Astrochemistry

Publication Abstract

A BIMA Array Search for Biomolecules in Comet Hale-Bopp(C/1995 O1)

Remijan, A., Snyder, L. E., Friedel, D. N., Veal, J. M., Palmer, Patrick, Woodney, L. M., A'Hearn, Michael F., Forster, J. R., Wright, M. C. H., and de Pater, I.

The relevance of the chemistry of hot molecular cores (HMCs) to that of the solar nebula has been strengthened as evidence emerges for a hot core phase in low mass star formation regions. Consequently, interferometric studies of large highly saturated molecules of biological interest (biomolecules) in HMCs have been extended to comets. A key goal was the interferometric detection and mapping of large biomolecules, which could be formed along chemical pathways similar to those for HMC species. In this poster, we discuss single-field images, cross-correlation spectra and production rates of CO, HNC, HC3N, OCS, H2CO, and CH3OH obtained from Comet Hale-Bopp (C/1995 O1) with the BIMA Array. For CO we find a total beam averaged column density of 4.7x1016 cm-2 and a CO production rate of 4.3x1030 s-1. Using an H2O production rate range of (5-10)x1030 s-1, we find a relative CO/H2O production rate ratio range of 43-86%. For HNC, we find a total beam averaged column density of 2.3x1013 cm-2 and a HNC production rate of 3.0x1027 s-1. This gives a relative HNC/H2O production rate ratio range of 0.03-0.06%. For HC3N, we find a total beam averaged column density of 6.7x1012 cm-2 and an HC3N production rate of 1.1x1027 s-1. This gives a relative HC3N/H2O production rate ratio range of (0.01-0.02)%. For OCS, we find a total beam averaged column density of 9.2x1015 cm-2 and a OCS production rate of 1.9x1028 s-1. This gives a relative OCS/H2O production rate ratio range of 0.2-0.4%. For H2CO, we find a total column density of 1.4x1014 cm-2 and an H2CO production rate of 3.8x1028 s-1. This gives a relative H2CO/H2O production rate ratio range of (0.4-0.8)%. Finally, for CH3OH, we find an total beam averaged column density of 2.7x1015 cm-2 and a CH3OH production rate of 3.2x1029 s-1. For CH3OH, we find a production rate range relative to H2O of 3.2-6.4%. Upper limits were found for SO, SO2, DCN, DNC, HCO+, C2H, C3N, C4H, HCONH2, HCOOH, CH3C2H, CH3COOH, HCOOCH3, CH3CH2CN, CH3CH2OH, and (CH3)2O.

This work was partially funded by: NASA NAG5-4292, NAG5-4080, NAG5-8708, and NGT5-0083; NSF AST96-13998, AST96-13999, AST96-13716, AST96-15608, and AST99-81363; and the Universities of Illinois, Maryland, and California, Berkeley.

Presented at the 36th Meeting of the Division of Planetary Sciences, American Asronomical Society, Nov. 2004



Any comments or questions, contact me: friedel@astro.illinois.edu
© 2015, D. N. Friedel