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Cov pob zeb C-hom uas muaj zog thiab nplua nuj nyob rau hauv cov organic matter yuav yog ib qho ntawm cov dej tseem ceeb hauv ntiaj teb. Tam sim no, cov chondrites uas muaj carbon muab lub tswv yim zoo tshaj plaws ntawm lawv cov tshuaj lom neeg, tab sis cov ntaub ntawv hais txog cov meteorites raug cuam tshuam: tsuas yog cov hom ruaj khov tshaj plaws thiaj li muaj sia nyob nkag mus rau hauv huab cua thiab tom qab ntawd cuam tshuam nrog lub ntiaj teb ib puag ncig. Ntawm no peb nthuav qhia cov txiaj ntsig ntawm kev tshawb fawb txog volumetric thiab microanalytical ntawm cov khoom me me Ryugu thawj zaug xa mus rau lub ntiaj teb los ntawm Hayabusa-2 spacecraft. Cov khoom me me Ryugu qhia txog kev sib phim ze rau cov tshuaj lom neeg tsis muaj feem cuam tshuam tab sis dej-hloov CI (Iwuna-hom) chondrites, uas tau siv dav ua qhov qhia txog kev sib xyaw ua ke ntawm lub hnub ci. Cov qauv no qhia txog kev sib raug zoo ntawm qhov chaw ntawm cov organic aliphatic nplua nuj thiab cov silicates layered thiab qhia txog qhov kub siab tshaj plaws ntawm kwv yees li 30 ° C thaum lub sijhawm dej yaig. Peb pom muaj ntau ntawm deuterium thiab diazonium sib xws nrog keeb kwm extrasolar. Cov khoom me me Ryugu yog cov khoom siv txawv teb chaws uas tsis muaj kuab paug thiab tsis tuaj yeem sib cais tau tshaj plaws uas tau kawm thiab zoo tshaj plaws rau tag nrho cov khoom ntawm lub hnub ci.
Txij lub Rau Hli 2018 txog rau lub Kaum Ib Hlis 2019, lub koom haum tshawb nrhiav dav hlau Nyiv Pooj (JAXA) Hayabusa2 tau ua kev tshawb nrhiav deb ntawm lub hnub qub Ryugu. Cov ntaub ntawv los ntawm Near Infrared Spectrometer (NIRS3) ntawm Hayabusa-2 qhia tias Ryugu tej zaum yuav muaj cov khoom zoo ib yam li cov chondrites carbonaceous thermally thiab/lossis shock-metamorphic. Qhov sib phim ze tshaj plaws yog CY chondrite (Yamato hom) 2. Ryugu qhov albedo qis tuaj yeem piav qhia los ntawm qhov muaj ntau cov khoom muaj carbon ntau, nrog rau qhov loj me ntawm cov khoom me me, porosity, thiab cov teebmeem ntawm huab cua. Lub dav hlau Hayabusa-2 tau tsaws ob zaug thiab sau cov qauv ntawm Ryuga. Thaum lub sijhawm tsaws thawj zaug rau lub Ob Hlis 21, 2019, cov khoom siv saum npoo tau txais, uas tau khaws cia rau hauv qhov chaw A ntawm lub capsule rov qab, thiab thaum lub sijhawm tsaws thib ob rau lub Xya Hli 11, 2019, cov khoom siv tau sau ze ntawm lub qhov av dag uas tsim los ntawm lub impactor me me. Cov qauv no khaws cia rau hauv Ward C. Kev piav qhia thawj zaug tsis ua puas tsuaj ntawm cov khoom me me hauv Theem 1 hauv cov chav tshwj xeeb, tsis muaj kuab paug thiab ntshiab uas muaj nitrogen ntawm JAXA-tswj cov chaw qhia tau hais tias cov khoom me me Ryugu zoo ib yam li CI4 chondrites thiab tau pom "ntau qib ntawm kev hloov pauv"3. Qhov kev faib tawm zoo li tsis sib xws ntawm Ryugu, zoo ib yam li CY lossis CI chondrites, tsuas yog daws tau los ntawm kev piav qhia ntxaws ntxaws ntawm isotopic, elemental, thiab mineralogical ntawm Ryugu cov khoom me me. Cov txiaj ntsig tau nthuav tawm ntawm no muab lub hauv paus ruaj khov rau kev txiav txim siab seb qhov twg ntawm ob qho kev piav qhia ua ntej rau tag nrho cov khoom ntawm lub hnub qub Ryugu feem ntau yuav muaj.
Yim lub Ryugu pellets (kwv yees li 60mg tag nrho), plaub los ntawm Chamber A thiab plaub los ntawm Chamber C, tau raug xa mus rau Theem 2 los tswj hwm pab pawg Kochi. Lub hom phiaj tseem ceeb ntawm txoj kev tshawb fawb no yog los piav qhia txog qhov xwm txheej, keeb kwm thiab keeb kwm ntawm lub asteroid Ryugu, thiab los sau cov kev zoo sib xws thiab qhov sib txawv nrog lwm cov qauv extraterrestrial xws li chondrites, interplanetary plua plav particles (IDPs) thiab rov qab los comets. Cov qauv sau los ntawm NASA lub luag haujlwm Stardust.
Kev tshuaj xyuas cov mineralogical ntxaws ntawm tsib Ryugu noob (A0029, A0037, C0009, C0014 thiab C0068) qhia tau hais tias lawv feem ntau yog tsim los ntawm cov phyllosilicates zoo thiab cov noob loj (~ 64–88 vol.%; Daim Duab 1a, b, Daim Duab Ntxiv 1). thiab lub rooj ntxiv 1). Phyllosilicates loj tshwm sim ua cov pob zeb pinnate (txog li kaum tawm microns loj) hauv cov matrices nplua nuj, phyllosilicate (tsawg dua ob peb microns loj). Cov khoom silicate txheej yog serpentine-saponite symbionts (Daim Duab 1c). Daim ntawv qhia (Si + Al) -Mg-Fe kuj qhia tau hais tias cov txheej silicate matrix muaj cov khoom nruab nrab ntawm serpentine thiab saponite (Daim Duab 2a, b). Cov phyllosilicate matrix muaj cov zaub mov carbonate (~ 2–21 vol.%), cov zaub mov sulfide (~ 2.4–5.5 vol.%), thiab magnetite (~ 3.6–6.8 vol.%). Ib qho ntawm cov khoom me me uas tau tshuaj xyuas hauv txoj kev tshawb fawb no (C0009) muaj me me (~ 0.5 vol.%) ntawm anhydrous silicates (olivine thiab pyroxene), uas yuav pab txheeb xyuas cov khoom siv uas ua rau cov pob zeb Ryugu nyoos5. Cov silicate anhydrous no tsis tshua muaj nyob rau hauv Ryugu pellets thiab tsuas yog pom zoo hauv C0009 pellet. Carbonates muaj nyob rau hauv lub matrix ua cov khoom me me (tsawg dua ob peb puas microns), feem ntau yog dolomite, nrog me me ntawm calcium carbonate thiab brinell. Magnetite tshwm sim ua cov khoom me me, framboids, plaques, lossis spherical aggregates. Sulfides feem ntau yog sawv cev los ntawm pyrrhotite hauv daim ntawv ntawm cov prisms hexagonal tsis sib xws / phaj lossis laths. Lub matrix muaj ntau ntawm submicron pentlandite lossis ua ke nrog pyrrhotite. Cov theem nplua nuj carbon (<10 µm loj) tshwm sim nyob rau hauv lub phyllosilicate-nplua nuj matrix. Cov theem nplua nuj carbon (<10 µm loj) tshwm sim nyob rau hauv lub phyllosilicate-nplua nuj matrix. Богатые углеродом фазы (размером <10 мкм) встречаются повсеместно в богатой филлосиликатами матрице. Cov theem nplua nuj carbon (<10 µm loj) tshwm sim nyob rau hauv lub phyllosilicate-nplua nuj matrix.富含碳的相（尺寸<10 µm）普遍存在于富含层状硅酸盐的基质中。富含碳的相（尺寸<10 µm）普遍存在于富含层状硅酸盐的基质中。 Богатые углеродом фазы (размером <10 мкм) преобладают в богатой филлосиликатами матрице. Cov theem nplua nuj carbon (<10 µm loj) feem ntau nyob hauv cov phyllosilicate-rich matrix.Lwm cov zaub mov ntxiv tau qhia nyob rau hauv Rooj Ntxiv 1. Daim ntawv teev cov zaub mov txiav txim siab los ntawm X-ray diffraction qauv ntawm C0087 thiab A0029 thiab A0037 sib xws heev nrog qhov txiav txim siab hauv CI (Orgueil) chondrite, tab sis txawv heev ntawm CY thiab CM (Mighei hom) chondrites (Daim Duab 1 nrog cov ntaub ntawv nthuav dav thiab Daim Duab Ntxiv 2). Tag nrho cov ntsiab lus ntawm Ryugu nplej (A0098, C0068) kuj sib xws nrog chondrite 6 CI (cov ntaub ntawv nthuav dav, Daim Duab 2 thiab Rooj Ntxiv 2). Qhov sib txawv, CM chondrites raug depleted hauv cov ntsiab lus nruab nrab thiab siab volatile, tshwj xeeb tshaj yog Mn thiab Zn, thiab siab dua hauv cov ntsiab lus refractory7. Qhov concentration ntawm qee cov ntsiab lus sib txawv heev, uas tej zaum yuav yog qhov kev cuam tshuam ntawm qhov sib txawv ntawm cov qauv vim qhov me me ntawm cov khoom me me thiab qhov tshwm sim ntawm kev kuaj xyuas. Txhua yam petrological, mineralogical thiab elemental yam ntxwv qhia tau hais tias Ryugu cov noob zoo ib yam li chondrites CI8,9,10. Ib qho kev zam tshwj xeeb yog qhov tsis muaj ferrihydrite thiab sulfate hauv Ryugu noob, qhia tias cov zaub mov no hauv CI chondrites tau tsim los ntawm kev hloov pauv hauv av.
a, Duab X-ray Composite ntawm Mg Kα (liab), Ca Kα (ntsuab), Fe Kα (xiav), thiab S Kα (daj) qhuav polished seem C0068. Cov feem muaj cov silicates layered (liab: ~88 vol%), carbonates (dolomite; ntsuab lub teeb: ~1.6 vol%), magnetite (xiav: ~5.3 vol%) thiab sulfides (daj: sulfide = ~2.5% vol. essay. b, duab ntawm thaj tsam contour hauv cov electrons backscattered ntawm a. Bru - tsis paub tab; Dole - dolomite; FeS yog hlau sulfide; Mag - magnetite; kua txiv - xab npum; Srp - serpentine. c, duab high-resolution transmission electron microscopy (TEM) ntawm ib qho saponite-serpentine intergrowth uas qhia txog serpentine thiab saponite lattice bands ntawm 0.7 nm thiab 1.1 nm, feem.
Cov khoom sib xyaw ntawm cov matrix thiab cov txheej silicate (ntawm %) ntawm Ryugu A0037 (cov voj voog liab khov kho) thiab C0068 (cov voj voog xiav khov kho) cov khoom me me tau pom hauv (Si + Al) -Mg-Fe ternary system. a, Electron Probe Microanalysis (EPMA) cov txiaj ntsig tau npaj tawm tsam CI chondrites (Ivuna, Orgueil, Alais) 16 tau pom hauv grey rau kev sib piv. b, Scanning TEM (STEM) thiab lub zog dispersive X-ray spectroscopy (EDS) kev tshuaj xyuas tau pom rau kev sib piv nrog Orgueil9 thiab Murchison46 meteorites thiab hydrated IDP47. Cov phyllosilicates zoo thiab cov khoom loj tau tshuaj xyuas, zam cov khoom me me ntawm hlau sulfide. Cov kab dotted hauv a thiab b qhia cov kab yaj ntawm saponite thiab serpentine. Cov khoom muaj hlau nplua nuj hauv a tej zaum yuav yog vim submicron hlau sulfide nplej hauv cov txheej silicate nplej, uas tsis tuaj yeem tshem tawm los ntawm qhov kev daws teeb meem ntawm EPMA kev tshuaj xyuas. Cov ntsiab lus ntaub ntawv nrog cov ntsiab lus Si siab dua li saponite hauv b tej zaum yuav tshwm sim los ntawm qhov muaj cov khoom siv nanosized amorphous silicon-nplua nuj hauv qhov sib tshuam ntawm cov txheej phyllosilicate. Tus naj npawb ntawm kev tshuaj xyuas: N = 69 rau A0037, N = 68 rau EPMA, N = 68 rau C0068, N = 19 rau A0037 thiab N = 27 rau C0068 rau STEM-EDS. c, daim ntawv qhia isotope ntawm trioxy particle Ryugu C0014-4 piv nrog cov nqi chondrite CI (Orgueil), CY (Y-82162) thiab cov ntaub ntawv sau (CM thiab C2-ung) 41,48,49. Peb tau txais cov ntaub ntawv rau Orgueil thiab Y-82162 meteorites. CCAM yog ib kab ntawm anhydrous carbonaceous chondrite minerals, TFL yog ib kab faib av. d, Δ17O thiab δ18O daim ntawv qhia ntawm Ryugu particle C0014-4, CI chondrite (Orgueil), thiab CY chondrite (Y-82162) (kev tshawb fawb no). Δ17O_Ryugu: Tus nqi ntawm Δ17O C0014-1. Δ17O_Orgueil: Tus nqi nruab nrab Δ17O rau Orgueil. Δ17O_Y-82162: Tus nqi nruab nrab Δ17O rau Y-82162. Cov ntaub ntawv CI thiab CY los ntawm cov ntaub ntawv 41, 48, 49 kuj tau qhia rau kev sib piv.
Kev tshuaj xyuas cov isotope loj ntawm cov pa oxygen tau ua tiav rau ntawm 1.83 mg qauv ntawm cov khoom siv rho tawm los ntawm granular C0014 los ntawm laser fluorination (Txoj Kev). Piv txwv li, peb tau khiav xya daim ntawv theej ntawm Orgueil (CI) (tag nrho qhov hnyav = 8.96 mg) thiab xya daim ntawv theej ntawm Y-82162 (CY) (tag nrho qhov hnyav = 5.11 mg) (Supplementary Table 3).
Hauv daim duab 2d qhia txog kev sib cais meej ntawm Δ17O thiab δ18O ntawm qhov hnyav nruab nrab ntawm cov khoom me me ntawm Orgueil thiab Ryugu piv rau Y-82162. Δ17O ntawm Ryugu C0014-4 khoom me me siab dua li ntawm Orgeil khoom me me, txawm tias muaj kev sib tshooj ntawm 2 sd. Ryugu khoom me me muaj cov nqi Δ17O siab dua piv rau Orgeil, uas tej zaum yuav qhia txog qhov kev ua qias tuaj hauv av txij li thaum nws poob rau xyoo 1864. Kev puas tsuaj hauv ib puag ncig hauv av11 yuav tsum ua rau muaj cov pa oxygen hauv huab cua, coj qhov kev tshuaj xyuas tag nrho ze rau kab sib cais hauv av (TFL). Qhov xaus lus no yog sib xws nrog cov ntaub ntawv mineralogical (tham ua ntej) tias Ryugu cov nplej tsis muaj hydrates lossis sulfates, thaum Orgeil muaj.
Raws li cov ntaub ntawv mineralogical saum toj no, cov txiaj ntsig no txhawb nqa kev sib raug zoo ntawm Ryugu cov noob thiab CI chondrites, tab sis tsis lees paub kev sib raug zoo ntawm CY chondrites. Qhov tseeb tias Ryugu cov noob tsis cuam tshuam nrog CY chondrites, uas qhia meej meej txog kev qhuav dej mineralogy, yog qhov xav tsis thoob. Kev soj ntsuam orbital ntawm Ryugu zoo li qhia tias nws tau dhau los ntawm kev qhuav dej thiab yog li ntawd yuav muaj cov khoom siv CY. Cov laj thawj rau qhov sib txawv pom tseeb no tseem tsis meej. Kev tshuaj xyuas oxygen isotope ntawm lwm cov khoom Ryugu tau nthuav tawm hauv daim ntawv sib koom tes 12. Txawm li cas los xij, cov txiaj ntsig ntawm cov ntaub ntawv txuas ntxiv no kuj sib xws nrog kev sib raug zoo ntawm Ryugu cov khoom thiab CI chondrites.
Siv cov txheej txheem sib koom tes microanalysis (Supplementary Fig. 3), peb tau tshuaj xyuas qhov kev faib tawm ntawm cov pa roj carbon organic thoob plaws tag nrho thaj chaw ntawm cov ion beam fraction (FIB) C0068.25 (Figs. 3a – f). Cov qauv zoo X-ray absorption spectra ntawm carbon (NEXAFS) ntawm ntug ze hauv ntu C0068.25 qhia ntau pawg ua haujlwm - aromatic lossis C = C (285.2 eV), C = O (286.5 eV), CH (287.5 eV) thiab C (= O) O (288.8 eV) - cov qauv graphene tsis muaj ntawm 291.7 eV (Fig. 3a), uas txhais tau tias qib qis ntawm kev hloov pauv thermal. Lub zog CH ncov (287.5 eV) ntawm cov organics ib nrab ntawm C0068.25 txawv ntawm cov organics insoluble ntawm cov pa roj carbonaceous chondrites uas tau kawm yav dhau los thiab zoo ib yam li IDP14 thiab cov khoom me me tau los ntawm Stardust lub hom phiaj. Lub ncov CH muaj zog ntawm 287.5 eV thiab lub ncov aromatic tsis muaj zog heev lossis C = C ntawm 285.2 eV qhia tias cov organic compounds muaj ntau cov aliphatic compounds (Daim Duab 3a thiab Daim Duab Ntxiv 3a). Cov cheeb tsam nplua nuj hauv aliphatic organic compounds yog nyob rau hauv cov phyllosilicates coarse-grained, nrog rau cov cheeb tsam uas muaj cov qauv carbon aromatic tsis zoo (lossis C = C) (Daim Duab 3c, d). Qhov sib piv, A0037,22 (Daim Duab Ntxiv 3) ib feem qhia txog cov ntsiab lus qis dua ntawm cov cheeb tsam aliphatic carbon-nplua nuj. Cov mineralogy hauv qab ntawm cov noob no yog nplua nuj hauv carbonates, zoo ib yam li chondrite CI 16, qhia txog kev hloov pauv ntawm cov dej qhov chaw (Daim Ntawv Ntxiv 1). Cov xwm txheej oxidizing yuav nyiam cov concentration ntawm carbonyl thiab carboxyl functional pawg hauv cov organic compounds cuam tshuam nrog carbonates. Kev faib tawm submicron ntawm cov organics nrog aliphatic carbon qauv tuaj yeem txawv ntawm kev faib tawm ntawm cov txheej txheem silicates coarse-grained. Cov lus qhia ntawm cov organic compounds aliphatic uas cuam tshuam nrog phyllosilicate-OH tau pom nyob rau hauv Tagish Lake meteorite. Cov ntaub ntawv microanalytical sib koom ua ke qhia tias cov organic matter nplua nuj nyob rau hauv aliphatic compounds yuav kis tau dav hauv C-hom asteroids thiab cuam tshuam nrog phyllosilicates. Qhov xaus lus no yog sib xws nrog cov ntawv ceeb toom yav dhau los ntawm aliphatic / aromatic CHs hauv Ryugu particles uas tau ua pov thawj los ntawm MicroOmega, lub tshuab microscope ze-infrared hyperspectral. Ib lo lus nug tseem ceeb thiab tsis tau daws teeb meem yog seb cov khoom tshwj xeeb ntawm aliphatic carbon-rich organic compounds cuam tshuam nrog coarse-grained phyllosilicates pom hauv kev tshawb fawb no tsuas yog pom ntawm lub asteroid Ryugu.
a, NEXAFS carbon spectra normalized rau 292 eV hauv aromatic (C = C) thaj tsam nplua nuj (liab), hauv aliphatic nplua nuj thaj tsam (ntsuab), thiab hauv matrix (xiav). Cov kab grey yog Murchison 13 insoluble organic spectrum rau kev sib piv. au, chav tsev txiav txim siab. b, Scanning transmission X-ray microscopy (STXM) spectral duab ntawm ib tug carbon K-edge qhia tias qhov seem yog dominated los ntawm carbon. c, RGB composite plot nrog aromatic (C = C) thaj tsam nplua nuj thaj tsam (liab), aliphatic nplua nuj thaj tsam (ntsuab), thiab matrix (xiav). d, organics nplua nuj nyob rau hauv aliphatic compounds yog concentrated nyob rau hauv coarse-grained phyllosilicate, lub cheeb tsam yog nthuav dav los ntawm cov thawv dawb dotted hauv b thiab c. e, loj nanospheres (ng-1) nyob rau hauv lub cheeb tsam nthuav dav los ntawm cov thawv dawb dotted hauv b thiab c. Rau: pyrrhotite. Pn: nickel-chromite. f, Nanoscale Secondary Ion Mass Spectrometry (NanoSIMS), Hydrogen (1H), Carbon (12C), thiab Nitrogen (12C14N) cov duab elemental, 12C/1H element ratio cov duab, thiab cross δD, δ13C, thiab δ15N isotope cov duab - Seem PG-1: presolar graphite nrog extreme 13C enrichment (Supplementary Table 4).
Kev tshawb fawb Kinetic ntawm cov organic teeb meem degradation hauv Murchison meteorites tuaj yeem muab cov ntaub ntawv tseem ceeb txog kev faib tawm heterogeneous ntawm aliphatic organic teeb meem nplua nuj hauv Ryugu nplej. Kev tshawb fawb no qhia tau hais tias aliphatic CH bonds hauv organic teeb meem nyob twj ywm txog qhov kub siab tshaj plaws txog li 30 ° C ntawm niam txiv thiab / lossis hloov pauv nrog lub sijhawm-kub kev sib raug zoo (piv txwv li 200 xyoo ntawm 100 ° C thiab 0 ° C 100 lab xyoo). . Yog tias tus precursor tsis tau cua sov ntawm qhov kub thiab txias rau ntau dua ib lub sijhawm, qhov kev faib tawm thawj zaug ntawm aliphatic organics nplua nuj hauv phyllosilicate yuav raug khaws cia. Txawm li cas los xij, qhov chaw pob zeb dej hloov pauv yuav ua rau qhov kev txhais lus no nyuaj, vim tias carbonate-nplua nuj A0037 tsis qhia txog cov cheeb tsam aliphatic nplua nuj carbon cuam tshuam nrog phyllosilicates. Qhov kev hloov pauv kub qis no kwv yees li sib xws rau qhov muaj cubic feldspar hauv Ryugu nplej (Supplementary Table 1) 20.
Feem C0068.25 (ng-1; Figs. 3a–c, e) muaj ib lub nanosphere loj uas qhia txog cov aromatic heev (lossis C = C), moderately aliphatic, thiab cov spectra tsis muaj zog ntawm C (= O) O thiab C = O. . Cov cim ntawm aliphatic carbon tsis phim cov cim ntawm cov organic insoluble thiab organic nanospheres uas cuam tshuam nrog chondrites (Daim Duab 3a) 17,21. Raman thiab infrared spectroscopic tsom xam ntawm nanospheres hauv Lake Tagish qhia tau hais tias lawv muaj cov organic aliphatic thiab oxidized organic compounds thiab disordered polycyclic aromatic organic compounds nrog cov qauv nyuaj 22,23. Vim tias lub matrix nyob ib puag ncig muaj cov organic nplua nuj hauv aliphatic compounds, cov cim ntawm aliphatic carbon hauv ng-1 tej zaum yuav yog ib qho khoom siv analytical. Nthuav, ng-1 muaj embedded amorphous silicates (Daim Duab 3e), ib qho kev ntxhib los mos uas tseem tsis tau tshaj tawm rau txhua yam extraterrestrial organics. Cov amorphous silicates tej zaum yuav yog cov khoom ntuj tsim ntawm ng-1 lossis yog los ntawm amorphization ntawm aqueous / anhydrous silicates los ntawm ion thiab / lossis electron beam thaum lub sijhawm tshuaj xyuas.
Cov duab NanoSIMS ion ntawm ntu C0068.25 (Daim Duab 3f) qhia txog kev hloov pauv sib xws hauv δ13C thiab δ15N, tshwj tsis yog cov noob presolar nrog cov khoom loj 13C ntawm 30,811‰ (PG-1 hauv daim duab δ13C hauv Daim Duab 3f) (Cov Lus Qhia Ntxiv 4). Cov duab noob theem pib X-ray thiab cov duab TEM siab daws teeb meem tsuas yog qhia txog qhov concentration ntawm cov pa roj carbon thiab qhov deb ntawm cov dav hlau basal ntawm 0.3 nm, uas sib raug rau graphite. Nws yog qhov tsim nyog tias cov nqi ntawm δD (841 ± 394‰) thiab δ15N (169 ± 95‰), nplua nuj hauv aliphatic organic matter cuam tshuam nrog cov phyllosilicates coarse-grained, tig mus rau qhov siab dua me ntsis ntawm qhov nruab nrab rau tag nrho thaj tsam C (δD = 528 ± 139‰). ‰, δ15N = 67 ± 15 ‰) hauv C0068.25 (Supplementary Table 4). Qhov kev soj ntsuam no qhia tau hais tias cov organics aliphatic-nplua nuj hauv cov phyllosilicates coarse-grained tej zaum yuav yog cov qub dua li cov organics nyob ib puag ncig, txij li thaum kawg tej zaum yuav tau dhau los ua kev sib pauv isotopic nrog cov dej nyob ib puag ncig hauv lub cev qub. Xwb, cov kev hloov pauv isotopic no kuj tseem yuav muaj feem cuam tshuam nrog cov txheej txheem tsim thawj zaug. Nws tau txhais hais tias cov silicates zoo-grained layered hauv CI chondrites tau tsim los ntawm kev hloov pauv tas mus li ntawm cov coarse-grained anhydrous silicate clusters qub. Aliphatic-nplua nuj organic matter tej zaum yuav tau tsim los ntawm cov precursor molecules hauv lub protoplanetary disk lossis interstellar medium ua ntej tsim lub hnub ci system, thiab tom qab ntawd tau hloov pauv me ntsis thaum lub sijhawm hloov dej ntawm Ryugu (loj) niam txiv lub cev. Qhov loj (<1.0 km) ntawm Ryugu me dhau los tswj tau qhov kub sab hauv kom txaus rau kev hloov pauv dej los tsim cov minerals hydrous25. Qhov loj (<1.0 km) ntawm Ryugu me dhau los tswj tau qhov kub sab hauv txaus rau kev hloov pauv dej los tsim cov minerals hydrous25. Размер (<1.0 км) Рюгу слишком мал, чтобы поддерживать достаточное внутреннее тепло для водяного образованием водных минералов25. Loj (<1.0 km) Ryugu me dhau los ua kom muaj cua sov txaus rau kev hloov pauv dej los tsim cov minerals hauv dej25. Ryugu 的尺寸（<1.0公里）太小，不足以维持内部热量以进行水蚀变形成含水矿物25. Ryugu 的尺寸（<1.0公里）太小，不足以维持内部热量以进行水蚀变形成含水矿物25. Размер Рюгу (<1,0 км) слишком мал, чтобы поддерживать внутреннее тепло для изменения водновы с в обра минералов 25. Qhov loj ntawm Ryugu (<1.0 km) me dhau los txhawb nqa cua sov sab hauv kom hloov dej los ua cov dej minerals25.Yog li ntawd, tej zaum yuav xav tau cov neeg ua ntej Ryugu uas muaj kaum mais loj. Cov khoom siv organic uas nplua nuj nyob rau hauv aliphatic compounds yuav khaws lawv cov isotope piv qub vim yog kev sib raug zoo nrog cov phyllosilicates coarse-grained. Txawm li cas los xij, qhov tseeb ntawm cov isotopic hnyav carriers tseem tsis meej vim yog qhov sib xyaw ua ke thiab sib xyaw ntawm ntau yam khoom hauv cov FIB fractions no. Cov no tuaj yeem yog cov khoom siv organic nplua nuj nyob rau hauv aliphatic compounds hauv Ryugu granules lossis coarse phyllosilicates nyob ib puag ncig lawv. Nco ntsoov tias cov khoom siv organic hauv yuav luag txhua cov carbonaceous chondrites (suav nrog CI chondrites) feem ntau yuav nplua nuj dua hauv D dua li hauv phyllosilicates, tshwj tsis yog CM Paris 24, 26 meteorites.
Cov duab ntawm qhov ntim δD thiab δ15N ntawm FIB daim tau txais rau A0002.23 thiab A0002.26, A0037.22 thiab A0037.23 thiab C0068.23, C0068.25 thiab C0068.26 FIB daim (tag nrho xya daim FIB los ntawm peb lub Ryugu me me) Kev sib piv ntawm NanoSIMS nrog lwm yam khoom ntawm lub hnub ci system tau pom hauv daim duab 4 (Supplementary Table 4)27,28. Kev hloov pauv ntim hauv δD thiab δ15N hauv A0002, A0037, thiab C0068 profiles yog sib xws nrog cov hauv IDP, tab sis siab dua li hauv CM thiab CI chondrites (Daim duab 4). Nco ntsoov tias qhov ntau ntawm δD tus nqi rau Comet 29 qauv (-240 txog 1655‰) yog loj dua li ntawm Ryugu. Cov ntim δD thiab δ15N ntawm cov qauv Ryukyu, raws li txoj cai, me dua li qhov nruab nrab rau cov hnub qub comets ntawm tsev neeg Jupiter thiab huab Oort (Daim duab 4). Cov nqi qis dua δD ntawm CI chondrites yuav qhia txog kev cuam tshuam ntawm kev ua qias tuaj hauv av hauv cov qauv no. Muab qhov zoo sib xws ntawm Bells, Lake Tagish, thiab IDP, qhov sib txawv loj hauv δD thiab δN tus nqi hauv Ryugu cov khoom me me yuav qhia txog kev hloov pauv hauv cov cim isotopic thawj zaug ntawm cov organic thiab aqueous compositions hauv lub hnub ci thaum ntxov. Cov kev hloov pauv isotopic zoo sib xws hauv δD thiab δN hauv Ryugu thiab IDP cov khoom me me qhia tias ob qho tib si tuaj yeem tsim los ntawm cov khoom siv los ntawm tib qhov chaw. Nws ntseeg tias IDPs pib los ntawm cov chaw cometary 14. Yog li ntawd, Ryugu yuav muaj cov khoom zoo li hnub qub comet thiab / lossis tsawg kawg yog lub hnub ci sab nraud. Txawm li cas los xij, qhov no yuav nyuaj dua li peb hais ntawm no vim yog (1) qhov sib xyaw ntawm cov dej spherulitic thiab D-nplua nuj ntawm lub cev niam txiv 31 thiab (2) lub hnub qub comet's D/H piv ua ib qho kev ua haujlwm ntawm lub hnub qub cometary 32. Txawm li cas los xij, cov laj thawj rau qhov pom heterogeneity ntawm hydrogen thiab nitrogen isotopes hauv Ryugu cov khoom me me tsis tau nkag siab tag nrho, ib feem vim yog tus lej tsawg ntawm kev tshuaj xyuas muaj niaj hnub no. Cov txiaj ntsig ntawm hydrogen thiab nitrogen isotope systems tseem tsa qhov ua tau tias Ryugu muaj feem ntau ntawm cov khoom siv los ntawm sab nraud Lub Hnub Ci System thiab yog li ntawd yuav qhia qee qhov zoo sib xws rau cov hnub qub comets. Daim ntawv qhia Ryugu tsis qhia txog kev sib raug zoo ntawm δ13C thiab δ15N (Supplementary Table 4).
Tag nrho cov khoom sib xyaw ua ke ntawm H thiab N isotopic ntawm Ryugu cov khoom me me (lub voj voog liab: A0002, A0037; lub voj voog xiav: C0068) muaj feem cuam tshuam nrog lub hnub ci loj 27, tsev neeg Jupiter nruab nrab (JFC27), thiab Oort huab comets (OCC27), IDP28, thiab carbonaceous chondrules. Kev sib piv ntawm meteorite 27 (CI, CM, CR, C2-ung). Cov khoom sib xyaw ua ke yog muab rau hauv Supplementary Table 4. Cov kab dotted yog cov nqi isotope hauv av rau H thiab N.
Kev thauj cov khoom volatiles (piv txwv li cov organic matter thiab dej) mus rau lub ntiaj teb tseem yog qhov txhawj xeeb26,27,33. Cov khoom organic submicron cuam tshuam nrog cov phyllosilicates coarse hauv Ryugu cov khoom me me uas tau txheeb xyuas hauv kev tshawb fawb no yuav yog qhov tseem ceeb ntawm cov volatiles. Cov khoom organic hauv cov phyllosilicates coarse-grained yog kev tiv thaiv zoo dua los ntawm kev puas tsuaj16,34 thiab lwj35 dua li cov khoom organic hauv cov matrices zoo. Cov isotopic hnyav dua ntawm hydrogen hauv cov khoom me me txhais tau tias lawv tsis zoo li yuav yog tib qho chaw ntawm cov volatiles nqa mus rau lub ntiaj teb thaum ntxov. Lawv tuaj yeem sib xyaw nrog cov khoom nrog cov khoom sib xyaw hydrogen isotopic sib dua, raws li tau tshaj tawm tsis ntev los no hauv qhov kev xav ntawm qhov muaj dej los ntawm cua hnub ci hauv silicates.
Hauv kev tshawb fawb no, peb qhia tau tias CI meteorites, txawm tias lawv qhov tseem ceeb geochemical ua tus sawv cev ntawm tag nrho cov khoom ntawm lub hnub ci,6,10 yog cov qauv av uas muaj kuab paug. Peb kuj muab pov thawj ncaj qha rau kev sib cuam tshuam ntawm cov organic aliphatic nplua nuj thiab cov minerals hydrous nyob ze thiab qhia tias Ryugu tej zaum yuav muaj cov khoom extrasolar37. Cov txiaj ntsig ntawm kev tshawb fawb no qhia meej meej txog qhov tseem ceeb ntawm kev kuaj ncaj qha ntawm protoasteroids thiab qhov xav tau kev thauj cov qauv rov qab los hauv qab cov xwm txheej inert thiab sterile. Cov pov thawj uas tau nthuav tawm ntawm no qhia tau hais tias Ryugu particles yog ib qho ntawm cov khoom siv hnub ci tsis muaj kuab paug tshaj plaws muaj rau kev tshawb fawb hauv chaw kuaj mob, thiab kev kawm ntxiv ntawm cov qauv muaj nqis no yuav ua rau peb nkag siab txog cov txheej txheem hnub ci thaum ntxov. Ryugu particles yog qhov sawv cev zoo tshaj plaws ntawm tag nrho cov khoom ntawm lub hnub ci.
Txhawm rau txiav txim siab qhov nyuaj microstructure thiab cov khoom siv tshuaj lom neeg ntawm cov qauv submicron, peb siv synchrotron radiation-based computed tomography (SR-XCT) thiab SR X-ray diffraction (XRD)-CT, FIB-STXM-NEXAFS-NanoSIMS-TEM kev tshuaj xyuas. Tsis muaj kev puas tsuaj, kev ua qias tuaj vim yog huab cua hauv ntiaj teb, thiab tsis muaj kev puas tsuaj los ntawm cov khoom me me lossis cov qauv kho tshuab. Lub sijhawm no, peb tau ua qhov kev tshuaj xyuas volumetric siv scanning electron microscopy (SEM)-EDS, EPMA, XRD, instrumental neutron activation analysis (INAA), thiab laser oxygen isotope fluorination khoom siv. Cov txheej txheem assay tau qhia hauv Daim Duab Ntxiv 3 thiab txhua qhov kev sim tau piav qhia hauv cov ntu hauv qab no.
Cov khoom me me los ntawm lub hnub qub Ryugu tau rov qab los ntawm Hayabusa-2 reentry module thiab xa mus rau JAXA Control Center hauv Sagamihara, Nyiv, yam tsis ua rau lub ntiaj teb huab cua qias neeg4. Tom qab pib thiab tsis ua rau puas tsuaj ntawm qhov chaw tswj hwm JAXA, siv cov thawv hloov pauv ntawm qhov chaw kaw thiab cov hnab tshuaj ntsuam qauv (10 lossis 15 hli txoj kab uas hla sapphire siv lead ua thiab stainless hlau, nyob ntawm qhov loj ntawm cov qauv) kom tsis txhob muaj kev cuam tshuam ib puag ncig. ib puag ncig. y thiab / lossis cov pa phem hauv av (piv txwv li cov pa dej, hydrocarbons, cov pa roj hauv huab cua thiab cov khoom me me) thiab kev sib kis ntawm cov qauv thaum lub sijhawm npaj cov qauv thiab kev thauj mus los ntawm cov tsev kawm ntawv thiab cov tsev kawm qib siab38. Yuav kom tsis txhob muaj kev puas tsuaj thiab kev ua qias tuaj vim muaj kev sib cuam tshuam nrog huab cua hauv ntiaj teb (cov pa dej thiab cov pa oxygen), txhua hom kev npaj qauv (xws li kev txiav nrog lub tantalum chisel, siv lub tshuab txiav hlau pob zeb diamond sib npaug (Meiwa Fosis Corporation DWS 3400) thiab kev npaj txiav epoxy) rau kev teeb tsa) tau ua tiav hauv lub thawv hnab looj tes hauv qab N2 huv si thiab qhuav (dew point: -80 txog -60 °C, O2 ~50-100 ppm). Txhua yam khoom siv ntawm no raug ntxuav nrog kev sib xyaw ua ke ntawm dej ntshiab thiab ethanol siv cov nthwv dej ultrasonic ntawm ntau zaus sib txawv.
Ntawm no peb kawm txog National Polar Research Institute (NIPR) cov khoom meteorite ntawm Antarctic Meteorite Research Center (CI: Orgueil, CM2.4: Yamato (Y)-791198, CY: Y-82162 thiab CY: Y 980115).
Rau kev hloov pauv ntawm cov cuab yeej rau SR-XCT, NanoSIMS, STXM-NEXAFS thiab TEM kev tshuaj xyuas, peb siv lub thoob ntiaj teb ultrathin qauv tuav piav qhia hauv kev tshawb fawb yav dhau los38.
Kev tshuaj xyuas SR-XCT ntawm cov qauv Ryugu tau ua tiav los ntawm kev siv lub tshuab BL20XU/SPring-8 integrated CT system. Lub tshuab CT integrated muaj ntau hom kev ntsuas: hom kev pom dav thiab hom kev daws teeb meem qis (WL) kom ntes tau tag nrho cov qauv ntawm cov qauv, hom kev pom nqaim thiab hom kev daws teeb meem siab (NH) rau kev ntsuas qhov tseeb ntawm thaj chaw qauv. kev txaus siab thiab cov duab xoo hluav taws xob kom tau txais cov qauv diffraction ntawm qhov ntim ntawm cov qauv, thiab ua XRD-CT kom tau txais daim duab 2D ntawm cov theem minerals kab rov tav hauv cov qauv. Nco ntsoov tias txhua qhov kev ntsuas tuaj yeem ua tiav yam tsis siv lub tshuab ua kom tshem tawm cov qauv tuav ntawm lub hauv paus, uas tso cai rau kev ntsuas CT thiab XRD-CT kom raug. Lub tshuab ntes X-ray hom WL (BM AA40P; Hamamatsu Photonics) tau nruab nrog lub koob yees duab ntxiv 4608 × 4608 pixel hlau-oxide-semiconductor (CMOS) (C14120-20P; Hamamatsu Photonics) nrog lub scintillator uas muaj 10 lutetium txhuas garnet ib leeg siv lead ua tuab µm (Lu3Al5O12:Ce) thiab lub lens relay. Qhov loj me ntawm pixel hauv hom WL yog li 0.848 µm. Yog li, qhov pom kev (FOV) hauv hom WL yog li 6 hli hauv hom offset CT. Lub tshuab ntes X-ray hom NH (BM AA50; Hamamatsu Photonics) tau nruab nrog lub scintillator gadolinium-aluminium-gallium garnet (Gd3Al2Ga3O12) tuab 20 µm, lub koob yees duab CMOS (C11440-22CU) nrog qhov kev daws teeb meem ntawm 2048 × 2048 pixels; Hamamatsu Photonics) thiab lub lens ×20. Qhov loj me ntawm pixel hauv hom NH yog ~0.25 µm thiab qhov pom kev yog ~0.5 hli. Lub tshuab ntes rau hom XRD (BM AA60; Hamamatsu Photonics) tau nruab nrog lub scintillator uas muaj 50 µm tuab P43 (Gd2O2S:Tb) tshuaj ntsuam hmoov, lub koob yees duab CMOS 2304 × 2304 pixel daws teeb meem (C15440-20UP; Hamamatsu Photonics) thiab lub lens relay. Lub tshuab ntes muaj qhov loj me ntawm pixel zoo ntawm 19.05 µm thiab qhov pom kev ntawm 43.9 mm2. Txhawm rau kom nce FOV, peb tau siv cov txheej txheem offset CT hauv hom WL. Daim duab teeb xa mus rau CT reconstruction muaj ib daim duab hauv qhov ntau ntawm 180 ° txog 360 ° cuam tshuam kab rov tav ib ncig ntawm lub axis ntawm kev tig, thiab ib daim duab hauv qhov ntau ntawm 0 ° txog 180 °.
Hauv hom XRD, lub teeb X-ray raug tsom los ntawm lub phaj Fresnel cheeb tsam. Hauv hom no, lub tshuab ntes tau muab tso rau 110 hli tom qab tus qauv thiab lub teeb nres yog 3 hli ua ntej ntawm lub tshuab ntes. Cov duab diffraction hauv 2θ ntau ntawm 1.43° txog 18.00° (grating pitch d = 16.6–1.32 Å) tau txais nrog qhov chaw X-ray tsom rau hauv qab ntawm lub tshuab ntes lub teb pom. Cov qauv txav mus rau ntsug ntawm lub sijhawm tsis tu ncua, nrog ib nrab tig rau txhua kauj ruam scan ntsug. Yog tias cov khoom me me ua tau raws li Bragg mob thaum tig los ntawm 180°, nws muaj peev xwm tau txais diffraction ntawm cov khoom me me hauv lub dav hlau kab rov tav. Cov duab diffraction tom qab ntawd tau muab tso ua ke rau hauv ib daim duab rau txhua kauj ruam scan ntsug. Cov xwm txheej SR-XRD-CT assay yuav luag zoo ib yam li cov rau SR-XRD assay. Hauv hom XRD-CT, lub tshuab ntes tau muab tso rau 69 hli tom qab tus qauv. Cov duab diffraction hauv 2θ ntau yam yog txij li 1.2° txog 17.68° (d = 19.73 txog 1.35 Å), qhov twg ob qho tib si lub teeb X-ray thiab lub teeb txwv nyob hauv kab nrog qhov chaw nruab nrab ntawm lub tshuab ntes pom. Luam theej duab cov qauv kab rov tav thiab tig cov qauv 180°. Cov duab SR-XRD-CT tau rov tsim dua nrog cov khoom siv mineral siab tshaj plaws ua cov nqi pixel. Nrog kev luam theej duab kab rov tav, cov qauv feem ntau raug luam theej duab hauv 500–1000 kauj ruam.
Rau txhua qhov kev sim, lub zog X-ray tau kho ntawm 30 keV, vim qhov no yog qhov txwv qis tshaj plaws ntawm X-ray nkag mus rau hauv cov hnub qub meteorites nrog lub cheeb ntawm kwv yees li 6 hli. Tus naj npawb ntawm cov duab tau txais rau txhua qhov kev ntsuas CT thaum lub sijhawm tig 180 ° yog 1800 (3600 rau qhov kev pab cuam offset CT), thiab lub sijhawm raug rau cov duab yog 100 ms rau hom WL, 300 ms rau hom NH, 500 ms rau XRD, thiab 50 ms. ms rau XRD-CT ms. Lub sijhawm luam theej duab qauv ib txwm yog li 10 feeb hauv hom WL, 15 feeb hauv hom NH, 3 teev rau XRD, thiab 8 teev rau SR-XRD-CT.
Cov duab CT tau rov tsim dua los ntawm kev tsim rov qab los ntawm kev sib txuas thiab ua kom zoo rau qhov coefficient linear attenuation ntawm 0 txog 80 cm-1. Cov software Slice tau siv los tshuaj xyuas cov ntaub ntawv 3D thiab cov software muXRD tau siv los tshuaj xyuas cov ntaub ntawv XRD.
Cov khoom me me Ryugu uas muaj epoxy kho (A0029, A0037, C0009, C0014 thiab C0068) tau maj mam txhuam rau ntawm qhov chaw mus rau theem ntawm 0.5 µm (3M) pob zeb diamond lapping zaj duab xis nyob rau hauv cov xwm txheej qhuav, zam kom cov khoom siv los kov qhov chaw thaum lub sijhawm txhuam. Qhov chaw txhuam ntawm txhua tus qauv tau kuaj xyuas thawj zaug los ntawm lub teeb microscopy thiab tom qab ntawd rov qab cov electrons kom tau txais cov duab mineralogy thiab cov qauv (BSE) ntawm cov qauv thiab cov khoom NIPR zoo siv JEOL JSM-7100F SEM nruab nrog lub zog dispersive spectrometer (AZtec). zog) daim duab. Rau txhua tus qauv, cov ntsiab lus ntawm cov ntsiab lus tseem ceeb thiab me me tau soj ntsuam siv lub tshuab hluav taws xob microanalyzer (EPMA, JEOL JXA-8200). Tshuaj xyuas cov khoom me me phyllosilicate thiab carbonate ntawm 5 nA, cov qauv ntuj thiab cov qauv tsim ntawm 15 keV, sulfides, magnetite, olivine, thiab pyroxene ntawm 30 nA. Cov qib modal tau suav los ntawm cov ntawv qhia ntsiab lus thiab cov duab BSE siv ImageJ 1.53 software nrog cov qib tsim nyog teeb tsa rau txhua lub mineral.
Kev tshuaj xyuas cov isotope oxygen tau ua tiav ntawm Open University (Milton Keynes, UK) siv lub tshuab infrared laser fluorination. Cov qauv Hayabusa2 tau xa mus rau Open University 38 hauv cov thawv uas muaj nitrogen rau kev xa mus ntawm cov chaw.
Kev thauj cov qauv tau ua tiav hauv lub thawv hnab looj tes nitrogen nrog qib oxygen saib xyuas qis dua 0.1%. Rau Hayabusa2 kev ua haujlwm tshuaj ntsuam xyuas, lub thawv Ni tshiab tau tsim, muaj tsuas yog ob lub qhov qauv (txoj kab uas hla 2.5 hli, qhov tob 5 hli), ib qho rau Hayabusa2 cov khoom me me thiab lwm qhov rau obsidian sab hauv tus qauv. Thaum lub sijhawm tshuaj ntsuam xyuas, lub qhov qauv uas muaj cov khoom siv Hayabusa2 tau npog nrog lub qhov rais BaF2 sab hauv kwv yees li 1 hli tuab thiab 3 hli hauv txoj kab uas hla los tuav cov qauv thaum lub sijhawm laser. Cov dej ntws BrF5 mus rau cov qauv tau tswj hwm los ntawm cov roj sib xyaw channel txiav hauv lub thawv Ni. Lub chamber qauv kuj tau rov kho dua kom nws tuaj yeem raug tshem tawm ntawm kab nqus tsev fluorination thiab tom qab ntawd qhib hauv lub thawv hnab looj tes uas muaj nitrogen. Lub chamber ob daim tau kaw nrog lub foob tooj liab gasketed compression thiab EVAC Quick Release CeFIX 38 saw clamp. Lub qhov rais BaF2 3 hli tuab rau saum lub chamber tso cai rau kev soj ntsuam tib lub sijhawm ntawm cov qauv thiab laser cua sov. Tom qab thauj cov qauv, clamp lub chamber dua thiab rov txuas rau kab fluorinated. Ua ntej kev tshuaj xyuas, lub chamber qauv tau raug cua sov hauv lub tshuab nqus tsev kom txog li 95 ° C ib hmos kom tshem tawm cov dej noo uas nqus tau. Tom qab cua sov ib hmos, lub chamber tau cia kom txias mus rau qhov kub thiab txias hauv chav tsev thiab tom qab ntawd qhov feem uas raug rau huab cua thaum lub sijhawm hloov cov qauv tau raug ntxuav nrog peb aliquots ntawm BrF5 kom tshem tawm cov dej noo. Cov txheej txheem no ua kom ntseeg tau tias cov qauv Hayabusa 2 tsis raug rau huab cua thiab tsis muaj kuab paug los ntawm cov dej noo los ntawm qhov ntawm cov kab fluorinated uas raug tso rau hauv huab cua thaum lub sijhawm thauj cov qauv.
Cov qauv ntawm Ryugu C0014-4 thiab Orgueil (CI) tau raug tshuaj xyuas hauv hom "ib leeg" hloov kho42, thaum Y-82162 (CY) kev tshuaj xyuas tau ua tiav rau ntawm ib lub tais nrog ntau lub qhov dej kuaj41. Vim lawv cov khoom tsis muaj dej, nws tsis tas yuav siv ib txoj kev rau CY chondrites. Cov qauv tau raug cua sov siv Photon Machines Inc. infrared CO2 laser. lub zog ntawm 50 W (10.6 µm) ntsia rau ntawm XYZ gantry nyob rau hauv qhov muaj BrF5. Lub kaw lus video ua ke saib xyuas qhov kev ua haujlwm ntawm cov tshuaj tiv thaiv. Tom qab fluorination, O2 uas tau tso tawm tau raug txhuam siv ob lub cryogenic nitrogen traps thiab lub txaj sov ntawm KBr kom tshem tawm cov fluorine ntau dhau. Cov khoom sib xyaw isotopic ntawm cov pa oxygen ntshiab tau raug tshuaj xyuas ntawm Thermo Fisher MAT 253 dual-channel mass spectrometer nrog qhov kev daws teeb meem ntawm kwv yees li 200.
Qee zaum, qhov ntau ntawm cov pa roj O2 uas tso tawm thaum lub sijhawm ua cov qauv yog tsawg dua 140 µg, uas yog qhov kwv yees txwv ntawm kev siv lub cuab yeej bellows ntawm MAT 253 mass spectrometer. Hauv cov xwm txheej no, siv microvolumes rau kev tshuaj xyuas. Tom qab tshuaj xyuas cov khoom me me Hayabusa2, tus qauv sab hauv obsidian tau fluorinated thiab nws cov pa oxygen isotope tau txiav txim siab.
Cov ions ntawm NF+ NF3+ fragment cuam tshuam rau lub beam nrog qhov hnyav 33 (16O17O). Txhawm rau tshem tawm qhov teeb meem no, feem ntau cov qauv raug ua tiav siv cov txheej txheem sib cais cryogenic. Qhov no tuaj yeem ua tiav rau pem hauv ntej ua ntej MAT 253 kev tshuaj xyuas lossis ua qhov kev tshuaj xyuas thib ob los ntawm kev xa cov roj uas tau tshuaj xyuas rov qab mus rau lub molecular sieve tshwj xeeb thiab rov xa nws tom qab kev sib cais cryogenic. Kev sib cais cryogenic cuam tshuam nrog kev muab roj rau lub molecular sieve ntawm qhov kub ntawm nitrogen kua thiab tom qab ntawd tso nws mus rau hauv lub molecular sieve thawj zaug ntawm qhov kub ntawm -130 ° C. Kev sim dav dav tau qhia tias NF+ tseem nyob ntawm thawj lub molecular sieve thiab tsis muaj kev faib ua feem tseem ceeb tshwm sim siv txoj kev no.
Raws li kev tshuaj xyuas rov ua dua ntawm peb cov qauv obsidian sab hauv, qhov tseeb tag nrho ntawm lub kaw lus hauv hom bellows yog: ± 0.053‰ rau δ17O, ± 0.095‰ rau δ18O, ± 0.018‰ rau Δ17O (2 sd). Kev tshuaj xyuas oxygen isotope yog muab rau hauv tus qauv delta notation, qhov twg delta18O yog xam raws li:
Tsis tas li ntawd, siv qhov sib piv 17O/16O rau δ17O. VSMOW yog tus qauv thoob ntiaj teb rau Vienna Mean Sea Water Standard. Δ17O sawv cev rau qhov sib txawv ntawm kab faib av, thiab cov qauv xam yog: Δ17O = δ17O - 0.52 × δ18O. Tag nrho cov ntaub ntawv uas tau nthuav tawm hauv Supplementary Table 3 tau raug kho qhov sib txawv.
Cov seem uas muaj li ntawm 150 txog 200 nm tuab tau rho tawm ntawm cov khoom me me Ryugu siv lub cuab yeej Hitachi High Tech SMI4050 FIB ntawm JAMSTEC, Kochi Core Sampling Institute. Nco ntsoov tias txhua qhov seem FIB tau rov qab los ntawm cov khoom me me uas tsis tau ua tiav tom qab raug tshem tawm ntawm cov hlab ntsha uas muaj roj N2 rau kev hloov pauv ntawm cov khoom. Cov seem no tsis tau ntsuas los ntawm SR-CT, tab sis tau ua tiav nrog kev raug rau huab cua hauv ntiaj teb tsawg kawg nkaus kom tsis txhob muaj kev puas tsuaj thiab kev ua qias tuaj yeem cuam tshuam rau cov pa roj carbon K-edge spectrum. Tom qab tso cov txheej txheem tiv thaiv tungsten, thaj chaw txaus siab (txog li 25 × 25 μm2) tau txiav thiab nyias nrog Ga+ ion beam ntawm qhov hluav taws xob nrawm ntawm 30 kV, tom qab ntawd ntawm 5 kV thiab qhov tam sim no ntawm 40 pA kom txo qhov puas tsuaj ntawm qhov chaw. Cov seem ultrathin tom qab ntawd tau muab tso rau ntawm lub mesh tooj liab loj dua (Kochi mesh) 39 siv lub micromanipulator nruab nrog FIB.
Ryugu A0098 (1.6303mg) thiab C0068 (0.6483mg) pellets tau kaw ob zaug hauv cov ntawv polyethylene ntshiab huv si hauv lub thawv hnab looj tes nitrogen ntshiab ntawm SPring-8 yam tsis muaj kev cuam tshuam nrog huab cua hauv ntiaj teb. Kev npaj qauv rau JB-1 (lub pob zeb siv geological los ntawm Geological Survey of Japan) tau ua tiav ntawm Tokyo Metropolitan University.
INAA muaj nyob rau ntawm Lub Tsev Kawm Ntawv rau Kev Sib Koom Tes Hluav Taws Xob thiab Kev Tshawb Fawb Txog Nuclear, Kyoto University. Cov qauv tau raug irradiated ob zaug nrog cov voj voog irradiation sib txawv xaiv raws li lub sijhawm ib nrab ntawm nuclide siv rau kev ntsuas cov ntsiab lus. Ua ntej, cov qauv tau raug irradiated hauv lub raj cua irradiation rau 30 vib nas this. Cov dej ntws ntawm thermal thiab ceev neutrons hauv daim duab 3 yog 4.6 × 1012 thiab 9.6 × 1011 cm-2 s-1, raws li, rau kev txiav txim siab cov ntsiab lus ntawm Mg, Al, Ca, Ti, V thiab Mn. Cov tshuaj xws li MgO (99.99% purity, Soekawa Chemical), Al (99.9% purity, Soekawa Chemical), thiab Si hlau (99.999% purity, FUJIFILM Wako Pure Chemical) kuj tau raug irradiated kom kho rau kev cuam tshuam nuclear xws li (n, n). Cov qauv kuj tau raug tshuaj sodium chloride (99.99% purity; MANAC) kom kho qhov kev hloov pauv ntawm neutron flux.
Tom qab kev siv neutron irradiation, daim ntawv polyethylene sab nraud tau hloov nrog ib daim tshiab, thiab cov hluav taws xob gamma uas tawm los ntawm cov qauv thiab qhov siv tau ntsuas tam sim ntawd nrog Ge detector. Cov qauv tib yam tau rov ua dua rau 4 teev hauv lub raj cua irradiation. 2 muaj cov cua sov thiab cov neutron fluxes ceev ntawm 5.6 1012 thiab 1.2 1012 cm-2 s-1, raws li, rau kev txiav txim siab Na, K, Ca, Sc, Cr, Fe, Co, Ni, Zn, Ga, As, Cov ntsiab lus Se, Sb, Os, Ir thiab Au. Cov qauv tswj ntawm Ga, As, Se, Sb, Os, Ir, thiab Au tau raug irradiated los ntawm kev siv cov nqi tsim nyog (los ntawm 10 txog 50 μg) ntawm cov txheej txheem daws teeb meem ntawm cov ntsiab lus paub ntawm cov ntsiab lus no rau ntawm ob daim ntawv lim dej, ua raws li kev irradiation ntawm cov qauv. Kev suav gamma ray tau ua tiav ntawm Lub Tsev Kawm Ntawv ntawm Kev Sib Koom Tes Hluav Taws Xob thiab Nuclear Sciences, Kyoto University thiab RI Research Center, Tokyo Metropolitan University. Cov txheej txheem tshuaj xyuas thiab cov ntaub ntawv siv rau kev txiav txim siab ntau ntawm INAA cov ntsiab lus yog tib yam li cov uas tau piav qhia hauv peb cov haujlwm dhau los.
Ib lub tshuab ntsuas X-ray diffractometer (Rigaku SmartLab) tau siv los sau cov qauv diffraction ntawm Ryugu cov qauv A0029 (<1 mg), A0037 (≪1 mg) thiab C0087 (<1 mg) ntawm NIPR. Ib lub tshuab ntsuas X-ray diffractometer (Rigaku SmartLab) tau siv los sau cov qauv diffraction ntawm Ryugu cov qauv A0029 (<1 mg), A0037 (≪1 mg) thiab C0087 (<1 mg) ntawm NIPR. Рентгеновский дифрактометр (Rigaku SmartLab) использовали для сбора дифракционных картин образцов Ryugu A0029 (≈ 1г) C0087 (<1 мг) rau NIPR. Ib lub tshuab X-ray diffractometer (Rigaku SmartLab) tau siv los sau cov qauv diffraction ntawm Ryugu A0029 (<1 mg), A0037 (≪1 mg), thiab C0087 (<1 mg) cov qauv hauv NIPR.使用X 射线衍射仪(Rigaku SmartLab) 在NIPR 收集Ryugu 样品A0029 (<1 mg), A0037 (<1 mg) 和C0087 (<1 mg) 的衍塰。使用X 射线衍射仪(Rigaku SmartLab) 在NIPR 收集Ryugu 样品A0029 (<1 mg), A0037 (<1 mg) 和C0087 (<1 mg) 的衍塰。 Дифрактограммы образцов Ryugu A0029 (<1 мг), A0037 (<1 мг) и C0087 (<1 мг) были получены в NIPR с овннкголь зовани дифрактометра (Rigaku SmartLab). Cov qauv X-ray diffraction ntawm cov qauv Ryugu A0029 (<1 mg), A0037 (<1 mg) thiab C0087 (<1 mg) tau txais ntawm NIPR siv lub X-ray diffractometer (Rigaku SmartLab).Tag nrho cov qauv tau raug zom ua hmoov zoo rau ntawm lub silicon non-reflective wafer siv lub phaj iav sapphire thiab tom qab ntawd nthuav kom sib npaug rau ntawm lub silicon non-reflective wafer yam tsis muaj kua (dej lossis cawv). Cov xwm txheej ntsuas yog raws li nram no: Cu Kα X-ray hluav taws xob yog tsim los ntawm lub raj hluav taws xob ntawm 40 kV thiab lub raj tam sim no ntawm 40 mA, qhov ntev ntawm qhov txwv yog 10 hli, lub kaum sab xis sib txawv yog (1/6) °, qhov ceev tig hauv dav hlau yog 20 rpm, thiab qhov ntau yog 2θ (ob chav Bragg lub kaum sab xis) yog 3-100 ° thiab siv sijhawm li 28 teev los tshuaj xyuas. Bragg Brentano optics tau siv. Lub tshuab ntes yog lub tshuab ntes semiconductor silicon ib-dimensional (D/teX Ultra 250). X-rays ntawm Cu Kβ tau raug tshem tawm siv lub lim Ni. Siv cov qauv muaj, kev ntsuas ntawm cov magnesian saponite tsim (JCSS-3501, Kunimine Industries CO. Ltd), serpentine (nplooj serpentine, Miyazu, Nikka) thiab pyrrhotite (monoclinic 4C, Chihua, Mexico Watts) tau muab piv rau kev txheeb xyuas cov ncov thiab siv cov ntaub ntawv hmoov diffraction los ntawm International Center for Diffraction Data, dolomite (PDF 01-071-1662) thiab magnetite (PDF 00-019-0629). Cov ntaub ntawv diffraction los ntawm Ryugu kuj tau muab piv rau cov ntaub ntawv ntawm hydroaltered carbonaceous chondrites, Orgueil CI, Y-791198 CM2.4, thiab Y 980115 CY (cua sov theem III, 500–750°C). Kev sib piv qhia tau zoo sib xws nrog Orgueil, tab sis tsis yog nrog Y-791198 thiab Y 980115.
Cov spectra NEXAFS nrog cov pa roj carbon K ntawm cov ntu ultrathin ntawm cov qauv ua los ntawm FIB tau ntsuas siv STXM BL4U channel ntawm UVSOR synchrotron chaw ntawm Lub Tsev Kawm Ntawv ntawm Molecular Sciences (Okazaki, Nyiv). Qhov loj me ntawm lub teeb pom kev zoo nrog lub phaj Fresnel yog kwv yees li 50 nm. Cov kauj ruam zog yog 0.1 eV rau cov qauv zoo ntawm thaj tsam ze ntug (283.6–292.0 eV) thiab 0.5 eV (280.0–283.5 eV thiab 292.5–300.0 eV) rau thaj tsam pem hauv ntej thiab tom qab. lub sijhawm rau txhua daim duab pixel tau teeb tsa rau 2 ms. Tom qab kev tshem tawm, lub STXM analytical chamber tau puv nrog helium ntawm qhov siab ntawm kwv yees li 20 mbar. Qhov no pab txo qis thermal drift ntawm cov khoom siv X-ray optics hauv lub chamber thiab tus tuav qauv, nrog rau kev txo cov qauv puas tsuaj thiab / lossis oxidation. NEXAFS K-edge carbon spectra tau tsim los ntawm cov ntaub ntawv sib dhos siv aXis2000 software thiab STXM cov ntaub ntawv ua software. Nco ntsoov tias lub thawv hloov pauv qauv thiab lub thawv hnab looj tes yog siv los tiv thaiv cov qauv oxidation thiab kev ua qias tuaj.
Tom qab kev tshuaj xyuas STXM-NEXAFS, cov khoom sib xyaw isotopic ntawm hydrogen, carbon, thiab nitrogen ntawm Ryugu FIB slices tau tshuaj xyuas siv isotope imaging nrog JAMSTEC NanoSIMS 50L. Lub teeb Cs + thawj zaug ntawm kwv yees li 2 pA rau kev tshuaj xyuas carbon thiab nitrogen isotope thiab kwv yees li 13 pA rau kev tshuaj xyuas hydrogen isotope yog rasterized hla thaj tsam ntawm kwv yees li 24 × 24 µm2 txog 30 × 30 µm2 ntawm cov qauv. Tom qab 3-feeb prespray ntawm qhov tam sim no muaj zog heev, txhua qhov kev tshuaj xyuas tau pib tom qab kev ruaj khov ntawm qhov muaj zog ntawm lub teeb theem nrab. Rau kev tshuaj xyuas cov carbon thiab nitrogen isotopes, cov duab ntawm 12C–, 13C–, 16O–, 12C14N– thiab 12C15N– tau txais tib lub sijhawm siv xya electron multiplier multiplex nrhiav nrog qhov kev daws teeb meem ntawm kwv yees li 9000, uas txaus los cais txhua yam isotopic sib xyaw. kev cuam tshuam (piv txwv li 12C1H ntawm 13C thiab 13C14N ntawm 12C15N). Rau kev tshuaj xyuas cov hydrogen isotopes, cov duab 1H-, 2D- thiab 12C- tau txais nrog qhov kev daws teeb meem ntawm kwv yees li 3000 nrog ntau qhov kev kuaj pom siv peb lub electron multipliers. Txhua qhov kev tshuaj xyuas muaj 30 daim duab scanned ntawm tib thaj chaw, nrog rau ib daim duab muaj 256 × 256 pixels rau kev tshuaj xyuas carbon thiab nitrogen isotope thiab 128 × 128 pixels rau kev tshuaj xyuas hydrogen isotope. Lub sijhawm ncua yog 3000 µs ib pixel rau kev tshuaj xyuas carbon thiab nitrogen isotope thiab 5000 µs ib pixel rau kev tshuaj xyuas hydrogen isotope. Peb tau siv 1-hydroxybenzotriazole hydrate ua cov qauv hydrogen, carbon thiab nitrogen isotope los calibrate cov cuab yeej pawg fractionation45.
Txhawm rau txiav txim siab qhov sib xyaw ua ke ntawm silicon isotopic ntawm presolar graphite hauv FIB C0068-25 profile, peb siv rau lub electron multipliers nrog qhov kev daws teeb meem ntawm kwv yees li 9000. Cov duab muaj 256 × 256 pixels nrog lub sijhawm ncua ntawm 3000 µs ib pixel. Peb tau calibrate lub cuab yeej siv pawg faib ua pawg siv silicon wafers ua cov qauv hydrogen, carbon, thiab silicon isotope.
Cov duab isotope tau ua tiav siv NASA's NanoSIMS45 imaging software. Cov ntaub ntawv tau kho rau lub sijhawm tuag ntawm electron multiplier (44 ns) thiab cov teebmeem tuaj txog quasi-simultaneous. Kev sib phim scan sib txawv rau txhua daim duab kom kho qhov kev txav ntawm daim duab thaum tau txais. Daim duab isotope kawg yog tsim los ntawm kev ntxiv cov ions thib ob los ntawm txhua daim duab rau txhua lub pixel scan.
Tom qab STXM-NEXAFS thiab NanoSIMS kev tshuaj xyuas, tib ntu FIB tau kuaj xyuas siv lub tshuab hluav taws xob kis tau tus mob (JEOL JEM-ARM200F) ntawm qhov hluav taws xob nrawm ntawm 200 kV ntawm Kochi, JAMSTEC. Lub microstructure tau pom siv lub teeb ci ntsa iab TEM thiab lub kaum sab xis scanning TEM hauv qhov tsaus ntuj. Cov theem mineral tau txheeb xyuas los ntawm qhov chaw electron diffraction thiab lattice band imaging, thiab kev tshuaj ntsuam tshuaj tau ua los ntawm EDS nrog 100 mm2 silicon drift detector thiab JEOL Analysis Station 4.30 software. Rau kev tshuaj ntsuam xyuas kom muaj nuj nqis, qhov tshwj xeeb X-ray zog rau txhua lub ntsiab lus tau ntsuas hauv TEM scanning hom nrog lub sijhawm tau txais cov ntaub ntawv ruaj khov ntawm 30 s, thaj chaw scanning beam ntawm ​​~ 100 × 100 nm2, thiab lub zog beam ntawm 50 pA. Qhov piv (Si + Al) -Mg-Fe hauv cov txheej silicates tau txiav txim siab siv cov coefficient sim k, kho rau qhov tuab, tau txais los ntawm tus qauv ntawm pyropagarnet ntuj.
Tag nrho cov duab thiab kev tshuaj xyuas siv hauv txoj kev tshawb fawb no muaj nyob rau ntawm JAXA Data Archiving and Communication System (DARTS) https://www.darts.isas.jaxa.jp/curation/hayabusa2. Tsab xov xwm no muab cov ntaub ntawv qub.
Kitari, K. et al. Cov khoom sib xyaw ntawm qhov chaw ntawm lub hnub qub 162173 Ryugu raws li tau pom los ntawm Hayabusa2 NIRS3 ntsuas. Science 364, 272–275.
Kim, AJ Yamato-hom carbonaceous chondrites (CY): cov analogues ntawm Ryugu asteroid nto? Geochemistry 79, 125531 (2019).
Pilorjet, S. et al. Thawj qhov kev tshuaj xyuas cov khoom sib xyaw ntawm Ryugu cov qauv tau ua tiav siv lub tshuab microscope MicroOmega hyperspectral. National Astron. 6, 221–225 (2021).
Yada, T. et al. Kev tshuaj xyuas ua ntej ntawm cov qauv Hyabusa2 rov qab los ntawm lub hnub qub C-hom Ryugu. National Astron. 6, 214–220 (2021).