J/AJ/158/129 Near-infrared hydrogen & helium QSO emission lines (Kenyon+, 2019)
Near-infrared hydrogen and helium QSO emission lines.
Kenyon C.E.G., Labrie K., Webster R.L., King A.L.
<Astron. J., 158, 129-129 (2019)>
=2019AJ....158..129K 2019AJ....158..129K (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Spectra, infrared ; Equivalent widths
Keywords: quasars: emission lines - quasars: general - infrared: galaxies
Abstract:
We present 14 near-infrared (NIR) quasar spectra observed with the
Flamingos-2 NIR spectrometer instrument at the Gemini South Observatory.
The targets were selected with redshifts of (0.58~<z~<0.63) to ensure the
spectral wavelength range included specifically identified hydrogen and
helium broad emission lines. We present measurements of their FWHM,
equivalent widths, and flux ratios relative to Hα. The quasars are
all within the Sloan Digital Sky Survey (SDSS) Stripe 82 region which,
then also provides multi-epoch rest-frame UV and optical spectroscopic
observations of our targets. In future work, these data and those from
Galaxy Evolution Explorer and NUV spectra will be utilized to constrain
photoionization models to determine physical conditions within the broad
emission line regions, such as the incident ionizing photon flux and
gas density.
Description:
A total of 14 quasar observations were carried out at Gemini South
Observatory, Cerro Pachon, Chile using the Flamingos-2 NIR spectrometer
between 2015 June and November. The data for each target consists of two
individual two-pixel slit (0.36") spectral observations using JH
(0.9-1.8 µ) and HK (1.2-2.4 µ) band grisms, ultimately producing
two spectra per target (JH and HK). In this configuration, the grisms had
a moderate resolution with a maximum possible resolution of R∼1250 in
the center of each spectrum. The quasar targets were chosen from the
Sloan Digital Sky Survey (SDSS) Stripe 82 region (spanning the area of
22h24m<R.A.<04h08m and |decl.|<1.27° (∼290 square degrees
on the sky)).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 89 17 Summary of the observations
table2.dat 121 70 Profile fit data for each source
table3.dat 120 70 Measurement data for each source
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See also:
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
J/ApJ/640/579 : Near-infrared spectra of 27 SDSS quasars (Glikman+, 2006)
J/ApJ/753/125 : Near-IR spectroscopy follow-up of 60 SDSS-DR7 QSOs
(Shen+, 2012)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 A18 --- SDSS SDSS source name (HHMMSS.ss+DDMMSS.s)
20- 26 F7.5 --- z [0.5851/0.6212] Redshift
28- 32 F5.2 mag Hmag [15.59/16.58] H band Vega magnitude
34- 44 A11 "date" Date Observation date
46- 51 A6 --- Grism Band grisms of observation for sources viewed
over more than one night
53- 54 I2 --- Nobs-JH [4/12] Number of observations for JH grism
(0.9-1.8 µ)
56- 58 I3 s Texp-JH [100/180] Total exposure time for JH grism
60 I1 --- Nobs-HK [4/8]? Number of observations for HK grism
(1.2-2.4 µ)
62- 64 I3 s Texp-HK [90/170]? Total exposure time for HK grism
66- 71 A6 --- SpType Telluric classification
73- 82 A10 --- Star Telluric standard star identifier
84- 89 F6.4 mag Avt [0.0603/0.3284]? V-band Milky Way extinction
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- SDSS SDSS source name (HHMMSS.ss+DDMMSS.s)
20 A1 --- n_SDSS [g] Note on SDSS (1)
22- 51 A30 --- Line Emission line
53 A1 --- n_Line [cdefi] Note on Line (G1)
55- 56 A2 --- Grism [JHK] Grism
58 A1 --- n_Grism [h] Note on Grism (G2)
60- 67 F8.2 0.1nm Lc [6552.8/12828.1] Line center (Å)
69 A1 --- lELc [<] Limit flag on E_Lc
70- 74 F5.2 0.1nm E_Lc [0.01/20] Upper limit uncertainty in Lc (Å)
76 A1 --- leLc [<] Limit flag on e_Lc
77- 81 F5.2 0.1nm e_Lc [0.01/20] Lower limit uncertainty in Lc (Å)
83- 87 F5.2 --- Skew [-1.06/1.83] Skew value (2)
89- 92 F4.2 --- E_Skew [0.03/8.46] Upper limit uncertainty in Skew
94- 97 F4.2 --- e_Skew [0.03/6.98] Lower limit uncertainty in Skew
99-104 F6.2 --- ag [12.23/227.09] α=γ value (3)
106-111 F6.2 --- E_ag [0.81/217.25] Upper limit uncertainty in ag
113-119 F7.2 --- e_ag [0.79/1518.38] Lower limit uncertainty in ag
121 A1 --- Grade [abcd] Fit grade (4)
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Note (1): Note as follows:
g = The S/N in this spectrum is low, resulting in the omission of many
poor-quality fits from this table.
Note (2): Skew values relate to the cumulative distribution function of the
standard normal distribution function.
Note (3): The default fitting process sets α (the Lorentzian contribution
to the skewed Voigt function) equal to γ (the Gaussian contribution to
the skewed Voigt function).
Note (4): Fit grades indicate our basic visual confidence in the profiling of
each line, with grade "a" representing a high confidence and "d" representing
a low confidence in the profile fit.
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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- 18 A18 --- SDSS SDSS source name (HHMMSS.ss+DDMMSS.s)
20 A1 --- n_SDSS [f] Note on SDSS (1)
22- 51 A30 --- Line Emission line
53 A1 --- n_Line [cdef] Note on Line (G1)
55- 56 A2 --- Grism [JHK] Grism
58 A1 --- n_Grism [h] Note on Grism (G2)
60- 65 F6.2 0.1nm FWHM [0.36/392.72] Full width at half maximum (Å)
67- 72 F6.2 0.1nm E_FWHM [0.24/173.32] Upper limit uncertainty in FWHM
(Å)
74- 79 F6.2 0.1nm e_FWHM [0.34/455.49] Lower limit uncertainty in FWHM
(Å)
81- 86 F6.2 --- Flux [0.02/109.88] Line flux ratio, relative
to Hα blend (2)
88- 92 F5.2 --- E_Flux [0.01/55.93]? Upper limit uncertainty in Flux
94- 99 F6.2 --- e_Flux [0.01/108.16]? Lower limit uncertainty in Flux
101-106 F6.2 0.1nm EW [0.11/581.02]? Equivalent width (Å)
108-113 F6.2 0.1nm E_EW [8.9/729.66]? Upper limit uncertainty in EW (Å)
115-120 F6.2 0.1nm e_EW [0.35/698.92]? Lower limit uncertainty in EW
(Å)
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Note (1): Note as follows:
f = The S/N in this spectrum is low, resulting in fits (wherever possible) of
relatively poor quality.
Note (2): It is possible that the Hα blend is affected by line-of-sight
extinction from grains. Typically, the effect of this can be estimated from
its flux ratio with Hβ, however this line was not within the wavelength
range for these spectra.
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Global notes:
Note (G1): Note as follows:
c = Noisy continuum gives a poor fit;
d = Less trustworthy than the JH measurement of the same line due to a high
level of noise in the continuum;
e = Complex suffers continuum distortion at the redward edge of the spectrum,
affecting the quality of fit;
f = It is currently unclear why this line has this shape and flux;
i = Both He I 6678 and He I 7065 show individual spikes in the JH spectrum,
but upon closer inspection appear to be due to noise.
Note (G2): Note as follows:
h = The He I 10830 + Pa γ complex is visible in the HK spectrum, however
in the JH spectrum, the emission lines are clearly separable, resulting in
an inability to measure the emission lines as a complex.
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History:
From electronic version of the journal
(End) Tiphaine Pouvreau [CDS] 22-Oct-2019