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 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:
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FileName Lrecl Records Explanations
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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
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See also:
I/284 : The USNO-B1.0 Catalog (Monet+ 2003)
Byte-by-byte Description of file: tables3.dat
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Bytes Format Units Label Explanations
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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
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Byte-by-byte Description of file: tables4.dat
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Bytes Format Units Label Explanations
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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
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Note (1): Sample as follows:
A = dM binary sample set
B = WD-dM binary sample set
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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)
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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.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 24-Jul-2017