NICER Proposal Tools
The following documentation and applications can be used to
support the preparation of NICER observing proposals:
- NICER Mission Guide: The NICER team has developed a
Mission Guide document which describes NICER's technical
capabilities and concept of operations.
- Visibility: The standard HEASARC
can be used to determine target visibilities for NICER. The tool
reports a "preferred" visibility window, which has a Sun angle
constraint of 60-180 degrees, and a ``nominal'' visibility window,
which has a Sun angle constraint of 45-180 degrees. The Moon
avoidance angle is 15 degrees.
- NICER Tips: Prospective proposers may wish to consult
which provides NICER data analysis tips and caveats.
- Count Rate and Spectral Simulations:
The standard HEASARC count rate and spectral simulations
and WebSpec, are available
for NICER simulations. They were updated in Aug./Sep. 2018 to
include the most recent NICER responses and background files.
- The NICER responses and background files can also be downloaded
directly by following the links below. These files can be used to
simulate spectra in spectral analysis software such as XSPEC. They are
suitable for the preparation of Cycle 1 proposals.
In addition, the NICER team has made available a set of files to assist users in
performing XSPEC analyses of NICER data.
Gzipped tar file containing the RMF, ARF, and background PI files:
- NICER Redistribution Matrix File (RMF): This is the most recent RMF, and is also
available within CALDB.
- NICER Ancillary Response File (ARF): This is the most recent ARF, and is
also available within CALDB.
- NICER Background PI: Example background spectral file.
This file reproduces a "typical" NICER non-source count spectrum, including
particle-induced and cosmic diffuse X-ray background. A model consisting of a broken
power-law and six Gaussians was fit to several datasets drawn from blank-sky and
soft-source observations. A simulated 1 Msec spectrum was then created from the
The background can deviate greatly from this typical spectrum, and can
do so to different degrees at low (<0.3 keV) and high energies,
depending on the details of the observation and the data screening
strategy that is applied.
Last Updated: October 15, 2018