Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.naic.edu/vscience/schedule/tpfiles/McCandlisstagA2233tp.ps Дата изменения: Tue Aug 15 22:45:14 2006 Дата индексирования: Sat Dec 22 23:50:20 2007 Кодировка: Поисковые слова: reflection nebula

Proposal Identification No.: A2233 Date Received: 2006­May­31 23:23:18
Technical Page
Proposal Type: Short
General Category: Astronomy
Sub­Category: Spectroscopy
Observation Category: Galactic
Total Time Requested: 3 Hours
Minimum Useful Time: 90 minutes
Proposal Title: Neutral Hydrogen Mapping of the Planetary Nebula M27
ABSTRACT:
We propose to acquire a spatial­velocity data cube of the neutral hydrogen distribution in direction of the the
planetary nebula M27 with 18 в 18 point spatial grid covering (0.5 # ) 2 and a velocity resolution of 1 km/s. HI 21
cm observations by the Dwingeloo survey and Lyman series absorption line data from FUSE indicate column
densities of # 3 в 10 19 cm -2 are associated with nebular outflow in the velocity interval # 30 -- 70 km/s with
respect to the central star. Dwingeloo data can be fit with a nine velocity component model, four components of
which can be directly associated with the nebular absorption seen with FUSE. Unfortunately the specifics
regarding the nebular velocity distribution is rendered uncertain because of the sparse sampling and large beam
size of the Dwingeloo survey. Here we seek to confirm or deny the apparent detection of M27 and the velocity
structures implied by the Dwingeloo data. If confirmed this will be the first detection of a PN in the HI 21 cm line.
The dense pack of the data cube will yield unprecedented spatial and spectral resolution of the neutral hydrogen
remaining in the remnant ejected by the PN progenitor, and provide information on the degree to which this ejecta
is clumped. This will further allow for the determination of the neutral hydrogen abundance along with its filling
factor, and provide critical constraint to the chemical and kinematic evolution of this object.
Name Institution E­mail Phone Student
Stephan R. McCandliss The Johns Hopkins
University
stephan@pha.jhu.edu 410.516.5272 no
Remote Observing Request
Observer will travel to AO
Remote Observing
X In Absentia (instructions to oper­
ator)
Instrument Setup
ALFA
1

Atmospheric Observation Instruments:
Special Equipment or setup: none
RFI Considerations
Frequency Ranges Planned
1418 ­ 1422
2