J/MNRAS/247/182 Catalogue of quasar candidates (Beauchemin+, 1990)
A homogeneous catalogue of quasar candidates found with slitless spectroscopy
BEAUCHEMIN. M., BORRA. E.F., EDWARDS G.
<Mon. Not. R. Astron. Soc. 247, 182 (1990)>
=1990MNRAS.247..182B 1990MNRAS.247..182B (SIMBAD/NED Reference)
ADC_Keywords: QSOs; Spectroscopy
Abstract:
This paper gives a list of all quasar candidates obtained from an
automated computer search performed on 11 grens plates. The description
of the main characteristics of the survey is given along with the
latest improvements in the selection techniques. Particular attention
has been paid to understanding and quantifying selection effects.
This allows the construction of homogeneous samples having
well-understood characteristics. The noteworthy aspect of our
homogenization process is the correction that we apply to our
probability classes in order to take into account the signal-to-noise
differences; at a given magnitude, among plates of different limiting
magnitudes. Since such homogeneous material is rare, this catalogue
is of general interest. Each grens plate covers about 1 square degree
with typical limiting magnitude of B∼21. Data are given with all
relevant quantities needed to understand the characteristics of the
survey. We expect that over 100 of the 125 higher probability class
candidates are quasars. A third of the ∼400 lower probability
objects should also be quasars. This material is well-suited to
follow-up spectroscopy with fibre spectrographs.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table5 90 758 Catalogue of quasar candidates
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Field Field name
6- 9 I4 --- Id Grens reference number inside the field
11- 12 I2 h RAh Right ascension 1950
14- 15 I2 min RAm Right ascension 1950
17- 21 F5.2 s RAs Right ascension 1950
23 A1 --- DE- Declination sign
24- 25 I2 deg DEd Declination 1950
27- 28 I2 arcmin DEm Declination 1950
30- 33 F4.1 arcsec DEs Declination 1950
34- 35 A2 --- u_DEs [* ] Uncertainty flag on DE (1)
37- 41 F5.2 mag Jmag J magnitude
43 I1 --- PrClass Probability class (2)
45- 49 F5.2 mag gb-gv gb-gv grens colour index
51- 55 F5.2 mag gu-gb gu-gb grens colour index
59 I1 --- Dms Distance of the candidate from the nominal
locus of the main sequence of stars (3)
63- 69 A7 --- Sample Sample membership of the candidate
72- 81 A10 0.1nm EmLine Wavelength of the emission lines detected on
grens plates for the highest probability
classes candidates PC1
83 A1 --- Type [QS] Object type of some candidates (4)
86- 90 F5.3 --- z []? Emmision line redshift confirmed by
slit spectroscopy
--------------------------------------------------------------------------------
Note (1): *: Astrometry accurate to 0.6 arcsec
**: Astrometry accurate to about 3 arcsec (evaluated on grens plates)
Note (2): 1: line s/n > 8 or 2 lines with s/n > 5 separated by at least 600 A
2: 6 < line s/n < 8
3: 5 < line s/n < 6 and colours more than 1 sigma away from the
stellar main-sequence
4: no line and unusual colours (colour indices more than 2 standard
deviations away from the stellas main-sequence locus)
Note (3): 0: the distance is between 0 and 1 standard deviation
1: the distance is between 1 and 2 standard deviations
2: the distance is between 2 and 3 standard deviations
3: the distance is greater than 3 standard deviations
Note (4): Q = quasar, S = star
--------------------------------------------------------------------------------
(End) Marie-Jose Wagner, Patricia Bauer [CDS] 20-Jan-1995