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7/18/2019 Fisika Modern

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15.6 STELLAR EVOLUTION AND BLACKHOLES

Such large graviai!"al #el$% ca" !ccur &!ll!'i"g he

c!lla(%e !& a %ar i"! a )!re c!)(ac !*+ec, a 'hie$'ar&- a "eur!" %ar- !r a *lac h!le. /e c!"%i$ere$ hec!lla(%e !& a" !r$i"ar0 %ar lie he Su" ! a 'hie $'ar&%ar a% a" ea)(le !& he a((licai!" !& 2er)i3Dirac%ai%ic%. Higher3e"erg0 elecr!"% i" he ail !& he 2er)i3

Dirac $i%ri*ui!" 'ill have %u4cie" e"erg0 ! (r!$uce hei"ver%e *ea3$eca0 reaci!", evnpe ++

Thi% reaci!" re)!ve% %!)e elecr!"% &r!) he %ar-re$uci"g he eec% !& auli re(ul%i!"- a"$ all!'i"g he

%ar ! c!lla(%e a *i. The %ar i% "!' c!)(!%e$ !&"eur!"%- i"%ea$ !& (r!!"% a"$ elecr!"%.


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Ra$i! a%r!"!)er% aCa)*ri$ge U"iver%i0$i%c!vere$ a" u"u%ual%ig"al a)!"g heir!*%ervai!"%7a regular(ul%ai!"- %uch a% i% %h!'"i" 2igure 15.89.

FIGURE 15.24 The radiosignals from two dierent

pulsars. The top signal is

the reord of the !rst pulsardiso"ered.

FIGURE 15.25 #harged partilestrapped $% the magneti !eld lines ofa neutron star are gi"en largeaelerations near the magneti

poles& from whih a diretionalradiation $eam emerges. If this

radiation $eam interepts the Earthas the neutron star rotates we see it

The i"e"%e )ag"eic #el$ !& %uch ara(i$l0 r!ai"g !*+ec ra(% a"0e)ie$ charge$ (aricle% a"$accelerae% he) ! high %(ee$%-e%(eciall0 "ear he )ag"eic (!le%-'here he0 give ! ra$iai!" :2igure15.85;.


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FIGURE 15.2' The #ra$(e$ula& remnant of asuperno"a o$ser"ed in the

%ear 1)54.

/he" care&ul )ea%ure% areae"- h!'ever- he *li"i"geec ca" *e %ee"


4/14

The $ecrea%e a"$ i"crea%e !& he (ul%e rae c!ul$ *ee(lai"e$ a% a D!((ler %hi& i& he "eur!" %ar 'ere )!vi"g #r%a'a0 &r!) a"$ laer !'ar$ he Earh. T! )!ve i" hi% 'a0- he(ul%ar )u% *e i" !r*i ar!u"$ a" u"%ee" c!)(a"i!". Thu% 'ehave a (ul%ar a% (ar !& a *i"ar0 %ar %0%e)- !r a >*i"ar0 (ul%ar.?

A)!"g he ge"eral relaivi0 eec% ha have *ee" !*%erve$i" he *i"ar0 (ul%ar %0%e) i% he $ela0 !& he (ul%e% $ue ! hecurvaure !& %(acei)e. Thi% %iuai!" i% %i)ilar ! 2igure% 15.8@

a"$ 15.81- ece( ha he (ul%ar :i"%ea$ !& Ve"u%; i% he !rigi"!& he %ig"al% a"$ he curvaure i% $ue ! he c!)(a"i!" %ar:i"%ea$ !& he Su";.

A BINARY PULSAR

BLACK HOLES

22222

2

22

2

22 )(sin)(2

1

)()(

21)( drdr

rc

GM

drdt

rc

GMcds

=

In spherial oordinates -r& & /0& he %(acei)e i"erval &!r hi%%!lui!" i%


5/14

The ra$ial (ar !& hi% %!lui!" :he dr term0 has 'ha a((ear% !*e a %eri!u% (r!*le), he &ac!r i" he $e"!)i"a!r ca" *ec!)eer! &!r a (aricular r& ausing that term in the euation to $low

up.3 This ours 'he" r has the "alue2

2cGMrs= r% hwar6shild radius 7 e"ent

hori6on

A" !*+ec 'h!%e )a%% 8 lies totall% within the orrespondingradius r%is said ! *e a $la, hole.

TABLE 15.2 Black Hole Event Hor!on"


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15.# COS$OLO%Y AN& %ENERAL RELATI'ITY

S!lvi"g he e


7/14

15.( THE BI% BAN% COS$OLO%Y

The e


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15.6 THE 7OR$ATION O7 NUCLEI AN& ATO$S

Devel!()e"% i" he Big Ba"g c!%)!l!g0 u( ! t ' s.-10; hot& $e"%e u"iver%e- &ull !& (h!!"% a"$ ele)e"ar0

(aricle% !& all varieie%- ha% c!!le$ ! *el!' 1@1@K.:8;F!% !& he u"%a*le (aricle% have $eca0e$ a'a0.:;All !& he !rigi"al a"i)aer a"$ )!% !& he !rigi"al )aer

a""ihilae$ !"e a"!her- leavi"g a %)all "u)*er !& (r!!"%-a" e


9/14

A %)all &raci!" !& he (h!!"% ha% e"ergie% a$o"e 2.22 8eD& andthese (h!!"% c!"i"ue ! *rea a(ar he $euer!"% :2igure15.8G;.

FIGURE 15.2 The thermalradiation spetrum. The

photons a$o"e E) 2.22

8eD are suientl%energeti to $rea, apartdeuterium nulei.

T)e 4"tr,*ton 3)ere E>>kT -or 3)c) t "aro8+atel0

T)e n*+,er 4en"t0 can ,e ")o3n to ,e

T)e -racton f a,ove E9" (NE>E9/V)/(N/V) 3)c) can ,e

eval*ate4 to ,e

dEehc

E

V

NkTEEE /

3

2

)(

80 < =

+

+

== < 2242.0

/

/0

2

0/0

kT

E

kT

Ee

VN

VNf kTE

EE

+

+

= < 22

)(8 0

2

0/3

2

0

kTE

kTEe

hcE

VN kTEEE


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&e*teron" -or+ an4 t)en react 3t) t)e +an0 roton"an4 ne*tron" avala,le to /ve

T)e :nal "te" n t)e -or+aton o- t)e )eaver n*cleare

++ HepH 43

++ HenHe 43

++ HepH 32

++ HnH 32

an4

an4


11/14

The $eail% !& he Big Ba"g c!%)!l!g0 are %u))arie$ i"2igure 15.8.

FIGURE 15.2 E"olution of the uni"erse aording to the >ig>ang osmolog%. The $lue line shows the temperature and

time in the radiation:dominated era $efore deoupling. Themost important reations in eah era are shown.


12/14

15.19 E;PERI$ENTAL COS$OLO%Y

$ATTER AN& ANTI$ATTER

The $i%i"ci!" *e'ee" )aer a"$ a"i)aer !ccurre$ a a"earl0 %age i" he ev!lui!" !& he u"iver%e- $uri"g he


13/14

THE HORI


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THE CO$POSITION AN& A%E O7 THE UNI'ERSE

The c!)(!%ii!" !& u"iver%e are !r$i"ar0 *ar0!"ic )aerc!"ri*ue% a*!u 9.6 !& he criical $e"%i0- a"$ $ar:"!"*ar0!"ic; )aer c!"ri*ue% 8. T!geher- he '! i"$%!& )aer )ae u( 8G !& he criical $e"%i0. I& he $e"%i0 !&he u"iver%e i% e$ar e"erg0.?Alh!ugh here are %everal he!rie% a*!u he "aure !& he $ar

e"erg0- here i% "! c!"vi"ci"g e(la"ai!" !& i% !rigi" !r i% r!lei" he (h0%ical '!rl$. I ha% *ee" %ugge%e$ ha he $are"erg0 $e"%i0 $!e% "! $i)i"i%h a% he u"iver%e e(a"$%- %!ha a% he $e"%iie% !& )aer :*!h *ar0!"ic a"$ "!"3*ar0!"ic;$ecrea%e 'ih he e(a"%i!"- eve"uall0 he $ar e"erg0 *egi"%

! $!)i"ae a"$ accelerae% he e(a"%i!".

There i% ge"eral agree)e" ha he age i% 1.* H 1)%ears&with an u"cerai"0 !& a*!u 1.

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