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Eric Q to Michael “can you say more about how you are fitting/estimating the light curves features (peak time, rise and fall times)”.
A. Rise time is the what was peak magnitude, what was the starting magnitude and what was the time between the two. Polynomial fit applied. This depends on the number of points available.
Julien P Q to Michael - Are predictions done using the aggregated light-curve or the last alert information ? What about the evolution of score, do you report the full history of classification or just the last score? Julien asked if prediction is based on light curve
A. Prediction is based on position in parameter space of candidate. This is done for all features and results normalised to create score.
A Lasair will only store the most recent classification from FastFinder, but hope to have option to click through to history of FastFinder classiificatons.
Cosimo asked whether FastFinder needs information from different bands to be on same day or in 3--4 day timeframe?
Features are extracted as they become available, and information is derived as is possible based on available features. So, need to advise how many features have been used to create classification, as indication of relative reliability of classification.
Jacob noted using absolute magniture, which relies on good redshift. how sensitive is classifier. Also why not run on ZTF?
Redshifts have been measured from Sherlock, so errors are attributable to Sherlock. If host nearby does not have redshift then object is ignored. Risk is minimal if have secure association with galaxy of known redshift. Likely dominated by errors in photometry (if spectroscopic). If not, then photometry is likey source of error, so make assumption know distance and filter on that. Idea is to filter down to small number of objects to follow up (quickly) for further follow-up. Michael noted absolute magnitudes do contain redshift error bars, so FastFinder can consider that as part of prediction.
FastFinder is being run on ZTF.
Andy L noted that this is important as resolves argument of whether or not to provide lightcurve classifier within main Lasair service. Michael has provided an alternative method and, by
Cosimo also asked is there plan to increase the database [of templates] to deal with new discoveries?
Cosimo Q on chat “Do you need a data point in each band or not? What are the plans to increase the data templates.”
StephenS answered on chat . “one band is enough to get a score. The date templates are the most work, and yes we do plan to increase templates “
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