Data Release Three (DR3)
The PTF Third Public Data Release (DR3) occurred September 1, 2016. This release adds to DR1 and DR2 by including selected g- and R-band data obtained from January 1, 2013 through January 28, 2015. This represents the first 25 months of the Intermediate Palomar Transient Factory (iPTF) phase, defined primarily by a change in partnership and science goals. It also includes a new user interface with direct access to lightcurves derived from source-detected aperture photometry.
Only a subset of the data acquired over this period will be released. The selection criteria are driven by the construction of a Lightcurve Database whereby a significant fraction of low quality data in the galactic plane were omitted. This data will be included in a future release. DR3 includes only nights where the number of galactic plane exposures (with |b| < 15 deg) was <= 20. iPTF does not use a uniform coverage observation strategy and so there exist significant gaps in sky coverage. Also, there is less coverage at g-band than R-band.
In summary, DR3 includes:
651,393 more epochal image products (496,714 in R ; 154,679 in g). These are individual, instrumentally calibrated CCD-based single exposures, with associated catalog files extracted from those images. These catalog files contain the calibrated photometry and shape measurements for all sources (see documentation).
- Here's the full listing of new images in DR3.
- Following DR3, the total number of epochal images publicly available will be ~ 3.47 million in R and ~ 0.72 million in g.
9,638 more co-added (reference) images (7,090 in R ; 2,548 in g). These are similar in size to the individual image exposures (~ 0.6 x 1.1 degrees), and also come with extracted photometric catalogs. The image co-adder places strict quality requirements on the input exposures. Therefore, some areas of the sky that have a few exposures (typically <= 5) will not have co-added images. Furthermore, the tiling scheme is designed to cover inter-CCD gaps; therefore, a given location on the sky is potentially covered by more than one reference image.
- Following DR3, the total number of co-added images publicly available will be 41,200 in R and 15,240 in g.
Searchable database tables (accessible via a user-interface) containing:
- sources extracted from a subset of epochal images acquired from Mar 1, 2009 to Jan 28, 2015;
- sources extracted from the co-add (reference) images;
- photometrically calibrated lightcurves that link the extractions across multiple epochs. In most cases, the photometry in each epoch is further refined through small offsets derived from non-varying stars in the field. See the documentation for details.