Cyanide chemistry in comet Hale-Bopp (C/1995 O1)

Lucy M Ziurys, C. Savage, M. A. Brewster, A. J. Apponi, T. C. Pesch, S. Wyckoff

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Abstract

Observations of comet Hale-Bopp (C/1995 O1) have been carried out near perihelion (1997 March) at millimeter wavelengths using the NRAO 12 m telescope. The J = 1 → 0, 2 → 1, and 3 → 2 lines of HCN at 88, 177, and 265 GHz were measured in the comet as well as the J = 3 → 2 lines of H13CN, HC15N, and HNC. The N = 2 → 1 transition of CN near 226 GHz was also detected, and an upper limit was obtained for the J = 2 → 1 line of HCNH+. From the measurements, column densities and production rates have been estimated. A column density ratio of [HCN]/[HNC] = 7 ± 1 was observed near perihelion, while it was found that [HCN]/[HCNH+] ≳ 1. The production rates at perihelion for HCN and CN were estimated to be Q(HCN) ∼ 1 × 1028 s-1 and Q(CN) ∼ 2.6 × 1027 s-1, respectively, resulting in a ratio of [HCN]/[CN] ≃ 3. Consequently, HCN is sufficiently abundant to be the parent molecule of CN in Hale-Bopp, and HCNH+ could be a source of HNC. Finally, carbon and nitrogen isotope ratios of 12C/13C = 109 ± 22 and 14N/15N = 330 ± 98 were obtained from HCN measurements, in agreement with previous values obtained from J = 4 → 3 data. Such ratios suggest that comet Hale-Bopp formed coevally with the solar system.

Original languageEnglish (US)
JournalAstrophysical Journal
Volume527
Issue number1 PART 2
StatePublished - Dec 10 1999

Fingerprint

Hale-Bopp comet
Hale-Bopp
cyanides
cyanide
comet
nitrogen isotopes
chemistry
carbon isotopes
isotope ratios
comets
solar system
isotopes
nitrogen isotope
telescopes
carbon isotope
wavelengths
wavelength
molecules
rate

Keywords

  • Comets: individual (Hale-Bopp 1995 O1)
  • Molecular processes
  • Radio lines: solar system

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Ziurys, L. M., Savage, C., Brewster, M. A., Apponi, A. J., Pesch, T. C., & Wyckoff, S. (1999). Cyanide chemistry in comet Hale-Bopp (C/1995 O1). Astrophysical Journal, 527(1 PART 2).

Cyanide chemistry in comet Hale-Bopp (C/1995 O1). / Ziurys, Lucy M; Savage, C.; Brewster, M. A.; Apponi, A. J.; Pesch, T. C.; Wyckoff, S.

In: Astrophysical Journal, Vol. 527, No. 1 PART 2, 10.12.1999.

Research output: Contribution to journalArticle

Ziurys, LM, Savage, C, Brewster, MA, Apponi, AJ, Pesch, TC & Wyckoff, S 1999, 'Cyanide chemistry in comet Hale-Bopp (C/1995 O1)', Astrophysical Journal, vol. 527, no. 1 PART 2.
Ziurys LM, Savage C, Brewster MA, Apponi AJ, Pesch TC, Wyckoff S. Cyanide chemistry in comet Hale-Bopp (C/1995 O1). Astrophysical Journal. 1999 Dec 10;527(1 PART 2).
Ziurys, Lucy M ; Savage, C. ; Brewster, M. A. ; Apponi, A. J. ; Pesch, T. C. ; Wyckoff, S. / Cyanide chemistry in comet Hale-Bopp (C/1995 O1). In: Astrophysical Journal. 1999 ; Vol. 527, No. 1 PART 2.
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