Table information for 'ztf.forced_photometry'

General

Table Description:

Forced photometry measurements obtained at object positions for all ZTF epochs, including flux measurements, photometric calibration parameters, and image quality metrics.

This table is available for ADQL queries and through the TAP endpoint.

Resource Description:

Legacy ZTF astronomical catalog containing objects, detections, photometric measurements, classifications, and cross-matches from the Zwicky Transient Facility (ZTF) survey, as processed by the ALeRCE broker pipeline.

For a list of all services and tables belonging to this table's resource, see Information on resource 'ALeRCE ZTF Legacy Catalog'

Citing this table

To cite the table as such, we suggest the following BibTeX entry:

@MISC{vo:ztf_forced_photo,
  year=2026,
  title={{ZTF} Forced Photometry},
  author={{ALeRCE} Team},
  url={http://tap.alerce.online/tableinfo/ztf.forced_photometry},
  howpublished={{VO} resource provided by the {ALeRCE} {TAP} service}
}

Columns

Sorted alphabetically. [Sort by DB column index]

NameTable Head DescriptionUnitUCD
adpctdif1 Adpctdif1 Adaptive percent difference in astrometric solution (axis 1) N/A stat.fit.residual
adpctdif2 Adpctdif2 Adaptive percent difference in astrometric solution (axis 2) N/A stat.fit.residual
chinr Chinr Chi value of nearest source match in reference image N/A stat.fit.chi2
clrcoeff Clrcoeff Color coefficient for photometric calibration N/A phot.color;arith.ratio
clrcounc Clrcounc Uncertainty in color coefficient N/A stat.error;phot.color;arith.ratio
corrected Corrected Whether photometric correction was applied N/A meta.code.qual
dec Dec Declination (ICRS) deg pos.eq.dec;meta.main
decnr Decnr Declination of nearest source in reference image deg pos.eq.dec
diffmaglim Diffmaglim 5-sigma limiting magnitude in difference image mag phot.mag;stat.max
distnr Distnr Distance to nearest source in reference image arcsec pos.angDistance
dubious Dubious Flag indicating a potentially unreliable measurement N/A meta.code.qual
e_dec E_dec Uncertainty in declination deg stat.error;pos.eq.dec
e_mag E_mag Uncertainty in forced photometry magnitude mag stat.error;phot.mag
e_mag_corr E_mag_corr Uncertainty in corrected forced photometry magnitude mag stat.error;phot.mag
e_mag_corr_ext E_mag_corr_ext Extended uncertainty including systematics in corrected forced photometry magnitude mag stat.error;phot.mag
e_ra E_ra Uncertainty in right ascension deg stat.error;pos.eq.ra
exptime Exptime Exposure time s time.duration;obs.exposure
fid Fid Filter identifier (1=g, 2=r, 3=i) N/A meta.id;instr.filter
field Field ZTF field identifier N/A obs.field
has_stamp Has_stamp Whether a postage stamp image is available N/A meta.code
isdiffpos Isdiffpos Sign of flux in difference image (1=positive, -1=negative) N/A meta.code
mag Mag Magnitude from forced photometry mag phot.mag
mag_corr Mag_corr Corrected forced photometry magnitude mag phot.mag
magnr Magnr Magnitude of nearest source in reference image mag phot.mag
magzpsci Magzpsci Photometric zero-point magnitude for science image mag phot.calib
magzpscirms Magzpscirms RMS of zero-point magnitude fit mag stat.rms;phot.calib
magzpsciunc Magzpsciunc Uncertainty in photometric zero-point magnitude mag stat.error;phot.calib
mjd Mjd Modified Julian Date of observation d time.epoch
oid Oid Object identifier N/A meta.id;src
parent_candid Parent_candid Parent candidate identifier N/A meta.id;meta.parent
pid Pid Processing identifier N/A meta.id
procstatus Procstatus Processing status code N/A meta.code.status
programid Programid ZTF program identifier N/A meta.id;obs
ra Ra Right ascension (ICRS) deg pos.eq.ra;meta.main
ranr Ranr Right ascension of nearest source in reference image deg pos.eq.ra
rcid Rcid Readout channel identifier N/A meta.id;instr.det
rfid Rfid Reference image field identifier N/A meta.id
scibckgnd Scibckgnd Background level in science image N/A instr.background
sciinpseeing Sciinpseeing Seeing FWHM of science image arcsec instr.obsty.seeing
scisigpix Scisigpix Pixel-level noise (sigma) in science image N/A stat.error;instr.background
sharpnr Sharpnr Sharpness of nearest source in reference image N/A src.morph.param
sigmagnr Sigmagnr Uncertainty in magnitude of nearest source in reference image mag stat.error;phot.mag

Columns that are parts of indices are marked like this.

VOResource

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