Publ. Astron. Soc. Pac., 129, part no 4, 4501-44501 (2017/April-0)
Image subtraction reduction of open clusters M35 & NGC 2158 in the K2 campaign 0 super stamps.
SOARES-FURTADO M., HARTMAN J.D., BAKOS G.A., HUANG C.X., PENEV K. and BHATTI W.
Abstract (from CDS):
We observed the open clusters M35 and NGC 2158 during the initial K2 campaign (C0). Reducing these data to high-precision photometric timeseries is challenging due to the wide point-spread function (PSF) and the blending of stellar light in such dense regions. We developed an image-subtraction-based K2 reduction pipeline that is applicable to both crowded and sparse stellar fields. We applied our pipeline to the data-rich C0 K2 super stamp, containing the two open clusters, as well as to the neighboring postage stamps. In this paper, we present our image subtraction reduction pipeline and demonstrate that this technique achieves ultra-high photometric precision for sources in the C0 super stamp. We extract the raw light curves of 3960 stars taken from the UCAC4 and EPIC catalogs and de-trend them for systematic effects. We compare our photometric results with the prior reductions published in the literature. For de-trended TFA-corrected sources in the 12-12.25 Kp
magnitude range, we achieve a best 6.5-hour window running rms of 35 ppm, falling to 100 ppm for fainter stars in the 14-14.25 Kp
magnitude range. For stars with Kp
14, our de-trended and 6.5-hour binned light curves achieve the highest photometric precision. Moreover, all our TFA-corrected sources have higher precision on all timescales investigated. This work represents the first published image subtraction analysis of a K2 super stamp. This method will be particularly useful for analyzing the Galactic bulge observations carried out during K2 campaign 9. The raw light curves and the final results of our de-trending processes are publicly available at http://k2.hatsurveys.org/archive/.
© 2017. The Astronomical Society of the Pacific. All rights reserved.
View the reference in ADS
To bookmark this query, right click on this link: simbad:2017PASP..129d4501S and select 'bookmark this link' or equivalent in the popup menu