J/other/Nat/605.244 XQR-30 quasars sample (Bischetti+, 2022)
Suppression of black-hole growth by strong outflows at redshifts 5.8-6.6.
Bischetti M., Feruglio C., D'Odorico V., Arav N., Banados E., Becker G.,
Bosman S.E.I., Carniani S., Cristiani S., Cupani G., Davies R., Eilers A.C.,
Farina E.P., Ferrara A., Maiolino R., Mazzucchelli C., Mesinger A.,
Meyer R.A., Onoue M., Piconcelli E., Ryan-Weber E., Schindler J.-T.,
Wang F., Yang J., Zhu Y., Fiore F.
<Nature, 605, 244-247 (2022)>
=2022Natur.605..244B 2022Natur.605..244B (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Redshifts ; Photometry, infrared
Abstract:
Bright quasars, powered by accretion onto billion-solar-mass black
holes, already existed at the epoch of reionization, when the Universe
was 0.5-1 billion years old. How these black holes formed in such a
short time is the subject of debate, particularly as they lie above
the correlation between black-hole mass and galaxy dynamical mass in
the local Universe. What slowed down black-hole growth, leading
towards the symbiotic growth observed in the local Universe, and when
this process started, has hitherto not been known, although black-hole
feedback is a likely driver. Here we report optical and near-infrared
observations of a sample of quasars at redshifts 5.8≲z≲6.6. About
half of the quasar spectra reveal broad, blueshifted absorption line
troughs, tracing black-hole-driven winds with extreme outflow
velocities, up to 17% of the speed of light. The fraction of quasars
with such outflow winds at z≳5.8 is ∼2.4 times higher than at z≳2-4.
We infer that outflows at z≳5.8 inject large amounts of energy into
the interstellar medium and suppress nuclear gas accretion, slowing
down black-hole growth. The outflow phase may then mark the beginning
of substantial black-hole feedback. The red optical colours of outflow
quasars at z≳5.8 indeed suggest that these systems are dusty and may
be caught during an initial quenching phase of obscured accretion.
Description:
XQR-30 quasars were selected to match the following requirements:
declination δ<+27°, to be observable from the European
Southern Observatory (ESO)/Very Large Telescope; redshift z≥5.8, to
require the MgII emission line in the K band; J magnitude JAB≤19.8
for z<6.0 sources and JAB≤20.0 for quasars at z≥6.0; no existing
deep X-shooter data, defined as S/N≳25 per 50km/s pixel at
1600-1700Å. The application of those constraints to the literature
and newly discovered quasars resulted in a sample of 30 sources
covering the redshift range 5.8≤z≤6.6, presented in table 1.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 99 30 The XQR-30 sample properties and
BAL system parameters
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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- 14 A14 --- Name Quasar name
16- 17 I2 h RAh Right ascension (J2000)
19- 20 I2 min RAm Right ascension (J2000)
22- 26 F5.2 s RAs Right ascension (J2000)
28 A1 --- DE- Declination sign (J2000)
29- 30 I2 deg DEd Declination (J2000)
32- 33 I2 arcmin DEm Declination (J2000)
35- 39 F5.2 arcsec DEs Declination (J2000)
41- 43 I3 --- SNR Median signal to noise per pixel in the
1600-1700Å wavelength range,
for a 50km/s spectral resolution
44 A1 --- n_SNR [*] Note (1)
46- 50 F5.3 --- z MgII-based redshift (2)
52- 56 F5.2 mag Jmag J magnitude (AB)
58- 62 F5.2 mag W1mag ?=- WISE W1 magnitude (AB)
64- 68 F5.2 mag W2mag ?=- WISE W1 magnitude (AB)
70- 74 I5 --- BI ?=- Balnicity index
76- 80 I5 km/s Vmin ?=- Minimum velocity of the CIV BAL outflows (2)
82- 86 I5 km/s Vmax ?=- Maximum velocity of the CIV BAL outflows (2)
88- 93 A6 --- Type BAL/no-BAL classification
95- 96 A2 --- r_Jmag Refernece for J magnitude (3)
97 A1 --- --- [,]
98- 99 A2 --- r_W1mag Reference for W1 and W2 magnitudes (3)
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Note (1): Note on SNR as follows:
* = in the case of PSOJ242-12, two hours of observations are still
needed to obtain the final spectrum
Note (2): Strong (weak) BAL outflows typically have BI0>1000km/s
(BI0<1000 km/s). Positive Vmin and vmax values indicate
blue-shifted C IV absorption.
Note (3): References for the J and WISE magnitudes as follows:
39 = Ross & Cross, 2020MNRAS.494..789R 2020MNRAS.494..789R, Cat. J/MNRAS/494/789
40 = Jiang et al., 2015AJ....149..188J 2015AJ....149..188J
41 = Lawrence et al., 2007MNRAS.379.1599L 2007MNRAS.379.1599L, Cat. II/314
42 = Cross et al., 2012A&A...548A.119C 2012A&A...548A.119C
43 = Mazzucchelli et al., 2017ApJ...849...91M 2017ApJ...849...91M
44 = Banados et al., 2019ApJ...885...59B 2019ApJ...885...59B
* = presented in this work
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 20-Jun-2023