THE FORMATION OF CYANOPOLYYNE MOLECULES IN IRC+10216

被引：107

作者：

CHERCHNEFF, I ^{[1
]}

GLASSGOLD, AE ^{[1
]}

MAMON, GA ^{[1
]}

机构：

[1] OBSERV MEUDON,DAEC,F-92195 MEUDON,FRANCE

来源：

ASTROPHYSICAL JOURNAL | 1993年 / 410卷 / 01期

关键词：

CIRCUMSTELLAR MATTER; ISM; MOLECULES; MOLECULAR PROCESSES; STARS; CARBON; INDIVIDUAL; (IRC+10216);

D O I：

10.1086/172737

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Molecule formation in the outer envelope of the carbon-rich star IRC + 10216 is investigated, with special emphasis on the chemistry of the cyanopolyynes HC(i)N (i = 3, 5, 7). Basic elements of the photochemical model of Glassgold, Lucas, & Omont are revised. A dust model suitable to IRC + 10216 is used, for which the extinction properties in the far-UV are those of 500 angstrom amorphous carbon particles. A new chemical route to the formation of large cyanopolyynes is proposed, based on reactions of the radicals C3N and C5N with acetylene, and shown to be efficient. Our results agree qualitatively with observations of the spatial distributions of HCN, CN, HC3N, and C3N, but the calculated column densities of the higher-order cyanopolyynes appear to be too small. The amount of the allenic radical HC2N produced by molecular ion reactions with atomic N agrees with recent observations.

引用

页码：188 / 201

页数：14

共 73 条

[1] THE DISSOCIATIVE RECOMBINATION RATE COEFFICIENTS OF H-3+, HN2+, AND HCO+ [J].