J/A+A/703/A250 HE0435-1223 V and R light curves (Sorgenfrei+, 2025)
Detection of colour variations from gravitational microlensing observations in
the quadruple quasar HE0435-1223: Implications for the accretion disc.
Sorgenfrei C., Schmidt R.W., Wambsganss J.
<Astron. Astrophys. 703, A250 (2025)>
=2025A&A...703A.250S 2025A&A...703A.250S (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Gravitational lensing ; Photometry ; Optical
Keywords: accretion, accretion disks - gravitational lensing: micro -
quasars: individual: HE0435-1223
Abstract:
We present monitoring observations of quasar microlensing in the
quadruple quasar HE0435-1223. The microlensing-induced light curves of
the quasar images are chromatic, i.e. they depend on the applied
filter band. Comparison with microlensing simulations allows us to
infer properties of the accretion disk.
We determine the R and V band light curves of the four images of
HE0435-1223 from 79 and 80 epochs respectively, taken from 2014 to
2024 at the Las Cumbres Observatory using difference imaging analysis.
We consider difference light curves to remove the intrinsic quasar
variability. This reveals a prominent long-term chromatic microlensing
event in image B. We use microlensing light curve simulations with
both Gaussian and standard thin accretion disk brightness profiles to
analyse this signal.
The particularly strong signal observed in image B of HE0435-1223
makes it possible to detect a size ratio of the accretion disk in the
R band compared to the V band of 1.24+0.08-0.20 and
1.42+0.11-0.22 for the Gaussian and the thin disk model,
respectively. These values are in agreement with standard thin disk
theory. For the absolute size we find large disk half-light radii of
around 0.7 to 1.0 Einstein radii with an uncertainty of about 0.6dex
(depending on the filter bands and the models). Finally, our
calculations show that image B undergoes caustic crossings about once
per year.
Description:
The two files contain the light curves of the four images of the
gravitationally lensed quasar HE0435-1223 in the R band and the
V band from data taken at the Las Cumbres Observatory (LCO) from 2014
to 2024.
Objects:
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RA (2000) DE Designation(s)
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04 38 14.87 -12 17 14.6 HE 0435-1223 = [VV2003] J043814.8-122314
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
he0435v.dat 72 80 V band light curves of HE0435-1223
he0435r.dat 72 79 R band light curves of HE0435-1223
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Byte-by-byte Description of file: he0435v.dat
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Bytes Format Units Label Explanations
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1- 10 F10.4 d MJD Modified Julian Date
12- 18 F7.4 mag VmagA V band magnitude of image A
20- 25 F6.4 mag e_VmagA 1-sigma error of VmagA
27- 33 F7.4 mag VmagB V band magnitude of image B
35- 40 F6.4 mag e_VmagB 1-sigma error of VmagB
42- 48 F7.4 mag VmagC V band magnitude of image C
50- 55 F6.4 mag e_VmagC 1-sigma error of VmagC
57- 63 F7.4 mag VmagD V band magnitude of image D
65- 70 F6.4 mag e_VmagD 1-sigma error of VmagD
72 A1 --- Band [V] Band
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Byte-by-byte Description of file: he0435r.dat
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Bytes Format Units Label Explanations
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1- 10 F10.4 d MJD Modified Julian Date
12- 18 F7.4 mag RmagA R band magnitude of image A
20- 25 F6.4 mag e_RmagA 1-sigma error of RmagA
27- 33 F7.4 mag RmagB R band magnitude of image B
35- 40 F6.4 mag e_RmagB 1-sigma error of RmagB
42- 48 F7.4 mag RmagC R band magnitude of image C
50- 55 F6.4 mag e_RmagC 1-sigma error of RmagC
57- 63 F7.4 mag RmagD R band magnitude of image D
65- 70 F6.4 mag e_RmagD 1-sigma error of RmagD
72 A1 --- Band [R] Band
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Acknowledgements:
Christian Sorgenfrei, c.sorgenfrei(at)stud.uni-heidelberg.de
(End) Patricia Vannier [CDS] 12-Sep-2025