J/MNRAS/400/1493 QSOs Lyman alpha emission line spectra (Kramer+, 2009) ================================================================================ Probing re-ionization with quasar spectra: the impact of the intrinsic Lyman{alpha} emission line shape uncertainty. Kramer R.H., Haiman Z. =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 Lyman{alpha} 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 Lyman{alpha} 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 Lyman{alpha} line relative to the metal lines. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 189 120 HST (FOS and GHRS) quasar Lyman-{alpha} 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 -------------------------------------------------------------------------------- See also: J/ApJ/614/75 : Lyman{alpha} emitting galaxies at z=2.38 (Francis+, 2004) J/A+A/458/427 : Lyman alpha absorbers in 0.54 QSOs (Guimaraes+, 2009) Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 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 -------------------------------------------------------------------------------- Byte-by-byte Description of file:table[34].dat -------------------------------------------------------------------------------- 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^-15^erg/cm^2^/s/{AA}) 113-116 F4.2 --- x2/nup Reduced {chi}^2^ for the line-profile fit 118-121 F4.2 --- x2/nuc Reduced {chi}^2^ 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 -------------------------------------------------------------------------------- Note (1): corrected for redshift using the NED value of z, see Table 1 Note (2): calculated with the NED redshift -------------------------------------------------------------------------------- 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