Periodic variation in the water production of comet C/2001 Q4 (NEAT) observed with the Odin satellite
Artikel i vetenskaplig tidskrift, 2009

Context: Comet C/2001 Q4 (NEAT) was extensively studied with the 1.1-m submillimetre telescope of the Odin satellite. The H2O line at 557 GHz was regularly observed from 6 March to 16 May 2004 and nearly continuously monitored during 3 periods between 26 April and 2 May 2004. Aims: This last set of data shows periodic variations in the line intensity, and we looked for characterising the long- and short-term behaviour of this comet. Methods: We used the variance ratio method and χ2 minimization to find the period of variation in the water production rate and simulations to infer its amplitude at the nucleus surface. Results: A 40% periodic variation in the water production rate is measured with a period of 0.816±0.004 day (19.58±0.1 h). The comet also exhibits a seasonal effect with a mean peak of outgassing around 2.7×1029 molec. s-1 taking place about 18 days before perihelion.

astrochemistry

submillimetre

radio lines

comets

C/2001 Q4 (NEAT)

solar system

Författare

N. Biver

D. Bockelée-Morvan

P. Colom

J. Crovisier

A. Lecacheux

U. Frisk

Åke Hjalmarson

Chalmers, Institutionen för radio- och rymdvetenskap, Radioastronomi och astrofysik

Michael Olberg

Chalmers, Institutionen för radio- och rymdvetenskap, Nationella anläggningen för radioastronomi

Aa. Sandqvist

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 501 359-366

Ämneskategorier

Astronomi, astrofysik och kosmologi