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.
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Epochal coverage maps for R-band (left) and g-band (right) following the Third Data Release (including DR1 and DR2 data). The intensity scale is proportional to the number of epochal exposures in the data release. Each image is centered at equatorial 0h,0d.
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Reference image (co-added epoch) coverage maps for R-band (left) and g-band (right) following the Third Data Release (including DR1 and DR2 data). The intensity scale is proportional to the depth (number of epochs) used in each co-add tile. Each image is centered at equatorial 0h,0d.
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In summary, DR3 includes:
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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.
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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.
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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.
