PIMMS v4.13q now available

Version 4.13a contains a minor update of the XRISM/Xtend effective area curve and updated mission-specific outputs for the XRISM instruments.

Version 4.13 newly supports XRISM and SRG/eROSITA.

The XRISM (Resolve and Xtend) effective area curves, and instrument-specific routines, are suitable for Cycle 1 proposal preparation.

The SRG/eROSITA effective area curves are suitable for use with DR1.

If you would like to be informed whenevera 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.

Bugs and Caveats

  • Calibration files used by PIMMS are adequate for simulation purposes. In many cases, the results are accurate to 5% or better but higher fidelity is not guaranteed.
  • In particular, PIMMS contains 1-d effective area curves, not 2-d redistribution matrices. It should therefore be used only with caution for narrow energy ranges. For example, "ASCA SIS 2-4" does not mean "ASCA SIS count rate in the channels whose nominal channel energies are in the range 2-4 keV"; PIMMS provides, in this case, ASCA SIS counts produced by 2-4 keV photons. The differences are likley to be small enough to be acceptable when the energy range is large compared with the instrumental resolution.


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 Friday, 24-May-2024 13:20:56 EDT