The massive black holes found at the centers of most nearby galaxies including our own, are believed to be the ashes of the fuel that powered quasars early in...
Stellar mass fraction and quasar accretion disk size in SDSS J1004+4112 from photometric follow-up
The gravitational lens SDSS J1004+4112 was the first discovered system where a background quasar is lensed by a galaxy cluster instead of a single galaxy. We...
STRIDES: automated uniform models for 30 quadruply imaged quasars
Gravitational time delays provide a powerful one-step measurement of H 0, independent of all other probes. One key ingredient in time-delay cosmography are high...
Strong Chromatic Microlensing in HE0047–1756 and SDSS1155+6346
We use spectra of the double-lensed quasars HE0047–1756 and SDSS1155+6346 to study their unresolved structure through the impact of microlensing. There is no...
Strong lensing reveals jets in a sub-microJy radio-quiet quasar
We present e-MERLIN and European VLBI Network observations which reveal unambiguous jet activity within radio-quiet quasar HS 0810+2554. With an intrinsic flux...
Structure of the Accretion Disk in the Lensed Quasar Q2237+0305 from Multi-epoch and Multi-wavelength Narrowband Photometry
We present estimates for the size and the logarithmic slope of the disk temperature profile of the lensed quasar Q2237+0305, independent of the component...
Study of the Extended Narrow-Line Region in the Host Galaxy of the Lensed QSO 2237+0305 (z = 1.69)
The detection of spatially extended line emission in multiply imaged QSOs offers a new possibility to study the properties (kinematics and structure) of the...
Subarcsecond Optical Images of the Radio Gravitational Lens B1152+199
We present R-band observations of the Cosmic Lens All-Sky Survey gravitational lens system B1152+199, obtained with the active optics system at the Telescopio...
Superluminal non-ballistic jet swing in the quasar NRAO 150 revealed by mm-VLBI
Context: NRAO 150, a compact and bright radio to mm source showing core/jet structure, has been recently identified as a quasar at redshift z = 1.52 through a...