J/ApJS/61/569 KPD UV-excess objects (Downes+, 1986)
The KPD survey for galactic plane ultraviolet-excess objects:
space densities of white dwarfs and subdwarfs.
Downes R.A.
<Astrophys. J. Suppl. Ser., 61, 569-584 (1986)>
=1986ApJS...61..569D 1986ApJS...61..569D
ADC_Keywords: Stars, white dwarf ; Stars, subdwarf ; Spectral types;
Photometry, UBV
Keywords: stars: faint blue ; stars: stellar statistics ; stars: subdwarfs ;
stars: white dwarfs
Abstract:
A survey for ultraviolet-excess objects has been performed for over
about 1000sq.deg of the Galactic plane. Photographic blue and
ultraviolet plates were obtained to select ultraviolet-excess
candidates, and spectroscopic observations were used to determine
the nature of those objects. Over 70 white dwarfs and subdwarfs were
identified from the survey plates, and these objects were analyzed
statistically to determine scale heights and space densities. The
sample was complete to B=15.3mag, with the space density of white
dwarfs for Mv<12.25 equal to 0.72±0.25 per 1000pc3, slightly
higher than that from the Palomar-Green survey. The average absolute
magnitude determined for both the subdwarf O and the subdwarf B stars
was considerably fainter than previous determinations, while the scale
height for the subdwarfs was lower than earlier suggested values. The
space density for the subdwarf O stars is about 7x10-7pc-3, while
the value for the subdwarf B stars is about 2x10-6pc^-3, both values
considerably higher than previous estimates. The space densities can
be used to place evolutionary constraints on these objects.
Description:
The Kitt Peak-Downes (KPD) survey consists of 3 parts:
* photographic data obtained between 1981 July and 1983 July with the
0.6m Warner and Swasey Burrell Schmidt telescope at Kitt Peak, on
IIa-O plates with a Schott UG-2 filter for the ultraviolet plates
and a Schott UG-2 filter for the blue plates, the same filters used
for the PG survey (Green et al. Cat. II/207). The collection is made
of 52 plate pairs in regions within 12° of the Galactic plane with
declination < 60°
* spectroscopic observations of the UV-excess candidates were obtained
on the Mount Lemmon UCSD/Minnesota 1.5m telescope equipped with the
Robinson-Wampler image-tube scanner, with a low-resolution grating
of about 15Å in the 4000-6800Å range.
* photoelectric photometry was obtained with the 1.3m telescope at Kitt
Peak with the Mark II photometer.
The original semi-accurate positions scatter by typically 30" to 60";
most of the stars have charts, and the accurate positions were derived
by B. Skiff (Lowell Obs.) in 2009 April.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
kpd.dat 110 94 White dwarfs (table 3), sdO (table 6) and B (table 8)
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See also:
II/106 : Kiso Ultraviolet Catalog (KUV) (Noguchi+ 1980-1984)
II/207 : Palomar-Green catalog UV-excess stellar objects (Green+ 1986)
Byte-by-byte Description of file: kpd.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [KPD]
5- 13 A9 --- KPD KPD source name (HHMM+DDMM, B1950 equinox)
17- 18 I2 h RAh Right Ascension J2000 (hours)
20- 21 I2 min RAm Right Ascension J2000 (minutes)
23- 27 F5.2 s RAs Right Ascension J2000 (seconds)
29 A1 --- DE- Declination J2000 (sign)
30- 31 I2 deg DEd Declination J2000 (degrees)
33- 34 I2 arcmin DEm Declination J2000 (minutes)
36- 39 F4.1 arcsec DEs Declination J2000 (seconds)
41 A1 --- s [BbCgLMU] Source of position (1)
43- 47 F5.2 mag Vmag Johnson V magnitude (2)
49- 53 F5.2 mag B-V ? B-V color index (2)
55- 59 F5.2 mag U-B U-B color index (2)
62- 66 A5 --- SpT Spectral type
72-110 A39 --- Rem Notes and remarks, by B. Skiff
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Note (1): position sources (column 's'):
B = Bordeaux meridian circle (2006A&A...448.1235D 2006A&A...448.1235D, I/300)
b = USNO-B1.0 (2003AJ....125..984M 2003AJ....125..984M, I/284)
C = Carlsberg meridian circle CMC14 (2006yCat.1304.....C 2006yCat.1304.....C, I/304)
g = GSC-2.3 (2006yCat.1305.....S 2006yCat.1305.....S, Cat. I/305)
L = LSPM (2005AJ....129.1483L 2005AJ....129.1483L, I/298)
M = 2MASS (2006AJ....131.1163S 2006AJ....131.1163S, II/246)
U = UCAC2 (2000AJ....120.2131Z 2000AJ....120.2131Z, I/289)
Note (2): for 2 stars (KPD 2026+2205 and 2349+5009) (B-V) is blank;
V is an estimation and U-B is photographic,
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History:
Prepared by B. Skiff (Lowell Obs.); photometry added at CDS.
(End) Brian Skiff [Lowell Obs.], Francois Ochsenbein [CDS] 14-Apr-2009