Detection of the linear radical HC4N in IRC+10216

被引:46
作者
Cernicharo, J
Guelin, M
Pardo, JR
机构
[1] CSIC, Inst Estructura Mat, Dept Mol & Infrared Astrophys, Madrid 28006, Spain
[2] Inst Radioastron Millimetr, F-38406 St Martin Dheres, France
关键词
astrochemistry; ISM : molecules; line : identification; stars : AGB and post-AGB; stars : individual (IRC+10216);
D O I
10.1086/426439
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We report the detection of the linear radical HC4 N in the C- rich envelope of IRC + 10216. After HCCN, HC4N is the second member of the allenic chain family HC2nN observed in space. The column density of HC4N is found to be 1.5 x 10(12) cm(-2). The abundance ratio HC2N/HC4N is 9, a factor of 2 larger than the decrement observed for the cyanopolyynes (HC2n+1 N/HC2n+3N). Linear HC4N has a (3)Sigma electronic ground state and is one of the three low- energy isomeric forms of this molecule. We have searched for the bent and ringed HC4N isomers but could only derive an upper limit to their column densities: less than or equal to 3 x 10(12) cm(-2) (at 3 sigma).
引用
收藏
页码:L145 / L148
页数:4
相关论文
共 26 条
[1]   MOST STABLE ISOMER AND SINGLET-TRIPLET ENERGY SEPARATION IN THE HC4N MOLECULE [J].
AOKI, K ;
IKUTA, S ;
MURAKAMI, A .
CHEMICAL PHYSICS LETTERS, 1993, 209 (03) :211-215
[2]   IS A TRIPLET HC4N MOLECULE LINEAR [J].
AOKI, K ;
IKUTA, S .
JOURNAL OF CHEMICAL PHYSICS, 1993, 98 (09) :7661-7662
[3]   A λ2 mm molecular line survey of the C-star envelope IRC+10216 [J].
Cernicharo, J ;
Guélin, M ;
Kahane, C .
ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES, 2000, 142 (02) :181-215
[4]   Methylpolyynes and small hydrocarbons in CRL 618 [J].
Cernicharo, J ;
Heras, AM ;
Pardo, JR ;
Tielens, AGGM ;
Guélin, M ;
Dartois, E ;
Neri, R ;
Waters, LBFM .
ASTROPHYSICAL JOURNAL, 2001, 546 (02) :L127-L130
[5]   Infrared Space Observatory's discovery of C4H2, C6H2, and benzene in CRL 618 [J].
Cernicharo, J ;
Heras, AM ;
Tielens, AGGM ;
Pardo, JR ;
Herpin, F ;
Guélin, M ;
Waters, LBFM .
ASTROPHYSICAL JOURNAL, 2001, 546 (02) :L123-L126
[6]  
CERNICHARO J, 1987, ASTRON ASTROPHYS, V181, pL1
[7]  
Cernicharo J, 1996, ASTRON ASTROPHYS, V309, pL27
[8]  
CERNICHARO J, 1985, ATM PROGRAM COMPUTE
[9]   THE FORMATION OF CYANOPOLYYNE MOLECULES IN IRC+10216 [J].
CHERCHNEFF, I ;
GLASSGOLD, AE ;
MAMON, GA .
ASTROPHYSICAL JOURNAL, 1993, 410 (01) :188-201
[10]  
Cioni MRL, 2000, ASTRON ASTROPHYS, V358, pL9