ4−4M⊙,with3.0þ0.5−0.5M⊙c2radiated in gravitational waves.All uncertainties define90%credible intervals.These observations demonstrate the existence of binary stellar-mass black hole systems.This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.DOI:10.1103/PhysRevLett.116.061102I.INTRODUCTIONIn1916,the year after the final formulation of the field equations of general relativity,Albert Einstein predicted the existence of gravitational waves.He found that the linearized weak-field equations had wave solutions: transverse waves of spatial strain that travel at the speed of light,generated by time variations of the mass quadrupole moment of the source[1,2].Einstein understood that gravitational-wave amplitudes would be remarkably small;moreover,until the Chapel Hill conference in 1957there was significant debate about the physical reality of gravitational waves[3].Also in1916,Schwarzschild published a solution for the field equations[4]that was later understood to describe a black hole[5,6],and in1963Kerr generalized the solution to rotating black holes[7].Starting in the1970s theoretical work led to the understanding of black hole quasinormal modes[8–10],and in the1990s higher-order post-Newtonian calculations[11]preceded extensive analytical studies of relativistic two-body dynamics[12,13].These advances,together with numerical relativity breakthroughs in the past decade[14–16],have enabled modeling of binary black hole mergers and accurate predictions of their gravitational waveforms.While numerous black hole candidates have now been identified through electromag-netic observations[17–19],black hole mergers have not previously been observed.The discovery of the binary pulsar system PSR B1913þ16 by Hulse and Taylor[20]and subsequent observations of its energy loss by Taylor and Weisberg[21]demonstrated the existence of gravitational waves.This discovery, along with emerging astrophysical understanding[22], led to the recognition that direct observations of the amplitude and phase of gravitational waves would enable studies of additional relativistic systems and provide new tests of general relativity,especially in the dynamic strong-field regime.Experiments to detect gravitational waves began with Weber and his resonant mass detectors in the1960s[23], followed by an international network of cryogenic reso-nant detectors[24].Interferometric detectors were first suggested in the early1960s[25]and the1970s[26].A study of the noise and performance of such detectors[27], and further concepts to improve them[28],led to proposals for long-baseline broadband laser interferome-ters with the potential for significantly increased sensi-tivity[29–32].By the early2000s,a set of initial detectors was completed,including TAMA300in Japan,GEO600 in Germany,the Laser Interferometer Gravitational-Wave Observatory(LIGO)in the United States,and Virgo in binations of these detectors made joint obser-vations from2002through2011,setting upper limits on a variety of gravitational-wave sources while evolving into a global network.In2015,Advanced LIGO became the first of a significantly more sensitive network of advanced detectors to begin observations[33–36].A century after the fundamental predictions of Einstein and Schwarzschild,we report the first direct detection of gravitational waves and the first direct observation of a binary black hole system merging to form a single black hole.Our observations provide unique access to the*Full author list given at the end of the article.Published by the American Physical Society under the terms of the Creative Commons Attribution3.0License.Further distri-bution of this work must maintain attribution to the author(s)and the published article’s title,journal citation,and DOI.properties of space-time in the strong-field,high-velocity regime and confirm predictions of general relativity for the nonlinear dynamics of highly disturbed black holes.II.OBSERVATIONOn September14,2015at09:50:45UTC,the LIGO Hanford,W A,and Livingston,LA,observatories detected the coincident signal GW150914shown in Fig.1.The initial detection was made by low-latency searches for generic gravitational-wave transients[41]and was reported within three minutes of data acquisition[43].Subsequently, matched-filter analyses that use relativistic models of com-pact binary waveforms[44]recovered GW150914as the most significant event from each detector for the observa-tions reported here.Occurring within the10-msintersite FIG.1.The gravitational-wave event GW150914observed by the LIGO Hanford(H1,left column panels)and Livingston(L1,rightcolumn panels)detectors.Times are shown relative to September14,2015at09:50:45UTC.For visualization,all time series are filtered with a35–350Hz bandpass filter to suppress large fluctuations outside the detectors’most sensitive frequency band,and band-reject filters to remove the strong instrumental spectral lines seen in the Fig.3spectra.Top row,left:H1strain.Top row,right:L1strain.GW150914arrived first at L1and6.9þ0.5−0.4ms later at H1;for a visual comparison,the H1data are also shown,shifted in time by this amount and inverted(to account for the detectors’relative orientations).Second row:Gravitational-wave strain projected onto each detector in the35–350Hz band.Solid lines show a numerical relativity waveform for a system with parameters consistent with those recovered from GW150914[37,38]confirmed to99.9%by an independent calculation based on[15].Shaded areas show90%credible regions for two independent waveform reconstructions.One(dark gray)models the signal using binary black hole template waveforms [39].The other(light gray)does not use an astrophysical model,but instead calculates the strain signal as a linear combination of sine-Gaussian wavelets[40,41].These reconstructions have a94%overlap,as shown in[39].Third row:Residuals after subtracting the filtered numerical relativity waveform from the filtered detector time series.Bottom row:A time-frequency representation[42]of the strain data,showing the signal frequency increasing over time.propagation time,the events have a combined signal-to-noise ratio(SNR)of24[45].Only the LIGO detectors were observing at the time of GW150914.The Virgo detector was being upgraded, and GEO600,though not sufficiently sensitive to detect this event,was operating but not in observational mode.With only two detectors the source position is primarily determined by the relative arrival time and localized to an area of approximately600deg2(90% credible region)[39,46].The basic features of GW150914point to it being produced by the coalescence of two black holes—i.e., their orbital inspiral and merger,and subsequent final black hole ringdown.Over0.2s,the signal increases in frequency and amplitude in about8cycles from35to150Hz,where the amplitude reaches a maximum.The most plausible explanation for this evolution is the inspiral of two orbiting masses,m1and m2,due to gravitational-wave emission.At the lower frequencies,such evolution is characterized by the chirp mass[11]M¼ðm1m2Þ3=5121=5¼c3G596π−8=3f−11=3_f3=5;where f and_f are the observed frequency and its time derivative and G and c are the gravitational constant and speed of light.Estimating f and_f from the data in Fig.1, we obtain a chirp mass of M≃30M⊙,implying that the total mass M¼m1þm2is≳70M⊙in the detector frame. This bounds the sum of the Schwarzschild radii of thebinary components to2GM=c2≳210km.To reach an orbital frequency of75Hz(half the gravitational-wave frequency)the objects must have been very close and very compact;equal Newtonian point masses orbiting at this frequency would be only≃350km apart.A pair of neutron stars,while compact,would not have the required mass,while a black hole neutron star binary with the deduced chirp mass would have a very large total mass, and would thus merge at much lower frequency.This leaves black holes as the only known objects compact enough to reach an orbital frequency of75Hz without contact.Furthermore,the decay of the waveform after it peaks is consistent with the damped oscillations of a black hole relaxing to a final stationary Kerr configuration. Below,we present a general-relativistic analysis of GW150914;Fig.2shows the calculated waveform using the resulting source parameters.III.DETECTORSGravitational-wave astronomy exploits multiple,widely separated detectors to distinguish gravitational waves from local instrumental and environmental noise,to provide source sky localization,and to measure wave polarizations. The LIGO sites each operate a single Advanced LIGO detector[33],a modified Michelson interferometer(see Fig.3)that measures gravitational-wave strain as a differ-ence in length of its orthogonal arms.Each arm is formed by two mirrors,acting as test masses,separated by L x¼L y¼L¼4km.A passing gravitational wave effec-tively alters the arm lengths such that the measured difference isΔLðtÞ¼δL x−δL y¼hðtÞL,where h is the gravitational-wave strain amplitude projected onto the detector.This differential length variation alters the phase difference between the two light fields returning to the beam splitter,transmitting an optical signal proportional to the gravitational-wave strain to the output photodetector. To achieve sufficient sensitivity to measure gravitational waves,the detectors include several enhancements to the basic Michelson interferometer.First,each arm contains a resonant optical cavity,formed by its two test mass mirrors, that multiplies the effect of a gravitational wave on the light phase by a factor of300[48].Second,a partially trans-missive power-recycling mirror at the input provides addi-tional resonant buildup of the laser light in the interferometer as a whole[49,50]:20W of laser input is increased to700W incident on the beam splitter,which is further increased to 100kW circulating in each arm cavity.Third,a partially transmissive signal-recycling mirror at the outputoptimizes FIG. 2.Top:Estimated gravitational-wave strain amplitude from GW150914projected onto H1.This shows the full bandwidth of the waveforms,without the filtering used for Fig.1. The inset images show numerical relativity models of the black hole horizons as the black holes coalesce.Bottom:The Keplerian effective black hole separation in units of Schwarzschild radii (R S¼2GM=c2)and the effective relative velocity given by the post-Newtonian parameter v=c¼ðGMπf=c3Þ1=3,where f is the gravitational-wave frequency calculated with numerical relativity and M is the total mass(value from Table I).the gravitational-wave signal extraction by broadening the bandwidth of the arm cavities [51,52].The interferometer is illuminated with a 1064-nm wavelength Nd:Y AG laser,stabilized in amplitude,frequency,and beam geometry [53,54].The gravitational-wave signal is extracted at the output port using a homodyne readout [55].These interferometry techniques are designed to maxi-mize the conversion of strain to optical signal,thereby minimizing the impact of photon shot noise (the principal noise at high frequencies).High strain sensitivity also requires that the test masses have low displacement noise,which is achieved by isolating them from seismic noise (low frequencies)and designing them to have low thermal noise (intermediate frequencies).Each test mass is suspended as the final stage of a quadruple-pendulum system [56],supported by an active seismic isolation platform [57].These systems collectively provide more than 10orders of magnitude of isolation from ground motion for frequen-cies above 10Hz.Thermal noise is minimized by using low-mechanical-loss materials in the test masses and their suspensions:the test masses are 40-kg fused silica substrates with low-loss dielectric optical coatings [58,59],and are suspended with fused silica fibers from the stage above [60].To minimize additional noise sources,all components other than the laser source are mounted on vibration isolation stages in ultrahigh vacuum.To reduce optical phase fluctuations caused by Rayleigh scattering,the pressure in the 1.2-m diameter tubes containing the arm-cavity beams is maintained below 1μPa.Servo controls are used to hold the arm cavities on resonance [61]and maintain proper alignment of the optical components [62].The detector output is calibrated in strain by measuring its response to test mass motion induced by photon pressure from a modulated calibration laser beam [63].The calibration is established to an uncertainty (1σ)of less than 10%in amplitude and 10degrees in phase,and is continuously monitored with calibration laser excitations at selected frequencies.Two alternative methods are used to validate the absolute calibration,one referenced to the main laser wavelength and the other to a radio-frequencyoscillator(a)FIG.3.Simplified diagram of an Advanced LIGO detector (not to scale).A gravitational wave propagating orthogonally to the detector plane and linearly polarized parallel to the 4-km optical cavities will have the effect of lengthening one 4-km arm and shortening the other during one half-cycle of the wave;these length changes are reversed during the other half-cycle.The output photodetector records these differential cavity length variations.While a detector ’s directional response is maximal for this case,it is still significant for most other angles of incidence or polarizations (gravitational waves propagate freely through the Earth).Inset (a):Location and orientation of the LIGO detectors at Hanford,WA (H1)and Livingston,LA (L1).Inset (b):The instrument noise for each detector near the time of the signal detection;this is an amplitude spectral density,expressed in terms of equivalent gravitational-wave strain amplitude.The sensitivity is limited by photon shot noise at frequencies above 150Hz,and by a superposition of other noise sources at lower frequencies [47].Narrow-band features include calibration lines (33–38,330,and 1080Hz),vibrational modes of suspension fibers (500Hz and harmonics),and 60Hz electric power grid harmonics.[64].Additionally,the detector response to gravitational waves is tested by injecting simulated waveforms with the calibration laser.To monitor environmental disturbances and their influ-ence on the detectors,each observatory site is equipped with an array of sensors:seismometers,accelerometers, microphones,magnetometers,radio receivers,weather sensors,ac-power line monitors,and a cosmic-ray detector [65].Another∼105channels record the interferometer’s operating point and the state of the control systems.Data collection is synchronized to Global Positioning System (GPS)time to better than10μs[66].Timing accuracy is verified with an atomic clock and a secondary GPS receiver at each observatory site.In their most sensitive band,100–300Hz,the current LIGO detectors are3to5times more sensitive to strain than initial LIGO[67];at lower frequencies,the improvement is even greater,with more than ten times better sensitivity below60Hz.Because the detectors respond proportionally to gravitational-wave amplitude,at low redshift the volume of space to which they are sensitive increases as the cube of strain sensitivity.For binary black holes with masses similar to GW150914,the space-time volume surveyed by the observations reported here surpasses previous obser-vations by an order of magnitude[68].IV.DETECTOR VALIDATIONBoth detectors were in steady state operation for several hours around GW150914.All performance measures,in particular their average sensitivity and transient noise behavior,were typical of the full analysis period[69,70]. Exhaustive investigations of instrumental and environ-mental disturbances were performed,giving no evidence to suggest that GW150914could be an instrumental artifact [69].The detectors’susceptibility to environmental disturb-ances was quantified by measuring their response to spe-cially generated magnetic,radio-frequency,acoustic,and vibration excitations.These tests indicated that any external disturbance large enough to have caused the observed signal would have been clearly recorded by the array of environ-mental sensors.None of the environmental sensors recorded any disturbances that evolved in time and frequency like GW150914,and all environmental fluctuations during the second that contained GW150914were too small to account for more than6%of its strain amplitude.Special care was taken to search for long-range correlated disturbances that might produce nearly simultaneous signals at the two sites. No significant disturbances were found.The detector strain data exhibit non-Gaussian noise transients that arise from a variety of instrumental mecha-nisms.Many have distinct signatures,visible in auxiliary data channels that are not sensitive to gravitational waves; such instrumental transients are removed from our analyses [69].Any instrumental transients that remain in the data are accounted for in the estimated detector backgrounds described below.There is no evidence for instrumental transients that are temporally correlated between the two detectors.V.SEARCHESWe present the analysis of16days of coincident observations between the two LIGO detectors from September12to October20,2015.This is a subset of the data from Advanced LIGO’s first observational period that ended on January12,2016.GW150914is confidently detected by two different types of searches.One aims to recover signals from the coalescence of compact objects,using optimal matched filtering with waveforms predicted by general relativity. The other search targets a broad range of generic transient signals,with minimal assumptions about waveforms.These searches use independent methods,and their response to detector noise consists of different,uncorrelated,events. However,strong signals from binary black hole mergers are expected to be detected by both searches.Each search identifies candidate events that are detected at both observatories consistent with the intersite propa-gation time.Events are assigned a detection-statistic value that ranks their likelihood of being a gravitational-wave signal.The significance of a candidate event is determined by the search background—the rate at which detector noise produces events with a detection-statistic value equal to or higher than the candidate event.Estimating this back-ground is challenging for two reasons:the detector noise is nonstationary and non-Gaussian,so its properties must be empirically determined;and it is not possible to shield the detector from gravitational waves to directly measure a signal-free background.The specific procedure used to estimate the background is slightly different for the two searches,but both use a time-shift technique:the time stamps of one detector’s data are artificially shifted by an offset that is large compared to the intersite propagation time,and a new set of events is produced based on this time-shifted data set.For instrumental noise that is uncor-related between detectors this is an effective way to estimate the background.In this process a gravitational-wave signal in one detector may coincide with time-shifted noise transients in the other detector,thereby contributing to the background estimate.This leads to an overestimate of the noise background and therefore to a more conservative assessment of the significance of candidate events.The characteristics of non-Gaussian noise vary between different time-frequency regions.This means that the search backgrounds are not uniform across the space of signals being searched.To maximize sensitivity and provide a better estimate of event significance,the searches sort both their background estimates and their event candidates into differ-ent classes according to their time-frequency morphology. The significance of a candidate event is measured against the background of its class.To account for having searchedmultiple classes,this significance is decreased by a trials factor equal to the number of classes [71].A.Generic transient searchDesigned to operate without a specific waveform model,this search identifies coincident excess power in time-frequency representations of the detector strain data [43,72],for signal frequencies up to 1kHz and durations up to a few seconds.The search reconstructs signal waveforms consistent with a common gravitational-wave signal in both detectors using a multidetector maximum likelihood method.Each event is ranked according to the detection statistic ηc ¼ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi2E c =ð1þE n =E c Þp ,where E c is the dimensionless coherent signal energy obtained by cross-correlating the two reconstructed waveforms,and E n is the dimensionless residual noise energy after the reconstructed signal is subtracted from the data.The statistic ηc thus quantifies the SNR of the event and the consistency of the data between the two detectors.Based on their time-frequency morphology,the events are divided into three mutually exclusive search classes,as described in [41]:events with time-frequency morphology of known populations of noise transients (class C1),events with frequency that increases with time (class C3),and all remaining events (class C2).Detected with ηc ¼20.0,GW150914is the strongest event of the entire search.Consistent with its coalescence signal signature,it is found in the search class C3of events with increasing time-frequency evolution.Measured on a background equivalent to over 67400years of data and including a trials factor of 3to account for the search classes,its false alarm rate is lower than 1in 22500years.This corresponds to a probability <2×10−6of observing one or more noise events as strong as GW150914during the analysis time,equivalent to 4.6σ.The left panel of Fig.4shows the C3class results and background.The selection criteria that define the search class C3reduce the background by introducing a constraint on the signal morphology.In order to illustrate the significance of GW150914against a background of events with arbitrary shapes,we also show the results of a search that uses the same set of events as the one described above but without this constraint.Specifically,we use only two search classes:the C1class and the union of C2and C3classes (C 2þC 3).In this two-class search the GW150914event is found in the C 2þC 3class.The left panel of Fig.4shows the C 2þC 3class results and background.In the background of this class there are four events with ηc ≥32.1,yielding a false alarm rate for GW150914of 1in 8400years.This corresponds to a false alarm probability of 5×10−6equivalent to 4.4σ.FIG.4.Search results from the generic transient search (left)and the binary coalescence search (right).These histograms show the number of candidate events (orange markers)and the mean number of background events (black lines)in the search class where GW150914was found as a function of the search detection statistic and with a bin width of 0.2.The scales on the top give the significance of an event in Gaussian standard deviations based on the corresponding noise background.The significance of GW150914is greater than 5.1σand 4.6σfor the binary coalescence and the generic transient searches,respectively.Left:Along with the primary search (C3)we also show the results (blue markers)and background (green curve)for an alternative search that treats events independently of their frequency evolution (C 2þC 3).The classes C2and C3are defined in the text.Right:The tail in the black-line background of the binary coalescence search is due to random coincidences of GW150914in one detector with noise in the other detector.(This type of event is practically absent in the generic transient search background because they do not pass the time-frequency consistency requirements used in that search.)The purple curve is the background excluding those coincidences,which is used to assess the significance of the second strongest event.For robustness and validation,we also use other generic transient search algorithms[41].A different search[73]and a parameter estimation follow-up[74]detected GW150914 with consistent significance and signal parameters.B.Binary coalescence searchThis search targets gravitational-wave emission from binary systems with individual masses from1to99M⊙, total mass less than100M⊙,and dimensionless spins up to 0.99[44].To model systems with total mass larger than 4M⊙,we use the effective-one-body formalism[75],whichcombines results from the post-Newtonian approach [11,76]with results from black hole perturbation theory and numerical relativity.The waveform model[77,78] assumes that the spins of the merging objects are alignedwith the orbital angular momentum,but the resultingtemplates can,nonetheless,effectively recover systemswith misaligned spins in the parameter region ofGW150914[44].Approximately250000template wave-forms are used to cover this parameter space.The search calculates the matched-filter signal-to-noiseratioρðtÞfor each template in each detector and identifiesmaxima ofρðtÞwith respect to the time of arrival of the signal[79–81].For each maximum we calculate a chi-squared statisticχ2r to test whether the data in several differentfrequency bands are consistent with the matching template [82].Values ofχ2r near unity indicate that the signal is consistent with a coalescence.Ifχ2r is greater than unity,ρðtÞis reweighted asˆρ¼ρ=f½1þðχ2rÞ3 =2g1=6[83,84].The final step enforces coincidence between detectors by selectingevent pairs that occur within a15-ms window and come fromthe same template.The15-ms window is determined by the10-ms intersite propagation time plus5ms for uncertainty inarrival time of weak signals.We rank coincident events basedon the quadrature sumˆρc of theˆρfrom both detectors[45]. To produce background data for this search the SNR maxima of one detector are time shifted and a new set of coincident events is computed.Repeating this procedure ∼107times produces a noise background analysis time equivalent to608000years.To account for the search background noise varying acrossthe target signal space,candidate and background events aredivided into three search classes based on template length.The right panel of Fig.4shows the background for thesearch class of GW150914.The GW150914detection-statistic value ofˆρc¼23.6is larger than any background event,so only an upper bound can be placed on its false alarm rate.Across the three search classes this bound is1in 203000years.This translates to a false alarm probability <2×10−7,corresponding to5.1σ.A second,independent matched-filter analysis that uses adifferent method for estimating the significance of itsevents[85,86],also detected GW150914with identicalsignal parameters and consistent significance.When an event is confidently identified as a real gravitational-wave signal,as for GW150914,the back-ground used to determine the significance of other events is reestimated without the contribution of this event.This is the background distribution shown as a purple line in the right panel of Fig.4.Based on this,the second most significant event has a false alarm rate of1per2.3years and corresponding Poissonian false alarm probability of0.02. Waveform analysis of this event indicates that if it is astrophysical in origin it is also a binary black hole merger[44].VI.SOURCE DISCUSSIONThe matched-filter search is optimized for detecting signals,but it provides only approximate estimates of the source parameters.To refine them we use general relativity-based models[77,78,87,88],some of which include spin precession,and for each model perform a coherent Bayesian analysis to derive posterior distributions of the source parameters[89].The initial and final masses, final spin,distance,and redshift of the source are shown in Table I.The spin of the primary black hole is constrained to be<0.7(90%credible interval)indicating it is not maximally spinning,while the spin of the secondary is only weakly constrained.These source parameters are discussed in detail in[39].The parameter uncertainties include statistical errors and systematic errors from averaging the results of different waveform models.Using the fits to numerical simulations of binary black hole mergers in[92,93],we provide estimates of the mass and spin of the final black hole,the total energy radiated in gravitational waves,and the peak gravitational-wave luminosity[39].The estimated total energy radiated in gravitational waves is3.0þ0.5−0.5M⊙c2.The system reached apeak gravitational-wave luminosity of3.6þ0.5−0.4×1056erg=s,equivalent to200þ30−20M⊙c2=s.Several analyses have been performed to determine whether or not GW150914is consistent with a binary TABLE I.Source parameters for GW150914.We report median values with90%credible intervals that include statistical errors,and systematic errors from averaging the results of different waveform models.Masses are given in the source frame;to convert to the detector frame multiply by(1þz) [90].The source redshift assumes standard cosmology[91]. Primary black hole mass36þ5−4M⊙Secondary black hole mass29þ4−4M⊙Final black hole mass62þ4−4M⊙Final black hole spin0.67þ0.05−0.07 Luminosity distance410þ160−180MpcSource redshift z0.09þ0.03−0.04。
Extragaactic X-ray Binary Stars Beacons for Stellar- and ：河外星系的X射线双星的恒星和信标
Metallicity of Hot Gas in Ellipticals
MOS+PN for NGC4472, NGC4649, and NGC1399
O/Fe ~ 0.3 - 0.4 Mg/Fe ~ 1.2 - 1.5 Ni/Fe ~ 3 - 7
Stellar Source for Soft Component?
M31 (diffuse) LX (0.5-2 keV): 1.7 x 1038 ergs s-1 LX (2-7 keV): 5.3 x 1037 ergs s-1
LX(0.5-2 keV)/ LX(2-7 keV) = 3.2
Total 0.5 - 2.0 keV flux Source: 85% Background: 15%
Source 0.5 - 2.0 keV flux Gas: 85% LMXBs:15%
Source of Low Metallicity Gas
How are both LX/Lopt and low metallicity achieved? One solution: ongoing accretion of pristine gas surrounding galaxies dilutes to subsolar metallicities
Cause of LX vs. Lopt Dispersion
Environmental? ram pressure stripping: LX - cluster environment ICM pressure confinement: LX “stifling” Internal? - variation in Type Ia supernovae-driven winds - variation in depth of dark matter gravitational potential Low LX/Lopt in low density environments. High and low LX/Lopt in high density environments. (e.g., Brown & Bregman 2000)
【英语单词记忆】天文术语 G I
【英语单词记忆】天文术语 G I 【英语单词记忆】天文术语g-i
银河聚合星系恒星集
galacticastronomy银河系天文
银河系棒
galacticbar星系棒
银河食人银河吞噬
galacticcontent星系成分
银河合并
galacticpericentre近银心点
银河中心距离
galaxycluster星系团
伽利略环
galileantransformation伽利略变换
伽利略木星探测器
genesisrock创世岩
双子座望远镜
geoalert,geophysicalalertbroadcast地球物理警报广播巨大颗粒
giantgranule巨米粒
巨大无线电脉冲
ginga〈星系〉x射线天文卫星
乔托太空探测器
glassceramic微晶玻璃
Glitchactivity旋转突变活性
globalchange全球变化
全球敏感性
gmc,giantmolecularcloud巨分子云
G模式，重力模式
goldspot金斑病
龚，全球振荡网络
group
全球定位系统
granat〈石榴〉号天文卫星
大设计螺旋星系
gravitationalastronomy引力天文
引力透镜效应
gravitationalmicro-lensing微引力透镜效应 GreataTractor宏源
greatdarkspot大暗斑
大白点
grism棱栅
伽马射线天文台伽马钱德拉X射线天文台
guidscope导星镜
Gwvirgin star。
商务英语翻译 Unit 9
译文：毫无疑问，我们还必须作出更大的努力来对抗全 球变暖的威胁，这个威胁最能清楚地体现各国的 命运是如何紧紧相连的。
5. This Contract is made by and between the Buyer and the Seller, whereby the Buyer agrees to buy and the Seller agrees to sell the under-mentioned commodity according to the terms and conditions stipulated below. 译文：买卖双方同意按下列条款购买、出售下述商品， 并签订本合同。（reduction)
John… preached the baptism of repentance unto the forgiveness of sins.
John preached the message to the people; John baptized the people; The people repented of their sins; God forgave the people their sins; The people sinned. John preached that the people should repent and be baptized so that god would forgive the evil they had done. John preached, ―Repent and be baptized so that God will forgive the evil you have done.‖
译文：我的母亲简· 兰普顿· 克莱门斯88岁才去世。这对于 一位40岁就身体虚弱、被认为痼疾缠身、注定不久于 世的人来说，是难得的高龄。
托福阅读TPO25（试题+答案+译文）第1篇：ThesurfaceofMars
托福阅读TPO25(试题+答案+译文)第1篇:ThesurfaceofMarsTPO是我们常用的托福模考工具，对我们的备考很有价值，下面小编给大家带来托福阅读TPO25(试题+答案+译文)第1篇:The surface of Mars。
托福阅读原文【1】The surface of Mars shows a wide range of geologic features, including huge volcanoes-the largest known in the solar system-and extensive impact cratering. Three very large volcanoes are found on the Tharsis bulge, an enormous geologic area near Mars’s equator. Northwest of Tharsis is the largest volcano of all: Olympus Mons, with a height of 25 kilometers and measuring some 700 kilometers in diameter at its base. The three large volcanoes on the Tharsis bulge are a little smaller-a “mere”18 kilometers high.【2】None of these volcanoes was formed as a result of collisions between plates of the Martian crust-there is no plate motion on Mars. Instead, they are shield volcanoes — volcanoes with broad, sloping slides formed by molten rock. All four show distinctive lava channels and other flow features similar to those found on shield volcanoes on Earth. Images of the Martian surface reveal many hundreds of volcanoes. Most of the largest volcanoes are associated with the Tharsis bulge, but many smaller ones are found in the northern plains.【3】The great height of Martian volcanoes is a direct consequence of the planet’s low surface gravity. As lava flows and spreads to form a shield volcano, the volcano’s eventual height depends on the new mountain’s ability to support its own weight. The lower the gravity, the lesser the weight and thegreater the height of the mountain. It is no accident that Maxwell Mons on Venus and the Hawaiian shield volcanoes on Earth rise to about the same height (about 10 kilometers) above their respective bases-Earth and Venus have similar surface gravity. Mars’s surface gravity is only 40 percent that of Earth, so volcanoes rise roughly 2.5 times as high. Are the Martian shield volcanoes still active? Scientists have no direct evidence for recent or ongoing eruptions, but if these volcanoes were active as recently as 100 million years ago (an estimate of the time of last eruption based on the extent of impact cratering on their slopes), some of them may still be at least intermittently active. Millions of years, though, may pass between eruptions.【4】Another prominent feature of Mars’s surface is cratering. The Mariner spacecraft found that the surface of Mars, as well as that of its two moons, is pitted with impact craters formed by meteoroids falling in from space. As on our Moon, the smaller craters are often filled with surface matter-mostly dust-confirming that Mars is a dry desert world. However, Martian craters get filled in considerably faster than their lunar counterparts. On the Moon, ancient craters less than 100 meters across (corresponding to depths of about 20 meters) have been obliterated, primarily by meteoritic erosion. On Mars, there are relatively few craters less than 5 kilometers in diameter. The Martian atmosphere is an efficient erosive agent, with Martian winds transporting dust from place to place and erasing surface features much faster than meteoritic impacts alone can obliterate them.【5】As on the Moon, the extent of large impact cratering (i.e. craters too big to have been filled in by erosion since they were formed) serves as an age indicator for the Martian surface.Age estimates ranging from four billion years for Mars’s southern highlands to a few hundred million years in the youngest volcanic areas were obtained in this way.【6】The detailed appearance of Martian impact craters provides an important piece of information about conditions just below the planet’s surface. Martian craters are surrounded by ejecta (debris formed as a result of an impact) that looks quite different from its lunar counterparts. A comparison of the Copernicus crater on the Moon with the (fairly typical) crater Yuty on Mars demonstrates the differences. The ejecta surrounding the lunar crater is just what one would expect from an explosion ejecting a large volume of dust, soil, and boulders. However, the ejecta on Mars gives the distinct impression of a liquid that has splashed or flowed out of crater. Geologists think that this fluidized ejecta crater indicates that a layer of permafrost, or water ice, lies just a few meters under the surface. Explosive impacts heated and liquefied the ice, resulting in the fluid appearance of the ejecta.托福阅读试题1.The word “enormous”(paragraph 1)in the passage is closest in meaning toA.importantB.extremely largeC.highly unusualD.active2.According to paragraph 1, Olympus Mons differs from volcanoes on the Tharsis bulge in that Olympus MonsA.has more complex geologic featuresB.shows less impact crateringC.is tallerD.was formed at a later time3.The word “distinctive”(paragraph 1)in the passage is closest in meaning toA.deep.plex.C.characteristic.D.ancient.4.According to paragraphs 1 and 2, which of the following is NOT true of the shield volcanoes on the Tharsis bulge?A.They have broad, sloping sides.B.They are smaller than the largest volcano on Mars.C.They have channels that resemble the lava channels of volcanoes on Earth.D.They are over 25 kilometers tall.5.The word “roughly” in the passage is closest in meaning toA.typically.B.frequently.C.actually.D.approximately.6.In paragraph 3, why does the author compare Maxwell Mons on Venus to the Hawaiian shield volcanoes on Earth?A.To help explain the relationship between surface gravity and volcano height.B.To explain why Mars’s surface gravity is only 40 percent of Earth’s.C.To point out differences between the surface gravity of Earth and the surface gravity of Venus.D.To argue that there are more similarities than differences between volcanoes on different planets.7.Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaningin important ways or leave out essential information.A.Although direct evidence of recent eruptions is lacking, scientists believe that these volcanoes were active as recently as 100 million years ago.B.Scientists estimate that volcanoes active more recently than 100 years ago will still have extensive impact cratering on their slopes.C.If, as some evidence suggests, these volcanoes erupted as recently as 100 million years ago, they may continue to be intermittently active.D.Although these volcanoes were active as recently as 100 million years ago, there is no direct evidence of recent or ongoing eruptions.8.The word “considerably”(paragraph 3)in the passage is closest in meaning toA.frequently.B.significantly.C.clearly.D.surprisingly.9.According to paragraph 4, what is demonstrated by the fact that cratersfill in much faster on Mars than on the Moon?A.Erosion from meteoritic impacts takes place more quickly on Mars than on the Moon.B.There is more dust on Mars than on the Moon.C.The surface of Mars is a dry desert.D.Wind is a powerful eroding force on Mars.10.In paragraph 4, why does the author point out that Marshas few ancient craters that are less than 5 kilometers in diameter?A.To explain why scientists believe that the surface matter filling Martian craters is mostly dust.B.To explain why scientists believe that the impact craters on Mars were created by meteoroids.C.To support the claim that the Martian atmosphere is an efficient erosive agent.D.To argue that Mars experienced fewer ancient impacts than the Moon did.11.According to paragraph 5, what have scientists been able to determinefrom studies of large impact cratering on Mars?A.Some Martian volcanoes are much older than was once thought.B.The age of Mars’s surface can vary from area to area.rge impact craters are not reliable indicators of age in areas with high volcanic activity.D.Some areas of the Martian surface appear to be older than they actually are.12.According to paragraph 6, the ejecta of Mars’s crater Yuty differs fromthe ejecta of the Moon’s Copernicus crater in that the ejecta of the Yuty craterA.Has now become part of a permafrost layer.B.Contains a large volume of dust, soil and boulders.C.Suggests that liquid once came out of the surface at the crater site.D.Was thrown a comparatively long distance from the center of the crater.13. Look at the four squares【■】that indicate where the following sentence could be added to the passage.Where would the sentence best fit? Click on a square to add the sentence tothe passage. This surface feature has led to speculation about what may lie under Mars’s surface.The detailed appearance of Martian impact craters provides an important piece of information about conditions just below the planet’s surface. Martian craters are surrounded by ejecta (debris formed as a result of an impact) that looks quite different from its lunar counterparts. A comparison of the Copernicus crater on the Moon with the (fairly typical) crater Yuty on Mars demonstrates the differences. The ejecta surrounding the lunar crater is just what one would expect from an explosion ejecting a large volume of dust, soil, and boulders. ■【A】However, the ejecta on Mars gives the distinct impression of a liquid that has splashed or flowed out of crater. ■【B】Geologists think that this fluidized ejecta crater indicates that a layer of permafrost, or water ice, lies just a few meters under the surface. ■【C】Explosive impacts heated and liquefied the ice, resulting in the fluid appearance of the ejecta. ■【D】14. Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.Drag your answer choices to the spaces where they belong. To remove an answer choice, click on it. To review the passage, click VIEW NEXT.Volcanoes and impact craters are major features of Martiangeology.A.Plate motion on Mars, once considered to have played no role in shaping the planet’s s urface, is now seen as beingdirectly associated with the planet’s earliest volcanoes.B.Mars has shield volcanoes, some of which are extremely tall because of the planet’s low surface gravity.C.Although the erosive power of the Martian atmosphere ensures that Mars has fewer craters than the Moon does, impact craters are prominent on Mars’ s surface.D.Scientists cannot yet reliably estimate the age of the Martian surface because there has been too much erosion of it.E.Scientists have been surprised to discover that conditions just below the surface of Mars are very similar to conditions just below the surface of the MoonF.Studies of crater ejecta have revealed the possibility of a layer of permafrost below the surface of Mars.托福阅读答案1.enormous 巨大的，所以正确答案是B，extremely large。
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arXiv:astro-ph/0612415v1 15 Dec 2006DampMergers:RecentGaseousMergerswithoutSignificantGlobularClusterFormation?
DuncanA.Forbes1,RobertProctor,JayStrader,JeanP.BrodieCentreforAstrophysics&Supercomputing,SwinburneUniversity,Hawthorn,VIC3122,AustraliaUCO/LickObservatory,UniversityofCalifornia,SantaCruz,CA95064,USA
ABSTRACTHerewetesttheideathatnewglobularclusters(GCs)areformedinthesamegaseous(“wet”)mergersorinteractionsthatgiverisetotheyoungstellarpopulationsseeninthecentralregionsofmanyearly-typegalaxies.WecomparemeanGCcolorswiththeageofthecentralgalaxystarburst.TheredGCsubpopulationrevealsre-markablyconstantmeancolorsindependentofgalaxyage.AscenarioinwhichtheredGCsubpopulationisacombinationofoldandnewGCs(formedinthesameeventasthecentralgalaxystarburst)cannotberuledout;althoughthiswouldrequireanage-metallicityrelationforthenewlyformedGCsthatissteeperthantheGalacticrelation.However,thedataarealsowelldescribedbyascenarioinwhichmostredGCsareold,andfew,ifany,areformedinrecentgaseousmergers.ThisisconsistentwiththeoldagesinferredfromsomespectroscopicstudiesofGCsinexternalsystems.TheeventthatinducedthecentralgalaxystarburstmayhavethereforeinvolvedinsufficientgasmassforsignificantGCformation.Wetermsuchgas-poorevents“damp”mergers.
Subjectheadings:galaxies:interactions-galaxies:elliptical-globularclusters:general-galaxies:evolution
1.IntroductionSincethefirsthintsthatthecolordistributionsofglobularcluster(GC)systemsinsomeearly-typegalaxieswerebimodal(Couture,Harris&Allwright1991;Ashman&Zepf1993),bimodalityhasbeenshowntobethenorm(e.g.,Larsenetal.2001;Kundu&Whitmore2001;Straderetal.2006;Pengetal.2006).Thisblue/redbimodalityindicatesdistinctmetallicity(andperhapsage)subpopulationswithintheGCsystem.Themeancoloroftheblueandredsubpopulationsareknowntocorrelatewiththeirhostgalaxyluminosity(Strader,Brodie&Forbes2004).Basicinterpretationsofthesetwosubpopulationsincludedissipativeformationatearlyepochs(Forbes,Brodie&Grillmair1997),gaseousmergersatearlyorlateepochs(Ashman&Zepf1992),andthe–2–dissipationlessaccretionofGCs(Cote,West&Marzke2002).AkeypieceofevidenceinassessingthesescenariosistheagedistributionofthetwoGCsubpopulations.ThecurrentstateofaffairsissummarisedinthereviewofBrodie&Strader(2006),whichnotesthatsmallspectroscopicsamplestodatefindmostGCstobe10Gyrsold,implyinganearlyformationepochatredshiftsz2.However,suchworkislimitedbysamplingbiases:onlythebrightestGCsinnearby(25Mpc)galaxiescanbestudied.TocreatelargesamplesoftypicalGCs,onemustusephotometricstudies.
Manyearly-typegalaxiesarefoundtohaveyoungercentralstellarpopulations,indicativeofarecentinteractionorgaseous(“wet”)mergerwhichinducedsomestarformation(Trageretal.2000;Proctor&Samson2002;Terlevich&Forbes2002;Thomasetal.2005;Denicoloetal.2005;Sanchez-Blazquezetal.2006,SB06).2Theageofthisyoungstarbursthasbeenfoundtocorrelatewithagalaxy’slocationontheFundamentalPlaneandwithmorphologicalfinestructure(Schweizer&Seitzer1992;Forbes,Ponman&Brown1998).Thereisalsogoodevidencefortheformationofproto-GCsinongoingwetmergersliketheAntennae(Whitmore&Schweizer1995),whicharethoughttoultimatelyformanellipticalgalaxy(e.g.,Toomre&Toomre1972).Furthermore,asstarclustersappeartobetheprimarymodeofstarformation(Lada&Lada2003),weexpectGCstotracemajorstarformationepisodesinallstarbursts(Larsen&Richtler2000).Inthesemi-analyticmodelsofBeasleyetal.(2002)metal-poorGCsforminproto-galacticfragmentsathighredshift,whilemetal-richonesforminsubsequentgas-richmergingevents.However,ifformationconditionsarenotsuitable(e.g.,insufficientgasmassorlowGCformationefficiency)thenfewlong-lastingGCsmaybeproduced.LocalexamplesofthisincludetheGalaxy’sdiskandtheLMC,whichhaveexperiencedopenclusterformationwithoutGCformation.Also,inthecaseofgas-free(“dry”)accretionsormergersnoinducedstar,orstarcluster,formationisexpected.
Majorgaseousmergers(Ashman&Zepf1992)arepredictedtoformnewmetal-richGCswithameanagecorrespondingtothatofthemerger.AnynewGCsformedwilladdtotheexistingGCsystemoftheprogenitorgalaxies,i.e.anoldmetal-poor(blue)andpossiblyanoldbutmoreenriched(red)subpopulation.
Thenewlyformedmetal-richGCsubpopulationwillinitiallybeveryblue,howeveritwillreddenrapidly(e.g.,Whitmoreetal.1997).IfformedinthelastGyr,thesubpopulationmayhaveacolorsimilartothatobservedforbluesubpopulationsinearly-typegalaxies.ForthefirstcoupleofGyrs,dependingonitsmetallicity,itmayhaveintermediatecolors.However,olderthanafewGyrs,thecolorsresemblethoseofredsubpopulations,andcontinuetoreddenslowlywithage.IfsignificantnumbersofnewGCswereformedmorethanafewGyrsago,thentheredsubpopulationofthemergerremnantgalaxymaybedominatedbythesenewlyformedmetal-richGCs.ThemeancoloroftheredsubpopulationwillthereforebedeterminedbytherelativefractionofnewlyformedvsoldGCsandtheirrespectiveenrichmentlevels(metallicity)andtimeelapsed(age)sinceformation.