J/MNRAS/400/1493 QSOs Lyman alpha emission line spectra (Kramer+, 2009)
Probing re-ionization with quasar spectra: the impact of the intrinsic
Lymanα emission line shape uncertainty.
Kramer R.H., Haiman Z.
<Mon. Not. R. Astron. Soc., 400, 1493-1511 (2009)>
=2009MNRAS.400.1493K 2009MNRAS.400.1493K
ADC_Keywords: QSOs ; Spectra, ultraviolet ; Equivalent widths
Keywords: quasars: absorption lines - quasars: emission lines -
quasars: general - cosmology: observations - cosmology: theory -
ultraviolet: general
Abstract:
Arguably the best hope of understanding the tail end of the
re-ionization of the intergalactic medium (IGM) at redshift z>6 is
through the detection and characterization of the Gunn-Peterson
damping wing absorption of the IGM in bright quasar spectra. However,
the use of quasar spectra to measure the IGM damping wing requires a
model of the quasar's intrinsic Lymanα emission line. Here we
quantify the uncertainties in the intrinsic line shapes, and how those
uncertainties affect the determination of the IGM neutral fraction. We
have assembled a catalogue of high-resolution Hubble Space Telescope
spectra of the emission lines of unobscured low-redshift quasars, and
have characterized the variance in the shapes of their lines. We then
add simulated absorption from the high-redshift IGM to these quasar
spectra in order to determine the corresponding uncertainties in
re-ionization constraints using current and future samples of z>6
quasar spectra. We find that, if the redshift of the Lymanα
emission line is presumed to coincide with the systemic redshift
determined from metal lines, the inferred IGM neutral fraction is
systematically biased to low values due to a systematic blueshift of
the Lymanα line relative to the metal lines.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 189 120 HST (FOS and GHRS) quasar Lyman-α
emission line spectra
table3.dat 129 86 Best-fit spectral parameters from fits to the
full line profile
table4.dat 129 86 Best-fit spectral parameters from fits to the
red side only of the Lyman-alpha line
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See also:
J/ApJ/614/75 : Lymanα emitting galaxies at z=2.38 (Francis+, 2004)
J/A+A/458/427 : Lyman alpha absorbers in 0.5<z<1.9 QSOs (Janknecht+, 2006)
J/ApJ/662/72 : Lyman alpha forest of 55 QSOs (Becker+, 2007)
J/A+A/508/133 : Damped Lymanα absorbers in z>4 QSOs (Guimaraes+, 2009)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 24 A24 --- Name Name from NED (G1)
26- 30 F5.3 --- z Redshift from NED
32- 34 A3 --- Inst HST instrument
36- 38 A3 --- Ap Aperture
40- 44 A5 --- Grat Grating
46- 49 F4.1 --- S/N Mean signal-to-noise ratio
51-189 A139 --- Com Comments on spectra and fits
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Byte-by-byte Description of file:table[34].dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 24 A24 --- Name Name from NED (G1)
26- 28 A3 --- Inst HST Instrument
30- 32 A3 --- Grat Grating
34- 36 A3 --- Ap Aperture used to take the spectrum
38- 44 F7.3 0.1nm sigLa0 Width of narrow Lyman-alpha component (1)
45- 51 F7.2 --- aLa0 Amplitude of La0, normalized by the
continuum flux ap
53- 57 I5 km/s vLa0 Shift of La0 component center from the
nominal wavelength (2)
59- 63 F5.2 0.1nm sigLa1 Width of broad Lyman-alpha component (1)
65- 70 F6.2 --- aLa1 Amplitude of La1, normalized by the
continuum flux ap
72- 76 I5 km/s vLa1 Shift of La1 component center from the
nominal wavelength (2)
78- 86 E9.4 0.1nm sigNV Width of NV line (1)
87- 91 F5.2 --- aNV Amplitude of NV line, normalized by the
continuum flux ap
93- 97 I5 km/s vNV Shift of NV line center from the
nominal wavelength (2)
99-103 F5.2 --- p Continuum power law index
105-111 F7.3 10-17W/m2/nm ap Continuum flux at the nominal Lyman-alpha
central wavelength (10-15erg/cm2/s/Å)
113-116 F4.2 --- x2/nup Reduced χ2 for the line-profile fit
118-121 F4.2 --- x2/nuc Reduced χ2 for the continuum
123-125 I3 --- nup Number of degrees of freedom for
line-profile fit
127-129 I3 --- nuc Number of degrees of freedom for continuum
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Note (1): corrected for redshift using the NED value of z, see Table 1
Note (2): calculated with the NED redshift
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Global Notes:
Note (G1): FBQS names were fixed at CDS to match the NED conventions
(decimal point in the RA part of the name)
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 21-Nov-2011