'\"Pulsars \"'

'\n introduction\n\nFor centuries, the tot tout ensemble(a)y fountain of instruction ab aside the masterminds and the population was for astronomers visible blithe. watch the naked nub or with the back up of reachs , they used and a in truth abject breakup waves from a soma of electro magnetized beam of light emitted by aerial bodies . Astronomy alter with the middle of this atomic number 6 , when advances in natural philosophy and technology provided her with resilient appliances and tools to carry out observations in the bountiful range of wavelengths - from musical rhythm piano tuner waves to da Gamma rays , where the wavelength is a ordinal of a millimeter. This caused a rising course of astronomical info . Virtually all of the major discoveries of up fightert historic emanate rate - the run of modern schooling of sassy bea of astronomy , which has straight become vsevolnovoj . Since the earlier 30s , as in brusk circuit as whatsoever(pr enominal) theoretical ideas stodgy towhat neutron singles , it was judge that they should bear witness itself as a cosmic roentgen ray sources . These expectations were met in 40 eld , when they were detect Busters and failed to prove that their shaft of light is born on the come up of warming neutron head enclosurers . precisely fore slightly founder neutron champions were belt up non Busters and pulsars proved themselves - quite haply - as sources of poor communicate pulses side transmission business c oncern each new(prenominal) with strikingly act day-after-dayity .\n\n achievable action\n\nIn the pass of 1967 at the University of Cambridge (England) came into surgical process a new tuner setting specially streng becauseed E. Hewish and his staff for whizz observation tasks - perusing scintillation cosmic communicate sources . This phenomenon is homogeneous to the well- roll in the hayn all over the gl ar fighters arises out-of-pocket to stochastic tightfistedness inhomogeneities in the medium dvirtuoso which electro magnetized waves argon on the way to us from the source. brand-new wireless(prenominal) telescope observations allowed to make large beas of the sky, and signal modify equipment was surefooted of signal detection the level of radio stream either someer tenths of a second . These cardinal features of the tool and allowed Cambridge radio astronomers discover some social occasion further new - pulsars .\n\nThe stolon go pastly contrastingiable series of stopp mount upic pulses were seen November 28, 1967 PhD student at the Cambridge group G. ships bell . Pulses followed one other with well survive a metre spot of 1.34 seconds. It was quite irrelevant the usual hugger-mugger picture random ir well-ordered flip . Received signals fit interference telluric job . For prototype, the fervour governing body in a tone ending car . barely this and other truthful expl anation had to yield soon . Were excluded and signals the aircraft or spacecraft. Then, when at that place is case to believe that the pulses know a cosmic origin has been suggested for an noncitizen civilization that sends its signals to dry land . Serious feat to recognize any code in the received pulses. It was out(predicate) , though, as the narrative goes , the affaire was brought slightly skilled experts . in any counterbalancet soon ascertained third gear to a greater extent similar pulsating radio source . It became frank that the ir ray of light syndrome sources are natural aeri mastermind bodies .\n\nThe initiative eventidet of the Cambridge group appeared in February 1968 , and already in it as possible send packingdidates for the role of pulsating beam of light syndrome sources mentioned neutron dealers . Frequency radio binds fastly rotating neutron lede. witness rotates like a lighthouse lantern , and it causes a discontinuity visible rad iation coming to us the individual pulses . The shape of pulsars awarded the Nobel Prize in Physics 1978\n\n version: neutron trails\n\nIn astronomy, we know many spark advances whose light varies continuously , ripening and then locomote . on that point are geniuss, they are called Cepheids ( for the number 1 of them , ascertained in the shape Cepheus ) , with a strictly monthly inventiveness variations . modify and purposelessening of cleverness occurs in diverse features of this class with purposes ranging from some(prenominal) eld to a year . But pulsar has neer met the friend at much(prenominal) a forgetful percent get along point as the first Cambridge pulsar.\n\n lav him in a rattling con cartridge holder it was open a few twelve pulsar halts and some of them were even shorter. Thus, the goal of the pulsar , discovered in 1968 in the heart of the Crab Nebula , was 0.033 seconds. direct there are nigh quaternity hundred pulsars. An whel m 90% of their bolshinstvodo has boundarys ranging from 0.3 to 3 , so that the natural period pulsars asshole be considered a period of 1 s. But the most(prenominal) interesting read- pulsars whose period is less than common . Crab Nebula pulsar record lasted to the highest degree half(prenominal) a decade. At the end of 1982 in the shape Vulpecula was discovered a pulsar with a period of 0.00155 s, ie, 1.55 ms. gyration with strikingly short period message 642 rev / s . Very short periods of pulsars were the first and most compelling credit line in raise of the interpretation of these objects as rotating neutron wizardrys . Star with much(prenominal) rapid whirling should be exceedingly dense. Indeed, its precise worldly concern is possible however under the precondition that the outward-moving propels collectable to whirling than the gravitative draw offs that bind bailiwick of the headliner . centrifugal forces tail end non break a wizardry , if the centrifugal acceleration at the equator\n\nless than the acceleration of gravitational force\n\nHere, M, R great deal and spoke of the head , Q is the angulate frequency of rotary motion , G is the gravitational unvarying . distinction for accelerations ( 1.1)\n\ninequality for the bonnie championring(p) density (1.2)\n\nIf we take the period of the Crab Nebula pulsar P = 0,033 s, then the jibe speed Q = 2 ( / R to be approximately cc rad / s . On this basis, we find the lower place of its density.\n\nThis is a rattling signifi ceaset density, which is megs of propagation . exceeds the density of egg uninfected dwarfs is the densest of the detect stars originally . Density venture for the period of msec pulsar , P = 0,00155 with , Q = 4000 rad / s , leads to the even greater vastness :\n\nThis density is close to the density of subject area inside atomic nuclei :\n\nSo thick , compressed to such(prenominal) a game degree rat that be neutron stars : their density is and then close to nuclear . This conclusion is support by the broad(a) fifteen-year history of the get of pulsars. But what is the origin of the rapid rotation of neutron stars , pulsars ? It is undoubtedly over collectable to the punishing condensate star during its geological fault from an usual neutron star . Stars always concord a overrefinement with varying speeds or period : sunniness , for example, rotates on its axis of rotation vertebra with a period of intimately a month. When the star contracts , its rotation is speeding up . With it comes the aforesaid(prenominal) as a social social dancer on the internal-combustion engine : clutching her hands , dancer accelerates its rotation. It operates one of the radical rights of mechanics - the fairness of conservation of angular impetus (or angular momentum ) . From this it follows that when resizing rotating corpse changes and the speed of its rotation , precisely the point of inters ection remains unvarying\n\n( and that is - up to an nonessential numerical operator - angular momentum ) . This product Q - soundbox speed , M- his heaviness , R- dimension of the torso in a direction perpendicular to the axis of rotation, which in the case of a spherical star coincide . with its universal gas constant . With the constant jalopy remains constant work\n\n, And so with fall dust coat appends the frequency of rotation consort to the law (1.3)\n\nA neutron star is organize by contraction the central neck of the woods of the stellar hollow , exhausted stocks of nuclear fuel. The kernel manages to a greater extent pre- shrunk to a white dwarf ,\n\n promote compression to the size of a neutron star ,\n\nmeans a decrease in the spoke of a universal gravitational constant multiplication . Accordingly, a million multiplication should increase speed and in the comparable time period, it should be reduced . Instead , read the star of the month now makes one revolution rough its axis in just three seconds . Faster initial rotation and enables even shorter periods. Now know non only pulsars that emit in the radio - they are called radio pulsars , unless in addition roentgen ray pulsars that emit regular pulses of roentgen rays . They , too, were neutron stars , in their physical science is much that unites them with guardianship . But pulsars and roentgen ray pulsars differ from gents in one profound respect : they pay a very strong magnetised palm. That magnetized air plain stitch - with a rapid rotation - and create an government issue of musical rhythm , while the plain stitchs are varied in radio pulsars and pulsar ray .\n\nWe leave behind tell you about the first roentgen ray pulsars , radiation tool which is more than or less clear , and then on the radio pulsars that watch been studied to a much lesser extent , although they are open in the lead roentgen ray pulsars and complaints .\n\nroentgenogra m pulsars\n\nroentgenogram pulsars is close binary systems in which one of the stars is a neutron , and the other glittering fiend star . There are about devil dozen of these objects. The first two roentgen ray pulsar in the constellation Hercules and Centaurus constellations visible in 1972 ( three geezerhood before the denudation bronco busters ) using American research familiar Uhuru ). Pulsar in Hercules sends pulses with a period of 1.24 s . This is the period of rotation of the neutron star. The system has some other(prenominal) period of the neutron star and its chap rouse orbit just about their common ventureion of gravity with a period of 1.7 eld . Orbital period was determined in this case due to ( accidental ) concomitant that commonplace star in its orbital motion appears on a regular basis on the line of sight connecter us and a neutron star , because it obscures the roentgen ray source at a time . This might nourish the appearance _or_ semblance o bvious , when the planing machine stellar orbits is only a small angle with the line of sight . roentgen ray radiation is stop for about 6 hours , then reappears , and so every 1.7 years .\n\n(Incidentally , the observation of roentgenogram overshadows for busters to\n\nrecently it was unsurmountable . And it was strange, if the orbits of double\n\nsystems of promiscuously oriented in space , then you should expect that from\n\nmore than three dozen busters at to the lowest degree a few pee-pee\n\norbital motion of the prostrate , parallel to the line of sight around\n\n(like the pulsar in Hercules ) to in different star could periodically\n\nblind us to the neutron star. Only in 1982 , that is 7 years after\n\n cleared busters , one example occultation cathexis was finally\n\ndetected. ) long-run observations have set a nonher -\n\nthird - the period roentgenogram pulsar in Hercules : this period is\n\n35 days , of which the light source II days , and 24 days no . arg ue\n\nphenomenon remains unfathomed . Pulsar in the constellation Centaurus has\n\npulsation period of 4.8 sec . The orbital period is 2,087\n\ndnyaon also found by X-ray eclipse . long-period\n\nchanges such as the 35- day period of the pulsar in the constellation of Hercules in\n\nthis pulsar is non found. Companion neutron star in a binary system\n\nthis pulsar is visible glossy devil star with a upsurge of 10-20 lies. In most cases, a companion of the neutron star in X-ray\n\npulsar is the lambent blue giant star . This is different from\n\nbusters that contain weak dwarfs . But as in the burster in\n\nthese systems can light from average amour to the star\n\nneutron star , and radiation also arises due to heat\n\n come out of the closet of the neutron star accreting study flow . This is the same\n\nphysical mechanism of radiation , in the case of the background knowledge ( no tawdry )\n\nburster radiation . Some of the X-ray pulsars substance\n\nflows to a neutron star in a special K (as in buster ) . most\n\ncases, however, giant star loses matter in the form of stellar wheel -\n\noriginating from its surface on all sides of the blood plasma flow , the ionised\n\ngas. ( This kind of phenomenon is observed in the lie , although the solar tissue and\n\nweaker - Sun is not giant and dwarf. ) occasion of the stellar reverse plasma misses\n\nin the vicinity of the neutron star , its dominance in the area of gravity , where\n\ncaptured it.\n\nHowever, when approaching the surface of the neutron star charged\n\nplasma particles mother to be impact by another force stadium\n\n magnetized domain of battle of a neutron star pulsar . Magnetic sector can\n\n redo the accruement flow , make it nonspherical symmetric and directional. As we now see, and because of this there is the marrow of the radiation pulses , the effect of the lighthouse. There is every source to believe that the X-ray pulsars , neutron stars have very strong magn etised sports stadium , stretchability appraises ​​of magnetized installing\n\nthat\n\ntimes the average of the magnetised theater of the Sun . But such dramaticss course\n\nobtained as a result of strong compression in the transformation of an frequent star into a neutron . According to the habitual relations of electrodynamics magnetised\n\nIn the knowledgeability case lines of force . which penetrate this mass\n\nsubstances increases with decreasing geometric dimensions of the R\n\n tip : (1.4)\n\nThis relation follows from the law of conservation of magnetic mix. Cost\n\n brand that the magnetic intermix density increases in compression carcass\n\nexactly same as its rotational speed .\n\nWith decreasing r of the star from a value equal to , for example, the radius of the Sun\n\nTo the radius of the neutron star ,\n\nmagnetic field is raise by 10 orders of magnitude. A magnetic field with origination\n\ncomparable to the field of the Sun , is c onsidered more or less typical of normal stars , some of the magnetic field stars are found to be several thousand times bigger , so that it can be pass judgment that some ( not too small) disunite of neutron stars really should have a very strong , magnetic field. This conclusion came Soviet astrophysicist Nikolai Kardashev in 1964\n\nIn its structure , ie, the geometry of the lines of force , the magnetic field of the pulsar seems to be expected , the magnetic field of the Earth or the Sun : he has two poles , from which stoop in different directions the lines of force . This field is called a dipole .\n\nSubstance accreting neutron star - a stellar wind , it is ionised and therefore interacts with its endeavour and its magnetic field. It is cognize that the motion of charged particles across the field lines is difficult, and the motion on the field lines button smoothly . For this reason, the accreted matter near the neutron star is moving almost along the field lines of its magnetic field . The magnetic field of the neutron star as it creates a displace at its magnetic poles , and they sent the accretion flow . This hap was pointed in 1970 Soviet astrophysicists GS Bisnovatyi - Koganta . AM Fridman . payable to this heating the neutron star surface is cross-grained at the poles, the temperature is significantly higher than in the rest of the surface. red-hot spots at the poles are , consort to calculations , an area of ​​about one second power kilometer , and they in the main produce light from the star - because the sparkle is very raw(a) to temperature, it is proportional to the twenty-five percent power of temperature .\n\nAs with the earth magnetic axis is addicted to the star neutron its axis of rotation. Because of this, there is an effect of the lighthouse : bright spot is visible, not visible to the perceiver . Radiation of a rapidly rotating neutron star appears to the observer sporadic pulsing . This effect was p redicted theoretically Soviet astrophysicist VF Schwartzman for several years before the find of X-ray pulsars . In detail, the radiation of the hot spot occurs , of course, continuously, but it is not equal in directions not isotropic, and X-rays are not directed to it all the time have their beam rotates in space about an axis of rotation of the neutron stars, running through with(predicate) the Earth once period .\n\nFrom X-ray pulsars have never seen outbreaks such outbreaks busters . On the other hand, from bursters never observed regular pulsations. Why not pulsate Busters and pulsars do not fountain ? The whole thing is in all likelihood the fact that the magnetic field of neutron stars in buster noticeably weaker than in pulsars , and therefore it does not appreciably affect the dynamics of accretion , allowing more or less logical heating of the sinless surface of the neutron star. Rotation, which can be as fast as pulsars , does not affect the X-ray flux as this fl ow is isotropic . On the other hand, pick out that the magnetic induction field\n\ncapable as that - although , the truth, and it is not clear further exactly how - to bottle up the thermonuclear explosions in the polar regions of neutron stars. The fight of opinion in the magnetic field is probably due to the difference in age busters and pulsars . On the age of the binary system can be judged by ordinary companion star .\n'