Models

Here is a list of the response specification for each data model.

Object Response

Object Response Model

Name

Type

Description

oid

string

ZTF Object identifier

ndethist

string

Number of spatially-coincident detections falling within 1.5 arcsec going back to beginning of survey; only detections that fell on the same field and readout-channel ID where the input candidate was observed are counted. All raw detections down to a photometric S/N of ~ 3 are included.

ncovhist

integer

Number of times input candidate position fell on any field and readout-channel going back to beginning of survey

mjdstarthist

number

Earliest Modified Julian date of epoch corresponding to ndethist [days]

mjdendhist

number

Latest Modified Julian date of epoch corresponding to ndethist [days]

corrected

boolean

Whether the corrected light curve was computed and can be used

stellar

boolean

Whether the object is a likely stellar-like source

ndet

integer

Total number of detections for the object

g_r_max

number

Difference between the minimum g and r band difference magnitudes ( min(g) - min(r) )

g_r_max_corr

number

Difference between the minimum g and r band corrected magnitudes ( min(corrected(g)) - min(corrected(r)) )

g_r_mean

number

Difference between the mean g and r band difference magnitudes ( mean(g) - mean(r) )

g_r_mean_corr

number

Difference between the mean g and r band corrected magnitudes ( mean(corrected(g)) - mean(corrected(r)) )

firstmjd

number

First detection’s modified julian date

lastmjd

number

Last detection’s modified julian date

deltajd

number

Difference between last and first detection date

meanra

number

Mean Right Ascension

meandec

number

Mean Declination

sigmara

number

Right Ascension standard deviation

sigmadec

number

Declination standard deviation

class

string

Highest probability class or according to specified classifier and ranking (Default classifier: lc_classifier, ranking: 1)

classifier

string

Classifier name.

probability

number

Highest probability or according to specified classifier and ranking (Default classifier: lc_classifier, ranking: 1)

step_id_corr

string

CorrectionStep pipeline version.

Detection Response

Detection Response Model

Name

Type

Description

mjd

number

Modified julian Date

candid

string

Alert unique identifier.

fid

integer

Filter ID (1=g; 2=r; 3=i)

pid

integer

Processing ID for image

diffmaglim

number

5-sigma mag limit in difference image based on PSF-fit photometry [mag]

isdiffpos

number

1: candidate is from positive (sci minus ref) subtraction; -1: didate is from negative (ref minus sci) subtraction

nid

integer

Night ID

ra

number

Right Ascension of candidate [deg]

dec

number

Declination of candidate [deg]

magpsf

number

Magnitude from PSF-fit photometry [mag]

sigmapsf

number

1-sigma uncertainty in magap [mag]

magap

number

Aperture mag using 8 pixel diameter aperture [mag]

sigmagap

number

1-sigma uncertainty in magap [mag]

distnr

number

Distance to nearest source in reference image PSF-catalog within 30 arcsec [pixels]

rb

number

RealBogus quality score; range is 0 to 1 where closer to 1 is more reliable

rbversion

string

Version of RealBogus model/classifier used to assign rb quality score

drb

number

RealBogus quality score from Deep-Learning-based classifier; range is 0 to 1 where closer to 1 is more reliable

drbversion

string

Version of Deep-Learning-based classifier model used to assign RealBogus (drb) quality score

magapbig

number

Aperture mag using 18 pixel diameter aperture [mag]

sigmagapbig

number

1-sigma uncertainty in magapbig [mag]

rfid

number

Processing ID for reference image to facilitate archive retrieval

magpsf_corr

number

Corrected PSF magnitude

sigmapsf_corr

number

Error of the corrected PSF magnitude assuming no contribution from an extended component

sigmapsf_corr_ext

number

Error of the corrected PSF magnitude assuming a contribution from an extended component

corrected

boolean

Whether the corrected photometry was applied

dubious

boolean

Whether the corrected photometry should be flagged

parent_candid

number

Parent candid if alert coming from prv_detection (null if no parent)

has_stamp

boolean

Whether the detection has an associated image stamp triplet (when parent_candid = null)

step_id_corr

string

Correction step pipeline version

Non-Detection Response

Non-Detection Response Model

Name

Type

Description

mjd

number

Observation Julian date at start of exposure [days]

fid

integer

Filter ID (1=g; 2=r; 3=i)

diffmaglim

number

5-sigma mag limit in difference image based on PSF-fit photometry [mag]

Probability Response

Probability Response Model

Name

Type

Description

classifier_name

string

Classifier name

classifier_version

string

Classifier version

class_name

string

Class

probability

number

Probability

ranking

integer

Ranking within the classifier type

Magstats Response

Magstats Response Model

Name

Type

Description

fid

integer

Filter ID (1=g; 2=r; 3=i)

stellar

boolean

Whether the object appears to be unresolved in the given band

corrected

boolean

Whether the corrected photometry should be used

ndet

integer

Number of detections in the given band

ndubious

integer

Number of dubious corrections

dmdt_first

number

Initial rise estimate, the maximum slope between the first detection and any previous non-detection

dm_first

number

The magnitude difference used to compute dmdt_first

sigmadm_first

number

The error of the magnitude difference used to compute dmdt_first

dt_first

number

The time difference used to compute dmdt_first

magmean

number

The mean magnitude for the given fid

magmedian

number

The median magnitude for the given fid

magmax

number

The max magnitude for the given fid

magmin

number

The min magnitude for the given fid

magsigma

number

Magnitude standard deviation for the given fid

maglast

number

The last magnitude for the given fid

magfirst

number

The first magnitude for the given fid

magmean_corr

number

The mean corrected magnitude for the given fid

magmedian_corr

number

The median corrected magnitude for the given fid

magmax_corr

number

The max corrected magnitude for the given fid

magmin_corr

number

The min corrected magnitude for the given fid

magsigma_corr

number

Corrected magnitude standard deviation for the given fid

maglast_corr

number

The last corrected magnitude for the given fid

magfirst_corr

number

The first corrected magnitude for the given fid

firstmjd

number

The time of the first detection in the given fid

lastmjd

number

The time of the last detection in the given fid

step_id_corr

string

Correction step pipeline version