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THE UMASS GALAXY POSTAGE STAMP IMAGE ARCHIVE  (DRAFT FOR REVIEW)

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The UMASS galaxy postage stamp image archive contains 2,577,162 gzip compressed six plane fits images stored on 3-750 GB Reiser file system SATA hard disks. Galaxy postage stamp images are stored in the same directories as the scan-sized fits images.

Galaxy postage stamp image files are distributed on the hard disks in order of date of original observation.

• ia_1  Dates before February 17, 1998
• ia_2  Dates from February 17, 1998 through December 14, 1999
• ia_3  Dates from December 15, 1999 to end of the survey on February 15, 2001

Image files on these disks may be accessed by clicking on the links above. As the disks may be in the idle state and the directories are large it may take some time for the disk directory to appear.

The complete path from the top directory of an archive disk and the file name for postage stamp images in the archive is as follows:

/DDDDDDH/sSSS/gDDDDDDHSSSFCCCiIIIIII.fits.gz

/981029s/s028/g981029s0280221i003157.fits.gz

The fields in the above path/filename are Date, Hemis, Scan, F_type, Coadd, and Id. The first letter of the file name is 'g' to indicate that the file is a galaxy postage stamp. The file name for postage stamps is slightly different from that of image archive files because it was necessary to add the id field to make the file names unique.

A postgres loadable table gal_pstamps is available for searches on the galaxy postage stamp archive. An explanation of the gal_pstamps fields is given in format_gal_pstamps.html.  All of the postage stamp images have f_type='0', i.e. they have not been modified to to make them more compressible by removing low-order bit noise. All are gzip compressed. The gal_pstamps table entry for the postage stamp used for illustration on this page is:

date    | hemis | scan | scan_key | cat_scn | qual | coadd |  id  | naxis2 |             f_name             | f_size | f_type | disk |     ra      |     decl     | xsc_prox | ext_key | jskyval | jskysig  | hskyval | hskysig  | kskyval | kskysig  | jseesh | hseesh | kseesh | jmagzp  | hmagzp  | kmagzp ------------+-------+------+----------+---------+------+-------+------+--------+--------------------------------+--------+--------+------+-------------+--------------+----------+---------+---------+----------+---------+----------+---------+----------+--------+--------+--------+---------+---------+---------  1998-10-29 | s     |   28 |     7931 | y       |    9 |   221 | 3157 |     39 | g981029s0280221i003157.fits.gz |  17717 | 0      | ia_1 | 74.10629272 | -64.96828461 |    0.001 |  297801 | 67.9967 | 0.504965 | 280.043 | 0.788282 | 478.773 | 0.978596 |  1.002 |  0.988 |  1.013 | 20.7808 | 20.3702 | 19.8559

The size of this archive is as follows:

• All images in the postage stamp archive:                         69.2 GB
• All images with cat_scn='y'                                                 58.1 GB                                    

The gal_pstamps table can be downloaded from the following links to compressed comma delimited ascii files with null as \N:

• Postgres table including schema (220 MB).
• The schema only.
• The table data only (190 MB).

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 Requests for copies of image archive hard disks should be directed to Rae Stiening at the University of Massachusetts.  Last updated May 23, 2008