The Grizzly, March 21, 1980

Regulation in Business: UBEC Presents Symposium • Alumni to Speak at Career Seminar • Awards Available • Board Committees to Evaluate College • USGA Notes • Jazz Coffeehouse at the Union • Ride for Your Life • Letter to the Editor • Meistersingers Tour South • Pericles: The Bearpit\u27s Final Performance • Cub & Key Selected • Chemical Magic • Rating the Recordshttps://digitalcommons.ursinus.edu/grizzlynews/1036/thumbnail.jp

The IPAC Image Subtraction and Discovery Pipeline for the intermediate Palomar Transient Factory

We describe the near real-time transient-source discovery engine for the intermediate Palomar Transient Factory (iPTF), currently in operations at the Infrared Processing and Analysis Center (IPAC), Caltech. We coin this system the IPAC/iPTF Discovery Engine (or IDE). We review the algorithms used for PSF-matching, image subtraction, detection, photometry, and machine-learned (ML) vetting of extracted transient candidates. We also review the performance of our ML classifier. For a limiting signal-to-noise ratio of 4 in relatively unconfused regions, "bogus" candidates from processing artifacts and imperfect image subtractions outnumber real transients by ~ 10:1. This can be considerably higher for image data with inaccurate astrometric and/or PSF-matching solutions. Despite this occasionally high contamination rate, the ML classifier is able to identify real transients with an efficiency (or completeness) of ~ 97% for a maximum tolerable false-positive rate of 1% when classifying raw candidates. All subtraction-image metrics, source features, ML probability-based real-bogus scores, contextual metadata from other surveys, and possible associations with known Solar System objects are stored in a relational database for retrieval by the various science working groups. We review our efforts in mitigating false-positives and our experience in optimizing the overall system in response to the multitude of science projects underway with iPTF.Comment: 66 pages, 21 figures, 7 tables, accepted by PAS

The Grizzly, April 25, 1980

Campus Intruder Apprehended • Spring Fling Slated Tomorrow • Art Piece Missing • Campus Survey Shows Strong Contrast With Pennsylvania Primary Results • UC in Judo Tournament • Fun Run for Charity • Appeal for Jail Visitors • Sun Shines on Parents\u27 Day • Art in the Afternoon • Ursinus Springs Into Springtime • Summer is not Far Behind • Student Art Exhibit Opens • Progress at Ritter Center • Dr. Parsons Speaks at UCC College Heritage Day • Superstars 1980 • Men\u27s Lacrosse Shoots for a Winning Season • Sports Profile: Ken West • Thinclads Up Slate to 6-2 • Softball Shows Great Improvement • Baseball Playoff Picture Looks Dim • Women\u27s Lacrosse Maintains Traditionhttps://digitalcommons.ursinus.edu/grizzlynews/1039/thumbnail.jp