Data model: photoObj

General description: The photoObj files contain the full, calibrated outputs of the SDSS imager photometric pipeline. They are parallel with the CAS photoObjAll and photoProfile tables. All "magnitudes" in this file are of the asinh type.

Naming convention: photoObj-RUN6-CAMCOL-FIELD4.fits

Approximate size: 3 Mbytes.

File type: FITS

Read by products: sas

Written by products: photoop

Required header keywords:

• VERSION: photo version used during frames
• DERV_VER: dervish version used
• ASTR_VER: astrom version used
• ASTRO_ID: job ID and time for astrom
• BIAS_ID: bias version
• FRAME_ID: job ID and time for frames
• KO_VER: known objects version used
• PS_ID: PSP time and job id
• CREATIME: time of original fpObjc creation
• SEED: seed for photo random number generator
• REF_BAND: index of canonical band
• RUN: photo run
• CAMCOL: photo camcol
• FIELD: photo field
• FILTERS: filter order in arrays
• DARK_VAR: per-pixel variances at zero DN
• GAIN: mean gains of amps (e/DN)
• SOBJ_VER: photoop version used to produce photoObj

Required column names: (should be listed for Yanny and FITS)

• objID (string): Unique SDSS identifier composed from [skyVersion,rerun,run,camcol,field,obj].
• fieldID (string): Field identifier composed of [run, camcol, field, rerun, skyversion].
• parentID (string): Object identifier of parent (if object deblended) or BRIGHT detection (if object has one), else 0
• skyVersion (int8): Layer of catalog (currently only one layer, 0)
• mode (int8): 1: primary, 2: secondary, 3: other
• clean (int32): Clean photometry flag for point sources (1=clean, 0=unclean).
• run (int32): Run number
• rerun (string): Rerun number
• camcol (int32): Camera column
• field (int32): Field number
• id (int32): The object id within a field. Usually changes between reruns of the same field
• parent (int32): parent ID, if there is one
• nchild (int32): Number of children if this is a composite object that has been deblended. BRIGHT (in a flags sense) objects also have nchild == 1, the non-BRIGHT sibling.
• objc_type (int16): Type classification of the object (star, galaxy, cosmic ray, etc.)
• objc_prob_psf (float32): Probability that the object is a star. Currently 0 if type == 3 (galaxy), 1 if type == 6 (star).
• objc_flags (int32): photo object attribute flags
• objc_flags2 (int32): Second set of photo object attribute flags
• objc_rowc (float32): Row center position (r-band coordinates) (pix)
• objc_rowcerr (float32): Row center position error (r-band coordinates) (pix)
• objc_colc (float32): Column center position (r-band coordinates) (pix)
• objc_colcerr (float32): Column center position error (r-band coordinates) (pix)
• rowvdeg (float32): Row-component of object's velocity (deg/day)
• rowvdegerr (float32): Row-component of object's velocity error (deg/day)
• colvdeg (float32): Column-component of object's velocity (deg/day)
• colvdegerr (float32): Column-component of object's velocity error (deg/day)
• rowc[5] (float32): Row center (pix)
• rowcErr[5] (float32): ERROR Row center error (pix)
• colc[5] (float32): Column center (pix)
• colcErr[5] (float32): Column center error (pix)
• petrotheta[5] (float32): Petrosian radius (arcsec)
• petrothetaerr[5] (float32): Petrosian radius error (arcsec)
• petroth50[5] (float32): Radius containing 50% of Petrosian flux (arcsec)
• petroth50err[5] (float32): Error in radius with 50% of Petrosian flux error (arcsec)
• petroth90[5] (float32): Radius containing 90% of Petrosian flux (arcsec)
• petroth90err[5] (float32): Error in radius with 90% of Petrosian flux error (arcsec)
• q[5] (float32): Stokes Q parameter
• qErr[5] (float32): Stokes Q parameter error
• u[5] (float32): Stokes U parameter
• uErr[5] (float32): Stokes U parameter error
• m_E1[5] (float32): Adaptive E1 shape measure (pixel coordinates)
• m_E2[5] (float32): Adaptive E2 shape measure (pixel coordinates)
• m_E1E1Err[5] (float32): Covariance in E1/E1 shape measure (pixel coordinates)
• m_E1E2Err[5] (float32): Covariance in E1/E2 shape measure (pixel coordinates)
• m_E2E2Err[5] (float32): Covariance in E2/E2 shape measure (pixel coordinates)
• m_Rr_Cc[5] (float32): Adaptive ( + ) (pixel coordinates)
• m_Rr_CcErr[5] (float32): Error in adaptive ( + ) (pixel coordinates)
• m_Cr4[5] (float32): Adaptive fourth moment of object (pixel coordinates)
• m_E1_PSF[5] (float32): Adaptive E1 for PSF (pixel coordinates)
• m_E2_PSF[5] (float32): Adaptive E2 for PSF (pixel coordinates)
• m_Rr_Cc_PSF[5] (float32): Adaptive ( + ) for PSF (pixel coordinates)
• m_Cr4_PSF[5] (float32): Adaptive fourth moment for PSF (pixel coordinates)
• theta_dev[5] (float32): de Vaucouleurs fit scale radius (arcsec)
• theta_deverr[5] (float32): Error in de Vaucouleurs fit scale radius error (arcsec)
• ab_dev[5] (float32): de Vaucouleurs fit a/b
• ab_deverr[5] (float32): de Vaucouleurs fit a/b error
• theta_exp[5] (float32): Exponential fit scale radius (arcsec)
• theta_experr[5] (float32): Exponential fit scale radius error (arcsec)
• ab_exp[5] (float32): Exponential fit a/b
• ab_experr[5] (float32): Exponential fit a/b
• fracDeV[5] (float32): Weight of deV component in deV+Exp model
• flags[5] (int32): Object detection flags per band
• flags2[5] (int32): Second set of detection flags per band
• type[5] (int32): Object type classification per band
• prob_psf[5] (float32): Probability that the object is a star in each band
• nProf[5] (int32): Number of used Profile Bins
• profmean_nmgy[5] (float32): Calibrated mean flux in each photo annulus
• proferr_nmgy[5] (float32): Error in calibrated mean flux in each photo annulus
• star_lnl (float32): Star ln(likelihood)
• exp_lnl (float32): Exponential disk fit ln(likelihood)
• dev_lnl (float32): de Vaucouleurs fit ln(likelihood)
• psp_status[5] (int32): PSP output status (XXX should this be in CAS?)
• pixscale[5] (float32): pixel scale, arcsec (XXX should this be in CAS?)
• ra (float64): J2000 Right Ascension (r-band) (deg)
• dec (float64): J2000 Declination (r-band) (deg)
• cx (float64): unit vector for ra+dec
• cy (float64): unit vector for ra+dec
• cz (float64): unit vector for ra+dec
• raErr (float64): Error in RA (* cos(Dec), that is, proper units) (arcsec)
• decErr (float64): Error in Dec (arcsec)
• b (float64): Galactic latitude (deg)
• l (float64): Galactic longitude (deg)
• offsetRa[5] (float32): filter position RA minus final RA (* cos(Dec), that is, proper units) (arcsec)
• offsetDec[5] (float32): filter position Dec minus final Dec (arcsec)
• psf_fwhm[5] (float32): PSF FWHM (arcsec)
• mjd (int32): Date of observation (days)
• airmass[5] (float32): Airmass at time of observation
• phi_offset[5] (float32): Degrees to add to CCD-aligned angle to convert to E of N (deg)
• phi_dev_deg[5] (float32): deg --/U de Vaucouleurs fit position angle (+N thru E) (deg)
• phi_exp_deg (float32): Exponential fit position angle (+N thru E) (deg)
• extinction[5] (float32): Galactic extinction (SFD) (mag)
• skyflux[5] (float32): Sky flux at the center of object (allowing for siblings if blended). (nanomaggies)
• skyflux_ivar[5] (float32): Sky flux inverse variance (nanomaggies)
• psfMag[5] (float32): PSF magnitude (mag)
• psfMagErr[5] (float32): PSF magnitude error (mag)
• fiberMag[5] (float32): Magnitude in 3 arcsec diameter fiber radius (mag)
• fiberMagErr[5] (float32): Error in magnitude in 3 arcsec diameter fiber radius (mag)
• fiber2Mag[5] (float32): Magnitude in 2 arcsec diameter fiber radius (mag)
• fiber2MagErr[5] (float32): Error in magnitude in 2 arcsec diameter fiber radius (mag)
• petroMag[5] (float32): Petrosian magnitude (mag)
• petroMagErr[5] (float32): Petrosian magnitude error (mag)
• psfFlux[5] (float32): PSF flux (nanomaggies)
• psfFluxIvar[5] (float32): PSF flux inverse variance (nanomaggies)
• fiberFlux[5] (float32): Flux in 3 arcsec diameter fiber radius (nanomaggies)
• fiberFlux_Ivar[5] (float32): Inverse variance in flux in 3 arcsec diameter fiber radius (nanomaggies)
• fiber2Flux[5] (float32): Flux in 2 arcsec diameter fiber radius (nanomaggies)
• fiber2Flux_Ivar[5] (float32): Inverse variance in flux in 2 arcsec diameter fiber radius (nanomaggies)
• petroFlux[5] (float32): Petrosian flux (nanomaggies)
• petroFlux_Ivar[5] (float32): Petrosian flux inverse variance (nanomaggies)
• deVMag[5] (float32): mag (de)
• deVMagErr[5] (float32): mag (de)
• deVFlux[5] (float32): nanomaggies (de)
• deVFlux_Ivar[5] (float32): nanomaggies^{-2} (de)
• expMag[5] (float32): Exponential fit magnitude (mag)
• expMagErr[5] (float32): Exponential fit magnitude error (mag)
• modelMag[5] (float32): better of DeV/Exp magnitude fit; see modelFlux (mag)
• modelMagErr[5] (float32): Error in better of DeV/Exp magnitude fit (mag)
• cModelMag[5] (float32): DeV+Exp magnitude; see cModelFlux (mag)
• cModelMagErr[5] (float32): DeV+Exp magnitude error (mag)
• expFlux[5] (float32): Exponential fit flux (nanomaggies)
• expFlux_Ivar[5] (float32): Exponential fit flux inverse variance (nanomaggies)
• modelFlux[5] (float32): better of DeV/Exp flux fit; for these measurements, the structural parameters used in every band, are the r-band values, and only the amplitude is varied (nanomaggies)
• modelFlux_Ivar[5] (float32): Inverse variance in better of DeV/Exp flux fit (nanomaggies)
• cModelFlux[5] (float32): DeV+Exp flux; result of fitting coefficients in linear combination of models, with structural parameters fixed based on individual fits (nanomaggies)
• cModelFlux_Ivar[5] (float32): Inverse variance in DeV+Exp flux fit (nanomaggies)
• aperflux[8,5] (float32): Aperture flux within [0.223, 0.670, 1.024, 1.745, 2.972, 4.584, 7.359, 11.306] arcsec in each band (nanomaggies)
• aperflux_ivar[8,5] (float32): Inverse variance of aperture flux values (1/nanomaggies²)
• cloudCam[5] (int32): Cloud camera status for observation
• calib_status[5] (int32): Calibration status of object
• nMgyPerCount[5] (float32): nanomaggies per count (nmgy)
• nMgyPerCount_ivar[5] (float32): inverse variance on nanomaggies per count (nmgy)
• TAI[5] (float64): time of observation (TAI) in each filter (sec)
• resolve_status (int32): Resolve status of object
• thing_id (int32): Unique identifier from global resolve
• balkan_id (int32): What balkan object is in from window
• nObserve (int32): Number of observations of this position on the sky
• nDetect (int32): Number of detections of this object
• nEdge (int32): Number of observations of this object near an edge (not included in nObserve or nDetect)
• score (float32): Quality of field (0-1)

Example file: photoObj-004623-1-0030.fits