DiaSource
Properties of transient-object detections on the single-epoch difference images.
Columns
| name | datatype | description | unit | nullable | ivoa:ucd | votable:arraysize | votable:xtype | length | precision |
|---|---|---|---|---|---|---|---|---|---|
| visit foreign key | long | Id of the visit where this diaSource was measured. | false | meta.id;obs.image | |||||
| detector | long | Id of the detector where this diaSource was measured. | false | meta.id;obs.image | |||||
| band | char | Band used to take this observation. | true | 1 | |||||
| diaObjectId foreign key indexed | long | Id of the DiaObject that this DiaSource was associated with. | true | ||||||
| ssObjectId foreign key | long | Id of the ssObject this source was associated with, if any. If not, it is set to 0 | true | ||||||
| parentDiaSourceId | long | Unique ID of parent source. | true | ||||||
| midpointMjdTai | double | Mid-exposure time for the Visit for this DiaSource, expressed as Modified Julian Date, International Atomic Time. | d | true | |||||
| bboxSize | long | Bounding box of diaSource footprint. | true | ||||||
| time_processed | timestamp | Time when the image was processed and this DiaSource record was generated. | false | * | timestamp | 6 | |||
| ra | double | Position in right ascension. | deg | true | pos.eq.ra | ||||
| dec | double | Position in declination. | deg | true | pos.eq.dec | ||||
| raErr | float | Error in right ascension. | deg | true | stat.error;pos.eq.ra | ||||
| decErr | float | Error in declination. | deg | true | stat.error;pos.eq.dec | ||||
| ra_dec_Cov | float | Covariance between right ascension and declination. | deg**2 | true | stat.covariance;pos.eq.ra;pos.eq.dec | ||||
| x | double | Unweighted first moment centroid, overall centroid | pixel | true | |||||
| y | double | Unweighted first moment centroid, overall centroid | pixel | true | |||||
| xErr | float | 1-sigma uncertainty on x position | pixel | true | |||||
| yErr | float | 1-sigma uncertainty on y position | pixel | true | |||||
| apFlux | float | Flux in a 12 pixel radius aperture on the difference image. | nJy | true | |||||
| apFluxErr | float | Estimated uncertainty of apFlux. | nJy | true | |||||
| snr | double | The signal-to-noise ratio at which this source was detected in the difference image. | true | ||||||
| psfFlux | float | Flux derived from linear least-squares fit of PSF model. | nJy | true | |||||
| psfFluxErr | float | Flux uncertainty derived from linear least-squares fit of PSF model. | nJy | true | |||||
| psfChi2 | float | Chi^2 statistic of the point source model fit. | true | ||||||
| psfNdata | int | Number of pixels that were included in the PSF fit. | pixel | true | |||||
| trailFlux | float | Trailed source flux. | nJy | true | |||||
| trailRa | double | Trail centroid right ascension. | deg | true | pos.eq.ra | ||||
| trailDec | double | Trail centroid declination. | deg | true | pos.eq.dec | ||||
| trailLength | double | Trail length. | pixel | true | |||||
| trailAngle | double | Angle measured from +x-axis. | true | ||||||
| dipoleMeanFlux | double | Raw flux counts, positive lobe. | count | true | |||||
| dipoleMeanFluxErr | double | Raw flux uncertainty counts, positive lobe. | count | true | |||||
| dipoleFluxDiff | double | Raw flux counts, positive lobe. | nJy | true | |||||
| dipoleFluxDiffErr | double | Raw flux uncertainty counts, positive lobe. | nJy | true | |||||
| dipoleLength | double | Pixel separation between positive and negative lobes of dipole. | pixel | true | |||||
| dipoleAngle | double | Dipole orientation | deg | true | |||||
| dipoleChi2 | double | Chi2 per degree of freedom of dipole fit. | true | ||||||
| isDipole | boolean | Source well fit by a dipole. | true | ||||||
| dipoleFitAttempted | boolean | Attempted to fit a dipole model to this source. | true | ||||||
| dipoleNdata | long | Number of data points in the dipole fit | true | ||||||
| scienceFlux | float | Forced PSF flux measured on the direct image. | nJy | true | |||||
| scienceFluxErr | float | Forced PSF flux uncertainty measured on the direct image. | nJy | true | |||||
| ixx | double | Elliptical Gaussian adaptive moments. | arcsec**2 | true | |||||
| iyy | double | Elliptical Gaussian adaptive moments. | arcsec**2 | true | |||||
| ixy | double | Elliptical Gaussian adaptive moments. | arcsec**2 | true | |||||
| ixxPSF | double | Adaptive moments of the PSF model at the object position. | arcsec**2 | true | |||||
| iyyPSF | double | Adaptive moments of the PSF model at the object position. | arcsec**2 | true | |||||
| ixyPSF | double | Adaptive moments of the PSF model at the object position. | arcsec**2 | true | |||||
| extendedness | double | 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 | A measure of reliability, computed using information from the source and image characterization, as well as the information on the Telescope and Camera system (e.g., ghost maps, defect maps, etc.). | true | ||||||
| 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_offimage | boolean | DiaSource center is off image. | true | ||||||
| pixelFlags_edge | boolean | Some of the source footprint is outside usable exposure region (masked EDGE or centroid off image). | true | ||||||
| pixelFlags_interpolated | boolean | Interpolated pixel in the DiaSource footprint. | true | ||||||
| pixelFlags_saturated | boolean | Saturated pixel in the DiaSource footprint. | true | ||||||
| pixelFlags_cr | boolean | Cosmic ray in the DiaSource footprint. | true | ||||||
| pixelFlags_bad | boolean | Bad pixel in the DiaSource footprint. | true | ||||||
| pixelFlags_suspect | boolean | DiaSource's footprint includes suspect pixels. | true | ||||||
| pixelFlags_interpolatedCenter | boolean | Interpolated pixel in the 3x3 region around the centroid. | true | ||||||
| pixelFlags_saturatedCenter | boolean | Saturated pixel in the 3x3 region around the centroid. | true | ||||||
| pixelFlags_crCenter | boolean | Cosmic ray in the 3x3 region around the centroid. | true | ||||||
| pixelFlags_suspectCenter | boolean | Suspect pixel in the 3x3 region around the centroid. | true | ||||||
| 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_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 | Aperture did not fit within measurement image. | true | ||||||
| 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_noGoodPixels | boolean | Not enough non-rejected pixels in data to attempt the fit. | true | ||||||
| psfFlux_flag_edge | boolean | Object was too close to the edge of the image to use the full PSF model. | true | ||||||
| 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_noGoodPixels | boolean | Forced PSF flux not enough non-rejected pixels in data to attempt the fit. | true | ||||||
| forced_PsfFlux_flag_edge | boolean | Forced PSF flux object was too close to the edge of the image to use the full PSF model. | 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 to measure shape. | 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 | ||||||
| trail_flag_edge | boolean | This flag is set if a trailed source contains edge pixels. | 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 | Injection in the DiaSource footprint. | true | ||||||
| pixelFlags_injectedCenter | boolean | Injection in the 3x3 region around the centroid. | true | ||||||
| pixelFlags_injected_template | boolean | Template injection in the DiaSource footprint. | true | ||||||
| pixelFlags_injected_templateCenter | boolean | Template injection in the 3x3 region around the centroid. | 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 | ||||||
| coord_ra | double | Fiducial ICRS Right Ascension of centroid used for database indexing. | deg | true | pos.eq.ra;meta.main | ||||
| coord_dec | double | Fiducial ICRS Declination of centroid used for database indexing. | deg | true | pos.eq.dec;meta.main | ||||
| diaSourceId | long | Unique identifier of this DiaSource. | true |
Indexes
| Index | Definition | Description |
|---|---|---|
| idx_DiaSource_diaObjectId | diaObjectId | Non-unique index on the diaObjectId column; accelerates retrieval of light curves for DiaObjects |
Constraints
| Constraint | Type | Definition | Description |
|---|---|---|---|
| uniq_diaSourceId | Unique | diaSourceId | Unique constraint on diaSourceId |
| fk_DiaSource_Visit | ForeignKey |
Columns: visit
|
Link a DiaSource to its associated Visit |
| fk_DiaSource_DiaObject | ForeignKey |
Columns: diaObjectId
References: DiaObject.diaObjectId
|
Link a DiaObject to its associated DiaSources |
| fk_DiaSource_SSObject | ForeignKey |
Columns: ssObjectId
References: SSObject.ssObjectId
|
Link a DiaSource to its associated SSObject, if any |