Calendar
rif Daricello
8 ragazzi + 3 accompagnatori
Speaker: M. G. Dainotti (National Astronomical Observatory of Japan)
Title: The optical 2D and 3D correlation and their application as cosmological tool
Abstract: Gamma-ray bursts (GRBs) are fascinating events due to their
panchromatic nature. We study optical plateaus in GRB afterglows via
an extended search into archival data. We comprehensively analyze all
published GRBs with known redshifts and optical plateaus observed by
many ground-based telescopes (e.g., Subaru Telescope, RATIR) around
the world and several space-based observatories such as the Neil
Gehrels Swift Observatory. We fit 500 optical light curves, showing
the existence of the plateau in 179 cases. This sample is 75% larger
than the previous one, and it is the largest compilation so far of
optical plateaus. We discover the 3D fundamental plane relation at
optical wavelengths using this sample. This correlation is between the
rest-frame time at the end of the plateau emission, Topt * , its
optical luminosity, Lopt, and the peak in the optical prompt emission,
Lpeak,opt, thus resembling the three-dimensional (3D) X-ray
fundamental plane (the so-called 3D Dainotti relation). We correct our
sample for redshift evolution and selection effects, discovering that
this correlation is indeed intrinsic to GRB physics. We investigate
the rest-frame end-time distributions in X-rays and optical (Topt * ,
TX *), and conclude that the plateau is achromatic only when selection
biases are not considered. We also investigate 3D optical correlation
as a cosmological tool, finding that it is as efficacious as the X-ray
3D correlation.