J/A+A/250/370 Far-UV excess object survey (Bixler+ 1991)
A high galactic latitude survey of far-ultraviolet excess objects
Bixler J.V., Bowyer S., Laget M.
<Astron. Astrophys. 250, 370 (1991)>
=1991A&A...250..370B 1991A&A...250..370B (SIMBAD/NED BibCode)
ADC_Keywords: Spectra, ultraviolet ; Stars, subdwarf ; Photometry
Keywords: stars: faint blue - stars: subdwarf - surveys - UV radiation
Abstract:
Optical spectra have been obtained for a selection of objects included
in a catalog of far ultraviolet bright, high galactic latitude objects
detected with a balloon-borne survey telescope. The observed objects
provide a sample of subdwarf O and B stars, white dwarfs, and binary
systems including a hot sub-luminous member. Model atmospheres
analysis of the sub-dwarf sample is used to determine the
temperature, gravity, and helium to hydrogen ratio of the individual
objects. A smooth distribution of objects is found on the gravity
versus temperature diagram near the theoretical location of the
extended horizontal branch. A break between the helium rich and helium
poor objects occurs at 40000K. Suspected binary objects were found
and analyzed to determine the temperature and gravity of the hot
subluminous member in each system. The number of subdwarf stars
contained in binaries is determined to be from 65% to 100%. The number
versus ultraviolet magnitude distribution of the subdwarf B sample is
modeled to obtain a midplane density of 3.3x10-6pc-3 and a
population scale height of 240pc. The proportion of white dwarfs
that experience the subdwarf phase of evolution is found to be 0.94%.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3 37 15 Composite star candidates
appena 26 92 Coordinates of optically observed objects
appenc 110 32 Subdwarf B parameters
append 80 5 Subdwarf O parameters
appene 66 18 White dwarf parameters
appenf 33 43 UV (200nm, 12nm FWHM) magnitude of subdwarf B stars
identified in Palomar Green (Cat. II/207) survey
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See also:
II/207: Palomar-Green catalog UV-excess stellar objects (Green+ 1986)
Byte-by-byte Description of file: table3
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Bytes Format Units Label Explanations
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1- 9 I9 --- ID Ballon identification
11- 12 I2 --- Fig Figure number
14- 18 F5.2 mag ymag y magnitude
19 A1 --- n_ymag [a] See note (1)
21- 25 F5.2 mag m(UV)-b m(UV)-b color index (2)
26 A1 --- n_m(UV)-b [b] b: Anomalously large color
28- 31 F4.2 mag b-y b-y color index
32 A1 --- n_b-y [a] See note (1)
34- 37 F4.2 --- f(6750)/f(5450) fλ(6750)/fλ(5450) ratio
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Note (1): a: From Green et al. (1986ApJS...61..305G 1986ApJS...61..305G) Cat. II/207
Note (2): UV magnitude: effective wavelength 200nm, 12nm FWHM
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Byte-by-byte Description of file: appena
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Bytes Format Units Label Explanations
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1- 9 I9 --- ID Balloon number
11- 12 I2 h RAh Right ascension (1950)
14- 17 F4.1 min RAm Right ascension (1950)
20 A1 --- DE- Declination sign (1950)
21- 22 I2 deg DEd Declination (1950)
24- 25 I2 arcmin DEm Declination (1950)
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Byte-by-byte Description of file: appenc
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Bytes Format Units Label Explanations
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1- 9 I9 --- ID Balloon number
11- 15 F5.2 mag m(UV) ? m(UV) magnitude (200nm, 12nm FWHM)
17- 21 F5.2 mag ymag y magnitude
23- 27 F5.2 mag b-y b-y color index
29- 32 F4.1 0.1nm D[0.1]Hb Hβ line width
34- 37 F4.1 0.1nm D[0.1]Hg Hγ line width
39- 43 F5.2 0.1nm EWHb Hβ equivalent width
45- 49 F5.2 0.1nm EWHg Hγ equivalent width
51- 55 F5.3 0.1nm RHb Hβ line depth
57- 61 F5.3 0.1nm RHg Hγ line depth
63- 66 F4.2 [cm/s+2] logg Surface gravity
68- 72 I5 K Teff Effective temperature
74 A1 --- l_EWHeIa Limit flag on EWHeIa
75- 78 F4.2 0.1nm EWHeIa He I 4471A equivalent width
80 A1 --- l_EWHeIb Limit flag on EWHeIb
81- 84 F4.2 0.1nm EWHeIb He I 4922A equivalent width
86 A1 --- l_EWHeII Limit flag on EWHeII
87- 90 F4.2 0.1nm EWHeII He II 4686A equivalent width
92- 95 F4.2 0.1nm e_EW rms uncertainty on EW measurements
97 A1 --- l_He/H Limit flag on He/H
98-102 F5.3 --- He/H He/H ratio
105-112 A8 --- Com Comments (1)
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Note (1): 1: Blue photographic magnitude of Green et al. (1986) Cat. II/207
used to compute m(UV)-B
2: Balloon m(UV) not used due to large discrepancy with optical colors
3: Additional optical photometry used
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Byte-by-byte Description of file: append
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Bytes Format Units Label Explanations
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1- 9 I9 --- ID Balloon number
11- 15 F5.2 mag m(UV) m(UV) magnitude (200nm, 12nm FWHM)
17- 21 F5.2 mag ymag y magnitude
23- 27 F5.2 mag b-y b-y color index
29 A1 --- l_EWHeIa Limit flag on EWHeIa
30- 33 F4.2 --- EWHeIa He I 4388A equivalent width
35 A1 --- l_EWHeIb Limit flag on EWHeIb
36- 39 F4.2 --- EWHeIb He I 4471A equivalent width
41 A1 --- l_EWHeIc Limit flag on EWHeIc
42- 45 F4.2 --- EWHeIc He I 4921A equivalent width
47 A1 --- l_H/HeIIa Limit flag on H/HeIIa
48- 51 F4.2 --- H/HeIIa H/He II 4200 A ratio
53 A1 --- l_H/HeIIb Limit flag on H/HeIIb
54- 57 F4.2 --- H/HeIIb H/He II 4340 A ratio
59 A1 --- l_H/HeIIc Limit flag on H/HeIIc
60- 63 F4.2 --- H/HeIIc H/He II 4542 A ratio
65 A1 --- l_H/HeIId Limit flag on H/HeIId
66- 69 F4.2 --- H/HeIId H/He II 4686 A ratio
71- 74 F4.2 --- H/HeIIe H/He II 4861 A ratio
76 A1 --- l_H/HeIIf Limit flag on H/HeIIf
77- 80 F4.2 --- H/HeIIf H/He II 5412 A ratio
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Byte-by-byte Description of file: appene
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Bytes Format Units Label Explanations
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1- 9 I9 --- ID Balloon number
11- 15 F5.2 mag m(UV) ? m(UV) magnitude (200nm, 12nm FWHM)
17- 21 F5.2 mag ymag y magnitude
23- 26 F4.1 0.1nm D[0.1]Hb ? Hβ line width
28- 31 F4.1 0.1nm D[0.1]Hg ? Hγ line width
33- 37 F5.2 0.1nm EWHb Hβ equivalent width
39- 43 F5.2 0.1nm EWHg Hγ equivalent width
45- 49 F5.3 0.1nm RHb Hβ line depth
51- 55 F5.3 0.1nm RHg Hγ line depth
57- 60 F4.2 [cm/s+2] logg ? Surface gravity
62- 66 I5 K Teff ? Effective temperature
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Byte-by-byte Description of file: appenf
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Right ascension 1950
4- 7 F4.1 min RAm Right ascension
9 A1 --- DE- DEclination sign
10- 11 I2 deg DEd Declination 1950
13- 14 I2 arcmin DEm Declination
17- 25 I9 --- ID Balloon number
27- 31 F5.2 mag m(UV) m(UV) magnitude (200nm, 12nm FWHM)
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Table 4: Deconvolution results for composite objects
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Balloon Figure Sec. Temp. Fp-Fs Primary
number ID Sp. type (x103K) Optical UV MV logg
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113435001 1 K4 28 66-34 68-32 6.2 6.3
110607002 2 K0 14 13-87 12-88 8.0 6.6
114041002 3 K5 28 80-20 80-20 5.8 6.1
081300002 4 K1 21 72-28 69-31 5.4 5.9
081400003 6 K4 38 70-30 70-30 6.1 6.5
082800003 7 K1 21 53-47 57-43 6.2 6.6
092200002 12 K3 10 82-18 82-18 4.8 5.0
090900007 13 G2 24 37-63 33-67 5.5 5.9
083738002 14 K3 32 55-45 55-45 6.5 6.6
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Note to Fp-Fs: yp=-2.5log(Fp/Fs)+ys Fp where
Fp is the flux of the primary, Fs is the flux of the secondary,
yp is the primary y magnitude and ys the secondary y magnitude
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History: Prepared via OCR at CDS.
(End) James Marcout, Patricia Bauer [CDS] 25-Oct-1996