CaltechAUTHORS
Published April 2004 | Version Published
Journal Article Open

Combined BIMA and OVRO Observations of Comet C/1999 S4 (LINEAR)

Creators

  • 1. ROR icon University of California, Berkeley
  • 2. ROR icon University of Arizona
  • 3. ROR icon Leiden University
  • 4. ROR icon University of Illinois Urbana-Champaign
  • 5. ROR icon Lowell Observatory
  • 6. ROR icon University of Maryland, College Park
  • 7. ROR icon University of Chicago
  • 8. ROR icon National Taiwan Normal University
  • 9. ROR icon Institute of Astronomy and Astrophysics, Academia Sinica
  • 10. ROR icon California Institute of Technology
  • 11. ROR icon Harvard-Smithsonian Center for Astrophysics

Abstract

We present results from an observing campaign of the molecular content of the coma of comet C/1999 S4 (LINEAR) carried out jointly with the millimeter arrays of the Berkeley-Illinois-Maryland Association (BIMA) and the Owens Valley Radio Observatory (OVRO). Using the BIMA array in autocorrelation ("single-dish") mode, we detected weak HCN J = 1–0 emission from comet C/1999 S4 (LINEAR) at 14 ± 4 mK km s^(-1) averaged over the 143" beam. The 3 days over which emission was detected, 2000 July 21.9–24.2, immediately precede the reported full breakup of the nucleus of this comet. During this same period, we find an upper limit for HCN J = 1–0 of 144 mJy beam^(-1) km s^(-1) (203 mK km s^(-1)) in the 9" × 12" synthesized beam of combined observations of BIMA and OVRO in cross-correlation ("imaging") mode. Together with reported values of HCN J = 1–0 emission in the 28" IRAM 30 m beam, our data probe the spatial distribution of the HCN emission from radii of 1300 to 19,000 km. Using literature results of HCN excitation in cometary comae, we find that the relative line fluxes in the 12" × 9", 28", and 143" beams are consistent with expectations for a nuclear source of HCN and expansion of the volatile gases and evaporating icy grains following a Haser model.

Additional Information

© 2004 American Astronomical Society. Received 2001 October 10; accepted 2004 January 2. We are indebted to the staffs of the Owens Valley and Hat Creek Radio Observatories for providing excellent support during the observations. Wilson Hoffman and Steve Scott are especially thanked for creating and maintaining the software required to track fast-moving targets such as this comet. The research of M. R. H. in Berkeley was supported by the Miller Institute for Basic Research in Science. This work was partially funded by NASA NAG 5-4292, NAG 5-4080, NAG 5-8708, and NGT 5-0083, NSF AST 96-13998, AST 96-13999, AST 96-13716, AST 96-15608, and AST 99-81363, Taiwanese grants NSC 86-2112-M-003-T and 89-2112-M-003-004, and the Universities of Illinois, Maryland, and California, Berkeley. We greatly thank the referee, D. Bockelée-Morvan, for providing constructive criticism of our paper and pointing out ways in which to significantly improve our analysis.

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Additional details

Identifiers

Eprint ID
34191
Resolver ID
CaltechAUTHORS:20120918-154219610

Funding

NASA
NAG 5-4292
NASA
NAG 5-4080
NASA
NAG 5-8708
NASA
NAG 5-0083
NSF
AST 96-13998
NSF
AST 96-13999
NSF
AST 96-13716
NSF
AST 96-15608
NSF
AST 99-81363
National Science Council (Taipei)
86-2112-M-003-T
National Science Council (Taipei)
89-2112-M-003-004
University of Illinois
University of Maryland
University of California, Berkeley

Dates

Created
2012-09-19
Created from EPrint's datestamp field
Updated
2021-11-09
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Division of Geological and Planetary Sciences (GPS)