MILLIONS OF MULTIPLES: DETECTING AND CHARACTERIZING CLOSE-SEPARATION BINARY SYSTEMS IN SYNOPTIC SKY SURVEYS

Journal Article · Sat Jun 01 00:00:00 EDT 2013 · Astrophysical Journal, Supplement Series

DOI:https://doi.org/10.1088/0067-0049/206/2/18· OSTI ID:22118771

Terziev, Emil; Law, Nicholas M. ^[1]; Arcavi, Iair ^[2]; Baranec, Christoph; Bui, Khanh; Dekany, Richard G.; Kulkarni, S. R.; Riddle, Reed; Tendulkar, Shriharsh P. ^[3]; Bloom, Joshua S. ^[4]; Burse, Mahesh P.; Chorida, Pravin; Das, H. K.; Punnadi, Sujit; Ramaprakash, A. N. ^[5]; Kraus, Adam L. ^[6]; Nugent, Peter ^[7]; Ofek, Eran O. ^[8]; Sullivan, Mark ^[9]

---

1. Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, Ontario M5S 3H4 (Canada)
2. Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 76100 (Israel)
3. Cahill Center for Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States)
4. Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)
5. Inter-University Centre for Astronomy and Astrophysics, Ganeshkhind, Pune 411007 (India)
6. Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
7. Computational Cosmology Center, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)
8. Benoziyo Center for Astrophysics, Weizmann Institute of Science, 76100 Rehovot (Israel)
9. Department of Physics (Astrophysics), University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom)

The direct detection of binary systems in wide-field surveys is limited by the size of the stars' point-spread functions (PSFs). A search for elongated objects can find closer companions, but is limited by the precision to which the PSF shape can be calibrated for individual stars. Based on a technique from weak-lensing analysis, we have developed the BinaryFinder algorithm to search for close binaries by using precision measurements of PSF ellipticity across wide-field survey images. We show that the algorithm is capable of reliably detecting binary systems down to Almost-Equal-To 1/5 of the seeing limit, and can directly measure the systems' position angles, separations, and contrast ratios. To verify the algorithm's performance we evaluated 100,000 objects in Palomar Transient Factory (PTF) wide-field-survey data for signs of binarity, and then used the Robo-AO robotic laser adaptive optics system to verify the parameters of 44 high-confidence targets. We show that BinaryFinder correctly predicts the presence of close companions with a <11% false-positive rate, measures the detected binaries' position angles within 1 Degree-Sign to 4 Degree-Sign (depending on signal-to-noise ratio and separation), and separations within 25%, and weakly constrains their contrast ratios. When applied to the full PTF data set, we estimate that BinaryFinder will discover and characterize {approx}450,000 physically associated binary systems with separations <2 arcsec and magnitudes brighter than m{sub R} = 18. New wide-field synoptic surveys with high sensitivity and sub-arcsecond angular resolution, such as LSST, will allow BinaryFinder to reliably detect millions of very faint binary systems with separations as small as 0.1 arcsec.

• OSTI ID: 22118771
• Journal Information: Astrophysical Journal, Supplement Series, Vol. 206, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0067-0049
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ACCURACY
ALGORITHMS
ASTRONOMY
ASTROPHYSICS
DATA ANALYSIS
DETECTION
IMAGE PROCESSING
IMAGES
LENSES
OPTICS
RESOLUTION
SENSITIVITY
SIGNAL-TO-NOISE RATIO
SKY
STARS
STATISTICS