Fermi Gamma-ray Space Telescope

Fermi ToO 050600-1-1

A ToO observation to observe S3 0218+35 at RA, Dec = 35.2728, 45.9372 (J2000) was approved at 2012-09-20 17:59:40 UTC.

The justification for the ToO is: Bright g-ray flaring from this lensed blazar was detected with the LAT 2012 Sep 14-18 (up to the current day). We previously found a lag of 11 days in the g-ray lightcurve in an ACF analysis, consistent with the radio delay of 10.5 +/- 0.4 days. With the ToO on the new flare+echo event, we will refine the gamma-ray lens delay measurement (to be as or more precise than the radio one) and address discrepant observed radio/g-ray magnification ratios (lens should be achromatic). We will test the microlensing hypothesis (radio and gamma-ray emitting regions need not be co-spatial), by defining orbit-to-orbit g-ray variability to constrain the emitting region size, and (a submitted proposal) 10 epoch VLBA ToO 2/8/22 GHz monitoring data over 30 days.

The planned duration is 605.00 ks.

The autonomous request threshold during this ToO is LOW.

The ToO observation should begin between 2012-09-23 12:00:00 UTC and 2012-09-24 12:00:00 UTC.

The ToO observation was requested by DR. CHI (TEDDY) C CHEUNG.

The ToO commanding order was sent to the MOC at 2012-09-20 20:10:10 UTC.

The MOC acknowledged receipt of this order at 2012-09-20 20:11:26 UTC.

The MOC sent the ToO execution notification at 2012-09-24 00:20:54 UTC.

The ToO order status is Uplinked at or before: 2012-09-24 00:19:44 UT