J/A+A/391/481 R-band photometry of SBS1520+530 (Burud+, 2002)
Time delay and lens redshift for the doubly imaged BAL quasar SBS1520+530
Burud I., Hjorth J., Courbin F., Cohen J.G., Magain P., Jaunsen A.O.,
Kaas A.A., Faure C., Letawe G.
<Astron. Astrophys. 391, 481 (2002)>
=2002A&A...391..481B 2002A&A...391..481B
ADC_Keywords: Gravitational lensing; QSOs; Photometry
Keywords: Gravitational lensing - quasars: individual: SBS 1520+530 -
cosmological parameters
Abstract:
We present optical R-band light curves of the gravitationally lensed
quasar SBS 1520+530 derived from data obtained at the Nordic Optical
Telescope, from February 1999 to May 2001. A time delay of 130±3days
(1σ) is determined from the light curves. In addition, spectra
of SBS 1520+530 obtained at the Keck Observatory are spatially
deconvolved in order to extract the spectrum of the faint lensing
galaxy, free of any contamination by the light from the bright quasar
images. This spectrum indicates a lens redshift z=0.717, in agreement
with one of the absorption systems found in the quasar spectra. The
best mass model of the system includes a second nearby galaxy and a
cluster of galaxies in addition to the main lensing galaxy. Adopting
this model and an Ω=0.3, Λ=0.7 cosmology, our time-delay
measurement yields a Hubble constant of H0=51±9km/s/Mpc (1σ
error).
Description:
The table lists the data points obtained at the Nordic Optical
Telescope used to derive the time delay for the lensed quasar
QSO1520+530.
Objects:
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RA (2000) DE Designation(s)
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15 21 44.8 +52 54 49 SBS 1520+530 = SBSG 1520+530
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 48 58 R-band photometry of SBS 1520+530
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 8 F8.4 mag magA Relative magnitude for image A to the
reference star S3 (see Fig. 2 of the paper)
9- 16 F8.4 mag e_magA Error on A mag
17- 25 F9.4 mag magB Relative magnitude for image B to the
reference star S3 (see Fig. 2 of the paper)
26- 33 F8.4 mag e_magB Error on B mag
34- 46 F13.2 d JD Julian Date
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Acknowledgements: Ingunn Burud
(End) Ingunn Burud [STScI], Patricia Bauer [CDS] 08-Aug-2002