J/ApJ/571/665 Analysis of the Lyα forest at z=0-5. V. (Scott+, 2002)
A uniform analysis of the Lyα forest at z=0-5.
V. The extragalactic ionizing background at low redshift.
Scott J., Bechtold J., Morita M., Dobrzycki A., Kulkarni V.P.
<Astrophys. J. 571, 665 (2002)>
=2002ApJ...571..665S 2002ApJ...571..665S
ADC_Keywords: QSOs ; Spectroscopy
Keywords: diffuse radiation - intergalactic medium - quasars: absorption lines
Abstract:
In Paper III (Bechtlod et al., 2002, Cat. J/ApJS/140/143) of our
series, "A Uniform Analysis of the Lyα Forest at z=0-5", we
presented a set of 270 quasar spectra from the archives of the Faint
Object Spectrograph (FOS) on the Hubble Space Telescope (HST). A total
of 151 of these spectra, yielding 906 lines, are suitable for using
the proximity effect signature to measure J(ν0), the mean
intensity of the hydrogen-ionizing background radiation field, at low
redshift.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 86 178 Sample QSOs and Emission Line Redshifts
table3.dat 81 178 Spectrophotometric Properties
refs.dat 79 49 Redshift references
spectra/* . 37 Figures containing the spectra
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See also:
J/ApJS/140/143 : Analysis of the Lyα forest at z=0-5. III
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- QSO QSO name (1)
12 A1 --- f_QSO [3] Indicates observed only with
pre-COSTAR FOS and A-1 aperture
14- 32 A19 --- NEDdsc NED description
34 A1 --- f_NEDdsc Flag on NED description (2)
36- 41 F6.4 --- zLya ? Redshift from the Ly-α line
43 A1 --- n_zLya [KGHF] Note on zLya (3)
45- 50 F6.4 --- zMgII ? Redshift from the Mg II line
52- 57 F6.4 --- zOIII ? Redshift from the [O III] line
59- 64 F6.4 --- zBalmer ? Redshift from the Balmer lines
66- 67 I2 --- r_zLya ? Reference for zLya, in refs.dat file
69- 70 I2 --- r_zMgII ? Reference for zMgII, in refs.dat file
72- 73 I2 --- r_zOIII ? Reference for zOIII, in refs.dat file
75- 76 I2 --- r_zBalmer ? Reference for zBalmer, in refs.dat file
79- 86 A8 --- figFile File with figure in "spectra" subdirectory.
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Note (1): See Paper III, Table 1 for alternate names.
Note (2): Flag on NEDdsc:
2 = We classify this as an associated absorber, see Paper III,
Bechtlod et al., 2002ApJS..140..143B 2002ApJS..140..143B.
5 = Classified as blazar by Kinney et al. (1991ApJS...75..645K 1991ApJS...75..645K).
Note (3): Redshift reference, when only one redshift:
K = Knezek & Bregman, 1998AJ....115.1737K 1998AJ....115.1737K
G = Green et al., 1986, Cat. II/207
H = Hewitt & Burbidge, 1987ApJS...63....1H 1987ApJS...63....1H
F = Falomo et al., 1993ApJ...411L..63F 1993ApJ...411L..63F
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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 --- QSO QSO Name
12- 16 A5 --- f_QSO Flag on QSO (1)
18- 22 F5.2 10+20/cm2 NHI Hydrogen column density (2)
24- 27 F4.2 uJy FObs ? Direct measurement of flux at Lyman Limit
29- 33 F5.2 --- Sp-Index ? Measured spectral index
35- 39 F5.2 --- e_Sp-Index ? Uncertainty in Sp-Index
41- 45 F5.2 uJy FExt ? Extrapolated flux at Lyman Limit
47- 51 F5.3 uJy e_FExt ? Uncertainty in FExt
53- 57 F5.2 uJy FRest ? Measured flux at the rest wavelength
lambda
59- 62 I4 0.1nm lambda ? Wavelength where FRest is measured
in Angstroems
64- 68 F5.2 [-] RL ? Radio Loudness (3)
70- 71 I2 --- r_FObs ? Reference on FObs, in refs.dat file
73- 74 A2 --- r_Sp-Index Reference on Sp-Index, in refs.dat file
76- 77 A2 --- r_FExt Reference on FExt, in refs.dat file
79- 80 A2 --- r_FRest Reference on FRest, in refs.dat file
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Note (1): Notes on QSO:
1 = Object spectrum shows associated absorption;
2 = Observed only with pre-COSTAR FOS and A-1 aperture, not used for
proximity effect;
3 = Object is classified as a blazar or BL Lac;
4 = Flux estimated from scaling composite QSO spectrum to match V;
5 = Object spectrum shows damped Ly-α absorption;
6 = No Ly-α forest observed, not used for proximity effect;
7 = Binary quasar, not used for proximity effect;
8 = Flux estimated from scaling composite QSO spectrum to match B
Note (2): From Stark et al. (1992, Cat. J/ApJS/79/77),
Burstein & Heiles (1982, Cat. J/AJ/87/1165), and
Lockman & Dickey (1995, ADIL FL 01L).
Note (3): Where RL=log[S(5GHz)]/log[S(1450Å)].
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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 A2 --- Ref Reference code
4- 22 A19 --- BibCode BibCode
24- 53 A30 --- Aut Author's name
54- 78 A25 --- Com Comments
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History:
From electronic version of the journal
* 03-Dec-2002: Added the figure number in table1.
References:
Scott et al., Paper I 2000ApJS..130...37S 2000ApJS..130...37S
Scott et al., Paper II 2000ApJS..130...67S 2000ApJS..130...67S
Bechtlod et al., Paper III 2002ApJS..140..143B 2002ApJS..140..143B, Cat. J/ApJS/140/143
Dobrzycki et al., Paper IV 2002ApJ...571..654D 2002ApJ...571..654D
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 13-Sep-2002