• Homepage

• Who are we (contact us)

• Introduction to GL

• Our work

• Data & Software 

 Q0957+561

Optical Monitoring

HST-STIS Spectra

 PROGRAMS

Simple FORTRAN programs to apply the d² test (accurate and robust time delay measurements)

• Postgraduate Course on GL

ANGLES SCHOOL POSTER-PDF

• Workshop 2004

WORKSHOP POSTER-PDF

   ►  Photos

   ►  e-Proceedings

• Links

FBQ 0951+2635

OPTICAL MONITORING: Since 2007 February, this double quasar is being monitored with LRT (Liverpool Robotic Telescope) in the i band. The main goal is to study the probable extrinsic variability at large wavelengths, and to compare it with the observed extrinsic signal at shorter wavelengths (Paraficz et al. 2006). Each observation consists of five exposures of 100 sec, using a dither cross pattern. The 'cross' is done from offsets of + 10" and - 10" in both RA and declination. Five subframes associated with the five exposures on February 7 (FWHM of the seeing disc = 1") are depicted in the FIGURE. The lens system appears as an elongated structure (in comparison to the nearby point-like sources) in all these subframes: it is enclosed in a green circle.

(click on the figure to enlarge)