A SARARIN SAMANIYA, ƘWAYAR DA BA TA KAI ƘARKO BA CE KE RINJAYE

Ƙwayoyi (molecules) da yawa da aka samu a sararin samaniya an gina su ne daga abubuwa (elements) huɗu kawai: hydrogen, carbon, nitrogen da oxygen — tubalan ginin ilimin sinadarai na halitta (organic) da na kafin rayuwa (prebiotic). Idan aka jera su yadda ya dace, za su iya samar da haɗin peptide (peptide bond), –C(=O)–N(–H)–, wanda ke haɗa amino acid zuwa sunadarai (proteins). Marubutan suna ganin rukunin isocyanate (isocyanate group), –N=C=O, a matsayin muhimmin ɓangarensa: sarƙar N–C–O iri ɗaya. Cikin ƙwayoyi fiye da 350 da aka gano a tsakanin taurari, biyar kawai ke ɗauke da shi, ciki har da isocyanic acid, HNCO.

Hanyoyi biyu na ƙara proton

Isocyanic acid zai iya ɗaukar ƙarin proton a wurare biyu. A kan nitrogen, ya zama H₂NCO⁺, tsari mafi ƙarko, wanda tuni aka gano a sararin samaniya. A kan oxygen, ya zama HNCOH⁺, isomer — atom iri ɗaya, tsari daban — wanda kuzarinsa ya fi sama, da kilocalories 18 a kowace mole — kuzarin da iskar gas mai zafin kusan kelvin 9,000 ke ɗauke da shi, wanda ya zarce kusan kelvin 100 na gajimaren nesa ba kusa ba.

Ka’ida da ɗakin gwaje-gwaje sun nuna cewa siga ta biyu bai kamata ta zama ba kasafai ba. Lissafe-lissafe na baya-bayan nan na martani (reaction) tsakanin ion H₃⁺ da HNCO, wanda ake tunanin yana ɗaya daga cikin manyan hanyoyin da waɗannan ion ke samuwa, sun gano cewa yana samar da HNCOH⁺ a kusan kashi 80% na lokuta. A wani gwajin ɗakin gwaje-gwaje, yawan HNCOH⁺ ya ninka na H₂NCO⁺. Kuma da zarar ya samu, HNCOH⁺ da ƙyar zai iya komawa tagwansa mai ƙarko: wani babban shingen kuzari (energy barrier) yana kan hanya. Duk da haka babu wanda ya taɓa ganinsa a sararin samaniya.

Gajimare da karo ke girgizawa

Marta Rey-Montejo, ta Centro de Astrobiología na Spain, da abokan aikinta a Spain, Jamus, Japan, Amurka da Chile sun duba wajen G+0.693-0.027, wani gajimaren ƙwayoyi (molecular cloud) kusa da tsakiyar Milky Way. Manyan raƙuman girgiza (shocks), wataƙila daga karo tsakanin gajimarai, suna fizge abubuwa daga rigunan ƙanƙara (icy mantles) da tsakiyar ƙwayoyin ƙura kuma su sake su cikin iskar gas. Wannan ya sa gajimaren ya zama ɗaya daga cikin wurare mafi albarka don gano sababbin ƙwayoyi.

Sun yi amfani da wani bincike mai zurfin gaske (ultra-deep survey) na gajimaren da na’urorin hangen nesa na rediyo uku — farantan Yebes mai mita 40, IRAM mai mita 30 da APEX — wanda ya rufe kusan GHz 150 na mitoci tsakanin GHz 31 da 275.

Layuka bakwai, ƙwaya ɗaya

Ƙwayar da ke juyawa a sararin samaniya tana fitar da haske a wani tsani na ainihin mitocin rediyo, kowacce daga cikinsu tana bayyana a matsayin ƙololuwa siririya — layi na bakan haske (spectral line). Matakai biyu mafi ƙasa na HNCOH⁺ ne kawai aka auna a ɗakin gwaje-gwaje, don haka ƙungiyar ta yi hasashen sauran (extrapolated). Matakai takwas sun faɗa cikin binciken; bakwai za a iya nazarta, na takwas yana ƙarƙashin wani layi daga sararin iskar Duniya (atmosphere).

Dukkansu sun dace. Daidaitawar (fit) tana ba da yawan ginshiƙi (column density) na ƙwayoyi 9.9 × 10¹² a kowane santimita murabba’i a kan layin gani, yawa na kusan 7.3 × 10⁻¹¹ idan aka kwatanta da hydrogen na ƙwaya (molecular hydrogen), da zafin kusan kelvin 24 ga juyawar ƙwayar. Yawancin waɗannan layukan ba a taɓa auna su a kowane ɗakin gwaje-gwaje ba; daga gare su, ƙungiyar ta samo ƙima ta farko ta yadda ƙwayar mai juyawa ke miƙewa, wadda ta yi daidai sosai da lissafin sinadarai na quantum (quantum-chemical calculations).

Layukan juyawa (rotational lines) bakwai na HNCOH⁺ a wajen G+0.693: bakan da aka gani (toka), daidaitawa ga HNCOH⁺ (ja), dukkan ƙwayoyin da aka sani (shuɗi). An nuna tsarin ƙwayar a ƙasa a dama. — Hoto na 1, Rey-Montejo et al. (2026), arXiv:2610.39654.

Tagwan da bai kai ƙarko ba ne ke rinjaye

Da sababbin bayanai, ƙungiyar ta kuma sake auna tagwan mai ƙarko, H₂NCO⁺: 2.6 × 10¹² a kowane santimita murabba’i. Wannan ya sa HNCOH⁺ ya fi shi yawa sau 3.8.

Idan siffofin biyu sun daidaita ne kawai bisa kuzarinsu, a zafin gajimaren na kusan kelvin 70 zuwa 140, HNCOH⁺ zai yi ƙaranci fiye da H₂NCO⁺ da fiye da matakan ninki goma (orders of magnitude) 20. Maimakon haka, yawansa yana nuna yadda ake samar da shi: martanin da ke samar da waɗannan ion yana fifita siffar da ba ta kai ƙarko ba. Marubutan sun lura cewa wasu iyalan isomer a sararin samaniya suna nuna tsari iri ɗaya, inda siffofi masu yawan kuzari suka yi yawa kamar takwarorinsu masu ƙarko. Ion ɗin biyu kuma sun bambanta a saurin juyawarsu: HNCOH⁺ yana bayyana da ɗumi fiye da H₂NCO⁺ (kusan kelvin 24 idan aka kwatanta da 9, alhali iskar gas ɗin kanta tana kusan kelvin 70 zuwa 140). Wani dalili mai yiwuwa, a cewar marubutan: HNCOH⁺ ba shi da polarity sosai (less polar), don haka ba ya saurin sakin kuzarin juyawarsa a matsayin raƙuman rediyo, kuma karo da iskar gas yana sa shi ci gaba da juyawa da sauri.

Ƙwayoyi shida, kuma ana ci gaba da ƙirga

HNCOH⁺ ita ce ƙwaya ta shida da aka samu a sararin samaniya da ke ɗauke da rukunin isocyanate. Marubutan sun yi kira da a yi wani bincike na musamman a ɗakin gwaje-gwaje don a zana cikakken bakan juyawarsa (rotational spectrum). Babban darasinsu ya shafi yadda ilimin sinadarai ke aiki a tsakanin taurari: a can, tsari mafi ƙarko na atom ba lallai ba ne ya zama mafi yawa — abin da ke da muhimmanci shi ne hanyar da aka haifi ƙwaya ta bi.