alert_tools

collection of tooling for working with the ZTF alert stream

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Features for a Source

• We define a source as an astrophysical object with:
  • an associated light curve
  • attributes of the light curve summarized in the following summary table
• Features are metrics that describe the characteristic and context of a source.
• Many features are needed per source to discern which of many science classes, the source belongs to.

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Task Lists

• Create features
• update the schema to version 3.0
• Optimize the code
• Add all Richards attributes

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Light curve features calculated in the summary table

Field	Type	Contents
objectId	long	unique identifier for the object
meanRA	double	mean of the RA values for all the g, r, and i-band; J2000 [deg]
meanDec	double	mean of the Dec values for all the g, r, and i-band; J2000 [deg]
nobs	int	number of total observations
gNobs	int	number of observations for the g-band data
rNobs	int	number of observations for the r-band data
iNobs	int	number of observations for the i-band data
gMeanAB	float	weighted mean value of the g-band magnitudes; AB [mag]
rMeanAB	float	weighted mean value of the r-band magnitudes; AB [mag]
iMeanAB	float	weighted mean value of the i-band magnitudes; AB [mag]
gStdAB	float	sample standard-deviation of the g-band magnitudes
rStdAB	float	sample standard-deviation of the r-band magnitudes
iStdAB	float	sample standard-deviation of the i-band magnitudes
gMeanJy	double	weighted mean value of the g-band fluxes [Jy]
rMeanJy	double	weighted mean value of the r-band fluxes [Jy]
iMeanJy	double	weighted mean value of the i-band fluxes [Jy]
gStdJy	double	sample standard-deviation of the g-band fluxes
rStdJy	double	sample standard-deviation of the r-band fluxes
iStdJy	double	sample standard-deviation of the i-band fluxes
gRB	float	mean value of the g-band real-bogus data
rRB	float	mean value of the r-band real-bogus data
iRB	float	mean value of the i-band real-bogus data
gClasstar	float	mean value of the g-band Classtar data [(Galaxy) <-- 0 < Classtar score < 1 --> (Star)]
rClasstar	float	mean value of the r-band Classtar data [(Galaxy) <-- 0 < Classtar score < 1 --> (Star)]
iClasstar	float	mean value of the i-band Classtar data [(Galaxy) <-- 0 < Classtar score < 1 --> (Star)]
Distnr	float	distance to nearest source in reference image PSF-catalog within 30 arcsec [pixels]
gMagnr	float	g-band magnitude of nearest source in reference image PSF-catalog within 30 arcsec [mag]
gDmagnr	float	1-sigma uncertainty in gMagnr within 30 arcsec [mag]
rMagnr	float	r-band magnitude of nearest source in reference image PSF-catalog within 30 arcsec [mag]
rDmagnr	float	1-sigma uncertainty in rMagnr within 30 arcsec [mag]
iMagnr	float	i-band magnitude of nearest source in reference image PSF-catalog within 30 arcsec [mag]
iDmagnr	float	1-sigma uncertainty in iMagnr within 30 arcsec [mag]
gChinr	float	DAOPhot chi parameter of nearest source in the g-band reference image PSF-catalog within 30 arcsec
rChinr	float	DAOPhot chi parameter of nearest source in the r-band reference image PSF-catalog within 30 arcsec
iChinr	float	DAOPhot chi parameter of nearest source in the i-band reference image PSF-catalog within 30 arcsec
gSharpnr	float	DAOPhot sharp parameter of nearest source in the g-band reference image PSF-catalog within 30 arcsec
rSharpnr	float	DAOPhot sharp parameter of nearest source in the r-band reference image PSF-catalog within 30 arcsec
iSharpnr	float	DAOPhot sharp parameter of nearest source in the i-band reference image PSF-catalog within 30 arcsec
Distnrps1	float	Distance of closest source from PS1 catalog; if exists within 30 arcsec [arcsec]
gMagps1	float	g-band PSF magnitude of closest source from PS1 catalog; if exists within 30 arcsec [mag]
rMagps1	float	r-band PSF magnitude of closest source from PS1 catalog; if exists within 30 arcsec [mag]
iMagps1	float	i-band PSF magnitude of closest source from PS1 catalog; if exists within 30 arcsec [mag]
Sgscoreps1	float	Star/Galaxy score of closest source from PS1 catalog [(Galaxy) <-- 0 < Sgscore < 1 --> (Star)]