J/MNRAS/445/1745 Giant Gemini GMOS survey. I. (Worseck+, 2014)
The Giant Gemini GMOS survey of zem>4.4 quasars.
I. Measuring the mean free path across cosmic time.
Worseck G., Prochaska J. X., O'Meara J. M., Becker G. D., Ellison S. L.,
Lopez S., Meiksin A., Menard B., Murphy M. T., Fumagalli M.
<Mon. Not. R. Astron. Soc. 445, 1745 (2014)>
=2014MNRAS.445.1745W 2014MNRAS.445.1745W
ADC_Keywords: QSOs ; Spectra, ultraviolet
Keywords: galaxies: formation - intergalactic medium -
quasars: absorption lines - dark ages, reionization, first stars -
diffuse radiation
Description:
We present spectra of 163 quasars at zem>4.4 taken with the Gemini
Multi Object Spectrometers, the largest publicly available sample of
high-quality (signal-to-noise ratio S/N∼20 per 1.85Å pixel)
low-resolution (full width at half maximum FWHM∼320km/s) rest-frame
ultraviolet quasar spectra at these redshifts. The sample was selected
from SDSS Data Release 7 with the aim to obtain high-S/N follow-up
spectra of the intergalactic HI Lyman series and Lyman continuum
absorption at high redshift. Each quasar was observed with the GMOS
B600 (FWHM∼320km/s) and R400 (FWHM∼360km/s) gratings to cover the
rest-frame wavelength range from ∼850 to ∼1500Å. Here we make the
spectra available in reduced form. The accompanying paper presents a
detailed description the sample and a measurement of the mean free
path to Lyman limit photons in the IGM, based on stacked rest-frame
quasar spectra.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
objects.dat 159 163 Quasars observed with GMOS B600 and R400 gratings
table1.dat 93 172 GGG survey
table3.dat 82 163 GGG quasar emission redshifts
sp/* . 326 Individual calibrated spectra
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Byte-by-byte Description of file: objects.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [SDSS]
6- 24 A19 --- SDSS SDSS Quasar name (JHHMMSS.ss+DDMMSS.s)
26- 27 I2 h RAh Hour of Right Ascension (J2000)
29- 30 I2 min RAm Minute of Right Ascension (J2000)
32- 36 F5.2 s RAs Second of Right Ascension (J2000)
38 A1 --- DE- Sign of the Declination (J2000)
39- 40 I2 deg DEd Degree of Declination (J2000)
42- 43 I2 arcmin DEm Arcminute of Declination (J2000)
45- 48 F4.1 arcsec DEs Arcsecond of Declination (J2000)
50- 54 F5.2 mag imag SDSS i band magnitude
56- 60 F5.3 --- zSDSS SDSS pipeline redshift (2)
62- 66 F5.3 --- e_zSDSS Estimated SDSS redshift uncertainty (3)
68- 72 F5.3 --- zGMOS Redshift measured in GMOS spectra
74- 78 F5.3 --- e_zGMOS Estimated GMOS redshift uncertainty (1)
80- 85 A6 --- Inst Instrument used (GMOS-North, GMOS-South)
87- 90 I4 0.1nm minB600 Minimum wavelength in GMOS B600 spectrum
92- 95 I4 0.1nm maxB600 Maximum wavelength in GMOS B600 spectrum
97-100 I4 0.1nm minR400 Minimum wavelength in GMOS R400 spectrum
102-106 I5 0.1nm maxR400 Maximum wavelength in GMOS R400 spectrum
108-109 I2 --- SN Signal-to-Noise ratio (4)
111 I1 --- Flag [0/7]? Flag describing quasar spectrum (G1)
113-135 A23 --- File1 File with B600 spectrum in subdirectory "sp"
137-159 A23 --- File2 File with R400 spectrum in subdirectory "sp"
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Note (1): Redshift uncertainty varies with adopted emission line and presence
of absorption.
Note (2): From Schneider et al. (2010AJ....139.2360S 2010AJ....139.2360S, Cat. VII/260).
Note (3): We adopt sigmav=850km/s (Shen et al., 2011ApJS..194...45S 2011ApJS..194...45S,
Cat. J/ApJS/194/45).
Note (4): Measured per 2.76 Angstroem pixel in the R400 spectrum at rest-frame
wavelength 1450 Angstroem.
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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- 4 A4 --- --- [SDSS]
6- 24 A19 --- SDSS Quasar name (JHHMMSS.ss+DDMMSS.s)
26- 30 F5.2 mag imag SDSS i band magnitude
33- 37 F5.3 --- z SDSS pipeline redshift (Schneider et al.,
2010AJ....139.2360S 2010AJ....139.2360S, Cat. VII/260
39- 49 A11 "date" Obs.date UT date of observation with Gemini/GMOS
51- 56 A6 --- Inst Instrument (GMOS-N/S)
58- 61 I4 s ExpTimeB Exposure time with GMOS B600 grating
63- 65 I3 s ExpTimeR Exposure time with GMOS R400 grating
67- 70 I4 0.1nm lambdaBl ? Wavelength coverage with GMOS B600 grating
71 A1 --- --- [-]
72- 75 I4 0.1nm lambdaBu ? Wavelength coverage with GMOS B600 grating
77- 80 I4 0.1nm lambdaRl ? Wavelength coverage with GMOS R400 grating
81 A1 --- --- [-]
82- 86 I5 0.1nm lambdaRu ? Wavelength coverage with GMOS R400 grating
88- 89 I2 0.1nm S/N ? Signal-to-Noise ratio per 2.76A pixel at
rest-frame wavelength 1450A (R400)
91 I1 --- Flag [0/7]? Flag describing quasar spectrum (G1)
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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- 4 A4 --- --- [SDSS]
6- 24 A19 --- SDSS Quasar name (JHHMMSS.ss+DDMMSS.s)
26- 30 F5.3 --- zSDSS SDSS pipeline redshift (1)
32- 36 F5.3 --- e_zSDSS rms uncertainty on z
38- 42 F5.3 --- zGMOS Redshift measured in our GMOS spectra
44- 48 F5.3 --- e_zGMOS rms uncertainty on zGMOS
50- 58 A9 --- EmLines Emission lines used for our redshift estimate
with the Shen et al. (2007, Cat. J/AJ/133/2222)
method
60- 64 F5.3 --- zS Redshift using the Shen et al.
(2007, Cat. J/AJ/133/2222) method
66- 70 F5.3 --- e_zS rms uncertainty on zS
72- 76 F5.3 --- zH ?=- Redshift and 1sigma error from
Hewett & Wild (2010, Cat. J/MNRAS/405/2302)
78- 82 F5.3 --- e_zH ?=- rms uncertainty on zH
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Note (1): SDSS pipeline redshift (Schneider et al. 2010, AJ, 139, 2360) with
estimated error sigma_v=850km/s (Shen et al., 2011, Cat. J/ApJS/194/45).
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Byte-by-byte Description of file: sp/*
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Bytes Format Units Label Explanations
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1- 8 F8.2 0.1nm lambda Vacuum heliocentric wavelength
10- 21 E12.6 10-19W/m2/nm Flux *Calibrated flux (10-17erg/cm2/s/Å)
23- 34 E12.6 10-19W/m2/nm e_Flux *[] One-sigma error on flux (negatives
values when fluxes = 0, see note)
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Note on Flux and e_Flux:
Since many targets were observed in non-photometric conditions, the fluxes
have been rescaled to the SDSS DR7 spectrophotometry. No correction for
Galactic extinction has been applied.
GMOS R400 spectra have gaps due to physical gaps in the CCD array.
The gaps are indicated with zero flux and negative error.
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Note (G1): Flag as follows:
0 = No peculiarities
1 = Broad absorption line quasar
2 = Associated absorption
3 = Weak-lined quasar
4 = Candidate weak-lined quasar
5 = Proximate Damped Lyman alpha absorber
6 = Proximate Lyman limit system
7 = Spectrum contaminated by faint neighbour
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Acknowledgements:
Gabor Worseck, gabor(at)mpia-hd.mpg.de
Max-Planck-Institut fuer Astronomie
History:
* 17-Oct-2014: First on-line version
* 10-Feb-2016: tables 1 and 3 added (from electronic version)
Corrections in objects.dat files
zGMOS and zSDSS where interverted
(End) Gabor Worseck [Max-Planck-Inst.], Patricia Vannier [CDS] 23-Sep-2014