Quasi-stellar objects in the ALHAMBRA survey

Microlensing of quasi-stellar objects (QSOs)

Very close pairs of quasi-stellar objects

It is pointed out that there are now known four very close pairs of QSOs with separations < 5 arcsec and very different redshifts. Several estimates indicates that the probability that they are accidental configurations are small; a conservative estimate of the probability to have four such pairs by random projection yields 3.5 × 10−3. We conclude either that this is further evidence that QSOs ...

Optical Spectropolarimetry of Quasi-stellar Objects Discovered by the Two-micron All Sky Survey

Highly polarized QSOs discovered in the Two-Micron All Sky Survey (2MASS) have been observed to determine the source(s) of optical polarization in this near-infrared color-selected sample. Broad emission lines are observed in the polarized flux spectra of most objects, and the polarization of the lines is at about the same level and position angle as the continuum. Generally, the continuum is b...

Three quasi-stellar objects acting as strong gravitational lenses⋆

We report the discovery of three new cases of quasi-stellar objects (QSOs) acting as strong gravitational lenses on background emission line galaxies: SDSS J0827+5224 (zQSO = 0.293, zs = 0.412), SDSS J0919+2720 (zQSO = 0.209, zs = 0.558), SDSS J1005+4016 (zQSO = 0.230, zs = 0.441). The selection was carried out using a sample of 22,298 SDSS spectra displaying at least four emission lines at a r...

Quasi-stellar Objects, Ultraluminous Ir Galaxies, and Mergers

We test the hypothesis that QSOs are formed via strong tidal interactions or mergers, initially going through an ultraluminous infrared phase. Our approach is to look for traces to this phase in the host galaxies of QSOs. We select a sample of low-redshift bona fide QSOs that may be in a transitionary stage between ULIGs and QSOs. These objects, which we shall call transition QSOs, have an inte...