SBS 0909+532: A New Double Gravitational Lens or Binary Quasar?

Abstract

The z=1.377, B=17.0 mag quasar SBS 0909+532 A, B is a double with two images separated by 1.107 +/- 0.006 arcsec. Because the faint image has an emission line at the same wavelength as the MgII 2798 A emission line of the quasar, and lacks the broad MgIb absoption feature expected for a star with the same colors (a K star), we conclude that image B is a quasar with similar redshift to image A. The relative probabilities that the double is the smallest separation (4.8/h kpc for Ω_0=1) correlated quasar pair or a gravitational lens are \sim 1:10^6. If the object is a lens, the mean lens redshift is $<z_l>=0.5$ with 90% confidence bounds of 0.18 < z_l < 0.83 for Ω_0=1. If the lens is an elliptical galaxy, we expect it to be brighter than I < 19.5 mag. The broad band flux ratio varies with wavelength, with ΔI=0.31, ΔR=0.58, and ΔB=1.29 magnitudes, which is difficult to reconcile with the lensing hypothesis.

19 pages, 6 figures, ApJ in press

References in corpus (3)

• Is There A Cosmological Constant?
• Field Galaxy Evolution Since Z~1 from a Sample of QSO Absorption-Selected Galaxies
• On the Spatial and Kinematic Distributions of Mg II Absorbing Gas in <z>=0.7 Galaxies

Cited by in corpus (22)

• Dust and Extinction Curves in Galaxies with z>0: The Interstellar Medium of Gravitational Lens Galaxies
• The Sloan Digital Sky Survey Quasar Catalog II. First Data Release
• HST Observations of 10 Two-Image Gravitational Lenses
• Detection of the 2175ÅExtinction Feature at z=0.83
• A Keck Survey of Gravitational Lens Systems: I. Spectroscopy of SBS 0909+532, HST 1411+5211, and CLASS B2319+051
• Variability and the X-ray/UV ratio of Active Galactic Nuclei
• Gravitationally Lensed Quasars in Gaia: I. Resolving Small-Separation Lenses
• $H_0$ from ten well-measured time delay lenses
• X-ray Observations of Gravitationally Lensed Quasars; Evidence for a Hidden Quasar Population
• Differential X-ray Absorption and Dust-To-Gas Ratios of the Lens Galaxies SBS0909+523, FBQS0951+2635, and B1152+199
• SDSS J1650+4251: A New Gravitational Lens
• Time Delay and Accretion Disk Size Measurements in the Lensed Quasar SBS 0909+532 from Multiwavelength Microlensing Analysis
• XMM-Newton observations of high-luminosity radio-quiet QSOs
• Time delay of SBS 0909+532
• Determining the Lensing Fraction of SDSS Quasars: Methods and Results from the EDR
• First robotic monitoring of a lensed quasar: intrinsic variability of SBS 0909+532
• SDSS J131339.98+515128.3: A new gravitationally lensed quasar selected based on near-infrared excess
• New database for a sample of optically bright lensed quasars in the northern hemisphere
• COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses IV. Models of prospective time-delay lenses
• Revealing the nonlinear behaviour of the lensed quasar Q0957+561
• Significant H I and Metal Differences around the z = 0.83 Lens Galaxy Towards the Doubly Lensed Quasar SBS 0909+532
• New Dynamical Measurements from a Lensed Quasar Sample: Joint Analysis Constrains the Mass Profile Evolution of Lens Galaxies