彗星中异常的氮同位素比率。

Anomalous nitrogen isotope ratio in comets.

作者信息

Arpigny Claude, Jehin Emmanuël, Manfroid Jean, Hutsemékers Damien, Schulz Rita, Stüwe J A, Zucconi Jean-Marc, Ilyin Ilya

机构信息

Institut d'Astrophysique et de Géophysique, Sart-Tilman, Bâtiment B5c, B-4000 Liège, Belgium.

出版信息

Science. 2003 Sep 12;301(5639):1522-4. doi: 10.1126/science.1086711.

DOI:10.1126/science.1086711

PMID:12970562

Abstract

High-resolution spectra of the CN B2 summation operator +-X2 summation operator + (0,0) band at 390 nanometers yield isotopic ratios for comets C/1995 O1 (Hale-Bopp) and C/2000 WM1 (LINEAR) as follows: 165 +/- 40 and 115 +/- 20 for 12C/13C, 140 +/- 35 and 140 +/- 30 for 14N/15N. Our N isotopic measurements are lower than the terrestrial 14N/15N = 272 and the ratio for Hale-Bopp from measurements of HCN, the presumed parent species of CN. This isotopic anomaly suggests the existence of other parent(s) of CN, with an even lower N isotopic ratio. Organic compounds like those found in interplanetary dust particles are good candidates.

摘要

在390纳米处的CN B2 Σ +-X2 Σ + (0,0)带的高分辨率光谱得出了彗星C/1995 O1（海尔-波普彗星）和C/2000 WM1（LINEAR彗星）的同位素比值如下：12C/13C为165±40和115±20，14N/15N为140±35和140±30。我们对N同位素的测量值低于地球的14N/15N = 272以及从假定的CN母体物种HCN的测量中得到的海尔-波普彗星的比值。这种同位素异常表明存在其他CN母体，其N同位素比值更低。像在星际尘埃颗粒中发现的那些有机化合物是很好的候选对象。