Date: Tue, 22 Jan 2019 16:18:44 +0100
Subject: proposal 084088 - X-ray-bright neighbor
Full_Name: Adrian Lucy
Submission from: (NULL) (22.214.171.124)
I'm preparing a Priority C Phase II proposal (due Feb 1, proposal 084088), and
have a question about a neighboring X-ray bright source.
My target (EM* RJHA 101, 17 53 45.31 -01 07 46.85, ~0.01 counts/sec) has a
neighbor 19.78 arcmin away at 17 53 28.29 -01 27 06.26. The neighbor is a
variable X-ray-bright LMXB with EPIC pn count rates up to ~600 counts/sec (ref:
https://arxiv.org/pdf/1602.05816.pdf). Because it's variable, it's listed in
some heasarc catalogs as e.g. only 15 counts/sec, so I guess it might be missed
by the technical evaluation. My understanding is that the neighbor could cause a
problem for observing my target (~0.01 cps) if it landed in the FOV. There seems
to be a (quite small) possibility of that happening, since by my estimate the
CCD grid is only fully contained in a 19 arcmin circle and boresight is
misaligned from the center by maybe about 2 arcmin. The neighbor would have to
land rather unluckily on a diagonal (i.e., in a corner of the FOV), of course.
Do you recommend a special observing strategy (e.g., position angle constraints
or changing the boresight coordinates), or is this not a problem?