Cross-Matching Source Observations from the Palomar Transient Factory (PTF)

Details Cross-Matching Source Observations from the Palomar Transient Factory (PTF) Cross-Matching Source Observations from the Palomar Transient Factory (PTF)

Jan 2009

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009aas...21346906l&link_type=abstract

American Astronomical Society, AAS Meeting #213, #469.06; Bulletin of the American Astronomical Society, Vol. 41, p.419

Statistics

Scientific paper

Over the four-year lifetime of the PTF project, approximately 40 billion instances of astronomical-source observations will be extracted from the image data. The instances will correspond to the same astronomical objects being observed at roughly 25-50 different times, and so a very large catalog containing important object-variability information will be the chief PTF product. Organizing astronomical-source catalogs is conventionally done by dividing the catalog into declination zones and sorting by right ascension within each zone (e.g., the USNOA star catalog), in order to facilitate catalog searches. This method was reincarnated as the "zones" algorithm in a SQL-Server database implementation (Szalay et al., MSR-TR-2004-32), with corrections given by Gray et al. (MSR-TR-2006-52). The primary advantage of this implementation is that all of the work is done entirely on the database server and client/server communication is eliminated. We implemented the methods outlined in Gray et al. for a PostgreSQL database. We programmed the methods as database functions in PL/pgSQL procedural language. The cross-matching is currently based on source positions, but we intend to extend it to use both positions and positional uncertainties to form a chi-square statistic for optimal thresholding. The database design includes three main tables, plus a handful of internal tables. The Sources table stores the SExtractor source extractions taken at various times; the MergedSources table stores statistics about the astronomical objects, which are the result of cross-matching records in the Sources table; and the Merges table, which associates cross-matched primary keys in the Sources table with primary keys in the MergedSoures table. Besides judicious database indexing, we have also internally partitioned the Sources table by declination zone, in order to speed up the population of Sources records and make the database more manageable. The catalog will be accessible to the public after the proprietary period through IRSA (irsa.ipac.caltech.edu).

Affiliated with

Also associated with

No associations

Rating

Cross-Matching Source Observations from the Palomar Transient Factory (PTF) does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Cross-Matching Source Observations from the Palomar Transient Factory (PTF), we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cross-Matching Source Observations from the Palomar Transient Factory (PTF) will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1706463