J/A+A/591/A96 Robust detection of CID double stars in SDSS (Pourbaix+, 2016)
Robust detection of CID double stars in SDSS.
Pourbaix D., Knapp G.R., Gunn J.E., Lupton R.H., Ivezic Z., Siopis C.,
Rigaux M., Rubens A.
<Astron. Astrophys. 591, A96 (2016)>
=2016A&A...591A..96P 2016A&A...591A..96P (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Positional data ; Photometry, SDSS
Keywords: binaries: general - astrometry - methods: data analysis
Abstract:
The Sloan Digital Sky Survey (SDSS) offers a unique possibility of not
only detecting colour induced displacement (CID) double stars but also
confirming these detections. Successive cuts are applied to the SDSS
data release (DR) 12 database to reduce the size of the sample under
consideration. The resulting dataset is then screened with a criterion
based on the distance and orientation of the photocentres in different
photometric bands. About 3200 distinct objects are classified as CID
double stars, 40 of which are confirmed with at least a second
detection. A consistency check further validates these detections.
Description:
Whereas the possibility of detecting CID double stars with SDSS has
been known for more than a decade, the absence of repeated observation
(in particular of CID candidates) has prevented the validation of the
technique, despite its easy setup. We have shown here that some CID
are confirmed by at least a second observation.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 102 3212 Identified CID with their THING Id, position,
and SDSS dereddened magnitude for the five
photometric bands
table2.dat 70 3273 Accepted CID observations for the candidates
listed in Table 1 with their THING Id,
objectId, date, and offsets in right ascension
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See also:
http://www.sdss.org : SDSS Home page
Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [SDSS]
5- 23 A19 --- SDSS SDSS designation (JHHMMSS.ss+DDMMSS.s)
25- 33 I9 --- ID Primary key for any SDSS object, THING ID
35- 44 F10.6 deg RAdeg Right ascension (J2000)
46- 55 F10.6 deg DEdeg Declination (J2000)
57 I1 --- N Number of observations flagged as CID
59- 66 F8.4 mag u*mag0 Dereddened SDSS u* magnitude
68- 75 F8.4 mag g*mag0 Dereddened SDSS g* magnitude
77- 84 F8.4 mag r*mag0 Dereddened SDSS r* magnitude
86- 93 F8.4 mag i*mag0 Dereddened SDSS i* magnitude
95-102 F8.4 mag z*mag0 Dereddened SDSS z* magnitude
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- ID Primary key for any SDSS object, THING ID
11- 29 I19 --- objID Unique identifier for any SDSS observation
31- 38 F8.2 d MJD epoch of the observation
40- 46 F7.4 arcsec oRAu Offset in right ascension in the u band (1)
48- 54 F7.4 arcsec oDEu Offset in declination in the u band (1)
56- 62 F7.4 arcsec oRAz Offset in right ascension in the z band (1)
64- 70 F7.4 arcsec oDEz Offset in declination in the z band (1)
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Note (1): Offset in RA*cos(DE) and declination in the u and z bands with
respect to the position in the r band.
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Acknowledgements:
Dimitri Pourbaix, pourbaix(at)astro.ulb.ac.be
(End) Dimitri Pourbaix [FNRS, ULB, Belgium], Patricia Vannier [CDS] 24-May-2016