J/ApJ/543/552 z>3 damped Lyα absorption systems (Storrie-Lombardi+, 2000)
Surveys for z>3 damped Lyα absorption systems:
the evolution of neutral gas.
Storrie-Lombardi L.J., Wolfe A.M.
<Astrophys. J. 543, 552 (2000)>
=2000ApJ...543..552S 2000ApJ...543..552S
ADC_Keywords: QSOs ; Redshifts
Keywords: galaxies: evolution - intergalactic medium - quasars: absorption lines
Abstract:
We have completed spectroscopic observations using LRIS on the Keck 1
telescope of 30 very high redshift quasars, 11 selected for the
presence of damped Lyα absorption systems and 19 with redshifts
z>3.5 not previously surveyed for absorption systems. We have surveyed
an additional 10 QSOs with the Lick 120" and the Anglo-Australian
Telescope. We have combined these with previous data, resulting in a
statistical sample of 646 QSOs and 85 damped Lyα absorbers with
column densities NHI≥2 1020atoms/cm2 covering the redshift
range 0.008≤z≤4.694. Four main features of how the neutral gas in the
universe evolves with redshift are evident from these data.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 61 54 LRIS Journal of Observations
table2.dat 85 20 LRIS follow-up of Candidate damped Lymanα
absorbers
table3.dat 68 26 New LRIS Survey Data
table4.dat 89 10 New Lick/AAT Survey Data
table5.dat 68 86 Statistical Sample: QSOs with damped Lymanα
absorbers
table6.dat 65 566 Statistical sample: QSOs without damped
Lymanα absorbers
refs.dat 70 31 References
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See also:
VII/182 : Catalog of high-redshift QSOs, z≥2.2, in SGP & F401 (Warren+, 1991)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- QSO QSO name
16- 20 F5.3 --- zem Emission redshift
22- 31 A10 "YYYY/MM/DD" Date Observation date
33- 37 F5.2 mag Vmag ? V magnitude
39- 43 F5.2 mag Rmag ? R magnitude
45- 48 I4 0.1nm lambda Central wavelength of the grating setting
50- 53 I4 s ExpTime Exposure time
55- 58 I4 --- Grating Number of grooves per millimeter of the
grating
60- 61 I2 --- r_QSO ? Reference to observations reporting
discovery of the candidate (in ref.dat)
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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- 14 A14 ---- QSO QSO name
17- 21 F5.3 --- zem Emission redshift
23- 26 F4.1 mag Vmag ? V magnitude of the QSO
28- 31 F4.1 mag Rmag ? R magnitude of the QSO
33 A1 --- Ref Reference of the low-resolution survey (1)
35- 39 F5.3 --- zabs Survey absorption redshift
41- 44 F4.1 0.1nm EWLyα Survey Lyα equivalent width
46- 49 F4.1 [cm-2] logNHI ? Survey HI column density
51- 56 F6.4 --- zabs2 ? Follow-up absorption redshift (2)
57 A1 --- n_zabs2 [abc] Note on components (3)
59- 63 F5.2 [cm-2] logNHI2 ? Follow-up HI column density (2)
65- 68 F4.2 [cm-2] e_logNHI2 ? rms uncertainty on logNHI2
70- 79 A10 --- NotDamped Not damped (no zabs2 and logNHI2 values)
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Note (1): Reference of the low-resolution survey that identified the
candidate absorber, the absorption redshift, the Lyα equivalent
width, and the inferred logN(HI):
1: Strorrie-Lombardi et al. [81] 1996MNRAS.282.1330S 1996MNRAS.282.1330S
2: this paper
3: Sargent et al. [88] 1989ApJS...69..703S 1989ApJS...69..703S
Note (2): Absorption redshift and log N(H I) deduced by profile fitting
from the higher resolution LRIS spectra.
Note (3): Note on zabs2:
a: Component a
b: Component b
c: Components a and b combined.
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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- 14 A14 --- QSO QSO name (1)
16- 20 F5.3 --- zem Emission redshift
21 A1 --- n_zem [d] Note on zem (2)
23- 27 F5.3 --- zmin ? Minimum redshift value
29- 33 F5.3 --- zmax ? Maximum redshift value
35- 40 F6.4 --- zabs ? Absorption redshift
41 A1 --- n_zabs [abc] Note on Components (3)
42- 45 F4.1 0.1nm EWLyA ? Lyα equivalent width
47- 48 A2 --- l_logNHI [≤ ] Limit flag on logNHI
49- 52 F4.1 cm-2 logNHI ? H I column density
54- 56 F3.1 cm-2 e_logNHI ? rms uncertainty on logNHI
57 A1 --- n_logNHI [abc] Note on Components (3)
59- 68 A10 --- NotDamped Not damped (no logNHI value)
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Note (1): Confirmed systems have uncertainties quoted for the column
density measurements. The candidate systems do not. Previous
experience shows that the system in PSS J1443+2724 is highly likely to
be damped, and the candidates in PSS J1435+3057 are highly unlikely to
be damped. All the candidate and confirmed systems with
log(NHI)≥20.3 are included in the statistical sample in the
analysis that follows, except for Q0201+1120. It was observed because
of a known damped absorber, not in an unbiased survey.
Note (2): d: Emission redshifts for these QSOs have been determined from
the mean redshifts of the O I 1302, Si IV + O IV 1400, and C IV 1549
emission lines observed in the LRIS spectra.
Note (3): Components:
a: Component a.
b: Component b.
c: Components a and b combined.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- QSO QSO name
15 A1 --- n_QSO [b] Note on QSO (1)
17 I1 --- Ref Reference (2)
19- 22 F4.1 mag Rmag R magnitude
24- 27 A4 --- Obs Observation campaign (3)
29- 38 A10 "YYYY/MM/DD" Date Observation date
40- 49 A10 "YYYY/MM/DD" Date2 Second date of observation
51- 55 I5 s ExpTime Exposure time
57- 61 F5.3 --- zem ? Emission redshift
63- 67 F5.3 --- zmin ? Minimum redshift value
69- 73 F5.3 --- zmax ? Maximum redshift value
75- 79 F5.3 --- zabs ? Absoprtion redshift
81- 84 F4.1 0.1nm EWLyA ? Lyα equivalent width
86- 89 F4.1 [cm-2] logNHI ? HI column density
90 A1 --- n_logNHI [a] Note on logNHI (4)
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Note (1): b: This QSO exhibits broad absorption lines
and is excluded from further consideration.
Note (2): References:
1: Kennefick et al. [83] 1995AJ....110...78K 1995AJ....110...78K
and J. Kennefick 1995, priv. comm.
2: M. Irwin 1995, priv. comm.
Note (3): The Lick observations were taken at the 120" with the KAST
spectrograph, with simultaneous blue and red arm observations.
The Anglo-Australian Telescope observations were taken with the RGO
spectrograph. All are at approximately 6Å resolution (FWHM). For
the spectra with enough wavelength coverage to the red to see C IV,
the QSO emission redshifts have been determined from a mean of the
O I 1302, Si IV + O IV 1400, and C IV 1549 emission lines.
Note (4):
a: This damped candidate was subsequently observed with LRIS
(see Table 2 and Fig. 2)
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Byte-by-byte Description of file: table5.dat table6.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- QSO QSO name
19- 24 F6.4 --- z QSO redshift
27- 32 F6.4 --- zMin Lower redshift limit for detection
35- 40 F6.4 --- zMax Upper redshift limit for detection
43- 48 F6.4 --- zAbs ? Absorption redshift
51- 55 F5.2 [cm-2] log(NHI) ? Log of hydrogen column density
56 A1 --- Note [a] a: Candidate
58- 67 A10 --- r_QSO Reference code(s) detailed in refs.dat file
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference code
4- 22 A19 --- BibCode Bibcode
24- 70 A47 --- Com Authors and comments
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History:
From ApJ electronic version
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 15-Jan-2001