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J/AJ/106/426 Lick slit spectra of quasar (Tytler+, 1993)
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Lick slit spectra of thirty-eight objective prism quasar candidates and low
metallicity halo stars
Tytler D., Fan X.-M., Junkkarinen V.T., Cohen R.D.
<Astron. J. 106, 426 (1993)>
=1993AJ....106..426T (SIMBAD/NED Reference)
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ADC_Keywords: QSOs; Spectroscopy; Photometry, BV
Abstract:
We present Lick Observatory slit spectra of 38 objects which were
claimed to have pronounced ultraviolet excess and emission lines. Zhan
& Chen (ZC) selected these objects by eye from a UK Schmidt telescope
IIIaJ objective prism plate of a field at 0h 0.0deg
(l ~= 98 deg, b ~= -60 deg). We concentrate on m(J) ~= 18-19 objects
which Zhan and Chen (ZC) thought were most likely to be quasistellar
objects (QSOs) at redshift z(em) >= 2.8. Most of our spectra have FWHM
spectral resolutions of about 4 A, and relatively high S/N of
about 10-50, although some have FWHM ~= 15 A or lower S/N. We find
eleven QSOs, four galaxies at z ~= 0.1, twenty-two stars and one
unidentified object with a low S/N spectrum. The ZC lists are found to
contain many QSOs at low z but few at high z, as expected. Of eleven
objects which ZC suggested were QSOs with z(prism) <= 2.8,
eight (73%) are QSOs. But only three of twenty-five candidates with
z(prism) >= 2.8 are QSOs, and only two (8%) of these are at z >= 2.8.
Unfortunately, the ZC prism redshifts are often incorrect: only five
of the eleven QSOs are at redshifts similar to z(prism). Six of the
QSOs show absorption systems, including Q0000+027A with a relatively
strong associated C IV absorption system, and Q0008+008 (V ~= 18.9)
with a damped Ly alpha system with an HI column density of 10^21 cm^-2.
The stars include a wide variety of spectral types. There is one
new DA 4 white dwarf at 170 pc, one sdB at 14 kpc, and three M stars.
The rest are of types F, G, and K. We have measured the equivalent
widths of the Ca II K line, the G band, and the Balmer lines in ten
stars with the best spectra, and we derive metallicities. Seven of them
are in the range -2.5 <= [Fe/H] <= -1.7, while the others are less metal
poor. If the stars are dwarfs, then they are at distances of 1 to 7 kpc,
but if they are giants, typical distances will be about 10 kpc.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
notes.dat 80 172 Notes on individual objects
table1.dat 67 40 Journal of observations
table2.dat 104 38 Summary of spectra
table3.dat 74 40 Magnitudes and spectral indices
table5.dat 108 52 Emission lines
table6.dat 53 39 Major absorption lines in the QSO spectra
tables.tex 126 532 TeX version of the tables
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Object designation
14- 22 A9 "DD/MM/YY" Obs Observation date, U.T.
24- 27 I4 s Int.time Integration time
30 A1 --- Setup [ABC] Instrumental setup (see note (1))
33- 36 I4 0.1nm lamMin []? Minimum wavelength of the total range
(for setup A and B)
38- 41 I4 0.1nm lamMax []? Maximun wavelength of the total range
(for setup A and B)
43- 46 I4 0.1nm lambMin []? Minimum wavelength of the blue range
(for setup C)
48- 51 I4 0.1nm lambMax []? Maximun wavelength of the blue range
(for setup C)
54- 57 I4 0.1nm lamrMin []? Minimum wavelength of the red range
(for setup C)
59- 62 I4 0.1nm lamrMax []? Maximun wavelength of the red range
(for setup C)
65- 67 A3 --- Ref Zhan and Chen references (2)
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Note (1):
Setup A: 10 object with z =~ 3, observed with the UV Schmidt camera
Setup B: 11 intermediate z objects with close neighbours,
observed with the UV Schmidt camera
Setup C: 19 high z objects, observed with the Kast double spectrograph
Note (2):
ZC1: Zhan Y. & Chen J-S. 1987, AcApSn 7, 99; Trans. in Chin.A.Ap., 11, 191
ZC2: Zhan Y. & Chen J-S. 1987, AcApSn 7, 203; Trans. in Chin.A.Ap., 11, 299
ZC3: Zhan Y. & Chen J-S. 1989, AcApSn 9, 37; Trans. in Chin.A.Ap., 13, 139
ZC4: Zhan Y. & Chen J-S. 1989, AcApSn 9, 147; Trans. in Chin.A.Ap., 13, 321
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Object designation
12- 15 F4.2 --- zOP []? Objective prism redshift from the ZC
references (see table1)
18 I1 --- q_zOP Reliability index Q from the ZC references
(see note(1))
21- 23 A3 --- Type Object type (see note (2))
25- 27 A3 --- Sp1 Spectral type from the spectral features
29- 33 A5 --- Sp2 Spectral type from (B-V)0
34- 40 F7.4 --- z []? Redshift
41 A1 --- u_z [? ] Uncertainty flag on z
43-104 A62 --- lines Spectral lines
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Note (1):
The reliability index Q = Q1 + Q2, where Q1 is the given value 1, 2, or 3
according to increasing strength of the emission lines, and Q2 is similarly
valued according to increasing strength of UV excess. Thus, Q = 6 would
label the most reliable candidate
Note (2):
QSO = quasar
gal = galaxy
sta = star
WD = white dwarf
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Object designation
11 A1 --- Setup [AB] Note flag:
'A' for magnitudes measured from Setup A
spectrum, and likely to be systematically
too faint;
'B' for magnitudes measured from Setup B
spectrum.
14- 17 F4.1 mag B(J) B(J) magnitude from ZC references, obtained
from image sizes on a direct Schmidt plate.
20- 24 F5.2 mag U []? U magnitude. U is highly uncertain
27- 31 F5.2 mag B B magnitude. B is highly uncertain
34- 38 F5.2 mag V V magnitude. V is highly uncertain
41- 44 F4.2 mag (B-V)0 (B-V)0 color. (B-V)0 is highly uncertain
47- 50 F4.2 mag (B-V) []? (B-V) color estimated from the Balmer line
index HP using:
(B-V)0 = 0.962 - 0.292HP + 0.036HP^2
52- 56 F5.2 mag Delta []? Slit (B-V) minus HP index (B-V)
59- 62 F4.2 0.1nm HP []? Balmer line index HP, where
HP = -0.120 + 0.5Halpha + 0.555Hgamma,
which is the average of the measured
equivalent width of Halpha, and an estimate
of that width based on the measured
equivalent width of Hgamma.
64- 68 F5.2 0.1nm KP []? Index KP', the Ca II K equivalent width
measured in the 18 A interval, corrected for
interstellar Ca II K absorption by
subtracting 0.22 A.
71- 74 F4.2 0.1nm GP []? G-band (CH) index, GP, the equivalent
width in the 15 A band around 4300 A.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Object designation
12- 17 F6.4 --- <z(em)> []? Mean emission redshift
20- 32 A13 --- Ion Ion
35- 41 F7.2 0.1nm lamLab Laboratory vacuum wavelength
42 A1 --- u_lamLab Uncertainty flag on lamLab
44- 49 F6.1 0.1nm lamObs Observed wavelength
52- 56 F5.1 0.1nm EWobs Observed frame equivalent width. All values
have a decimal point, so that they will be
read correctly by a computer program, but
some of the values were originally integers
58- 63 F6.4 --- z(em) Emission redshift
64- 88 A25 --- Com Comments. The comment 'see notes' refers to
file notes
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Object designation
13- 14 I2 --- No Sequential number counting the line for this
object
17- 22 F6.1 0.1nm WObs []? Observed vacuum wavelength
23 A1 --- n_WObs [d] When 'd', it means that the line was seen
by reference ZC2 (see table1 description)
25- 28 F4.1 0.1nm EWobs []? Observed equivalent width
31- 36 A6 --- Ident Line identification
38- 41 I4 0.1nm WLab []? Laboratory wavelength
44- 45 A2 --- n_WLab [bc ] Note flags:
'b' Blended with C IV (1550 A)
'c' see notes file
48- 52 F5.3 --- z(abs) []? Absorption redshift
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Origin: AAS CD-ROM series, Volume 1, 1993
References:
ZC: Zhan Y. & Chen J-S. 1987, AcApSn 7, 99; Trans. in Chin.A.Ap., 11, 191
ZC: Zhan Y. & Chen J-S. 1987, AcApSn 7, 203; Trans. in Chin.A.Ap., 11, 299
ZC: Zhan Y. & Chen J-S. 1989, AcApSn 9, 37; Trans. in Chin.A.Ap., 13, 139
ZC: Zhan Y. & Chen J-S. 1989, AcApSn 9, 147; Trans. in Chin.A.Ap., 13, 321
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(End) Patricia Bauer [CDS] 25-Jul-1994