J/ApJS/221/2 Keck+Magellan survey for LLSs. III. (Prochaska+, 2015)
The Keck + Magellan survey for Lyman limit absorption.
III. Sample definition and column density measurements.
Prochaska J.X., O'Meara J.M., Fumagalli M., Bernstein R.A., Burles S.M.
<Astrophys. J. Suppl. Ser., 221, 2 (2015)>
=2015ApJS..221....2P 2015ApJS..221....2P (SIMBAD/NED BibCode)
ADC_Keywords: Spectroscopy ; Redshifts ; Surveys ; Interstellar medium ; QSOs
Keywords: intergalactic medium
Abstract:
We present an absorption-line survey of optically thick gas clouds
--Lyman Limit Systems (LLSs)-- observed at high dispersion with
spectrometers on the Keck and Magellan telescopes. We measure column
densities of neutral hydrogen NH1 and associated metal-line
transitions for 157 LLSs at zLLS=1.76-4.39 restricted to
1017.3cm-2≤NHI<1020.3cm-2. An empirical analysis of ionic
ratios indicates an increasing ionization state of the gas with
decreasing NH1 and that the majority of LLSs are highly ionized,
confirming previous expectations. The Si+/H0 ratio spans nearly
four orders of magnitude, implying a large dispersion in the gas
metallicity. Fewer than 5% of these LLSs have no positive detection of
a metal transition; by z∼3 nearly all gas that is dense enough to
exhibit a very high Lyman limit opacity has previously been polluted
by heavy elements. We add new measurements to the small subset of LLS
(∼5%-10%) that may have super-solar abundances. High Si+/Fe+
ratios suggest an α-enhanced medium, whereas the Si+/C+
ratios do not exhibit the super-solar enhancement inferred previously
for the Lyα forest.
Description:
The sample presented in this manuscript is intended to be a nearly
all-inclusive set of Lyman Limit Systems (LLSs) discovered in the
high-dispersion (echelle or echellette; R>5000) spectra that we have
gathered at the Keck and Magellan telescopes. Regarding Keck, we have
examined all of the data obtained by Principal Investigators (PIs) A.
M. Wolfe and J. X. Prochaska at the W. M. Keck Observatory through
2012 April, and from PIs Burles, O'Meara, Bernstein, and Fumagalli at
Magellan through 2012 July. We also include the Keck spectra analyzed
by Penprase et al. (2010, J/ApJ/721/1).
We present data obtained at the W. M. Keck and Las Campanas
Observatories using the twin 10m Keck I and Keck II telescopes and the
twin 6.5m Baade and Clay telescopes. Altogether, we used four
spectrometers: (1) the High Resolution Echelle Spectrometer (HIRES);
(2) the Echellette Spectrograph and Imager (ESI); (3) the Magellan
Inamori Kyocera Echelle (MIKE); and (4) the Magellan Echellette
Spectrograph (MagE). Observing logs for the HIRES and MIKE spectra are
provided in Tables 1 and 2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 101 65 Journal of HIRES observations
table2.dat 107 56 Journal of MIKE observations
table4.dat 90 162 Ionic column summary for Si and C
table5.dat 90 162 Ionic column summary for Al, Fe, and O
table6.dat 107 2487 Ionic column densities for 130 unique quasars
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See also:
J/MNRAS/445/1745 : Giant Gemini GMOS survey. I. (Worseck+, 2014)
J/ApJ/776/136 : QPQ VI. HI absorption of z∼2 quasars (Prochaska+, 2013)
J/ApJ/775/78 : Lyman limit absorption systems in z∼3 QSOs (Fumagalli+, 2013)
J/ApJ/770/138 : Metallicities of Lyman limit systems and DLA (Lehner+, 2013)
J/ApJ/769/54 : Spectroscopy of Damped Lyα systems (Neeleman+, 2013)
J/ApJ/765/137 : HST survey for Lyman limit systems. II. (O'Meara+, 2013)
J/ApJ/755/89 : Metallicities of damped Lyα systems (Rafelski+, 2012)
J/ApJ/736/42 : HST QSO Catalog (Ribaudo+, 2011)
J/ApJ/721/1 : Keck ESI observations of Lyα systems (Penprase+, 2010)
J/ApJ/718/392 : SDSS Lyman limit systems at z∼3.5 (Prochaska+, 2010)
J/ApJ/714/1521 : Spectroscopy of galaxies around distant QSOs (Chen+, 2010)
J/ApJ/700/1299 : Gas-phase element depletions in the ISM (Jenkins, 2009)
J/ApJ/675/1002 : Proximate DLA systems in SDSS-DR5 (Prochaska+, 2008)
J/ApJS/171/29 : UCSD/Keck DLA Abundance Database (Prochaska+, 2007)
J/ApJ/649/L61 : SDSS J155810.16-003120.0 abundances (O'Meara+, 2006)
J/ApJ/648/L97 : 2 SDSS supersolar super-Lyman limit systems (Prochaska+ 2006)
J/ApJ/596/768 : Optical depths in 19 QSOs (Schaye+, 2003)
http://www.ucolick.org/~xavier/HD-LLS/DR1/ : High dispersion-LLS sample
Byte-by-byte Description of file: table[12].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 A14 --- ID Quasar identifier
16- 29 A14 --- AName Alternative name
31- 32 I2 h RAh Hour of right ascension (J2000)
34- 35 I2 min RAm Minute of right ascension (J2000)
37- 41 F5.2 s RAs Second of right ascension (J2000)
43 A1 --- DE- Sign of declination (J2000)
44- 45 I2 deg DEd Degree of declination (J2000)
47- 48 I2 arcmin DEm Arcminute of declination (J2000)
50- 53 F4.1 arcsec DEs Arcsecond of declination (J2000)
55- 59 F5.2 --- mag [16/19.1] r-band or V-band magnitude (1)
61- 65 F5.3 --- zem [1.8/4.5] Quasar emission redshift
67- 77 A11 "Y/M/D" Date Observation UT date
79- 81 A3 --- Slit Slit (Decker employed for table1 or Slit Width
in arcsec for table 2) (2)
83- 88 A6 --- Mode Mode (only for table 1)
90- 94 I5 s Exp [1295/21600] Exposure time
96-101 A6 pix-1 S/N Signal to noise ratio (blue for MIKE) (3)
103-107 A5 pix-1 S/Nr Signal to noise ratio (red) (only for table2) (4)
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Note (1): Magnitude from the SDSS database (r band) or as listed in
the SIMBAD Astronomical Database (V band).
Note (2): For the MIKE blue (red) side, a 1" slit yields a FWHM resolution of
10.7 (13.6) km/s for a source that fills the slit.
Note (3): Median signal-to-noise ratio per 3.0km/s pixel in the quasar continuum
at ∼5000Å for the old HIRES detector (HIRESO), ∼3400/4000Å for
HIRESb, and ∼6000/8000Å for HIRESr.
Median signal-to-noise per 3.0km/s pixel in the quasar continuum at
∼3400/4000Å for MIKE blue side.
An "X" indicates no wavelength coverage or that the S/N was
compromised by an LLS.
Note (4): Median signal-to-noise per 4.2km/s pixel in the quasar continuum at
∼6000/8000Å for MIKE red side. An X designates no flux.
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- ID Quasar identifier
21- 26 F6.4 --- zabs [1.7/4.4] Redshift derived from
absorption lines
28- 32 F5.2 [cm-2] logNHI [16.9/20.3] Log H I column density
34- 37 F4.2 [cm-2] e_logNHI Lower uncertainty in logNHI
39- 42 F4.2 [cm-2] E_logNHI Upper uncertainty in logNHI
44 A1 --- l_logNC+ Lower or upper limit at 95% confidence limit
45- 49 F5.2 [cm-2] logNC+ ? Log C+ column density
51- 54 F4.2 [cm-2] e_logNC+ ? Uncertainty in logNC+
56 A1 --- l_logNC3+ Lower or upper limit at 95% confidence limit
57- 61 F5.2 [cm-2] logNC3+ ? Log C3+ column density
63- 66 F4.2 [cm-2] e_logNC3+ ? Uncertainty in logNC3+
68 A1 --- l_logNSi+ Lower or upper limit at 95% confidence limit
69- 73 F5.2 [cm-2] logNSi+ ? Log Si+ column density
75- 78 F4.2 [cm-2] e_logNSi+ ? Uncertainty in logNSi+
80 A1 --- l_logNSi3+ Lower or upper limit at 95% confidence limit
81- 85 F5.2 [cm-2] logNSi3+ ? Log Si3+ column density
87- 90 F4.2 [cm-2] e_logNSi3+ ? Uncertainty in logNSi3+
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- ID Quasar identifier
21- 26 F6.4 --- zabs [1.7/4.4] Redshift derived from
absorption lines
28- 32 F5.2 [cm-2] logNHI [16.9/20.3] Log H I column density
34- 37 F4.2 [cm-2] e_logNHI Lower uncertainty in logNHI
39- 42 F4.2 [cm-2] E_logNHI Upper uncertainty in logNHI
44 A1 --- l_logNO0 Lower or upper limit at 95% confidence limit
45- 49 F5.2 [cm-2] logNO0 ? Log O0 column density
51- 54 F4.2 [cm-2] e_logNO0 ? Uncertainty in logNO0
56 A1 --- l_logNAl+ Lower or upper limit at 95% confidence limit
57- 61 F5.2 [cm-2] logNAl+ ? Log Al+ column density
63- 66 F4.2 [cm-2] e_logNAl+ ? Uncertainty in logNAl+
68 A1 --- l_logNAl++ Lower or upper limit at 95% confidence limit
69- 73 F5.2 [cm-2] logNAl++ ? Log Al++ column density
75- 78 F4.2 [cm-2] e_logNAl++ ? Uncertainty in logNAl++
80 A1 --- l_logNFe+ Lower or upper limit at 95% confidence limit
81- 85 F5.2 [cm-2] logNFe+ ? Log Fe+ column density
87- 90 F4.2 [cm-2] e_logNFe+ ? Uncertainty in logNFe+
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- ID Quasar identifier
21- 22 I2 h RAh Hour of Right Ascension (J2000)
24- 25 I2 min RAm Minute of Right Ascension (J2000)
27- 31 F5.2 s RAs Second of Right Ascension (J2000)
33 A1 --- DE- Sign of the Declination (J2000)
34- 35 I2 deg DEd Degree of Declination (J2000)
37- 38 I2 arcmin DEm Arcminute of Declination (J2000)
40- 44 F5.2 arcsec DEs Arcsecond of Declination (J2000)
46- 52 F7.5 --- zabs [1.7/4.4] Absorption redshift of LLS
54- 58 F5.2 [cm-2] logNHI [17.3/20.3] Log H I column density
60- 68 F9.4 0.1nm lambda [922.2/2853] Transition rest wavelength
in Angstroms
70- 73 I4 km/s vmin [-984/75] Minimum velocity limit
75- 78 I4 km/s vmax [-183/2931] Maximum velocity limit
80 A1 --- l_logN Limit flag on logN
81- 85 F5.2 [cm-2] logN [11.1/18] Log column density
87- 90 F4.2 [cm-2] e_logN [0/0.2]? Standard deviation in logN)
92- 95 F4.1 --- Ion [6.2/30.2]? Numeric ion designation (1)
97 A1 --- l_logNion Limit flag on logNion
98-102 F5.2 [cm-2] logNion [11.1/15.8]? Log ion column density
104-107 F4.2 [cm-2] e_logNion [0.05/0.2]? Standard deviation in logNion
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Note (1): XX.Y where XX is the atomic number and Y is the ionization state.
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History:
From electronic version of the journal
References:
O'Meara et al. Paper I. 2007ApJ...656..666O 2007ApJ...656..666O
Prochter et al. Paper II. 2010ApJ...708.1221P 2010ApJ...708.1221P
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 19-Jan-2016