J/A+A/700/L8 QSO J0455-4216 medium-band filt. light curves (Pozo Nunez+, 2025)
Accretion disc reverberation mapping in a high-redshift quasar.
Pozo Nunez. F., Banados E., Panda S., Heidt J.
<Astron. Astrophys. 700, L8 (2025)>
=2025A&A...700L...8P 2025A&A...700L...8P (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Photometry, infrared
Keywords: galaxies: active - galaxies: high-redshift -
quasars: supermassive black holes
Abstract:
Powered by supermassive black holes at their centers, quasars are
among the most luminous objects in the universe, serving as important
probes of cosmic history and galaxy evolution.
The size of the accretion disc surrounding the black hole is a
critical parameter for understanding quasar physics and their
potential use as standard candles in cosmology.
However, direct measurements of accretion disc sizes have so far been
confined to the local universe (z<0.2), limiting our understanding of
quasars during the peak of cosmic activity. Here we report the first
direct measurement of the accretion disc size in the quasar QSO
J0455-4216 at z=2.66, when the Universe was only ∼2Gyrs old.
Medium-band filters mounted on the MPG/ESO 2.2-metre telescope at La
Silla Observatory were used to isolate continuum emission regions
during a six-month monitoring campaign.
The light curves exhibit pronounced variability features and enabled
the detection of inter-band time delays from different parts of the
disc. We map the disc and locate its ultraviolet-emitting outermost
region at 3.02+0.33-0.57) light-days from the black hole (∼500AU).
Surrounding a supermassive black hole 900 million times the mass of
the Sun, these measurements validate accretion disc theory at an
unprecedented redshift and pave the way for efficient black hole mass
estimates, reducing decades-long spectroscopic reverberation campaigns
to just a few years or less.
Description:
This table contains normalized flux density light curves of the
quasar QSO J0455-4216 in four medium-band filters
(4858, 5315, 6043, and 7705).
Flux-calibrated fluxes can be recovered by multiplying each
column's fluxes and errors by:
4858 : 0.12mJy
5315 : 0.19mJy
6043 : 0.13mJy
7705 : 0.22mJy
Objects:
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RA (2000) DE Designation(s)
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04 55 23.06 -42 16 17.3 QSO J0455-4216 = 2MASS J04552305-4216173
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
lc.dat 94 75 Light curves in 4 medium-bands
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Byte-by-byte Description of file: lc.dat
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Bytes Format Units Label Explanations
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1- 6 F6.2 d MJD4858 Observation date in filter 4858 (MJD - 60220)
9- 14 F6.4 --- F4858 Normalized flux in filter 4858 (4858Å)
17- 22 F6.4 --- e_F4858 1σ uncertainty in Flux 4858
25- 30 F6.2 d MJD5315 Observation date in filter 5315 (MJD - 60220)
33- 38 F6.4 --- F5315 Normalized flux in filter 5315 (5315Å)
41- 46 F6.4 --- e_F5315 1σ uncertainty in Flux 5315
49- 54 F6.2 d MJD6043 Observation date in filter 6043 (MJD - 60220)
57- 62 F6.4 --- F6043 Normalized flux in filter 6043 (6043Å)
65- 70 F6.4 --- e_F6043 1σ uncertainty in Flux 6043
73- 78 F6.2 d MJD7705 Observation date in filter 7705 (MJD - 60220)
81- 86 F6.4 --- F7705 Normalized flux in filter 7705 (7705Å)
89- 94 F6.4 --- e_F7705 1σ uncertainty in Flux 7705
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Acknowledgements:
Francisco Pozo Nunez, francisco.pozon(at)gmail.com
(End) Francisco Pozo Nunez [HITS, Germany], Patricia Vannier [CDS] 25-Jul-2025