P31A-1877: FUV spectroscopy of the comet C/2001 Q4 (NEAT) with FIMS
Authors: Yeo-Myeong Lim1, Kyoung W Min1, Wonyong Han2, Jerry Edelstein3
Author Institutions: 1. physics, Korea Advanced Inst Sci & Tech, Daejeon, Republic of Korea; 2. Korea Astronomy and Space Science Institute, Daejeon, Republic of Korea; 3. University of California, Berkeley, San Francisco, CA, USA
We present the results of far-ultraviolet (FUV) observations of comet C/2001 Q4 (NEAT) obtained with Far-ultraviolet Imaging Spectrograph (FIMS) on board the Korean microsatellite STSAT-1, which operated at an altitude of 700 km in a sun-synchronous orbit. FIMS is a dual channel imaging spectrograph (S-channel 900-1150 Å , L-channel 1350-1750 Å, Î»/Î”Î» ~ 550) with large image fields of view (S: 4 °.0_4′.6, L: 7 °.5_4′.3, angular resolution 5′-10′) optimized for the observation of diffuse emission of astrophysical radiation. Comet C/2001 Q4 (NEAT) was observed with a scanning survey mode when it was located around the perihelion between 8 and 15 May 2004. Several important emission lines were detected including S I (1425, 1474 Å), C I (1561, 1657 Å) and several emission lines of CO A1Î -X1Î£+ system in the L-channel. Production rates of the notable molecules, such as C I, S I and CO, were estimated from the photon fluxes of these spectral lines and compared with previous observations. We compare the flux and the production rates in the radius of 3_105 km with 2_106 km from the central coma. We obtained L-channel image which have map size 5 °_5 °. The image was constructed for the wavelength band of L-channel (1350 – 1710 Å). We also present radial profiles of S I, C I, CO obtained from the spectral images of the central coma. The radial profiles of 2_106 km region are compared with the Haser model.