PIMMS v4.12a now available

Version 4.12a contains a minor update in the output format for IXPE to prevent the possibility of uninformative lines when calculating the minimum exposure time needed to reach a desired level of MDP.

Version 4.12 newly supports the IXPE mission, providing, in addition to the count rate, the estimated minimum detectable polarization (MDP) levels, or the exposure time necessary to reach the desired level of MDP.

Version 4.12 also fixes a standard-compliance bug in one of the routines.

Version 4.12 also contains an updated set of effective area curves for Chandra instruments, suitable for Cycle 24 proposal preparation.

If you would like to be informed whenever a new version of PIMMS is released, please contact Koji Mukai, Koji.Mukai@nasa.gov.

PIMMS - Portable, Interactive Multi-Mission Simulator

Command-line tool and the Web interface

PIMMS was originally written as a stand-alone, interactive program (the "command line PIMMS").

WebPIMMS implements a subset of the functionalities of the command line PIMMS. While allowing easy access, without the need to install the software, it does not have all the functionality of the command line version.


PIMMS, as described here, is software for high-energy astrophysicists, and has nothing to do with PIMMS, the Project to Increase Mastery of Mathematics and Science. The program was named quite independently of this worthwhile project at Wesleyan University.

Time-Variable Instrumental Response

PIMMS currently does not support time-variable calibration of instruments. Because it is primarily intended as a planning tool for future observations, the responses in PIMMS is often applicable for upcoming observations.

For example, if you are a Chandra user who wishes to convert count rates in a past observation to flux, please see this note.

PIMMS Users' Guide

The PDF version of the guide is available here.

Installation Guide

PIMMS is currently supported on several flavors of UNIX workstations, on Linux PCs, Macs running OS X/Darwin. It requires a Fortran compiler, and make on UNIX machines. Please consult the Installation Guide for details, then download the latest version.

Revision History

Users' Guide

  1. Introduction
  2. Sample Sessions
  3. Using Multi-component Models
  4. Extended Sources
  5. Missions
  6. The User Interface
  7. PIMMS commands

Download the LaTeX, PDF, or PostScript version of the Guide.

Adding new missions and other future plans

At a very basic level, new missions can be added simply by creating a set of effective area curve files: they need to be two-column ASCII files, containing pairs of photon energy in keV and effective area in cm2.

PIMMS source code and data files are distributed freely, without restrictions. If you decide to add new missions to PIMMS, we would like to be able to distribute it from HEASARC.

We hope to have a programmers' guide some day to make it easier to add mission-specific information.

Credits and Feedback

PIMMS is mostly written and maintained by Koji Mukai. Effective area curves for current and future missions have been supplied by the respective projects. XTE specific subroutines have been written by Koji Mukai, with the help of Jim Lochner and Phil Blanco. The SAX specific subroutine has been written by the SAX Data Center and Lorella Angelini. Snowden R-band effective area curves for ROSAT PSPC have been created by Richard West of Leicester.

The only published article on PIMMS is in the HEASARC journal:

	Mukai, K. 1993, Legacy 3, 21-31.

Questions and comments on PIMMS can be sent to Koji Mukai, Koji.Mukai@nasa.gov.

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This file was last modified on Wednesday, 02-Feb-2022 12:27:55 EST