J/A+A/642/A150 Quasars as standard candles. III. (Lusso+, 2020)
Quasars as standard candles.
III. Validation of a new sample for cosmological studies.
Lusso E., Risaliti G., Nardini E., Bargiacchi G., Benetti M., Bisogni S.,
Capozziello S., Civano F., Eggleston L., Elvis M., Fabbiano G., Gilli R.,
Marconi A., Paolillo M., Piedipalumbo E., Salvestrini F., Signorini M.,
Vignali C.
<Astron. Astrophys. 642, A150 (2020)>
=2020A&A...642A.150L 2020A&A...642A.150L (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Active gal. nuclei ; Redshifts ; X-ray sources ;
Ultraviolet ; Optical ; Stars, distances
Keywords: galaxies: active - quasars: general -
quasars: supermassive black holes - methods: statistical
Abstract:
We present a new catalogue of ∼2400 optically selected quasars with
spectroscopic redshifts and X-ray observations from either Chandra or
XMM-Newton. The sample can be used to investigate the non-linear
relation between the UV and X-ray luminosity of quasars, and to build
a Hubble diagram up to redshift z∼7.5.
We selected sources that are neither reddened by dust in the
optical/UV nor obscured by gas in the X-rays, and whose X-ray fluxes
are free from flux-limit related biases. After checking for any
possible systematics, we confirm, in agreement with our previous
works, that (i) the X-ray to UV relation provides distance estimates
matching those from supernovae up to z∼1.5, and (ii) its slope shows
no redshift evolution up to z∼5. We provide a full description of the
methodology for testing cosmological models, further supporting a
trend whereby the Hubble diagram of quasars is well reproduced by the
standard flat LambdaCDM model up to z∼1.5-2, but strong deviations
emerge at higher redshifts. Since we have minimized all non-negligible
systematic effects, and proven the stability of the Lx-Lo relation at
high redshifts, we conclude that an evolution of the expansion rate of
the Universe should be considered as a possible explanation for the
observed deviation, rather than some systematic (redshift-dependent)
effect associated with high-redshift quasars.
Description:
Properties of the final quasar sample composed 2421 objects.
For each quasar name, equatorial coordinates, redshifts, UV rest-frame
monochromatic fluxes at 2500 Angstroem, X-ray rest-frame monochromatic
fluxes at 2keV, group numbering for each sub-sample, photon index,
distance modulus are given.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 152 2421 Properties of the final quasar sample
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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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3- 25 A23 --- Name Quasar name
29- 38 F10.6 deg RAdeg Right ascension (J2000.0)
40- 50 F11.7 deg DEdeg Declination (J2000.0)
52- 57 F6.4 --- z Redshift
61- 69 F9.5 [mW/m2] logFUV Rest-frame fluxes at 2500 Angstroem (1)
73- 79 F7.5 [mW/m2] e_logFUV Error on rest-frame fluxes at 2500 Angstroem
83- 91 F9.5 [mW/m2] logFX Rest-frame fluxes at 2keV (1)
95-101 F7.5 [mW/m2] e_logFX Error on rest-frame fluxes at 2keV
105 I1 --- Group [1/7] Group numbering for each sub-sample (2)
113-119 F7.5 --- gammax Photon index
123-129 F7.5 --- e_gammax Error on the photon index
133-141 F9.6 --- DM Distance modulus (3)
145-152 F8.6 --- e_DM Error on the distance modulus
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Note (1): Fluxes are in units of log(erg/s/cm2)
Note (2): The Group column flags the different subsamples as follows:
1 = XMM-Newton z∼3 sample
2 = new XMM-Newton z∼4 quasar
3 = High-z sample
4 = XXL
5 = SDSS - 4XMM
6 = SDSS - Chandra
7 = local AGN
Note (3): The column DM reports the distance moduli to reproduce Fig.9
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Acknowledgements:
Elisabeta Lusso, elisabeta.lusso(at)unifi.it
References:
Lusso & Risaliti, Paper I 2017A&A...602A..79L 2017A&A...602A..79L
Salvestrini et al., Paper II 2019A&A...631A.120S 2019A&A...631A.120S
(End) Patricia Vannier [CDS] 21-Aug-2020