DiaSource
Difference image sources detected 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 | long | Id of the visit where this diaSource was measured. | false | meta.id;obs.image | |||||
| detector | 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 | 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 | 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 | ||||||
| trailAlgorithm | int | Integer key indicating which algorithm was used to measure trailed source. 1=SDSSShape, 2=HSMShape. | 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 | |||||
| trail_flag | boolean | The trailed source fitting algorithm failed. | true | ||||||
| trail_flag_edge | boolean | This flag is set if a trailed source extends onto or past edge pixels. | 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 |