- ...Institute
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http://cas.sdss.org/edr/en
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- ...Fermilab
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http://www.sdss.org
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- ...(NAOJ)
- http://sdss.nao.ac.jp
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- ...Astrophysics
- http://www.sdss.mpg.de
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- ...web
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http://www.astro.princeton.edu/PBOOK/welcome.htm
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- ...interface
- http://archive.stsci.edu/index.html
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- ...web
- http://astro.princeton.edu/PBOOK/welcome.htm
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- ...systems
- In fact,
strictly
speaking, there is not one 2.5-meter system, but six, because
the detectors and filters in each CCD column are slightly different.
These differences are appreciable only in the z band, which is cut off
on the long-wavelength side by the detector response. While these
differences must be accounted for in detail for some work, for most
purposes the average response curves are
sufficient.
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- ...calibration
- Note that we only implemented the smear exposures
half-way through commissioning. Table 4 indicates
for each plate whether a smear exposure was actually taken.
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- ...chip
- The situation has improved since these data were
taken, as the telescope is now better collimated.
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- ...objects
- In order to keep up with the data processing, the
measure objects module of frames devotes only 20 milliseconds
per object on a 1 GHz Pentium III machine.
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- ...question
- Placeholders exist in the database for the errors on each of these
quantities, but they are not currently calculated.
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- ...changes
- Note
that these isophotal quantities are the only ones which require a
priori photometric calibrations before frames is run. They use
a preliminary calibration, which is only accurate to 0.05 mag or so.
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- ...photometry
- In future data releases,
we expect to improve on this technique by carrying out multiple smear
exposures of the fundamental SDSS standard stars.
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