QSO mass constraints from gravitational lensing studies of quasar pairs
نویسندگان
چکیده
New constraints on the mass of quasars are derived from gravitational lensing studies of the QSO pairs Q1548+114 A & B and Q1148+0055 A & B, for which new ground-based and Hubble Space Telescope (HST) direct imagery have been obtained. In the case of Q1548+114 A & B, QSO A has been resolved into its host galaxy and a close companion. The nondetection with HST of a secondary lensed image of the background QSO in the close vicinity of the foreground one and the modeling of the host of QSO A, of the companion and of field galaxies with Singular Isothermal Spheres (SIS) yield a robust upper limit on the central compact mass of 4.5 1011M . On the other hand, the combined mass of Q1148+0055 B plus host must be smaller than 6.5 1011M since no secondary lensed image has been detected with HST. Photometry and relative astrometry of all the detected objects are reported.
منابع مشابه
How many arcminute - separation lenses are expected in the 2 dF QSO survey ?
Wide separation lensing statistics offer information about the density profile and abundance of dark halos. Recently a possible discovery of six quasar pairs, which may be lensed multiple images, was reported by Miller et al. (2002). These pairs are selected from a catalog of the 2dF quasar (QSO) survey comprising 22163 quasars. We calculate expected numbers of lensed quasars taking account of ...
متن کاملLensing properties of 7 damped Lyα absorbing galaxy-QSO pairs
Le Brun et al. (1997) presented the first identifications of the galaxies giving rise to 7 intermediate redshift damped Lyα (DLA) absorption systems. Here, we study the gravitational lensing properties of these foreground galaxies based on their observed optical appearance and on the absence of any secondary lensed quasar image. We consider the possibility that any secondary image be hidden due...
متن کاملDetection of the Galaxy Lensing the Doubly–imaged Quasar Sbs 1520+530
H band observations with a spatial resolution of 0. 15 carried out with the Canada-France-Hawaii Telescope adaptive optics system show a galaxy between the components of the double BAL QSO SBS 1520+530, thereby confirming this system as a gravitational lens. The galaxy is located 0. 40 from the fainter of the two QSO images and is offset 0. 12 from the line joining them. The H magnitude of the ...
متن کاملImproved Constraints on the Gravitational Lens Q0957+561. I. Weak Lensing
Attempts to constrain the Hubble constant using the strong gravitational lens system Q0957+561 are limited by systematic uncertainties in the mass model, since the time delay is known very precisely. One important systematic effect is the mass sheet degeneracy, which arises because strong lens modeling cannot constrain the presence or absence of a uniform mass sheet κ, which rescales H0 by the ...
متن کاملDiscovery of a Probable Physical Triple Quasar
We report the discovery of the first known probable case of a physical triple quasar. A previously known double system, QQ 1429 008 at , is shown to contain a third, fainter QSO component at the same z p 2.076 redshift. Deep optical and IR imaging has failed to reveal a plausible lensing galaxy group or a cluster, and we are unable to construct any viable lensing model that could lead to the ob...
متن کامل