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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
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:
FileName Lrecl Records Explanations
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 90 10 New Lick/AAT Survey Data table5.dat 68 86 Statistical Sample: QSOs with damped Lymanα absorbers table6.dat 67 566 Statistical sample: QSOs without damped Lymanα absorbers refs.dat 70 31 References
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
Bytes Format Units Label Explanations
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)
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
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)
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 2: this paper 3: Sargent et al. [88] 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.
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
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)
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.
Byte-by-byte Description of file: table4.dat
Bytes Format Units Label Explanations
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)
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 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)
Byte-by-byte Description of file: table5.dat table6.dat
Bytes Format Units Label Explanations
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
Byte-by-byte Description of file: refs.dat
Bytes Format Units Label Explanations
1- 2 I2 --- Ref Reference code 4- 22 A19 --- BibCode Bibcode 24- 70 A47 --- Com Authors and comments
History: From ApJ electronic version
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 15-Jan-2001
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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