Hauv xyoo 1845, tus kws sau hnub qub Askiv Lord Ross tau tshawb pom tag nrho cov chav kawm ntawm kauv hom nebulae. Lawv qhov xwm txheej tau tsim tsuas yog thaum pib ntawm lub xyoo pua nees nkaum. Cov kws tshawb fawb tau ua pov thawj tias cov nebulae no yog cov hnub qub loj zoo ib yam li peb lub Galaxy, tab sis lawv nyob deb ntau lab lub teeb xyoo deb ntawm nws.
cov ntaub ntawv dav dav
Kauv galaxies (cov duab hauv kab lus no qhia txog cov yam ntxwv ntawm lawv cov qauv) zoo li ib khub ntawm saucers stacked ua ke los yog lub lens biconvex. Lawv tuaj yeem ntes ob lub hnub qub loj heev thiab lub halo. Lub hauv paus, uas pom zoo li o, feem ntau hu ua pob. Thiab qhov tsaus ntuj nti (ib txheej opaque ntawm interstellar nruab nrab) uas khiav raws lub disk hu ua interstellar plua plav.
Kauv galaxies feem ntau yog sau los ntawm tsab ntawv S. Ntxiv rau, lawv feem ntau muab faib raws li qib ntawm cov qauv. Ua li no, cov tsiaj ntawv a, b lossis c raug ntxiv rau lub cim tseem ceeb. Yog li, Sa sib raug rau lub galaxy nrog rau kev tsim kho tsis taukauv qauv, tab sis nrog ib tug loj core. Chav kawm thib peb - Sc - hais txog cov khoom sib txawv, nrog cov tub ntxhais tsis muaj zog thiab muaj zog kauv ceg. Qee lub hnub qub hauv nruab nrab yuav muaj lub jumper, uas feem ntau hu ua bar. Hauv qhov no, lub cim B tau ntxiv rau qhov kev xaiv. Peb Galaxy yog hom nruab nrab, tsis muaj jumper.
Kauv disk qauv ua li cas?
Cov ntaub ntawv tiaj tus disk zoo li tau piav qhia los ntawm kev sib hloov ntawm cov hnub qub pawg. Muaj ib qho kev xav tias thaum lub sij hawm tsim lub galaxy, lub zog centrifugal tiv thaiv lub compression ntawm lub thiaj li hu ua protogalactic huab nyob rau hauv ib qho kev taw qhia perpendicular mus rau lub axis ntawm kev sib hloov. Koj yuav tsum paub tias qhov xwm txheej ntawm kev txav ntawm cov pa roj thiab cov hnub qub hauv cov hnub qub tsis zoo ib yam: cov pawg diffuse rotate sai dua cov hnub qub qub. Piv txwv li, yog tias tus yam ntxwv kev sib hloov ceev ntawm cov roj yog 150-500 km / s, ces lub hnub qub halo yuav ib txwm txav qeeb dua. Thiab cov bulges uas muaj xws li cov khoom yuav muaj qhov ceev peb zaug qis dua disks.
Star gas
billions ntawm lub hnub qub tshuab txav hauv lawv lub orbits hauv galaxies tuaj yeem suav tias yog cov khoom sib sau ua ke uas tsim cov roj stellar. Thiab dab tsi yog qhov nthuav tshaj plaws, nws cov khoom yog ze heev rau cov pa roj. Xws li cov ntsiab lus xws li "concentration of particles", "density", "pressure", "temperature" tuaj yeem siv rau nws. Lub analogue ntawm qhov kawg parameter ntawm no yog qhov nruab nrab lub zog"chaotic" txav ntawm cov hnub qub. Nyob rau hauv rotating disks tsim los ntawm stellar gas, nthwv dej ntawm ib tug kauv hom ntawm rarefaction-compression ceev ze rau lub suab tsis tau propagate. Lawv muaj peev xwm khiav ib ncig ntawm lub galaxy ntawm ib tug tas mus li angular tshaj tawm rau ob peb puas lab xyoo. Lawv yog lub luag hauj lwm rau kev tsim ntawm kauv ceg. Thaum lub sij hawm thaum cov roj compression tshwm sim, cov txheej txheem ntawm kev tsim huab cua txias pib, uas ua rau lub hnub qub active tsim.
Hauv halo thiab elliptical systems, cov pa roj yog dynamic, uas yog, kub. Raws li txoj cai, cov lus tsa suab ntawm cov hnub qub hauv lub galaxy ntawm hom no yog chaotic. Yog li ntawd, qhov sib txawv nruab nrab ntawm lawv cov kev tshaj tawm rau cov khoom nyob ze yog ob peb puas kilometers ib ob (ceev dispersion). Rau stellar gases, qhov ceev dispersion feem ntau yog 10-50 km / s, ntsig txog, lawv "degree" yog noticeably txias. Nws ntseeg tias yog vim li cas rau qhov sib txawv no nyob rau lub sijhawm nyob deb (ntau tshaj kaum txhiab xyoo dhau los), thaum lub galaxies ntawm lub ntiaj teb tab tom pib tsim. Spherical Cheebtsam yog thawj tsim.
Kauv nthwv dej yog hu ua cov nthwv dej ntom ntom uas khiav raws lub voj voog tig. Yog li ntawd, tag nrho cov hnub qub ntawm lub galaxy ntawm hom no yog, raws li nws tau, raug yuam tawm mus rau hauv lawv cov ceg, ces tawm ntawm qhov ntawd. Tib qhov chaw uas qhov ceev ntawm kauv caj npab thiab cov hnub qub sib koom ua ke yog qhov hu ua corotation lub voj voog. Los ntawm txoj kev, qhov no yog qhov chaw uas lub hnub nyob. Rau peb lub ntiaj teb, qhov xwm txheej no zoo heev: Lub Ntiaj Teb muaj nyob rau hauv ib qho chaw ntsiag to hauv galaxy, vim li ntawd, rau ntau txhiab lab xyoo nws tsis tau cuam tshuam tshwj xeeb los ntawm cataclysms ntawm galactic nplai.
Ntawm kauv galaxies
Tsis zoo li cov qauv elliptical, txhua lub kauv galaxy (piv txwv tuaj yeem pom hauv cov duab qhia hauv kab lus) nws muaj nws tus kheej tsw. Yog hais tias thawj hom yog txuam nrog calmness, nyob ruaj khov, stability, ces hom thib ob yog dynamics, cua daj cua dub, rotations. Tej zaum yog vim li cas astronomers hais tias lub cosmos (lub ntug) yog "furious". Cov qauv ntawm lub kauv galaxy suav nrog lub hauv paus tseem ceeb, los ntawm cov caj npab zoo nkauj (txias) tshwm sim. Lawv maj mam poob lawv cov txheej txheem sab nraum lawv lub hnub qub pawg. Cov tsos mob zoo li no tsis tuaj yeem cuam tshuam nrog lub zog, nrawm nrawm. Kauv galaxies yog tus cwj pwm los ntawm ntau yam duab thiab cov qauv ntawm lawv cov ceg.
Yuav ua li cas galaxies cais
Txawm hais tias muaj ntau haiv neeg no, cov kws tshawb fawb muaj peev xwm txheeb xyuas txhua qhov paub txog cov kauv galaxies. Peb tau txiav txim siab los siv cov qib ntawm kev loj hlob ntawm caj npab thiab qhov loj ntawm lawv cov tub ntxhais ua qhov tseem ceeb, thiab qib ntawm compression faded rau hauv keeb kwm yav dhau yog qhov tsis tsim nyog.
Sa
Edwin P. Hubble tau muab rau Sa class cov kauv galaxies uas muaj cov ceg qis qis. Xws li pawg ib txwm muaj cov cores loj. Feem ntau yog qhov chaw nruab nrab ntawm lub galaxy ntawm ib chav kawmyog ib nrab qhov loj ntawm tag nrho pawg. Cov khoom no yog tus cwj pwm los ntawm qhov tsawg tshaj plaws nthuav tawm. Lawv tuaj yeem muab piv rau cov hnub qub elliptical. Feem ntau, cov kauv galaxies ntawm lub ntiaj teb muaj ob txhais caj npab. Lawv nyob rau ntawm opposite ntug ntawm lub nucleus. Cov ceg unwind nyob rau hauv ib tug symmetrical, zoo li txoj kev. Nrog kev ncua deb ntawm qhov chaw, qhov ci ntawm cov ceg txo qis, thiab ntawm qee qhov kev ncua deb lawv tsis pom txhua, poob rau hauv thaj chaw peripheral ntawm pawg. Txawm li cas los xij, muaj cov khoom uas tsis muaj ob, tab sis ntau lub tes tsho. Muaj tseeb, xws li cov qauv ntawm galaxy yog qhov tsawg heev. Txawm tias qhov tsawg tshaj plaws yog asymmetric nebulae, thaum ib ceg tau tsim ntau dua li lwm qhov.
Sb and Sc
Lub Edwin P. Hubble subclass Sb tau pom ntau dua caj npab, tab sis lawv tsis muaj kev nplua nuj. Cov nuclei yog qhov me me dua li cov thawj hom. Qhov thib peb subclass (Sc) ntawm kauv hnub qub pawg suav nrog cov khoom nrog cov ceg tsim tau zoo, tab sis lawv qhov chaw me me.
Puas rov yug dua tshiab?
Cov kws tshawb fawb tau pom tias cov qauv kauv yog qhov tshwm sim ntawm qhov tsis ruaj khov ntawm cov hnub qub, uas ua rau muaj zog compression. Tsis tas li ntawd, nws yuav tsum tau muab sau tseg tias, raws li txoj cai, kub giants yog concentrated nyob rau hauv lub caj npab thiab lub ntsiab pawg ntawm diffuse teeb meem - interstellar plua plav thiab interstellar gas - accumulate nyob rau hauv. Qhov tshwm sim no kuj tuaj yeem pom los ntawm lwm lub kaum sab xis. Tsis muaj kev ntseeg tias lub hnub qub compressed heev nyob rau hauv cov chav kawm ntawm nws evolutiontsis tuaj yeem poob nws qib ntawm compression. Yog li ntawd, qhov kev hloov pauv hloov pauv kuj tsis yooj yim sua. Yog li ntawd, peb txiav txim siab tias elliptical galaxies tsis tuaj yeem tig mus rau hauv ib qho kauv, thiab rov ua dua, vim qhov no yog li cas lub cosmos (Lub Ntiaj Teb) tau teeb tsa. Hauv lwm lo lus, ob hom hnub qub pawg no tsis yog ob theem sib txawv ntawm ib qho kev txhim kho evolutionary, tab sis txawv kiag li. Txhua yam zoo li no yog ib qho piv txwv ntawm txoj kev hloov pauv hloov pauv vim muaj qhov sib txawv compression piv. Thiab tus yam ntxwv no, nyob rau hauv lem, nyob ntawm qhov sib txawv ntawm kev sib hloov ntawm galaxies. Piv txwv li, yog lub hnub qub system tau txais kev sib hloov txaus thaum nws tsim, nws tuaj yeem cog lus thiab tsim cov caj npab kauv. Yog tias qhov ntsuas kev sib hloov tsis txaus, ces lub galaxy yuav qis dua, thiab nws cov ceg yuav tsis tsim - nws yuav yog cov duab elliptical classic.
Dab tsi yog qhov txawv
Muaj lwm qhov sib txawv ntawm lub hnub qub elliptical thiab kauv lub hnub qub. Yog li, thawj hom galaxy, uas muaj qis qis compression, yog tus cwj pwm los ntawm ib qho me me (lossis tsis tiav) ntawm cov teeb meem diffuse. Nyob rau tib lub sij hawm, kauv pawg nrog rau qib siab compression muaj ob qho tib si roj thiab hmoov av. Cov kws tshawb fawb piav txog qhov sib txawv no raws li hauv qab no. Cov plua plav thiab cov pa roj paug ib ntus sib tsoo thaum lawv txav mus los. Cov txheej txheem no yog inelastic. Tom qab kev sib tsoo, cov khoom poob qee qhov ntawm lawv lub zog, thiab yog li ntawd, lawv maj mam nyob rau hauv covqhov chaw hauv lub hnub qub uas muaj lub zog tsawg tshaj plaws.
Highly compressed systems
Yog tias cov txheej txheem tau piav qhia saum toj no tshwm sim hauv lub hnub qub uas muaj zog heev, ces qhov teeb meem diffuse yuav tsum nyob rau ntawm lub dav hlau loj ntawm lub galaxy, vim nws nyob ntawm no tias theem ntawm lub zog muaj peev xwm yog qhov qis tshaj. Qhov no yog qhov uas cov pa roj thiab hmoov av tau sau. Tsis tas li ntawd, diffuse teeb meem pib nws txoj kev txav mus rau hauv lub dav hlau loj ntawm lub hnub qub pawg. Cov khoom txav yuav luag sib luag hauv lub voj voog ncig. Yog li ntawd, kev sib tsoo ntawm no yog qhov tsawg heev. Yog hais tias lawv tshwm sim, ces lub zog poob yog negligible. Nws ua raws los ntawm qhov no tias qhov teeb meem tsis txav mus ntxiv mus rau qhov chaw nruab nrab ntawm lub galaxy, qhov twg lub zog muaj peev xwm muaj qib qis dua.
Tsis muaj zog compressed systems
Tam sim no xav txog seb lub ellipsoid galaxy coj li cas. Lub hnub qub system ntawm hom no yog qhov txawv los ntawm kev sib txawv kiag li ntawm cov txheej txheem no. Ntawm no, lub dav hlau tseem ceeb tsis yog nyob rau hauv tag nrho ib cheeb tsam hais nrog ib theem qis ntawm lub zog muaj peev xwm. Ib qho kev txo qis hauv qhov ntsuas no tsuas yog tshwm sim hauv nruab nrab ntawm lub hnub qub pawg. Thiab qhov no txhais tau hais tias interstellar plua plav thiab roj yuav raug nyiam mus rau qhov chaw ntawm lub galaxy. Yog li ntawd, qhov ceev ntawm diffuse teeb meem ntawm no yuav siab heev, ntau dua li nrog lub tiaj tus tawg nyob rau hauv ib tug kauv system. Cov khoom ntawm plua plav thiab roj sib sau ua ke nyob rau hauv nruab nrab ntawm cov tsub zuj zuj nyob rau hauv qhov kev txiav txim ntawm lub zog ntawm attraction yuav pib ntsws, yog li tsim ib tug me me cheeb tsam ntawm ntom. Cov kws tshawb fawb qhia tias los ntawm qhov teeb meem no yav tom ntejcov hnub qub tshiab pib tsim. Lwm yam tseem ceeb ntawm no - huab cua me me ntawm cov pa roj thiab hmoov av, nyob rau hauv lub hauv paus ntawm lub galaxy uas tsis muaj zog compressed, tsis tso cai rau nws tus kheej kom raug kuaj pom thaum lub sij hawm soj ntsuam.
theem nrab
Peb tau txiav txim siab ob lub ntsiab ntawm cov hnub qub pawg - nrog rau qhov tsis muaj zog thiab muaj zog ntawm compression. Txawm li cas los xij, tseem muaj cov theem nruab nrab thaum lub compression ntawm lub kaw lus nyob nruab nrab ntawm cov tsis. Nyob rau hauv xws li galaxies, tus yam ntxwv no tsis muaj zog txaus rau diffuse teeb meem nyob rau hauv tag nrho cov loj dav hlau ntawm pawg. Thiab nyob rau tib lub sijhawm, nws tsis muaj zog txaus rau cov khoom ntawm cov pa thiab plua plav kom mloog zoo hauv thaj tsam ntawm cov tub ntxhais. Nyob rau hauv xws li galaxies, diffuse teeb meem sib sau ua ke rau hauv ib lub dav hlau me me uas sib sau ua ke nyob ib ncig ntawm lub hauv paus ntawm lub hnub qub pawg.
Barred galaxies
Lwm yam subtype ntawm kauv galaxies paub - qhov no yog ib pawg hnub qub nrog lub bar. Nws feature yog raws li nram no. Yog hais tias nyob rau hauv ib tug pa kauv system cov caj npab tuaj ncaj qha los ntawm lub disk-puab tub ntxhais, ces nyob rau hauv hom no lub chaw yog nyob rau hauv nruab nrab ntawm lub ncaj choj. Thiab cov ceg ntawm xws li ib pawg pib los ntawm qhov kawg ntawm ntu no. Lawv kuj tseem hu ua galaxies ntawm crossed spirals. Los ntawm txoj kev, lub cev ntawm lub jumper no tseem tsis tau paub.
Ntxiv rau, cov kws tshawb fawb tau tshawb pom lwm hom hnub qub pawg. Lawv yog cov yam ntxwv los ntawm lub hauv paus, zoo li kauv galaxies, tab sis lawv tsis muaj caj npab. Lub xub ntiag ntawm ib qho tseem ceeb qhia tau hais tias muaj zog compression, tab sistag nrho lwm yam tsis zoo li ellipsoidal systems. Xws li pawg hu ua lenticular. Cov kws tshawb fawb qhia tias cov nebulae no tau tsim los ntawm qhov poob ntawm cov teeb meem diffuse los ntawm cov kauv galaxy.
