PS1 3pi DVO Database Snapshop 2011.04.21

The latest 3pi DVO database release can be found at the following location:

rsync://ipp0032.ifa.hawaii.edu/ps1-3pi-catdirs-20110421

This rsync location is protected with a password, see your DRAVG representative for information

The following plots show the coverage in g,r,i,z,y.

g
r
i
z
y

This database is similar in contents to the previous (2011/2/1) database.

Some notes on what this database contains:

• all¹ 3pi data taken since the start of demo month (2010/2/12) through the start of April (2011/4/1)
• 2MASS detections matched to all objects
• average fields for grizy and JHK (eg, avextract g i J K would work)
• zero point calibrations for the PS1 data come from the synthetic photometry database.
• astrometric calibration is the default in-line calibration relative to the 2MASS frame
• average magnitudes use a weighted mean, and skip detections that have PSF_QF < 0.85 (excessively masked objects). there is no iterative clipping, however.

¹ a caveat regarding coverage: there seem to be some gaps that do not correspond to known gaps in the data taken.

In addition, there are 4 bit flags available in the average table for each object to give a hint at quality and extendedness:

• for all PS1 detections, the detection is considered 'extended' if (mag_psf - mag_ap > 0.5)
• if the number of 'extended detections' exceeds the number of 'psf-like' detections, the object is flagged as "PS1 extended" (objflag & 0x01000000)
• if any of the detections have PSF_QF > 0.85, then the object is considered "PS1 good" (objflag & 0x04000000)
• similarly, if the 2MASS J-band flags indicate the source is extended, the object is considered "2MASS extended" (objflag & 0x02000000)
• if the 2MASS J-band detection is significant (), the source is considered "2MASS good" (objflag & 0x08000000)
  • A significant 2MASS source means their field ph_qual is one of the 3 classes A, B, or C, which means the source is > 5 sigma and has some quality limits.

For more information about 2MASS representation in DVO, see 2MASS_info_in_DVO.