Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.naic.edu/vscience/schedule/tpfiles/HowelltagA2031tp.ps Дата изменения: Tue Aug 15 18:09:01 2006 Дата индексирования: Sat Dec 22 21:50:44 2007 Кодировка: Поисковые слова: comet tail

Proposal Identification No.: A2031 Date Received: 2004 ­Oct­04 15:24:54
Technical Page
Proposal Type: Regular
General Category: Astronomy
Sub­Category: Spectroscopy
Observation Category: Solar System
Total Time Requested: 50 Hours
Proposal Title: OH Observations of Comets in 2005: Including Deep Impact Mission Target
9P/Tempel 1
ABSTRACT:
As part of a continuing e#ort to observe the 18­cm OH lines in comets we propose to observe 9P/Tempel 1 and
C/2003 T4 LINEAR in spring 2005. These comets are moderately bright, and the predicted strength of the OH
lines are easily detectable. Comet 9P/Tempel 1 is the target of the Deep Impact Mission. Unfortunately, the object
will not be in the declination range observable from Arecibo at the time of impact. However, it will be observable
for about 3 months prior to that time, so that we can establish the baseline water production rate and monitor any
variability prior to the impact. This will be very important in order to put the later observations into the proper
context. The C/2003 T4 (LINEAR) predicted OH line strength are near the limit at which we can make spatial
maps of the coma. We want to determine if collionsional quenching of the OH line in the coma can be detected for
these low­productivity comets in order to understand discrepancies between the predictions and observations of the
water production (Lovell et al. 2004). Since water makes up the bulk of a comet's mass, the mass loss rate inferred
from the OH line flux strongly depends upon understanding the quenching mechanism and outflow kinematics.
Name Institution E­mail Phone Student
Ellen S. Howell ehowell@naic.edu 787 878­2612
x282
no
Service Observing Request Remot e Observing Request
X None X No
All of the observing run. Maybe
Part of the observing run. Yes
Queue Observing
Instrument Setup
L­wide ALFA
Atmospheric Observation Instruments:
1

Special Equipment or setup: ALFA with the OH filters (1600­1750 MHz) would improve the
scientific return for the Deep Impact Mission target, Comet 9P/Tempel1. However, if ALFA is
unavailable in OH mode, we can use L­wide.
RFI Considerations
Frequency Ranges Planned
1610
1665
1667
1720
2