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IRTF Near-IR Spectra of Comet 9P/Tempel 1 |
Status: Archived
This data set contains raw near-IR spectra of comet 9P/Tempel 1 obtained with SpeX, the low- to medium-resolution spectrograph and imager, at the NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii, during the period from 24 June through 08 July 2005 UT. The observations were taken as part of a campaign designed to support the science objectives of the Deep Impact spacecraft around the time of its encounter with Tempel 1. Included are flat fields, Argon lamp frames, and standard star frames for the reduction and photometric calibration of the comet observations.
The data products include:
The entire data set is over 9 GB in size. The data have been divided into separate files by observation date and mode (nodded pairs or "movie sequences") to make them marginally easier to download:
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In case you're wondering...
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An overview of the volume contents is provided in the aareadme.txt file.
Catalog files contain the overview information and parameters used in loading the PDS central catalog, specifically, or for developing other interfaces to the data outside of PDS. The information they contain, particularly in their descriptive text fields, should be clear, complete, and understandable to a research user who is not necessarily a mission or instrument specialist.
These files are located in the catalog/ directory. The directory contents are described by the catinfo.txt file.
In addition to the small text files located throughout the volume to describe directory contents, some specific documents are provided to assist with understanding the data and processing involved. These files are located in the document/ directory. The directory contents are described by the docinfo.txt file.
In addition, in this directory you will also find ads.txt and its label, which contains information for the ADS Abstract Service database.
The data/ directory contains raw spectra of comet 9P/Tempel and calibration targets (flats, Argon lamp, and standard stars) grouped by sequential night. These data are presented as FITS files with detached PDS labels.
Included in the nightly subdirectories are A - B nodded pairs of 2-D FITS images (*a.fit and *b.fit):
Included in the three nightly "movie sequence" subdirectories are unnodded, A-beam, 3-D FITS images containing 16 low-resolution, time-sequenced comet frames (*movie.fit) acquired in "movie" mode:
For each "movie", there is an ASCII table which provides the observation time for each spectral frame included in the time sequence. Each 3-D FITS image and table has a detached PDS label. PDS does not have a standard for labeling FITS image files with more than 2 dimensions. Therefore, the PDS labels for these 3-D FITS files define only the first stacked image which causes PDS readers such as NASAView to display only the first frame. The entire 3-D FITS file can be properly viewed using a standard FITS reader such as SAOImage's DS9 or IDL's readfits program.
The index/ directory contains the required PDS index into the files in the data directory, as well as the checksum file.