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J/ApJ/836/14   LCs & spectra of SDSS J1515+1511 lens system   (Shalyapin+, 2017)

Doubly imaged quasar SDSS J1515+1511: time delay and lensing galaxies. Shalyapin V.N., Goicoechea L.J. <Astrophys. J., 836, 14-14 (2017)> =2017ApJ...836...14S (SIMBAD/NED BibCode)
ADC_Keywords: Gravitational lensing ; Photometry, SDSS ; Spectroscopy ; QSOs Keywords: gravitational lensing: strong; quasars: individual: "SDSS J1515+1511" Abstract: We analyze new optical observations of the gravitational lens system SDSS J1515+1511. These include a 2.6-year photometric monitoring with the Liverpool Telescope (LT) in the r band, as well as a spectroscopic follow-up with the LT and the Gran Telescopio Canarias (GTC). Our r-band LT light curves cover a quiescent microlensing period of the doubly imaged quasar at zs=2.049, which permits us to robustly estimate the time delay between the two images A and B: 211±5d (1σ confidence interval; A is leading). Unfortunately, the main lensing galaxy (G1) is so faint and close to the bright quasar that it is not feasible to accurately extract its spectrum through the GTC data. However, assuming the putative redshift zG1=0.742, the GTC and LT spectra of the distant quasar are used to discuss the macrolens magnification, and the extinction and microlensing effects in G1. The new constraints on the time delay and macrolens magnification ratio essentially do not change previous findings on the mass scale of G1 and external shear, while the redshift of the lensing mass is found to be consistent with the assumed value of zG1. This is clear evidence that G1 is indeed located at zG1=0.742. From the GTC data, we also obtain the redshift of two additional objects (the secondary galaxy G2 and a new absorption system) and discuss their possible roles in the lens scenario. Description: We conducted a photometric monitoring campaign of SDSS J1515+1511 from early February of 2014 to mid September of 2016, i.e., for 2.6yr with an average sampling rate of about two nights every week. All optical observations were performed with the 2.0m fully robotic Liverpool Telescope (LT) at the Roque de los Muchachos Observatory, Canary Islands (Spain). Deep long-slit spectra of SDSS J1515+1511 were obtained using the R500B and R500R grisms in the OSIRIS spectrograph on the 10.4m Gran Telescopio Canarias (GTC). We took a single 1800s exposure with the blue grism (R500B) on 2015 April 15. We also observed the lens system with the red grism (R500R) on 2015 April 16. Hence, the new data cover a wavelength range of 3570-9250Å with a resolving power of ∼300-400. We observed SDSS J1515+1511 with the SPRAT long-slit spectrograph on 2015 August 16 (red grating) and 2015 August 18 (blue). We have re-observed the system on 2016 March 17 (blue). Objects: ------------------------------------------------------------------------- RA (ICRS) DE Designation(s) ------------------------------------------------------------------------- 15 15 38.59 +15 11 35.8 SDSS J1515+1511 = [IOR2014] SDSS J1515+1511 ------------------------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 48 150 *LT r-band light curves of SDSS J1515+1511AB table2.dat 22 1024 *GTC-OSIRIS-R500B spectra of SDSS J1515+1511AB table3.dat 29 916 *GTC-OSIRIS-R500R spectra of SDSS J1515+1511ABG1 table4.dat 22 880 *LT-SPRAT-blue/red spectra of SDSS J1515+1511AB (2015 August) table5.dat 22 880 *LT-SPRAT-blue spectra of SDSS J1515+1511AB (2016 March)
Note on table*dat: See the "Description" section above for the observations description.
Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 9 F9.3 d MJD Modified Julian Date 11- 16 F6.3 mag rmagA [18/18.3] r-band magnitude of SDSS J1515+1511A 18- 22 F5.3 mag e_rmagA [0.004/0.03] Uncertainty in rmagA 24- 29 F6.3 mag rmagB [18.3/18.7] r-band magnitude of SDSS J1515+1511B 31- 35 F5.3 mag e_rmagB [0.004/0.03] Uncertainty in rmagB 37- 42 F6.3 mag rmagS [18.1/18.2] r-band magnitude of the field (control) star S 44- 48 F5.3 mag e_rmagS [0.003/0.02] Uncertainty in rmagS
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 8 F8.3 0.1nm lambda [3567/7244] GTC-OSIRIS-R500B spectral wavelength, in Angstroms 10- 15 F6.3 10-19W/m2/nm FluxA [9.6/95.2] Flux, SDSS J1515+1511A, in 10-17erg/cm2/s/Å units 17- 22 F6.3 10-19W/m2/nm FluxB [7/58.3] Flux, SDSS J1515+1511B, in 10-17erg/cm2/s/Å units
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 8 F8.3 0.1nm lambda [4846.6/9252] GTC-OSIRIS-R500R spectral wavelength, in Angstroms 10- 15 F6.3 10-19W/m2/nm FluxA [5.2/26.3] Flux, SDSS J1515+1511A, in 10-17erg/cm2/s/Å units 17- 22 F6.3 10-19W/m2/nm FluxB [3.9/19] Flux, SDSS J1515+1511B, in 10-17erg/cm2/s/Å units 24- 29 F6.3 10-19W/m2/nm FluxG1 [-0.1/1.2] Flux, SDSS J1515+1511G1, in 10-17erg/cm2/s/Å units
Byte-by-byte Description of file: table4.dat
Bytes Format Units Label Explanations
1- 8 F8.3 0.1nm lambda [3980.4/8055.8] LT-SPRAT-blue/red spectral wavelength, in Angstroms 10- 15 F6.3 10-19W/m2/nm FluxA [7.3/51.5] Flux, SDSS J1515+1511A, in 10-17erg/cm2/s/Å units 17- 22 F6.3 10-19W/m2/nm FluxB [4.5/32] Flux, SDSS J1515+1511B, in 10-17erg/cm2/s/Å units
Byte-by-byte Description of file: table5.dat
Bytes Format Units Label Explanations
1- 8 F8.3 0.1nm lambda [3968.4/8060] LT-SPRAT-blue spectral wavelength, in Angstroms 10- 15 F6.3 10-19W/m2/nm FluxA [7.6/51] Flux, SDSS J1515+1511A, in 10-17erg/cm2/s/Å units 17- 22 F6.3 10-19W/m2/nm FluxB [5.7/35.1] Flux, SDSS J1515+1511B, in 10-17erg/cm2/s/Å units
History: From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 07-Sep-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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