{"paper":{"title":"A large 12C/13C isotopic ratio in M82 and NGC253","arxiv_id":"1006.5409","primary_cat":"astro-ph.CO","submitted_at":"2010-06-28T17:09:40+00:00","version_compiled":"v1"},"notice":"Every quoted sentence is the authors' text from the arXiv listing abstract. Labels and probabilities are the outputs of classifier-1.13-20260917 on the question bank abstract-p1-20260923, exactly as returned. No sentence in this record was written by a language model.","schema":"pith.compiled-record/v0","status":"compiled","abstract":{"source":"arXiv listing abstract v1","sentences":[{"i":0,"p":0.76,"id":"s0","own":true,"role":"contribution","text":"To derive carbon isotopic ratios from optically thin tracers in the central regions of the starburst galaxies M82 and NGC253.","hedge":{"p":0.84,"label":"unclear"},"own_p":0.69,"main_claim_p":0.03,"quantitative":false,"quantitative_p":0.04,"role_probabilities":{"gap":0.01,"method":0.08,"result":0.0,"background":0.15,"limitation":0.0,"future_work":0.0,"contribution":0.76,"interpretation":0.0}},{"i":1,"p":0.77,"id":"s1","own":true,"role":"method","text":"We present high sensitivity observations of CCH and two of its 13C isotopologues, C13CH and 13CCH, as well as the optically thin emission from C18O and 13C18O.","hedge":{"p":1.0,"label":"asserted"},"own_p":0.96,"main_claim_p":0.02,"quantitative":true,"quantitative_p":0.59,"role_probabilities":{"gap":0.0,"method":0.77,"result":0.0,"background":0.0,"limitation":0.0,"future_work":0.0,"contribution":0.23,"interpretation":0.0}},{"i":2,"p":0.99,"id":"s2","own":false,"role":"method","text":"We assume the column density ratio between isotopologues is representative of the 12C13C isotopic ratio.","hedge":{"p":0.84,"label":"asserted"},"own_p":0.32,"main_claim_p":0.04,"quantitative":false,"quantitative_p":0.05,"role_probabilities":{"gap":0.0,"method":0.99,"result":0.0,"background":0.0,"limitation":0.01,"future_work":0.0,"contribution":0.0,"interpretation":0.0}},{"i":3,"p":1.0,"id":"s3","own":true,"role":"result","text":"From CCH, lower limits to the 12C/13C isotopic ratio of 138 in M82, and 81 in NGC253, are derived.","hedge":{"p":1.0,"label":"asserted"},"own_p":0.96,"main_claim_p":0.45,"quantitative":true,"quantitative_p":0.99,"role_probabilities":{"gap":0.0,"method":0.0,"result":1.0,"background":0.0,"limitation":0.0,"future_work":0.0,"contribution":0.0,"interpretation":0.0}},{"i":4,"p":1.0,"id":"s4","own":true,"role":"result","text":"Lower limits to the 12C/13C ratios from CO isotopologues support these. 13C18O is tentatively detected in NGC253, which is the first reported detection in the extragalactic ISM.","hedge":{"p":0.74,"label":"asserted"},"own_p":0.94,"main_claim_p":0.09,"quantitative":false,"quantitative_p":0.21,"role_probabilities":{"gap":0.0,"method":0.0,"result":1.0,"background":0.0,"limitation":0.0,"future_work":0.0,"contribution":0.0,"interpretation":0.0}},{"i":5,"p":0.98,"id":"s5","own":true,"role":"result","text":"Based on these limits, we infer ratios of 16O/18O>350 and >300 in M82 and NGC253, respectively, and 32S/34S>16 in NGC253. and the H2 column density determination through the optically thin tracers 13CO and C18O.","hedge":{"p":0.86,"label":"asserted"},"own_p":0.91,"main_claim_p":0.11,"quantitative":true,"quantitative_p":0.99,"role_probabilities":{"gap":0.0,"method":0.0,"result":0.98,"background":0.0,"limitation":0.0,"future_work":0.0,"contribution":0.0,"interpretation":0.02}},{"i":6,"p":0.93,"id":"s6","own":true,"role":"result","text":"The derived CCH fractional abundances toward these galaxies of <~1.1\\times10^-8 are in good agreement with those of molecular clouds in the Galactic disk.","hedge":{"p":0.91,"label":"asserted"},"own_p":0.94,"main_claim_p":0.04,"quantitative":true,"quantitative_p":0.98,"role_probabilities":{"gap":0.0,"method":0.0,"result":0.93,"background":0.0,"limitation":0.0,"future_work":0.0,"contribution":0.0,"interpretation":0.07}},{"i":7,"p":0.93,"id":"s7","own":true,"role":"result","text":"Our lower limits to the 12C/13C ratio from CCH are a factor of 2-3 larger than previous limits.","hedge":{"p":1.0,"label":"asserted"},"own_p":0.89,"main_claim_p":0.11,"quantitative":true,"quantitative_p":0.99,"role_probabilities":{"gap":0.0,"method":0.0,"result":0.93,"background":0.0,"limitation":0.0,"future_work":0.0,"contribution":0.04,"interpretation":0.03}},{"i":8,"p":0.9,"id":"s8","own":false,"role":"interpretation","text":"The results are discussed in the context of molecular and nucleo-chemical evolution.","hedge":{"p":0.72,"label":"unclear"},"own_p":0.31,"main_claim_p":0.04,"quantitative":false,"quantitative_p":0.03,"role_probabilities":{"gap":0.0,"method":0.01,"result":0.0,"background":0.01,"limitation":0.0,"future_work":0.02,"contribution":0.06,"interpretation":0.9}},{"i":9,"p":1.0,"id":"s9","own":true,"role":"interpretation","text":"The large 12C/13C isotopic ratio of the molecular ISM in these starburst galaxies suggest that the gas has been recently accreted toward their nuclear 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