Bibcode
Ullán, A.; Goicoechea, L. J.; Muñoz, J. A.; Mediavilla, E.; Serra-Ricart, M.; Puga, E.; Alcalde, D.; Oscoz, A.; Barrena, R.
Referencia bibliográfica
Monthly Notices of the Royal Astronomical Society, Volume 346, Issue 2, pp. 415-423.
Advertised on:
12
2003
Número de citas
9
Número de citas referidas
7
Descripción
The Gravitational Lenses International Time Project (GLITP)
collaboration observed the first gravitational lens system (QSO
0957+561) from 2000 February 3 to March 31. The daily VR observations
were made with the 2.56-m Nordic Optical Telescope at Roque de los
Muchachos Observatory, La Palma, Spain. We have derived detailed and
robust VR light curves of the two components Q0957+561A and Q0957+561B.
In spite of the excellent sampling rate, we have not found evidence in
favour of true daily variability. With respect to variability on
time-scales of several weeks, we measure VR gradients of about -0.8 mmag
d-1 in Q0957+561A and +0.3 mmag d-1 in Q0957+561B.
The gradients are very probably originated in the far source. Thus,
adopting this reasonable hypothesis (intrinsic variability), we compare
them to the expected gradients during the evolution of a compact
supernova remnant at the redshift of the source quasar. The starburst
scenario is roughly consistent with some former events, but the new
gradients do not seem to be caused by supernova remnant activity.