Go Long, Go Deep: Finding Optical Jet Breaks for Swift-Era GRBs with the LBT
Abstract
Using the 8.4m Large Binocular Telescope, we observed six GRB afterglows from 2.8 hours to 30.8 days after the burst triggers to systematically probe the late time behaviors of afterglows including jet breaks, flares, and supernova bumps. We detected five afterglows with Sloan r' magnitudes ranging from 23.0-26.3 mag. The depth of our observations allows us to extend the temporal baseline for measuring jet breaks by another decade in time scale. We detected two jet breaks and a third candidate, all of which are not detectable without deep, late time optical observations. In the other three cases, we do not detect the jet breaks either because of contamination from the host galaxy light, the presence of a supernova bump, or the intrinsic faintness of the optical afterglow. This suggests that the basic picture that GRBs are collimated is still valid and that the apparent lack of Swift jet breaks is due to poorly sampled afterglow light curves, particularly at late times.
Keywords
Cite
@article{arxiv.0712.2239,
title = {Go Long, Go Deep: Finding Optical Jet Breaks for Swift-Era GRBs with the LBT},
author = {X. Dai and P. M. Garnavich and J. L. Prieto and K. Z. Stanek and C. S. Kochanek and J. Bechtold and N. Bouche and P. Buschkamp and E. Diolaiti and X. Fan and E. Giallongo and R. Gredel and J. M. Hill and L. Jiang and C. McClellend and P. Milne and F. Pedichini and R. W. Pogge and R. Ragazzoni and J. Rhoads and R. Smareglia and D. Thompson and R. M. Wagner},
journal= {arXiv preprint arXiv:0712.2239},
year = {2012}
}
Comments
Accepted by ApJ Letters, 14 pages, 2 figures