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J/MNRAS/457/133     Displaced red and blue components objects     (Jayson, 2016)

Application of USNO-B1.0 towards selecting objects with displaced blue and red components. Jayson J.S. <Mon. Not. R. Astron. Soc., 457, 133-146 (2016)> =2016MNRAS.457..133J (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple Keywords: methods: data analysis - binaries: visual - white dwarfs - galaxies: starburst Abstract: We have conducted a feasibility study to determine the effectiveness of using USNO-B1.0 data to preferentially detect objects with displaced red and blue components. A procedure was developed to search catalogue entries for such objects, which include M dwarfs paired with white dwarfs or with earlier main-sequence stars, and galaxies with asymmetric colour distributions. Residual differences between red and blue and infrared and blue scanned emulsion images define vectors, which, when appropriately aligned and of sufficient length, signal potential candidates. Test sample sets were analysed to evaluate the effective discrimination of the technique. Over 91000 USNO-B1.0 catalogue entries at points throughout the celestial sphere were then filtered for acceptable combinations of entry observations and magnitudes and the resulting total of about 17000 entries was winnowed down to a little more than 200 objects of interest. These were screened by visual examination of photo images to a final total of 146 candidates. About one quarter of these candidates coincide with SDSS (Sloan Digital Sky Survey) data. Those constituents fall into two groups, single and paired objects. SDSS identified several galaxies in the first group. Regarding the second group, at least half of its members were tentatively identified as main-sequence pairs, the greater portion being of widely separated spectral types. Two white dwarf-main-sequence pairs were also identified. Most importantly, the vectors formed from USNO-B1.0 residuals were in alignment with corresponding SDSS pair position angles, thereby supporting this work's central thesis. Description: This feasibility study aimed at demonstrating the value of the USNO-B catalogue for selecting objects with displaced blue and red components. The specifics of the approach were developed with the aid of analysis of three sample test sets of known properties. Over 91000 USNO-B entries were then sifted and analysed and the results visually screened to obtain a candidate list of 144 objects. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file tables3.dat 70 40 Single star sample set tables4.dat 88 80 Binary sample sets tables6.dat 94 144 Candidate list
See also: I/284 : The USNO-B1.0 Catalog (Monet+ 2003) Byte-by-byte Description of file: tables3.dat
Bytes Format Units Label Explanations
1- 12 A12 --- USNO USNO-B1.0 name 14- 36 A23 --- AName Alternative name 39- 40 I2 h RAh Right ascension (J2000) 42- 43 I2 min RAm Right ascension (J2000) 45- 49 F5.2 s RAs Right ascension (J2000) 51 A1 --- DE- Declination sign (J2000) 52- 53 I2 deg DEd Declination (J2000) 55- 56 I2 arcmin DEm Declination (J2000) 58- 62 F5.2 arcsec DEs Declination (J2000) 64- 67 F4.2 arcsec rrms sample deviation of the rms residual radius 69- 70 I2 --- pts ?=-1 Point count
Byte-by-byte Description of file: tables4.dat
Bytes Format Units Label Explanations
1 A1 --- Sample [AB] Sample (1) 3- 15 A13 --- USNO USNO-B1.0 name 17- 39 A23 --- AName Alternate name 41- 42 I2 h RAh Right ascension (J2000) 44- 45 I2 min RAm Right ascension (J2000) 47- 51 F5.2 s RAs Right ascension (J2000) 53 A1 --- DE- Declination sign (J2000) 54- 55 I2 deg DEd Declination (J2000) 57- 58 I2 arcmin DEm Declination (J2000) 60- 64 F5.2 arcsec DEs Declination (J2000) 66 A1 --- l_Sep [~<] Limit flag on Sep 67- 72 F6.3 arcsec Sep Separation 73 A1 --- n_Sep [-/] 74- 78 F5.3 arcsec Sep2 ? Second value of separation 79 A1 --- --- [/] 80- 82 A3 --- f_Sep [WDS ] 84 I1 --- r_Sep ? Reference for Sep 86 A1 --- Flag [Y] SDSS WD-dM ? 88 I1 --- pts ? Point count
Note (1): Sample as follows: A = dM binary sample set B = WD-dM binary sample set
Byte-by-byte Description of file: tables6.dat
Bytes Format Units Label Explanations
1- 12 A12 --- USNO USNO-B1.0 name 15- 16 I2 h RAh Right ascension (J2000) 18- 19 I2 min RAm Right ascension (J2000) 21- 25 F5.2 s RAs Right ascension (J2000) 27 A1 --- DE- Declination sign (J2000) 28- 29 I2 deg DEd Declination (J2000) 31- 32 I2 arcmin DEm Declination (J2000) 34- 38 F5.2 arcsec DEs Declination (J2000) 41 I1 --- Nobs Nunber of observations 44- 48 F5.1 deg PAR1-B1 ?=- R1-B1 position angle (1) 50- 54 F5.1 deg PAR2-B2 ?=- R2-B2 position angle (1) 57- 61 F5.1 deg PAI2-B2 ?=- I2-B2 position angle (1) 63- 66 F4.2 arcsec VectorR1-B1 ?=- Displacement vector between R1 and B1 (1) 69- 72 F4.2 arcsec VectorR2-B2 ?=- Displacement vector between R2 and B2 (1) 74- 77 F4.2 arcsec VectorI2-B2 ?=- Displacement vector between I2 and B2 (1) 79- 94 A16 --- img USNO-B1.0 image SDSS data (2)
Note (1): R1 refers to the epoch 1 red exposure residual value, B1 refers to the epoch 1 blue exposure residual value, R2 refers to the epoch 2 red exposure residual value, B2 refers to the epoch 2 blue exposure residual value, I2 refers to the epoch 2 infrared residual value Note (2): Subjective assessment of the USNO-B1.0 images, either compact (c) or extended (e). Ambiguous instances have been left blank. Multiple objects on the images are noted where there is a possibility of confused readings. SDSS indicates availability of SDSS data.
History: From electronic version of the journal
(End) Patricia Vannier [CDS] 24-Jul-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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