DiaSource

Table to store 'difference image sources'; - sources detected at SNR >=5 on difference images.

Columns

name datatype description unit nullable ivoa:ucd votable:arraysize value length autoincrement
diaSourceId primary key long Unique identifier of this DiaSource. false meta.id;obs.image false
visit indexed long Id of the visit where this diaSource was measured. false meta.id;obs.image
detector indexed short Id of the detector where this diaSource was measured. Datatype short instead of byte because of DB concerns about unsigned bytes. false meta.id;obs.image
diaObjectId indexed long Id of the diaObject this source was associated with, if any. If not, it is set to NULL (each diaSource will be associated with either a diaObject or ssObject). true meta.id;src
ssObjectId indexed long Id of the ssObject this source was associated with, if any. If not, it is set to NULL (each diaSource will be associated with either a diaObject or ssObject). true meta.id;src
parentDiaSourceId long Id of the parent diaSource this diaSource has been deblended from, if any. true meta.id;src
ssObjectReassocTimeMjdTai double Time when this diaSource was reassociated from diaObject to ssObject, expressed as Modified Julian Date, International Atomic Time (if such reassociation happens, otherwise NULL). true
midpointMjdTai double Effective mid-visit time for this diaSource, expressed as Modified Julian Date, International Atomic Time. d false time.epoch
exposureTime float Effective exposure time for this diaSource. s true time.interval
ra double Right ascension coordinate of the center of this diaSource. deg false pos.eq.ra
raErr float Angular error of Right Ascension (dRA*cos(Dec)). deg true stat.error;pos.eq.ra
dec double Declination coordinate of the center of this diaSource. deg false pos.eq.dec
decErr float Angular error of dec. deg true stat.error;pos.eq.dec
ra_dec_Cov float Covariance between Right Ascension (RA*cos(Dec)) and dec. deg**2 true stat.covariance
x float x position computed by a centroiding algorithm. pixel false pos.cartesian.x
xErr float Uncertainty of x. pixel true stat.error;pos.cartesian.x
y float y position computed by a centroiding algorithm. pixel false pos.cartesian.y
yErr float Uncertainty of y. pixel true stat.error;pos.cartesian.y
centroid_flag boolean General centroid algorithm failure flag; set if anything went wrong when fitting the centroid. Another centroid flag field should also be set to provide more information. true
apFlux float Flux in a 12 pixel radius aperture on the difference image. nJy true phot.count
apFluxErr float Estimated uncertainty of apFlux. nJy true stat.error;phot.count
apFlux_flag boolean General aperture flux algorithm failure flag; set if anything went wrong when measuring aperture fluxes. Another apFlux flag field should also be set to provide more information. true
apFlux_flag_apertureTruncated boolean The source is closer to the edge of the measurement image than the aperture radius. true
isNegative boolean The original peak on the PSF-convolved detection difference image was negative. true
snr float The signal-to-noise ratio at which this source was detected in the difference image. true stat.snr
psfFlux float Flux for Point Source model. Note this actually measures the flux difference between the template and the visit image. nJy true phot.count
psfFluxErr float Uncertainty of psfFlux. nJy true
psfLnL float Natural log likelihood of the observed data given the point source model. true stat.likelihood
psfChi2 float Chi^2 statistic of the point source model fit. true stat.fit.chi2
psfNdata int The number of data points (pixels) used to fit the point source model. false
psfFlux_flag boolean Failure to derive linear least-squares fit of psf model. Another psfFlux flag field should also be set to provide more information. true
psfFlux_flag_edge boolean Object was too close to the edge of the image to use the full PSF model. true
psfFlux_flag_noGoodPixels boolean Not enough non-rejected pixels in data to attempt the fit. true
trailFlux float Flux for a trailed source model. Note this actually measures the flux difference between the template and the visit image. nJy true
trailFluxErr float Uncertainty of trailFlux. nJy true
trailRa double Right ascension coordinate of centroid for trailed source model. deg true pos.eq.ra
trailRaErr float Angular error of trailRa (dRA*cos(Dec)). deg true stat.error;pos.eq.ra
trailDec double Declination coordinate of centroid for trailed source model. deg true pos.eq.dec
trailDecErr float Angular error of trailDec. deg true stat.error;pos.eq.dec
trailLength float Maximum likelihood fit of trail length. arcsec true
trailLengthErr float Uncertainty of trailLength. arcsec true
trailAngle float Maximum likelihood fit of the angle between the meridian through the centroid and the trail direction (bearing). deg true
trailAngleErr float Uncertainty of trailAngle. deg true
trailChi2 float Chi^2 statistic of the trailed source model fit. true stat.fit.chi2
trailNdata int The number of data points (pixels) used to fit the trailed source model. false 0
trailAlgorithm int Integer key indicating which algorithm was used to measure trailed source. 1=SDSSShape, 2=HSMShape. true
trail_flag_edge boolean This flag is set if a trailed source extends onto or past edge pixels. true
trail_flag boolean The trailed source fitting algorithm failed. true
dipoleMeanFlux float Maximum likelihood value for the mean absolute flux of the two lobes for a dipole model. nJy true
dipoleMeanFluxErr float Uncertainty of dipoleMeanFlux. nJy true stat.error
dipoleFluxDiff float Maximum likelihood value for the difference of absolute fluxes of the two lobes for a dipole model. nJy true
dipoleFluxDiffErr float Uncertainty of dipoleFluxDiff. nJy true stat.error
dipoleLength float Maximum likelihood value for the lobe separation in dipole model. arcsec true pos.angDistance
dipoleAngle float Maximum likelihood fit of the angle between the meridian through the centroid and the dipole direction (bearing, from negative to positive lobe). deg true pos.posAng
dipoleChi2 float Chi^2 statistic of the model fit. true stat.fit.chi2
dipoleNdata int The number of data points (pixels) used to fit the model. false
scienceFlux float Forced photometry flux for a point source model measured on the visit image centered at DiaSource position. nJy true phot.count
scienceFluxErr float Estimated uncertainty of scienceFlux. nJy true stat.error;phot.count
forced_PsfFlux_flag boolean Forced PSF photometry on science image failed. Another forced_PsfFlux flag field should also be set to provide more information. true
forced_PsfFlux_flag_edge boolean Forced PSF flux on science image was too close to the edge of the image to use the full PSF model. true
forced_PsfFlux_flag_noGoodPixels boolean Forced PSF flux not enough non-rejected pixels in data to attempt the fit. true
templateFlux float Forced photometry flux for a point source model measured on the template image centered at the DiaObject position. nJy true phot.count
templateFluxErr float Uncertainty of templateFlux. nJy true stat.error;phot.count
ixx float Adaptive second moment of the source intensity. arcsec**2 true
iyy float Adaptive second moment of the source intensity. arcsec**2 true
ixy float Adaptive second moment of the source intensity. arcsec**2 true
ixxPSF float Adaptive second moment of the PSF measured at the location of the source. arcsec**2 true
iyyPSF float Adaptive second moment of the PSF measured at the location of the source. arcsec**2 true
ixyPSF float Adaptive second moment of the PSF measured at the location of the source. arcsec**2 true
shape_flag boolean General source shape algorithm failure flag; set if anything went wrong when measuring the shape. Another shape flag field should also be set to provide more information. true
shape_flag_no_pixels boolean No pixels were useable for computing shape measurement. true
shape_flag_not_contained boolean Center not contained in footprint bounding box. true
shape_flag_parent_source boolean This source is a parent source; we should only be measuring on deblended children in difference imaging. true
extendedness float A measure of extendedness, computed by comparing an object's moment-based traced radius to the PSF moments. extendedness = 1 implies a high degree of confidence that the source is extended. extendedness = 0 implies a high degree of confidence that the source is point-like. true
reliability float Probability (0-1) that the diaSource is astrophysical, derived from a machine learning model. true
reliabilityVersion string Version of the reliability model. true 7* 7
band char Filter band this source was observed with. true 1
isDipole boolean Source well fit by a dipole. true
dipoleFitAttempted boolean Attempted to fit a dipole model to this source. true
timeProcessedMjdTai double Time when the image was processed and this DiaSource record was generated, expressed as Modified Julian Date, International Atomic Time. false time.epoch
timeWithdrawnMjdTai double Time when this record was marked invalid, expressed as Modified Julian Date, International Atomic Time. true time.epoch
bboxSize int Size of the square bounding box that fully contains the detection footprint. pixel false
pixelFlags boolean General pixel flags failure; set if anything went wrong when setting pixels flags from this footprint's mask. This implies that some pixelFlags for this source may be incorrectly set to False. true
pixelFlags_bad boolean Bad pixel in the DiaSource footprint. true
pixelFlags_cr boolean Cosmic ray in the DiaSource footprint. true
pixelFlags_crCenter boolean Cosmic ray in the 3x3 region around the centroid. true
pixelFlags_edge boolean Some of the source footprint is outside usable exposure region (masked EDGE or centroid off image). true
pixelFlags_nodata boolean NO_DATA pixel in the source footprint. true
pixelFlags_nodataCenter boolean NO_DATA pixel in the 3x3 region around the centroid. true
pixelFlags_interpolated boolean Interpolated pixel in the DiaSource footprint. true
pixelFlags_interpolatedCenter boolean Interpolated pixel in the 3x3 region around the centroid. true
pixelFlags_offimage boolean DiaSource center is off image. true
pixelFlags_saturated boolean Saturated pixel in the DiaSource footprint. true
pixelFlags_saturatedCenter boolean Saturated pixel in the 3x3 region around the centroid. true
pixelFlags_suspect boolean DiaSource's footprint includes pixels masked as SUSPECT that are approaching the saturation threshold. true
pixelFlags_suspectCenter boolean The 3x3 region around the centroid of the DiaSource includes pixels masked as SUSPECT that are approaching the saturation threshold true
pixelFlags_streak boolean Streak in the DiaSource footprint. true
pixelFlags_streakCenter boolean Streak in the 3x3 region around the centroid. true
pixelFlags_injected boolean A pixel in the diaSource footprint contains at least one pixel modified by injecting fake sources. true
pixelFlags_injectedCenter boolean A pixel in the 3x3 region around the centroid contains at least one pixel modified by injecting fake sources. true
pixelFlags_injected_template boolean A pixel in the diaSource footprint contains at least one pixel modified by injecting fake sources into the template. true
pixelFlags_injected_templateCenter boolean A pixel in the 3x3 region around the centroid contains at least one pixel modified by injecting fake sources into the template. true
glint_trail boolean This flag is set if the source is likely part of a glint trail from an artifical satellite. true

Indexes

Index Definition Description
IDX_DiaSource_visitDetector visit, detector
IDX_DiaSource_diaObjectId diaObjectId
IDX_DiaSource_ssObjectId ssObjectId