Chandra follow-up observation of the Crab nebula after the very high energy flare
ATel #2994; C. Ferrigno (ISDC/University of Geneva), A. Tennant (NASA/MSFC), D. Horns (Institut für Experimentalphysik, Univ. Hamburg) , M. C. Weisskopf (NASA/MSFC), A. Neronov (ISDC/University of Geneva), M. Tavani, E. Costa (INAF-IASF Roma), and P. Caraveo (INAF-IASF Milano)
on 1 Nov 2010; 11:40 UT
Credential Certification: Carlo Ferrigno (Carlo.Ferrigno@unige.ch)
Subjects: X-ray, Supernova Remnant, Pulsar
Referred to by ATel #: 3058
A Chandra TOO observation of the inner part of the Crab nebula has been performed on 2010 Oct 28 from 17:40 and 19:41 UT to monitor the evolution of the small scale structures in the region of the inner ring after the GeV flare detected by AGILE and FERMI on 2010-09-19 (ATels #2855 and #2861).
During a previous observation, performed on 2010-09-28 from 05:05 to 07:01 UT (ATel #2882), a series of three bright knots were noticed on the inner ring, at about 6 arcsec SE of the pulsar, in the region of apparent intersection with the jet. The brightening of these knots could be connected to the previous GeV flare.
In the current observation, the three structures are still present and have the same intensity within the statistical uncertainties with respect to the previous observation: 3 sigma upper limits on the variability are ~8% without background subtraction and pile-up corrections. Also the other nebular structures remained substantially unchanged. A third Chandra monitoring observation of the Crab nebula is scheduled on 2010-11-26.
We thank the CXC and its director, Harvey Tananbaum, for making this observation possible. The data are available in the Chandra public archive.
