J/ApJ/905/7 g- and r- band LCs of Q0957+561 & SBS0909+532 (Cornachione+, 2020)
Near-infrared and optical continuum emission region size measurements in the
gravitationally lensed quasars Q0957+561 and SBS0909+532.
Cornachione M.A., Morgan C.W., Burger H.R., Shalyapin V.N.,
Goicoechea L.J., Vrba F.J., Dahm S.E., Tilleman T.M.
<Astrophys. J., 905, 7 (2020)>
=2020ApJ...905....7C 2020ApJ...905....7C
ADC_Keywords: QSOs; Gravitational lensing; Photometry; Optical
Keywords: Quasar microlensing ; Gravitational lensing ;
Gravitational microlensing ; Quasars
Abstract:
We present a microlensing analysis of updated light curves in three
filters, the g-band, r-band, and H-band, for the gravitationally
lensed quasars Q0957+561 and SBS0909+532. Both systems display
prominent microlensing features which we analyze using our Bayesian
Monte Carlo technique to constrain the quasar continuum emission
region sizes in each band. We report sizes as half-light radii scaled
to a 60° inclination angle. For Q0957+561 we measure
log(r1/2/cm)=16.54-0.33+0.33, 16.66-0.62+0.37, and
17.37-0.40+0.49 in g-, r-, and H-band, respectively. For
SBS0909+532 we measure log(r1/2/cm)=15.83-0.33+0.33,
16.21-0.62+0.37, and 17.90-0.63+0.61 in the g-, r-, and H-band
respectively. With size measurements in three bands spanning the
quasar rest frame ultraviolet to optical, we can place constraints on
the scaling of accretion disk size with wavelength,
r∝λ1/β. In a joint analysis of both systems we
find a slope shallower than that predicted by thin disk theory,
β=0.35-0.08+0.16, consistent with other constraints from
multi-epoch microlensing studies.
Description:
Our r-band observations are extensions of the programs described in
Hainline+ (2012ApJ...744..104H 2012ApJ...744..104H) and Shalyapin+ (2008A&A...492..401S 2008A&A...492..401S &
2012, J/A+A/540/A132) for Q0957, and Hainline+ (2013ApJ...774...69H 2013ApJ...774...69H)
for SBS0909. These combine observations at the United States Naval
Observatory (USNO), using the 1.55m Kaj Strand Astrometric Reflector
at Flagstaff Station, and the 2.0m Liverpool Robotic Telescope (LRT)
with effective wavelengths of 4868Å and 6165Å in the g- and
r-band, respectively. For SBS0909 we also include one epoch from the
Hiltner 2.4m telescope at the MDM Observatory and two epochs from the
Wisconsin-Indiana-Yale-NOAO (WIYN) 3.5m telescope as detailed in
Hainline+ (2013ApJ...774...69H 2013ApJ...774...69H).
For Q0957, Hainline+ (2012ApJ...744..104H 2012ApJ...744..104H) and
Gil-Merino+ (2018, J/A+A/616/A118) included photometry from the
Instituto de Astrofisica de Canarias' (IAC) Teide Observatory from
1996 to 2005. We extend these curves with 48 new nights from the USNO
spanning 2011 November through 2017 April. We also present 76 new
nights from the LRT using the IO:O camera, with a pixel scale of
0.30", from 2016 October to 2020 January collected with a typical
cadence of one 300s exposure every week. Combining all of these
observations we have an exceptional r-band light curve with 1248
epochs spanning twenty-four years.
For SBS0909, we add an additional 44 nights from the USNO, with three
300s subexposures per night, covering 2012 February through 2017 April.
For the updated LRT observations, we present 81 nights from 2016
November through 2020 January. Altogether we have a combined r-band
light curve with 510 epochs spanning 16 years.
We include g-band observations of both targets collected from the LRT.
For Q0957, we present 198 new nights from 2010 December to 2020 January.
For SBS0909, we add 195 nights of LRT g-band observations from 2012
October to 2020 February from this work.
See Section 2 for further explanations.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
09 13 01.03 +52 59 28.9 SBS0909+532 = QSO B0909+5312
10 01 20.69 +55 53 55.6 Q0957+561 = QSO B0957+561A
----------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 38 1248 Q0957+561 combined r-band light curve from
Teide Observatory, LRT, and USNO
table2.dat 32 555 Q0957+561 g-band light curve from the LRT
table3.dat 37 510 SBS0909+532 combined r-band light curve from
the MDM, WIYN, LRT and USNO
table4.dat 32 238 SBS0909+532 g-band light curve from the LRT
--------------------------------------------------------------------------------
See also:
J/ApJ/613/682 : AGN central masses & broad-line region sizes (Peterson+, 2004)
J/ApJ/640/579 : Near-infrared spectra of 27 SDSS quasars (Glikman+, 2006)
J/ApJ/716/993 : LAMP: reverberation mapping of H and He lines (Bentz+, 2010)
J/A+A/540/A132 : Optical follow-up of Q0957+561 in 2005-2010 (Shalyapin+, 2012)
J/ApJ/806/129 : Space telescope RM project. II. Swift data (Edelson+, 2015)
J/ApJ/806/258 : Optical LCs of QSO J0924+0219 lensed quasar (MacLeod+, 2015)
J/ApJ/817/55 : NIR spectroscopy of 1.5<z<3.5 broad-band QSOs (Shen, 2016)
J/MNRAS/465/4914 : R-band light curves of HE 0435-1223 (Bonvin+, 2017)
J/A+A/616/A118 : Lensed QSOs LCs & spectral monitoring (Gil-Merino+ 2018)
J/ApJ/869/106 : SMARTS & Euler R-band obs. of WFI J2033-4723 (Morgan+, 2018)
J/ApJ/870/123 : Swift optical & UV flux of four AGNs (Edelson+, 2019)
J/A+A/637/A89 : QSO 2237+0305 photometry and light curves (Goicoechea+, 2020)
Byte-by-byte Description of file: table[1234].dat
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Bytes Format Units Label Explanations
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1- 8 F8.3 d HJD [117/8900] Heliocentric Julian Date,
HJD-2450000
10- 14 F5.3 mag Amag [2.19/3.2] Apparent image A magnitude in Filt
16- 20 F5.3 mag e_Amag [0.001/0.04] Uncertainty in Amag
22- 26 F5.3 mag Bmag [2.26/3.8] Apparent image B magnitude in Filt
28- 32 F5.3 mag e_Bmag [0.001/0.04] Uncertainty in Bmag
34- 38 A5 --- Obs Observatory (not for Tables 2 and 4) (1)
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Note (1): Observatory as follows:
lrt = the 2.0m Liverpool Robotic Telescope (LRT)
teide = the Instituto de Astrofisica de Canarias' (IAC) Teide Observatory
usno = the 1.55m Kaj Strand Astrometric Reflector at Flagstaff Station
at the United States Naval Observatory
wiyn = the Wisconsin-Indiana-Yale-NOAO (WIYN) 3.5m telescope
mdm = the Hiltner 2.4m telescope at the MDM Observatory
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 22-Apr-2022