J/AJ/136/181 Spectroscopy of PC 1643+4631A,B (Casey+, 2008)
PC 1643+4631A,B: the Lyman-α forest at the edge of coherence.
Casey C.M., Impey C.D., Petry C.E., Marble A.R., Dave R.
<Astron. J., 136, 181-196 (2008)>
=2008AJ....136..181C 2008AJ....136..181C
ADC_Keywords: QSOs ; Spectroscopy ; Equivalent widths ; Redshifts
Keywords: cosmology: observations - intergalactic medium -
quasars: absorption lines - quasars: individual (PC 1643+4631A, B)
Abstract:
This is the first measurement and detection of coherence in the
intergalactic medium (IGM) at substantially high redshift (z∼3.8)
and on large physical scales (∼2.5h-170Mpc). We perform the
measurement by presenting new observations of the high-redshift quasar
pair PC 1643+4631A, B and their Lyα-absorber coincidences. With
data collected from Keck I Low Resolution Imaging Spectrometer (LRIS)
in a 10200s integration, we have full coverage of the Lyα
forest over the redshift range 2.6<z<3.8 at a resolution of 3.6Å
(∼220km/s).
Description:
All data for this project were obtained with the Keck I Low Resolution
Imaging Spectrometer (LRIS) on 2001 July 21 and were reduced using the
standard IRAF longslit-spectra pipeline. To cover the wavelength range
of scientific interest, only the red side of the spectrograph and the
900/5500 grating was used.
Objects:
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RA (2000) DE Designation(s)
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16 45 00.7 +46 26 13 PC 1643+4631A = QSO B1643+465A
16 45 19.6 +46 25 38 PC 1643+4631B = QSO B1643+465B
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 28 4104 Flux and continuum of PC 1643+4631 A,B
table2.dat 68 240 Absorption lines for PC 1643+4631A
table3.dat 68 234 Absorption lines for PC 1643+4631B
table4.dat 45 152 Symmetrically matched Lyα lines
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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 A1 --- Comp [AB] Component of PC1643+4631
3- 8 F6.1 0.1nm lambda Wavelength in Angstroms (Å)
10- 15 F6.3 10-19W/m2/nm Flux Flux density (1)
17- 21 F5.3 10-19W/m2/nm e_Flux Error in Flux (1)
23- 28 F6.3 10-19W/m2/nm CFlux Continuum flux density (1)
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Note (1): In units of 10-17ergs/s/cm2/Å.
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Byte-by-byte Description of file: table[23].dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Line Line identification number
5- 11 F7.2 0.1nm lambda Central wavelength in Angstroms (Å)
13- 16 F4.2 0.1nm e_lambda Uncertainty in lambda in Angstroms (Å)
18- 21 F4.2 0.1nm Wobs Equivalent width in Angstroms (Å)
23- 26 F4.2 0.1nm e_Wobs Uncertainty in Wobs in Angstroms (Å)
28- 32 F5.2 --- chi Reduced χ2 value (1)
34- 38 F5.2 --- Sfit Equivalent width significance (2)
40- 45 F6.2 --- Sdet Detection limit significance (3)
47- 52 F6.4 --- z ? Redshift of absorber
54- 56 A3 --- f_z [a-f ,] Flag on line (4)
58- 68 A11 --- n_z Notes on line
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Note (1): If this value is identical to that of an adjacent line, it
indicates that the lines were fitted simultaneously.
Note (2): Defined as Wobs/σfit, where σfit is the error in
the equivalent width.
Note (3): Defined as Wobs/σdet, where σdet is the detection
limit of the data at λ (see text for further details).
Note (4): Flags as follows:
a = line included in the Lyα sample
b = line associated with the opaque system at z=3.777 that is also
labeled by its associated identification
c = line redward of Lyα emission which is clearly excluded from
the Lyα sample
d = line fitted in the damped region at z=3.818
e = line associated with the opaque system at z=3.818 that is also
labeled by its associated identification
f = the blended line removed due to low significance
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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- 3 I3 --- Match Symmetrically matched pair number
5- 11 F7.2 0.1nm Alambda Wavelength in spectrum A (in Å)
13- 19 F7.2 0.1nm Blambda Wavelength in spectrum B (in Å)
21- 24 F4.2 0.1nm Dlambda Wavelength separation of pair (in Å)
26- 30 F5.1 km/s dVel Velocity difference of pair
32- 35 F4.2 0.1nm W0A Rest equivalent width in spectrum A (in Å)
37- 40 F4.2 0.1nm W0B Rest equivalent width in spectrum B (in Å)
42- 45 F4.2 0.1nm dW0 Difference in rest equivalent widths (in Å)
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 21-Jan-2011