Aperture Photometry Tool Versus SExtractor for Noncrowded Fields

作者：Laher Russ R^*; Rebull Luisa M; Gorjian Varoujan; Masci Frank J; Fowler John W; Grillmair Carl; Surace Jason; Mattingly Sean; Jackson Ed; Hacopeans Eugean; Hamam Nouhad; Groom Steve; Teplitz Harry; Mi Wei; Helou George; van Eyken Julian C; Law Nicholas M; Dekany Richard G; Rahmer Gustavo; Hale David; Smith Roger; Quimby Robert M; Ofek Eran O; Kasliwal Mansi M; Zolkower Jeff; Velur Viswa; Walters Richard; Henning John; Bui Khahn; McKenna Dan

来源：Publications of the Astronomical Society of the Pacific, 2012, 124(917): 764-781.

DOI：10.1086/666507

Outputs from new software program Aperture Photometry Tool (APT) are compared with similar outputs from SExtractor for sources extracted from R-band optical images acquired by the Palomar Transient Factory (PTF), infrared mosaics constructed from Spitzer Space Telescope images, and a processed visible/near-infrared image from the Hubble Legacy Archive (HLA). Two large samples from the PTF images are studied, each containing around 3 x 10(3) sources from noncrowded fields. The median values of source-intensity relative percentage differences between the two software programs, computed separately for two PTF samples, are +0.13% and +0.17%, with corresponding statistical dispersions of 1.43% and 1.84%, respectively. For the Spitzer mosaics, a similar large sample of extracted sources for each of channels 1-4 of Spitzer's Infrared Array Camera (IRAC) are analyzed with two different sky annulus sizes, and we find that the median and modal values of source-intensity relative percentage differences between the two software programs are between -0.5% and +2.0%, and the corresponding statistical dispersions range from 1.4 to 6.7%, depending on the Spitzer IRAC channel and sky annulus. The results for the HLA image are mixed, as might be expected for a moderately crowded field. The comparisons for the three different kinds of images show that there is generally excellent agreement between APT and SExtractor. Differences in source-intensity uncertainty estimates for the PTF images amount to less than 3% for the PTF sources, and these are potentially caused by SExtractor's omission of the sky background uncertainty term in the formula for source-intensity uncertainty, as well as differing methods of sky background estimation.

• 出版日期2012-7