parameters
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by VITREO
g r i z
17.45 15.32 14.19 13.59 13.07
err_u err_g err_r err_i err_z
0.03 0.00 0.00 0.00 0.00
run rerun camcol field obj rowc colc
6212 301 4 36 1739 1055.8 1275.0
fiberMag_r petroMag_r devMag_r expMag_r psfMag_r modelMag_r
17.04 14.32 14.19 14.52 17.23 14.19
extinction_r petroRad_r parentId nChild
0.87 16.793 1237672155083441863 0where I find the explanation of these parameters?
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by Budgieye moderator
Colour explanation is in
3.9 Spectra Guide : Physics and biology of colour
https://talk.galaxyzoo.org/#/boards/BGZ0000001/discussions/DGZ0000ulp?page=3
Posted
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by Budgieye moderator
Glossary of terms in SDSS http://cas.sdss.org/dr7/en/help/docs/glossary.asp?search=run&submit1=Search
run rerun camcol field are images numbers.
Field is useful because it can give us the date the image was taken
to find the time and date an image was taken easily the SDSS help desk have told me that it is available as follows:
Go the 'Sky Server Object Explorer' for the image in question Under 'PhotoObj' click the field link In the table that will appear there are the following: mjd_u 5.20762784E4 mjd_g 5.20762801E4 mjd_r 5.20762767E4 mjd_i 5.20762776E4 mjd_z 5.20762792E4
These are the modified Julian Date+time that the images in each filter - note they are a little odd in being in scientific notation.
Just enter these values into your favourite MJD to real time conversion programme ( having removed the exponent if the programme does not understand it) and you should get the answer.
Here is a modified Julian date converter http://pdc.ro.nu/mjd.cgi
SDSS http://cas.sdss.org/dr7/en/help/docs/glossary.asp?key=field
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by Budgieye moderator
SDSS questions
http://cas.sdss.org/dr7/en/help/docs/cas_faq.asp#images
Posted
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by Budgieye moderator
Extinction is a measure of the amount of gas in between us and the galaxy. http://skyserver.sdss.org/dr7/en/help/docs/algorithm.asp?search=extinction&submit1=Search
petroRad is a measure of how the size of the galaxy affects its magntiude petroRad http://skyserver.sdss.org/dr7/en/help/docs/algorithm.asp?search=petrorad&submit1=Search
Child is a software estimate of whether two objects are separate or joined.
Posted