NEW! Second Orion Data Release: /photo.astro.princeton.edu/oriondatarelease
For the first Orion Data Release, see: /photo.astro.princeton.edu/oriondatarelease_dr1
In this document:
The imaging reductions are done using the "photo" product and its many dependencies, which is C and TCL code. Independent of that, we have a number of 6154444450 for using the data. The latter is described below.
# set directory
setenv IDL_DIR /usr/peyton/common/licensed/idl
setenv IDL_DEVICE X
# clear path
setenv IDL_PATH
# set generic path
setenv IDL_PATH $IDL_PATH{:}+$IDL_DIR/lib
If you are not at Princeton, you will need to type "which idl" and
maybe follow a symlink to find out what IDL_DIR should be set to.
Several environment variables should be set to point to the raw and the reduced data. At Princeton, the following could be put in your .cshrc file:
setenv SPECTRO_DATA /u/dss/spectro setenv PHOTO_DATA /u/dss/data setenv PHOTO_REDUX /u/dss/redux
At Princeton, the perl scripts and IDL tools can be put in your path with the following:
setenv EUPS_FLAVOR `/bin/uname` source /u/dss/products/evilups/bin/setups.csh setup idlspec2d setup photoop
setenv CVS_RSH ssh
setenv CVSROOT :pserver:anonymous@sdsscvs.astro.princeton.edu:/usr/local/cvsroot
cvs login
(hit a carriage return when it asks for the "CVS password")
cvs export -d evilups-temp -r v0_4 evilups
setenv PROD_DIR_PREFIX $HOME/products
setenv PRODUCTS $PROD_DIR_PREFIX/ups_db
setenv EUPS_DIR $PROD_DIR_PREFIX/evilups
cd evilups-temp
make clean
make install
setenv EUPS_FLAVOR `/bin/uname`
source $EUPS_DIR/bin/setups.csh
Download, build, and install the products "idlutils", "idlspec2d", and "photoop"
using the scripts available from evilups:
evilinstall idlutils v4_10_4 setup idlutils evilinstall idlspec2d v4_10_1 evilinstall photoop v1_0You'll probably want the following in your .cshrc file to set up your paths:
setenv EUPS_FLAVOR `/bin/uname` source $HOME/products/evilups/bin/setups.csh setup idlspec2d setup photoopIf you will be accessing the reduced data remotely (as described below), then set
setenv PHOTO_REDUX $HOMEand copy the file runList.par into your home directory (or wherever $PHOTO_REDUX points).
All 8 Tb of raw data and 4 Tb of reduced data are spinning on disk at Princeton. The raw images can be found in the directories:
$PHOTO_DATA/[1-9]*/fields/[1-6]The reduced data can be found in the directories:
$PHOTO_REDUX/[1-9]*These data are fully mirrored at MIT, and partially mirrored at NYU.
In order to view the actual images (e.g., using ATVSDSS), you either need a copy of the raw images, or need to be logged into the Princeton machines. In order to access the reduced data, you either need to have a copy of the data (and use SDSS_REAODBJ) or have permission in the alfred account at Princeton (and use SDSS_READOBJ_REMOTE).
IDL> foo=sdss_findimage(180,1,/print)To plot the locations of all the imaging data using an equal-area projection:
IDL> plotrunsky, /equalarea
IDL> plotrunsky, rerun=137 IDL> platelist, plist=plist IDL> soplot,plist.ra,plist.dec,psym=4,color='red'The list of these run numbers and other parameters can be printed with:
IDL> struct_print, sdss_runlist(rerun=137)
These reductions replace rerun 131, which contains 7500 square degrees of data.
IDL> atvsdss,ra=180,dec=1Make the same plot using the Princeton reductions known as "rerun 137", and over-plotting the SDSS spectral classifictions, and objects from the 2MASS, FIRST and Tycho-2 catalogs:
IDL> atvsdss,ra=180,dec=1,rerun=137,/catalog,/spec
% sdss_readobj_remote --user alfred --run 752 --rerun 137 --col 6 \
--filename foo.fits --fieldrange "243" --extra="/catalog"
The above command can be run outside of Princeton,
as long as you have access to the alfred account, and a copy
of the following file on your local machine:
$PHOTO_REDUX/runList.parThe above file tells this script how to tunnel into the appropriate machine at Princeton that has the data locally.
IDL> objs=sdss_readobj(752,6,243,rerun=137,/catalog)If you wish to load 50 fields for this run, but trim it to only a few columns of interest (but including all of the various flux measurements):
IDL> objs=sdss_readobj(752,6,200+lindgen(50),rerun=137,/catalog, $
select_tags=['*FLUX*','RA','DEC','OBJC_TYPE','OBJC_FLAGS')
The commands can be run on machines outside of Princeton
by using "sdss_readobj_remote" rather than "sdss_readobj".
This does the same tunnelling trick as the perl script above.
IDL> list = sdss_findobj(24.600318,-1.0067119,rerun=137) IDL> objs = sdss_readobjlist(inlist=list)The above can be done with lists of more than 1 object.
IDL> doc_library,'plotrunsky'This is equivalent to 970-666-6386.
RUN LONG Run number
RERUN STRING Rerun name
CAMCOL LONG Camera column [1..6]
FIELD LONG Field number
ID LONG Object ID, starting at 1 and unique in each field
PARENT LONG ID of parent, -1 if this is a parent object
NCHILD LONG Number of children deblended from this object
MJD LONG Modified Julian Day for date of observation
TAI DOUBLE[5] Mean time of observation for the object center
in each filter, where TAI = 24 * 3600 * MJD
AIRMASS FLOAT[5] Airmass approximated as csc(zenith-angle)
PSP_STATUS LONG[5] "Status" field from the psField file
CALIB_STATUS INT[5] Status of photometric calibration
RESOLVE_STATUS LONG (see below)
OBJC_TYPE LONG Classification:
0=unknown (only used for some edge objects)
1=CR
2=defect (unused)
3=galaxy
4=ghost (unused)
5=known object (unused)
6=star
7=trail (unused)
8=sky
OBJC_PROB_PSF FLOAT Classification: -9999=unknown, 0=galaxy, 1=star
CATID LONG (Unused)
OBJC_FLAGS LONG See sdss.org/dr1/products/catalogs/flags.html
OBJC_FLAGS2 LONG
FLAGS LONG[5]
FLAGS2 LONG[5]
TYPE LONG[5] Same as OBJC_TYPE, but for each filter
TEXTURE FLOAT[5] (Unused.)
STAR_L FLOAT[5]
STAR_LNL FLOAT[5]
EXP_L FLOAT[5]
EXP_LNL FLOAT[5]
DEV_L FLOAT[5]
DEV_LNL FLOAT[5]
FRACPSF FLOAT[5]
PROB_PSF FLOAT[5]
NMGYPERCOUNT FLOAT[5] Calibration of nano-maggies per count
NMGYPERCOUNT_IVAR FLOAT[5] Formal error in the photometric calibration as
an inverse variance; =0 if there wer no calibration
stars and a default calibration was used instead
CLOUDCAM INT[5] Photometricity in each filter:
-1=unknown, 0=cloudy, 1=clear
EXTINCTION FLOAT[5] Galactic extinction in magnitudes, defined as
[5.155, 3.793, 2.751, 2.086, 1.479] * E(B-V)
where E(B-V) is from the SFD98 dust maps.
Fluxes (and their errors) can be corrected
for Galactic extinction as follows:
Corrected-Flux = Flux * 10^(Extinction/2.5)
PIXSCALE FLOAT[5] Pixel scale [arcsec/pix]
PSF_FWHM FLOAT[5] PSF FWHM [arcsec]
PHI_OFFSET FLOAT[5] Calibration angle [degrees] to subtract from any
uncalibrated position angles such that they mean
degrees east of north.
OBJC_ROWC FLOAT Canonical row center (0.5-indexed) in r-band,
even if not detected in that band
OBJC_ROWCERR FLOAT
OBJC_COLC FLOAT Canonical column center (0.5-indexed) in r-band,
even if not detected in that band
OBJC_COLCERR FLOAT
ROWV FLOAT -- velocities ???
ROWVERR FLOAT
COLV FLOAT -- velocities ???
COLVERR FLOAT
ROWC FLOAT[5] Row center (0.5-indexed) in each filter
ROWCERR FLOAT[5]
COLC FLOAT[5] Column center (0.5-indexed) in each filter
COLCERR FLOAT[5]
SKY FLOAT[5] Sky level [raw counts/pixel]
SKYERR FLOAT[5]
PSFCOUNTS FLOAT[5]
PSFCOUNTSERR FLOAT[5]
FIBERCOUNTS FLOAT[5]
FIBERCOUNTSERR FLOAT[5]
PETROCOUNTS FLOAT[5]
PETROCOUNTSERR FLOAT[5]
PETRORAD FLOAT[5] Petrosian radius [pix]
PETRORADERR FLOAT[5]
PETROR50 FLOAT[5] Radius with 50 percent of Petrosian light [pix]
PETROR50ERR FLOAT[5]
PETROR90 FLOAT[5] Radius with 50 percent of Petrosian light [pix]
PETROR90ERR FLOAT[5]
Q FLOAT[5]
QERR FLOAT[5]
U FLOAT[5]
UERR FLOAT[5]
M_E1 FLOAT[5]
M_E2 FLOAT[5]
M_E1E1ERR FLOAT[5]
M_E1E2ERR FLOAT[5]
M_E2E2ERR FLOAT[5]
M_RR_CC FLOAT[5]
M_RR_CCERR FLOAT[5]
M_CR4 FLOAT[5]
M_E1_PSF FLOAT[5]
M_E2_PSF FLOAT[5]
M_RR_CC_PSF FLOAT[5]
M_CR4_PSF FLOAT[5]
ISO_ROWC FLOAT[5]
ISO_ROWCERR FLOAT[5]
ISO_ROWCGRAD FLOAT[5]
ISO_COLC FLOAT[5]
ISO_COLCERR FLOAT[5]
ISO_COLCGRAD FLOAT[5]
ISO_A FLOAT[5]
ISO_AERR FLOAT[5]
ISO_AGRAD FLOAT[5]
ISO_B FLOAT[5]
ISO_BERR FLOAT[5]
ISO_BGRAD FLOAT[5]
ISO_PHI FLOAT[5]
ISO_PHIERR FLOAT[5]
ISO_PHIGRAD FLOAT[5]
R_DEV FLOAT[5]
R_DEVERR FLOAT[5]
AB_DEV FLOAT[5] Isophotal ratio a/b in the range [0,1] or -9999
AB_DEVERR FLOAT[5]
PHI_DEV FLOAT[5]
PHI_DEVERR FLOAT[5]
COUNTS_DEV FLOAT[5]
COUNTS_DEVERR FLOAT[5]
R_EXP FLOAT[5]
R_EXPERR FLOAT[5]
AB_EXP FLOAT[5]
AB_EXPERR FLOAT[5]
PHI_EXP FLOAT[5]
PHI_EXPERR FLOAT[5]
COUNTS_EXP FLOAT[5]
COUNTS_EXPERR FLOAT[5]
COUNTS_MODEL FLOAT[5]
COUNTS_MODELERR FLOAT[5]
NPROF LONG[5] Number of measured radial profile SBs, where
the maximum is 15.
PROFMEAN FLOAT[15,5] Surface brightness in circular annuli
[mean raw counts/pixel], -9999 if not measured
PROFERR FLOAT[15,5]
RA DOUBLE J2000 RA [deg] in canonical (r-band) filter
DEC DOUBLE Declination [deg] in canonical (r-band) filter
OFFSETRA FLOAT[5] RA of center in this filter relative to RA [arcsec]
OFFSETDEC FLOAT[5] DEC of center in this filter relative to RA [arcs
PHI_ISO_DEG FLOAT[5] Isophotal fit, angle E of N [deg]
PHI_DEV_DEG FLOAT[5] De Vaucouleurs fit, angle E of N [deg]
PHI_EXP_DEG FLOAT[5] Exponential fit, angle E of N [deg]
SKYFLUX FLOAT[5] Sky level [nano-maggies/arcsec^2]
SKYFLUX_IVAR FLOAT[5]
PSFFLUX FLOAT[5]
PSFFLUX_IVAR FLOAT[5]
FIBERFLUX FLOAT[5]
FIBERFLUX_IVAR FLOAT[5]
MODELFLUX FLOAT[5]
MODELFLUX_IVAR FLOAT[5]
PETROFLUX FLOAT[5]
PETROFLUX_IVAR FLOAT[5]
DEVFLUX FLOAT[5]
DEVFLUX_IVAR FLOAT[5]
EXPFLUX FLOAT[5]
EXPFLUX_IVAR FLOAT[5]
APERFLUX FLOAT[NAPER,5] Aperture fluxes in radii of size 0.223,
0.670,1.024,1.745,2.972,4.584,7.359,11.306,
18.020,27.922,43.770,68.307,106.73,166.52,
260.37 arcsec; our default is to return
only those fluxes out to 11.3 arcsec,
unless NAPER is explicitly specified
APERFLUX_IVAR FLOAT[NAPER,5]
2MASS: If the /CATALOG option is used, then we include the closest 2MASS infrared source within 3 arcsec. The number of matches is reported in TMASS_NMATCH, and the closet match distance [in degrees] is TMASS_MDIST. Other 2MASS object parameters are specified in parameters whose names begin with "TMASS_". Details of 2MASS parameters can be found at: 605-763-8692
FIRST: If the /CATALOG option is used, then we include the closest FIRST radio source within 3 arcsec. The number of matches is reported in FIRST_NMATCH, and the closet match distance [in degrees] is FIRST_MDIST. Other FIRST object parameters are specified in parameters whose names begin with "FIRST_". Details of FIRST parameters can be found at: /sundog.stsci.edu/first/catalogs/
USNO-B: If the /CATALOG option is used, then we include the closest USNO-B1.0 source within 3 arcsec. The number of matches is reported in USNO_NMATCH, and the closet match distance [in degrees] is USNO_MDIST. Other USNO object parameters are specified in parameters whose names begin with "USNO_". Details of USNO parameters can be found at: 704-844-8813
RESOLVE_STATUS lets you know whether the object is unique within a particular run or within the survey.
The bit values are:
RESOLVE_STATUS 0 RUN_PRIMARY - Primary observation within a run
RESOLVE_STATUS 1 RUN_RAMP - At the very beginning or end of the run (in time)
RESOLVE_STATUS 2 RUN_OVERLAPONLY - Only appears in the overlap
RESOLVE_STATUS 3 RUN_IGNORE - "Bright" or "parent" object that should be ignored
RESOLVE_STATUS 4 RUN_EDGE - Near the NU boundary (X pixel position)
RESOLVE_STATUS 5 RUN_DUPLICATE - Duplicate measurement of the same object
(from the same raw pixels)
RESOLVE_STATUS 8 SURVEY_PRIMARY - Primary observation within the full survey,
where it appears in the primary observation
of this part of the sky
RESOLVE_STATUS 9 SURVEY_BEST - Best observation within the full survey, but it
does not appear in the primary observation
of this part of the sky
RESOLVE_STATUS 10 SURVEY_SECONDARY - Repeat (independent) observation of an
object that has a different primary or
best observation
The following bits are exclusive, and exactly one of these bits will be
set for each object: RUN_PRIMARY, RUN_RAMP, RUN_OVERLAPONLY, RUN_IGNORE,
RUN_DUPLICATE. In addition, RUN_EDGE can be set for any objects.
One typically wants all unique objects within a run that are not at the
edge of field. To select such objects, the RUN_PRIMARY bit should be set,
and the RUN_EDGE bit should not be set. The IDL code would be:
(resolve_status AND 2L^0) NE 0 AND (resolve_status AND 2L^4) EQ 0More properly, one could use the sdss_flagval() function:
(resolve_status AND sdss_flagval('RESOLVE_STATUS','RUN_PRIMARY')) NE 0 $
AND (resolve_status AND sdss_flagval('RESOLVE_STATUS','RUN_EDGE')) EQ 0
Calibrated quantities are presented in nano-Maggies (abbreviated nMgy, a flux density), where 1 Maggie is the flux density of a 0th magnitude star on the "SDSS natural magnitude system." Our 6-sigma detection limit is approximately at a magnitude of 22.5, corresponding to 1 nMgy. The spectroscopic limit of 17.67 for the SDSS main galaxy survey corresponds to 85.5 nMgy.
The official SDSS data releases present flux measurements in Asinh magnitudes, fondly known as Luptitudes (Lupton 1999, AJ, 118, 1406). This flux scaling is like magnitudes bright flux levels, and become approximately linear at a reference magnitude near the detection limit of the survey. This allows one to store zero and negative fluxes, and provides a quantity with (nearly) gaussian noise near the detection limit.
Looking ahead to reduction of co-added scans (we have as many as 20 observations of some parts of the sky), the noise limit would vary across the sky. If Asinh magnitudes were used, this would require a different reference magnitude in different parts of the sky, which would be extraordinarily confusing. A linear flux quantity (such as the Maggie) preserves the advantages of gaussian noise and allowing zero fluxes, and scales to co-added data reduction with no problems.
The nano prefix is used for convenience, since the faintest objects in the survey are ~ 1 nMgy.
Inverse variance is the quantity most often wanted (e.g. inverse variances add when computing a weighted average) and the situation of zero signal to noise (no measurement) can often be handled by setting ivar=0 rather than requiring an additional flag.
Implementation is also easy - to demand a S/N > 5 positive measurement, one would demand e.g. FLUX * sqrt(IVAR) GT 5 which always behaves correctly. The more conventional FLUX/SIG GT 5 requires checking that SIG is nonzero. Try it, you'll like it.
Exactly the same as the main survey. See the DR1 documentation at /www.sdss.org/dr1/algorithms/adaptive.html
All quoted fluxes are in terms of the "SDSS natural system". There are small corrections to convert to AB magnitudes, which is a physical system described by Oke & Gunn (1983). An estimation of these corrections as of Aug 2002 are (courtesy of David Hogg sdss-calib/845):
u(AB) = 22.5 - 2.5*log10(flux_u) - 0.042 g(AB) = 22.5 - 2.5*log10(flux_g) + 0.036 r(AB) = 22.5 - 2.5*log10(flux_r) + 0.015 i(AB) = 22.5 - 2.5*log10(flux_i) + 0.013 z(AB) = 22.5 - 2.5*log10(flux_z) - 0.002Daniel Eisenstein has been working on improved estimations from white dwarf models (c.f., sdss-calib/1043).
These quantities are related to physical units such that zero-th AB magnitude corresponds to 3631 Jy, where 1 Jy = 10-26W m-2 Hz-1 = 10-23 erg s-1 cm-2 Hz-1. This conversion to physical units is only known to about 5% (Oke & Gunn 1983). The measured calibrated magnitude or flux density of an object at the nominal central wavelength of a broad-band filter depends on the spectral shape of the source.
The Galactic plane runs (nicknamed "Orion") actually also cover parts of Taurus and other parts of the Galactic plane.
| Run | Date | MJD | Strip | Field start | Field end | Area | l | b |
|---|---|---|---|---|---|---|---|---|
| 211 | 1998/10/29 | 51115 | 82S | 11 | 385 | 71.25 | 210.16 | -3.33 |
| 250 | 1998/11/16 | 51133 | 82N | 11 | 455 | 84.55 | 201.89 | -18.03 |
| 259 | 1998/11/17 | 51134 | 82N | 11 | 567 | 105.83 | 206.66 | -9.54 |
| 273 | 1998/11/19 | 51136 | 82S | 11 | 534 | 99.56 | 206.07 | -11.11 |
| 297 | 1998/11/22 | 51139 | 82O | 11 | 203 | 36.67 | 206.00 | -10.95 |
| 307 | 1998/11/23 | 51140 | 82O | 11 | 186 | 33.44 | 212.38 | -0.00 |
| 308 | 1998/11/23 | 51140 | 10O | 11 | 216 | 39.14 | 215.95 | 4.19 |
| 994 | 1999/10/06 | 51457 | 76S | 11 | 133 | 23.37 | 209.88 | -4.99 |
| 1923 | 2000/12/08 | 51886 | 0O | 29 | 71 | 8.17 | 86.40 | 0.01 |
| 1924 | 2000/12/08 | 51886 | 0O | 34 | 78 | 8.55 | 168.61 | 11.91 |
| 1925 | 2000/12/08 | 51886 | 0O | 17 | 48 | 6.08 | 165.26 | 6.56 |
| 2955 | 2002/02/07 | 52312 | 82N | 21 | 166 | 27.74 | 209.30 | -4.54 |
| 2960 | 2002/02/08 | 52313 | 82S | 11 | 127 | 22.23 | 208.03 | -7.43 |
| 2968 | 2002/02/09 | 52314 | 82N | 19 | 94 | 14.44 | 207.84 | -7.33 |
| 3511 | 2002/12/06 | 52614 | 0O | 14 | 89 | 14.44 | 163.50 | -8.21 |
| 3512 | 2002/12/06 | 52614 | 0O | 11 | 90 | 15.20 | 177.31 | -9.27 |
| 3557 | 2002/12/31 | 52639 | 0O | 11 | 87 | 14.63 | 165.56 | -10.47 |
| 3559 | 2002/12/31 | 52639 | 0O | 11 | 86 | 14.44 | 176.43 | -9.95 |
| 3610 | 2003/01/27 | 52666 | 61N | 17 | 148 | 25.08 | 139.02 | -10.77 |
| 3628 | 2003/01/28 | 52667 | 61S | 17 | 165 | 28.31 | 137.32 | -10.88 |
| 3629 | 2003/01/28 | 52667 | 61N | 11 | 129 | 22.61 | 142.03 | -10.91 |
| 3634 | 2003/01/29 | 52668 | 62N | 18 | 162 | 27.55 | 159.08 | -13.00 |
| 3642 | 2003/02/01 | 52671 | 62S | 11 | 97 | 16.53 | 135.63 | -13.17 |
| 3643 | 2003/02/01 | 52671 | 62S | 11 | 119 | 20.71 | 159.07 | -13.21 |
| 4114 | 2003/09/20 | 52902 | 0S | 11 | 129 | ?? | ?? | ?? |
| 4115 | 2003/09/20 | 52902 | 0S | 11 | 71 | ?? | ?? | ?? |
| 4116 | 2003/09/20 | 52902 | 0O | 11 | 79 | ?? | ?? | ?? |
| 4119 | 2003/09/20 | 52902 | 0O | 11 | 72 | ?? | ?? | ?? |
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