Kev txaus siab zoo rau niaj hnub astrophysics thiab cosmology yog chav tshwj xeeb ntawm cov xwm txheej hu ua gamma-ray tawg. Tau ntau xyoo lawm, thiab tshwj xeeb tshaj yog nyob rau xyoo tas los no, kev tshawb fawb tau khaws cov ntaub ntawv soj ntsuam txog qhov tshwm sim loj hauv cosmic. Nws qhov xwm txheej tseem tsis tau piav qhia meej, tab sis muaj cov qauv theoretical txaus txaus uas thov piav qhia nws.
Lub tswvyim ntawm qhov tshwm sim
Gamma hluav taws xob yog thaj tsam nyuaj tshaj plaws ntawm cov electromagnetic spectrum, tsim los ntawm high zaus photons los ntawm kwv yees li 6∙1019 Hz. Lub wavelengths ntawm gamma rays tuaj yeem muab piv rau qhov loj ntawm lub atom, thiab tuaj yeem ua tau ntau qhov kev txiav txim ntawm qhov loj me me.
Gamma-ray tawg yog luv luv thiab ci ntsa iab ntawm cosmic gamma-rays. Nws lub sijhawm tuaj yeem yog los ntawm ntau kaum ntawm milliseconds mus rau ntau txhiab vib nas this; feem ntau sau npeflashes kav ntev txog ib pliag. Qhov ci ntsa iab ntawm qhov tawg tuaj yeem yog qhov tseem ceeb, ntau pua lub sij hawm siab dua qhov ci ntsa iab ntawm lub ntuj nyob rau hauv qhov muag gamma ntau. Cov yam ntxwv energies muaj xws li los ntawm ob peb kaum mus rau phav phav kiloelectronvolts ib tawg quantum.
Cov khoom siv hluav taws xob tau muab faib ua ke thoob plaws lub ntiaj teb xilethi-aus. Nws tau raug pov thawj tias lawv qhov chaw nyob deb heev, ntawm cosmological nrug ntawm qhov kev txiav txim ntawm billions ntawm lub teeb xyoo. Lwm qhov tshwj xeeb ntawm kev tawg yog lawv qhov sib txawv thiab txoj kev loj hlob profile, txwv tsis pub hu ua lub teeb nkhaus. Kev tso npe ntawm qhov tshwm sim no tshwm sim yuav luag txhua hnub.
Study history
Qhov kev tshawb pom tau tshwm sim xyoo 1969 thaum ua cov ntaub ntawv los ntawm Asmeskas tub rog Vela satellites. Nws hloov tawm tias xyoo 1967, cov satellites tau sau ob lub pulses luv luv ntawm gamma hluav taws xob, uas pab pawg neeg tsis tuaj yeem txheeb xyuas nrog dab tsi. Tau ntau xyoo, cov xwm txheej zoo li no tau nce ntxiv. Xyoo 1973, Vela cov ntaub ntawv tau raug cais tawm thiab luam tawm, thiab kev tshawb fawb tshawb fawb tau pib ntawm qhov tshwm sim.
Nyob rau xyoo 1970s thiab thaum ntxov 1980s hauv Soviet Union, cov kev sim ntawm KONUS tau tsim muaj qhov tshwm sim ntawm qhov tawg luv txog li 2 vib nas this nyob rau lub sijhawm, thiab kuj tau ua pov thawj tias tawg ntawm gamma hluav taws xob tau muab faib ua ntu zus.
Xyoo 1997, qhov tshwm sim ntawm "afterglow" tau pom - qhov qeeb qeeb ntawm qhov tawg ntawm qhov ntev wavelengths. Tom qab ntawd, cov kws tshawb fawb thawj zaug tau tswj xyuas qhov xwm txheej nrog cov khoom siv kho qhov muag - lub galaxy nyob deb heev redshift.z=0, 7. Qhov no ua rau nws muaj peev xwm paub meej txog qhov xwm txheej cosmological ntawm qhov tshwm sim.
Nyob rau xyoo 2004, Swift orbital gamma-ray observatory tau tsim tawm, nrog kev pab los ntawm qhov uas nws tuaj yeem txheeb xyuas gamma-ntau yam xwm txheej nrog X-ray thiab qhov muag hluav taws xob. Tam sim no, ntau yam khoom siv ntxiv tau ua haujlwm hauv lub voj voog, suav nrog Gamma-ray Space Telescope. Fermi.
Kev faib tawm
Tam sim no, raws li kev pom zoo, ob hom gamma-ray tawg yog qhov txawv:
- Long, yam ntxwv ntawm lub sijhawm 2 vib nas this lossis ntau dua. Muaj li ntawm 70% ntawm cov kab mob no. Lawv lub sijhawm nruab nrab yog 20-30 vib nas this, thiab qhov ntev tshaj plaws sau tseg ntawm GRB 130427A flare yog ntau tshaj 2 teev. Muaj ib qho kev xav raws li cov xwm txheej ntev ntev (tam sim no muaj peb ntawm lawv) yuav tsum tau paub qhov txawv raws li hom tshwj xeeb ntawm kev tawg ntev ntev.
- Short. Lawv tsim thiab ploj mus nyob rau hauv lub sij hawm nqaim - tsawg dua 2 vib nas this, tab sis qhov nruab nrab ntev li ntawm 0.3 vib nas this. Tus tuav ntaub ntawv kom deb li deb yog lub teeb, uas siv sijhawm li 11 milliseconds.
Tom ntej no, peb yuav saib qhov feem ntau yuav ua rau GRBs ntawm ob hom loj.
Hypernova echoes
Raws li cov kws tshawb fawb astrophysicists feem ntau, qhov tawg ntev yog qhov tshwm sim ntawm kev tawg ntawm cov hnub qub loj heev. Muaj cov qauv theoretical uas piav qhia txog lub hnub qub tig nrawm nrog ntau tshaj 30 hnub ci, uas thaum kawg ntawm nws lub neej ua rau lub qhov dub. Lub acretion diskxws li ib yam khoom, ib tug collapsar, tshwm sim vim qhov teeb meem ntawm lub hnab ntawv stellar sai sai poob rau hauv lub qhov dub. Lub qhov dub nqos nws hauv ob peb feeb.
Vim li ntawd, muaj zog polar ultrarelativistic roj dav hlau tsim - dav hlau. Qhov ceev ntawm qhov tawm ntawm cov teeb meem hauv dav hlau yog ze rau qhov ceev ntawm lub teeb, qhov kub thiab txias, thiab cov hlau nplaum hauv cheeb tsam no loj heev. Xws li lub dav hlau muaj peev xwm tsim tau ib qho flux ntawm gamma hluav taws xob. Qhov tshwm sim hu ua hypernova, los ntawm kev sib piv nrog lub sij hawm "supernova".
Ntau qhov tawg ntev ntawm gamma-rays yog qhov muaj kev ntseeg siab heev nrog cov supernovae nrog qhov txawv txav hauv cov galaxies nyob deb. Lawv qhov kev soj ntsuam hauv xov tooj cua tau qhia txog qhov muaj peev xwm ntawm cov dav hlau ultrarelativistic.
Neutron lub hnub qub sib tsoo
Raws li tus qauv, qhov tawg luv tshwm sim thaum lub hnub qub neutron loj lossis lub hnub qub neutron-dub qhov khub ua ke. Xws li ib qho kev tshwm sim tau txais lub npe tshwj xeeb - "kilon", txij li lub zog tawm hauv cov txheej txheem no tuaj yeem tshaj lub zog tso tawm ntawm lub hnub qub tshiab los ntawm peb qhov kev txiav txim loj.
Ib khub ntawm cov khoom loj heev ua ntej tsim cov kab ke binary emitting nthwv dej gravitational. Raws li qhov tshwm sim, lub kaw lus poob lub zog, thiab nws cov khoom tau poob sai sai rau ib leeg ntawm cov kab sib txuas. Lawv cov kev sib koom ua ke tsim cov khoom sib hloov ceev ceev nrog lub zog sib nqus ntawm qhov tshwj xeeb teeb tsa, vim tias, dua, cov dav hlau ultrarelativistic tau tsim.
Simulation qhia tau hais tias qhov tshwm sim yog lub qhov dub nrog cov ntshav plasma toroid ntog rau ntawm qhov dub hauv 0.3 vib nas this. Lub hav zoov ntawm ultrarelativistic jets generated los ntawm acretion kav tib lub sij hawm. Cov ntaub ntawv soj ntsuam feem ntau ua raws li tus qauv no.
Lub yim hli ntuj 2017, gravitational yoj ntes LIGO thiab Virgo pom lub hnub qub neutron sib koom ua ke hauv galaxy 130 lab lub teeb xyoo deb. Cov naj npawb ntawm cov kilonova tsis zoo ib yam li qhov simulation kwv yees. Tab sis qhov xwm txheej yoj gravitational tau nrog los ntawm qhov tawg luv luv hauv gamma-duab tshav, nrog rau cov teebmeem hauv X-ray rau infrared wavelengths.
Txiv nyem nyem
Hnub Lub Rau Hli 14, 2006, Swift Gamma Observatory tau tshawb pom qhov xwm txheej txawv txawv hauv lub galaxy uas tsis loj heev uas nyob 1.6 billion light-years deb. Nws cov yam ntxwv tsis sib haum mus rau qhov tsis muaj qhov ntev thiab luv flashes. Lub gamma-ray tawg GRB 060614 muaj ob lub pulses: thawj zaug, lub zog pulse tsawg dua 5 vib nas this ntev, thiab tom qab ntawd 100-thib ob ntawm cov gamma rays softer. Cov cim qhia ntawm supernova hauv galaxy tsis tuaj yeem kuaj pom.
Tsis ntev tas los no cov xwm txheej zoo sib xws twb tau pom lawm, tab sis lawv tsis muaj zog li 8 npaug. Yog li no hybrid surge tseem tsis tau haum rau hauv lub moj khaum ntawm tus qauv theoretical.
Muaj ntau qhov kev xav txog lub hauv paus chiv keeb ntawm gamma-ray anomalous tawg GRB 060614. Hauv-Ua ntej, peb tuaj yeem xav tias nws ntev heev, thiab cov yam ntxwv txawv txawv yog vim qee qhov xwm txheej tshwj xeeb. Qhov thib ob, lub flash yog luv luv, thiab "tail" ntawm qhov kev tshwm sim rau qee qhov laj thawj tau txais qhov ntev. Thib peb, nws tuaj yeem xav tias cov kws tshawb fawb astrophysicists tau ntsib ib hom tshiab tawg.
Tseem kuj muaj qhov kev xav txawv txawv kiag li: ntawm qhov piv txwv ntawm GRB 060614, cov kws tshawb fawb tau ntsib qhov hu ua "qhov dawb". Qhov no yog ib cheeb tsam hypothetical ntawm qhov chaw-lub sij hawm uas muaj ib qho kev tshwm sim lub qab ntug, tab sis txav raws lub sij hawm axis opposite mus rau ib txwm dub qhov. Hauv cov ntsiab lus, qhov sib npaug ntawm cov kev xav dav dav ntawm kev txheeb ze kwv yees qhov muaj nyob ntawm qhov dawb, tab sis tsis muaj qhov yuav tsum tau ua ua ntej rau lawv qhov kev txheeb xyuas thiab tsis muaj cov tswv yim theoretical txog cov txheej txheem ntawm kev tsim cov khoom zoo li no. Feem ntau yuav, qhov kev xav txog kev nyiam romantic yuav tsum tau tso tseg thiab tsom mus rau kev suav cov qauv.
Muaj peev xwm txaus ntshai
Gamma-ray tawg nyob rau hauv lub ntiaj teb no ubiquitous thiab tshwm sim heev heev. Ib lo lus nug ntuj tshwm sim: lawv puas tsim kev phom sij rau lub ntiaj teb?
Kev ntsuas qhov tshwm sim rau biosphere, uas tuaj yeem ua rau muaj zog gamma tawg. Yog li, nrog lub zog tso tawm ntawm 10 52 erg (uas sib raug rau 10 39 MJ lossis txog 3.3∙10 38 kWh) thiab qhov deb ntawm 10 lub teeb xyoo, qhov tshwm sim ntawm qhov tawg yuav raug kev puas tsuaj. Nws tau raug xam tias nyob rau txhua square centimeter ntawm lub ntiaj teb nto nyob rau hauv lub hemisphere uas yuav muaj hmoo yuav raug ntaus los ntawm gamma rays.ntws, 1013 erg, lossis 1 MJ, lossis 0.3 kWh ntawm lub zog yuav raug tso tawm. Lwm qhov hemisphere yuav tsis muaj teeb meem - txhua yam muaj sia yuav tuag nyob ntawd, tab sis tom qab me ntsis, vim muaj kev cuam tshuam thib ob.
Txawm li cas los xij, npau suav phem li no tsis zoo li yuav hem peb: tsuas yog tsis muaj hnub qub nyob ze lub hnub uas tuaj yeem muab lub zog loj heev tso tawm. Txoj hmoo uas dhau los ua lub qhov dub lossis lub hnub qub neutron tsis hem cov hnub qub nyob ze peb.
Tau kawg, gamma-ray tawg yuav ua rau muaj kev hem thawj loj rau biosphere thiab ntawm qhov deb ntau dua, txawm li cas los xij, nws yuav tsum nco ntsoov tias nws cov hluav taws xob tsis nthuav tawm isotropically, tab sis nyob rau hauv cov kwj nqaim., thiab qhov tshwm sim ntawm kev poob rau hauv nws los ntawm lub ntiaj teb yog tsawg dua qhov feem ntau tsis ceeb toom.
Kev Pom Kev Kawm
Cosmic gamma-ray tawg tau yog ib qho ntawm qhov loj tshaj plaws astronomical paub tsis meej rau yuav luag ib nrab xyoo pua. Tam sim no theem ntawm kev paub txog lawv tau nce siab heev vim kev txhim kho sai ntawm cov cuab yeej soj ntsuam (nrog rau qhov chaw), kev ua cov ntaub ntawv thiab kev ua qauv.
Piv txwv li, tsis ntev los no tau ua ib kauj ruam tseem ceeb hauv kev qhia meej txog keeb kwm ntawm qhov tshwm sim tawg. Thaum soj ntsuam cov ntaub ntawv los ntawm Fermi satellite, nws tau pom tias gamma hluav taws xob yog tsim los ntawm kev sib tsoo ntawm protons ntawm ultrarelativistic dav hlau nrog protons ntawm interstellar gas, thiab cov ntsiab lus ntawm cov txheej txheem no tau refined.
Nws yuav tsum siv lub sijhawm tom qab ntawm cov xwm txheej nyob deb kom ntsuas qhov tseeb dua ntawm kev faib cov roj sib txuas mus txog qhov deb tau txiav txim siab los ntawm redshift Z=10.
Tam sim noNtau qhov xwm txheej ntawm qhov tawg yog tseem tsis paub, thiab peb yuav tsum tau tos rau qhov tshwm sim ntawm qhov tseeb nthuav tshiab thiab kev vam meej ntxiv hauv kev kawm ntawm cov khoom no.
