J/A+A/669/A83 High-redshift quasars spectra (Deconto-Machado+, 2023)
High-redshift quasars along the main sequence.
Deconto-Machado A., del Olmo Orozco A., Marziani P., Perea J., Stirpe G.
<Astron. Astrophys. 669, A83 (2023)>
=2023A&A...669A..83D 2023A&A...669A..83D (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Spectra, infrared
Keywords: quasars: general - quasars: emission lines -
quasars: supermassive black holes
Abstract:
The 4D Eigenvector 1 empirical formalism (4DE1) and its main sequence
(MS) for quasars has emerged as a powerful tool for organising the
diversity among quasar populations, as several key observational
measures and physical parameters are systematically changing along it.
Trends revealed by 4DE1 are very well established to explain all the
diverse characteristics seen in low-redshift quasar samples.
Nevertheless, the situation is far less clear when dealing with
high-luminosity and high-redshift sources. Here, we aim to evaluate
the behaviour of our sample of 22 quasars at high redshift (2.2≤z≤3.7)
and high luminosity (47.39≤Lbol≤48.36) in the context of the 4DE1.
Our approach involves studying quasar physics through a spectroscopic
exploration of UV and optical emission line diagnostics. We used new
observations from the ISAAC instrument at ESO-VLT and primarily from
the SDSS to cover the optical and the UV rest-frames, respectively.
The emission lines were characterised both via a quantitative
parametrisation of the line profiles and a decomposition of the
emission line profiles using multicomponent fitting routines.
We provide spectrophotometric properties and line profile measurements
for Hβ+[OIII]4959,5007, as well as SiIV1397+OIV]1402,
CIV1549+HeII1640, and the 1900Å blend (including AlIII1860,
SiIII]1892, and CIII]1909). For six out of the 22 objects, a
significantly blueshifted component on the Hβ profile is present.
In 14 out of 22 cases, an Hβ outflowing component associated with
[OIII] is detected. The majority of [OIII]4959,5007 emission line
profiles show blueshifted velocities higher than 250km/s. We find
extremely broad [OIII]4959,5007 emission that is comparable to the
width of Hβ broad profile in some highly accreting quasars. The
[OIII]4959,5007 and CIV1549 blueshifts show very high amplitudes and a
high degree of correlation. The line widths and shifts are correlated
for both [OIII]4959,5007 and CIV1549, suggesting that emission from
outflowing gas is providing a substantial broadening effect to both
lines. Otherwise, the links between CIV1549 centroid velocity at half
intensity (c(1/2)), Eddington ratio (L/LEdd), and bolometric
luminosity are found to be in agreement with previous studies of
high-luminosity quasars.
Our analysis suggests that the behaviour of quasars of very high
luminosity all along the main sequence is strongly affected by
powerful outflows involving a broad range of spatial scales. The main
sequence correlations remain valid at high redshift and high
luminosity even if a systematic increase in line width is observed.
Scaling laws based on UV AlIII1860 and Hβ emission lines are
equally reliable estimators of MBH.
Description:
Our sample consists of 22 quasars with high redshift, going from
z=2.2 to z=3.7, and with high luminosity
(47.39≤logLbol≤48.36[erg/s]), including both radio-loud and
radio-quiet sources that were observed under the ESO programmes
083.B-0273(A) and 085.B-0162(A).
Our sample covers a redshift that allows for the detection and
observation of the Hα+[OIII]4959,5007 region through the
transparent window in the near-infrared with the ISAAC spectrograph at
VLT (Sulentic et al., 2006A&A...456..929S 2006A&A...456..929S, 2017A&A...608A.122S 2017A&A...608A.122S, Cat.
J/A+A/608/A122).
Table 1 presents the main properties of our sample.
Spectra were taken in service mode in 2009 and 2010, with the infrared
spectrometer ISAAC, mounted at the Nasmyth B focus of VLT-U1 (Antu)
until August 2009, and later at the Nasmyth A focus of VLT-U3
(Melipal) at the ESO Paranal Observatory.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 123 22 Source identification
sp/* . 22 Individual spectra
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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- 23 A23 --- Source Source name
25- 26 I2 h RAh Right ascension (J2000)
28- 29 I2 min RAm Right ascension (J2000)
31- 35 F5.2 s RAs Right ascension (J2000)
37 A1 --- DE- Declination sign (J2000)
38- 39 I2 deg DEd Declination (J2000)
41- 42 I2 arcmin DEm Declination (J2000)
44- 47 F4.1 arcsec DEs Declination (J2000)
49- 54 F6.4 --- z Redshift
55 A1 --- n_z Note on z (1)
57- 62 F6.4 --- e_z Redshift error
64- 68 F5.2 mag HKmag 2MASS H or K magnitude
70 A1 --- Band [HK] Band for HKmag
72- 77 F6.2 mag iMAG Absolute i magnitude
79- 83 F5.2 mag mVCV10 Optical magnitude in n_mVCV10 band
85 A1 --- n_mVCV10 Band for mVCV10 magnitude (2)
88 A1 --- l_Fradio Limit flag on Fradio
89- 94 F6.2 mJy Fradio Radio flux
96-100 A5 --- Survey Survey
102-103 A2 --- RClass Radio Class
105-123 A19 --- FileName Name of the spectrum file in subdirectory sp
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Note (1): Redshift estimation based on the [OIII]5007.
Note (2): Bands as follows:
c = O
d = R
e = B
f = Photographic B
g = V
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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- 7 F7.1 0.1nm lambda Wavelength
9- 18 E10.4 10mW/m2/nm Flux Flux in erg/s/cm2/Å
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Acknowledgements:
Alice Deconto-Machado, adeconto(at)iaa.es
(End) Patricia Vannier [CDS] 19-Dec-2022