EDP Sciences
Free access
Volume 437, Number 1, July I 2005
Page(s) L15 - L18
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:200500128

A&A 437, L15-L18 (2005)
DOI: 10.1051/0004-6361:200500128


Interpreting microlensing signal in QSO 2237+0305: Stars or planets?

R. Gil-Merino and G. F. Lewis

Institute of Astronomy, School of Physics, University of Sydney, NSW 2006, Australia
    e-mail: [rodrigo;gfl]@physics.usyd.edu.au

(Received 19 April 2005 / Accepted 18 May 2005)

The multiply imaged, gravitationally lensed quasar, QSO 2237+0305, has been the subject of recent optical monitoring campaigns, with its light curves displaying uncorrelated variability attributed to gravitational microlensing by masses in the foreground galaxy. Based on these light curves, it has been claimed that the dominant microlensing population must be a population of free-floating Jupiter-like objects; such a conclusion is not new, with several similar claims in the literature. Historically, however, it has been shown that such conclusions are flawed, with an incorrect interpretation of the complex caustic network that arises at significant optical depth. This paper examines this more recent claim, illustrating that it too is flawed.

Key words: gravitational lensing -- microlensing -- dark halo populations

SIMBAD Objects in preparation

© ESO 2005