J/ApJ/964/173 r-band LCs of a doubly imaged lensed SDSS quasar (Rivera+, 2024)
Accretion disk size and updated time-delay measurements in the gravitationally
lensed quasar SDSS J165043.44+425149.3.
Rivera A.B., Morgan C.W., Florence S.M., Kniezewski K., Millon M.,
Courbin F., Dahm S.E., Vrba F.J., Tilleman T.M., Cornachione M.A.,
Asfandiyarov I.M., Ehgamberdiev S.A., Burkhonov O.A.
<Astrophys. J., 964, 173 (2024)>
=2024ApJ...964..173R 2024ApJ...964..173R
ADC_Keywords: Gravitational lensing; QSOs; Photometry; Optical
Keywords: Quasar microlensing ; Quasars ; Gravitational lensing ;
Gravitational microlensing
Abstract:
We analyze variability in 15-season optical lightcurves from the
doubly imaged lensed quasar SDSS J165043.44+425149.3, comprising five
seasons of monitoring data from the Maidanak Observatory (277 nights
in total, including the two seasons of data previously presented in
Vuissoz+ 2007A&A...464..845V 2007A&A...464..845V), five seasons of overlapping data from
the Mercator telescope (269 nights), and 12 seasons of monitoring data
from the US Naval Observatory, Flagstaff Station at lower cadence
(80 nights). We update the 2007 time-delay measurement for
SDSS_J165043.44+425149.3 with these new data, finding a time delay of
ΔtAB=-55.1-3.7+4.0days, with image A leading image B. We
analyze the microlensing variability in these lightcurves using a
Bayesian Monte Carlo technique to yield measurements of the size of
the accretion disk at λrest=2420Å, finding a half-light
radius of log(r1/2/cm)=16.19-0.58+0.38 assuming a 60°
inclination angle. This result is unchanged if we model 30% flux
contamination from the broad-line region. We use the width of the MgII
line in the existing Sloan Digital Sky Survey spectra to estimate the
mass of this system's supermassive black hole, finding
MBH=2.47x109M☉. We confirm that the accretion disk size in
this system, whose black hole mass is on the very high end of the MBH
scale, is fully consistent with the existing quasar accretion disk
size-black hole mass relation.
Description:
In this investigation, we present a multiepoch microlensing analysis
of 15-season optical lightcurves from the doubly imaged
gravitationally lensed quasar SDSS J165043.44+425149.3, which has an
image separation of 1.2". The source redshift is zs=1.547 and the
lens redshift is zl=0.58 (Morgan+ 2003AJ....126.2145M 2003AJ....126.2145M).
We compiled a 626-epoch Sloan Digital Sky Survey (SDSS) r-band
lightcurve using observations from several sources.
We include 277 nights of data from the Maidanak Observatory 1.5m
Telescope, Uzbekistan, taken from 2004 May to 2008 October. The data
from 2004 May to 2005 September were previously published in
Vuissoz+ (2007A&A...464..845V 2007A&A...464..845V). For most of the epochs, six dithered
images were taken, each with an exposure time of 300s. The pixel scale
for the CCD was 0.266".
An additional 269 observations from the Mercator Observatory 1.2m
Telescope, La Palma, were taken between 2004 August and 2008 October.
Most of the data consist of five exposures per night, each with an
exposure time of 360s. The pixel scale of the CCD was 0.193".
Our new observations were taken using the 1.55m Kaj Strand Astrometric
Reflector at the US Naval Observatory (USNO) Flagstaff Station (NOFS)
with both the 2048x4096 EEV (OneChip) and 2048x2048 Tek2k CCDs. We
took observations with Tek2k from 2008 April to 2022 June and OneChip
observations between 2010 May and 2016 July, using three 600s
exposures in both cases. The pixel scale for OneChip is 0.18" and that
of Tek2k is 0.33".
Objects:
----------------------------------------------------------------
RA (ICRS) DE Designation(s)
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16 50 43.44 +42 51 49.3 SDSS J1650 = SDSS J165043.44+425149.3
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 45 626 r-band light curves for SDSS J165043.44+425149.3
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See also:
V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)
II/289 : SDSS quasar catalog, sixteenth data release (DR16Q) (Lyke+, 2020)
VII/290 : The Million Quasars (Milliquas) catalogue, version 7.2 (Flesch, 2021)
J/A+A/427/387 : QORG catalog of radio/X-ray sources (Flesch+, 2004)
J/ApJ/699/800 : Mass functions of active black holes (Vestergaard+, 2009)
J/MNRAS/405/2302 : Improved redshifts for SDSS quasar spectra (Hewett+, 2010)
J/AJ/143/119 : SDSS Quasar Lens Search. V. Final catalog (Inada+, 2012)
J/ApJS/206/4 : SED & bol. corrections for luminous QSOs (Krawczyk+, 2013)
J/ApJ/806/129 : Space telescope RM project. II. Swift data (Edelson+, 2015)
J/ApJ/869/106 : SMARTS+Euler R-band obs. of WFI J2033-4723 (Morgan+, 2018)
J/A+A/640/A105 : R-band light curves of 23 lensed QSOs (Millon+, 2020)
J/ApJ/888/73 : Varstrometry of SDSS quasars with Gaia DR2 (Hwang+, 2020)
J/ApJS/249/18 : The ZTF catalog of periodic variable stars (Chen+, 2020)
J/ApJS/250/3 : Variable MgII NALs in SDSS DR14 (Chen+, 2020)
J/AJ/161/45 : KODIAQ DR3: quasars (0.1<zem<6.4) with ESI (O'Meara+, 2021)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 F10.5 d HJD [3132.9/9748.72] Heliocentric Julian Date,
HJD-2450000
12- 17 F6.3 mag rmagImgA [17.57/18.12] Image A r band (AB) magnitude
19- 23 F5.3 mag e_rmagImgA [0.001/0.03] Uncertainty in ImageAmag
25- 30 F6.3 mag rmagImgB [19.15/19.95] Image B r band (AB) magnitude
32- 36 F5.3 mag e_rmagImgB [0.004/0.1] Uncertainty in ImageBmag
38- 45 A8 --- Obs Observatory (Maidanak, Mercator or USNO)
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History:
From electronic version of the journal
License: CC-BY-4.0
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 28-Jul-2026