J/ApJ/729/87 SiIV absorption systems (Cooksey+, 2011)
The last eight-billion years of intergalactic SiIV evolution.
Cooksey K.L., Prochaska J.X., Thom C., Chen H.-W.
<Astrophys. J., 729, 87 (2011)>
=2011ApJ...729...87C 2011ApJ...729...87C
ADC_Keywords: Spectra, ultraviolet ; QSOs ; Redshifts ; Equivalent widths
Keywords: intergalactic medium - quasars: absorption lines -
techniques: spectroscopic
Abstract:
We identified 24 SiIV absorption systems with z≲1 from a blind
survey of 49 low-redshift quasars with archival Hubble Space Telescope
ultraviolet spectra. We relied solely on the characteristic wavelength
separation of the doublet to automatically detect candidates. After
visual inspection, we defined a sample of 20 definite (group G=1)
and 4 "highly likely" (G=2) doublets with rest equivalent widths Wr
for both lines detected at ≥3σWr.
Description:
We included spectra from the Space Telescope Imaging Spectrograph
(STIS; pre-Servicing Mission 4) and the Goddard High-Resolution
Spectrograph (GHRS). Spectra from the Far Ultraviolet Spectroscopic
Explorer (FUSE) covered the transitions with rest wavelengths
λr<1100Å (e.g., higher order HI Lyman lines). All spectra
had resolution with full width at half-maximum (FWHM)≤15km/s and
signal-to-noise ratio (S/N)≥2pixel-1. The spectra were retrieved
from the Multimission Archive at Space Telescope (MAST).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
qsos.dat 42 48 List of targets
table1.dat 98 9686 SiIV candidates summary (48 targets)
table2.dat 98 197 SiIV systems summary (16 targets)
table3.dat 87 28 SiIV doublets summary (16 targets)
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See also:
J/MNRAS/401/2715 : CIV column densities in z<2.5 QSOs (D'odorico+, 2010)
J/ApJ/708/868 : CIV candidates (Cooksey+, 2010)
J/ApJ/702/1472 : Column densities for HI, AlIII, SiIV, CIV, OVI (Savage+,
2009)
J/ApJ/679/194 : Low-z intergalactic medium. III. (Danforth+, 2008)
J/ApJ/676/262 : PKS1302-102 intergalactic absorption system (Cooksey+, 2008)
J/ApJS/155/351 : Absorption toward PG 1116+215 (Sembach+, 2004)
Byte-by-byte Description of file: qsos.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- Name Target name (G3)
20- 21 I2 h RAh Simbad hour of right ascension (J2000)
23- 24 I2 min RAm Simbad minute of right ascension (J2000)
26- 30 F5.2 s RAs Simbad second of right ascension (J2000)
32 A1 --- DE- Simbad sign of declination (J2000)
33- 34 I2 deg DEd Simbad degree of declination (J2000)
36- 37 I2 arcmin DEm Simbad arcminute of declination (J2000)
39- 42 F4.1 arcsec DEs Simbad arcsecond of declination (J2000)
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Byte-by-byte Description of file: table[12].dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- Name Target name (G3)
19- 23 F5.3 --- z [0.002/2.736] Target redshift
25- 32 F8.5 --- z1393 ? SiIV 1393 candidate redshift
34- 40 F7.1 km/s dvabs ? SiIV 1402 candidate velocity difference
42- 48 F7.2 0.1nm lam.r Transition rest wavelength; in Angstroms
50- 56 F7.2 0.1nm lam.lo Lower absorption line boundary; in Angstroms
58- 64 F7.2 0.1nm lam.hi Upper absorption line boundary; in Angstroms
66 A1 --- l_EWr The 2σ limit flag on EWr
67- 73 I7 10-13m EWr Rest equivalent width; in milliAngstroms
75- 77 I3 10-13m e_EWr ? The 1σ uncertainty in EWr
79 A1 --- l_logN The 2σ limit flag on logN
81- 85 F5.2 [cm-2] logN Log column density (1)
87 A1 --- f_logN [ab] Flag on logN (G2)
89- 92 F4.2 [cm-2] e_logN ? The 1σ uncertainty in logN
94 I1 --- G [1/2]? Doublet flag (only for table 2) (G1)
96- 98 I3 --- Flag [79/511]? Binary flag
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Note (1): The column densities were measured by the AODM (apparent optical
depth method), unless the "curve of growth" (COG) flag (a) is
indicated in f_logN, in which case, the limit is from assuming Wr
results from the linear portion of the COG.
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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- 17 A17 --- Name Target name
19 I1 --- G [1/2] Doublets group (G1)
21- 27 F7.5 --- z1393 [0.004/1.148] Redshift at 1393
29 A1 --- l_Wr1393 Limit flag on Wr1393 (1)
30- 32 I3 0.1pm Wr1393 SiIV 1393 rest equivalent width in mÅ (1)
34- 35 I2 0.1pm e_Wr1393 ? Wr1393 uncertainty
37 A1 --- l_Wr1402 Limit flag on Wr1402 (1)
38- 40 I3 0.1pm Wr1402 SiIV 1402 rest equivalent width in mÅ (1)
42- 43 I2 0.1pm e_Wr1402 ? Wr1402 uncertainty
45 A1 --- l_logN1393 Limit flag on logN1393 (1)
46- 50 F5.2 [-] logN1393 SiIV 1393 column density (1)
51 A1 --- f_logN1393 [ab] Flag on logN1393 (G2)
53- 56 F4.2 [-] e_logN1393 ? logN1393 uncertainty
58 A1 --- l_logN1402 Limit flag on logN1402 (1)
59- 63 F5.2 [-] logN1402 SiIV 1402 column density (1)
64 A1 --- f_logN1402 [ab] Flag on logN4023 (G2)
66- 69 F4.2 [-] e_logN1402 ? logN1402 uncertainty
71 A1 --- l_logNSi Limit flag on logNSi (1)
72- 76 F5.2 [-] logNSi [12.68/14.4] Adopted Si+3 doublet column
density (1)
78- 82 F5.2 [-] logNSi2 ? Second value of Si+3 column density
84- 87 F4.2 [-] e_logNSi ? logNSi uncertainty
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Note (1): Upper limits are 2σ limits for both Wr and log N.
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Global notes:
Note (G1): The definite SiIV doublets are labeled group G=1, while
the "highly-likely" doublets are G=2.
Note (G2): Flag as follows:
a = logN measured by assuming Wr results from the linear portion
of the COG (curve of growth)
b = Limit due to blended line.
Note (G3): In table 1, HE0226-4410 is a misprint for HE0226-4110;
corrected at CDS.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 12-Sep-2012