WebPIMMS Help

Introduction
Convert From
Into
Model of Source
Multiple Models
Energy Range
Source Parameters
Redshift
Mission Dependent Parameters

Introduction

WebPIMMS is set up as a WWW interface to the command-line version of PIMMS. As such, it incorporates many of the features and all of the limitations of PIMMS. For information about PIMMS, or more detailed information about what WebPIMMS does, the the user should look at the PIMMS User Guide.
Note:This guide is written for the new version of WebPIMMS. Some features may not be available in the old WebPIMMS.

Convert From

The input source is selected here.

  • Flux/Unabsorbed Flux - input is an energy range in keV or Angstroms, not folded through any instrument.

  • FDensity - Flux Density at a single energy in ERGS (No Range Should Be Entered, and Photons is not an option at this point).

    Input Energy Range is a required field with these selections.

  • ASCA/SIS Count Rate - input is the count rate from the ASCA SIS.
    The default energy is in the 0.3-12 keV range.

  • ASCA/GIS Count Rate - input is the count rate from the ASCA GIS.
    The default energy is in the 0.4-12 keV range.

  • Chandra HRC Count Rate - input is the count rate from the Chandra HRC.
    The default energy is in the 0.1-10 keV range.

  • Chandra ACIS Count Rate - input is the count rate from the Chandra ACIS.
    The default energy is in the 0.1-10 keV range.

  • CGRO/OSSE Count Rate - input is the count rate from the CGRO OSSE.
    The default energy is in the 55-9190 keV range.

  • Einstein/HRI Count Rate - input is the count rate from the Einstein HRI.
    The default energy is in the 0.1-6 keV range.

  • Einstein/IPC Count Rate - input is the count rate from the Einstein IPC.
    The default energy is in the 0.1-6.4 keV range.

  • Exosat/GSPC Count Rate - input is the count rate from the Exosat GSPC.
    The default energy is in the 1-31 keV range.

  • Exosat/ME Count Rate - input is the count rate from the Exosat ME.
    The default energy is in the 0.4-36 keV range.

  • GINGA/LAC Count Rate - input is the count rate from the GINGA LAC.
    The default energy is in the 1-70 keV range.

  • ROSAT/HRI Count Rate - input is the count rate from the ROSAT HRI.
    The default energy is in the 0.1-2.4 keV range.

  • ROSAT/PSPC Count Rate - input is the count rate from the ROSAT PSPC.
    The default energy is in the 0.08-2.9 keV range.

  • RXTE/ASM Count Rate - input is the count rate from the RXTE ASM.
    The default energy is in the 1-12 keV range.

  • RXTE/PCA Count Rate - input is the count rate from the RXTE PCA.
    The default energy is in the 1.4-100 keV range.

  • RXTE/HEXTE Count Rate - input is the count rate from the RXTE HEXTE Default.
    The default energy is in the 10.1-552 keV range.

  • RXTE/HEXTE Count Rate - input is the count rate from the RXTE PDS.
    The default energy is in the 10.2-552 keV range.

  • SAX/LECS Count Rate - input is the count rate from the SAX LECS.
    The default energy is in the 0.1-14 keV range.

  • SAX/MECS Count Rate - input is the count rate from the SAX MECS.
    The default energy is in the 0.8-12 keV range.

  • SAX/PDS Count Rate - input is the count rate from the SAX PDS.
    The default energy is in the 7-477 keV range.

  • SWIFT/BAT - input is the count rate from the SWIFT BAT Onaxis.
    The default energy is in the 15-150 keV range.

  • SWIFT/XRT - input is the count rate from the SWIFT XRT Onaxis.
    The default energy is in the 0.2-10 keV range.

  • SWIFT/1to4 - input is the count rate from the SWIFT 1to4 Onaxis.
    The default energy is in the 0.2-10 keV range.

  • SWIFT/UVOT - input is the count rate from the SWIFT UVOT.
    The default energy is in the 0.01-0.1 keV range.

  • XMM/RGS Count Rate - input is the count rate from the XMM RGS Order1.
    The default energy is in the 0.3-2.5 keV range.

  • XMM/MOS Count Rate - input is the count rate from the XMM MOS Open.
    The default energy is in the 0.1-12 keV range.

  • XMM/PN Count Rate - input is the count rate from the XMM PN Open.
    The default energy is in the 0.1-12 keV range.

Into

The output mission/energy is selected here.
In the new WebPIMMS all the instruments are selected. In the old WebPIMMS you can choose the instruments you want to calculate.

  • ASCA - output is the ASCA count rate calculated from the input source.

  • SUZAKU - output is the SUZAKU count rate calculated from the input source.

  • CHANDRA - (AXAF) output is the CHANDRA count rate calculated from the input source.

  • INTEGRAL - output is the INTEGRAL count rate calculated from the input source.

  • ROSAT - output is the ROSAT count rate calculated from the input source.

  • RXTE - output is the RXTE count rate calculated from the input source.

  • SAX - output is the SAX count rate calculated from the input source.

  • Swift - output is the SAX count rate calculated from the input source.
    The BAT response in PIMMS v3.6c and later yields the counts per fully illuminated detector, which matches the BAT analysis software default units. One detector has a geometric area of 0.16 cm^2. An on-axis source illuminates 16384 detectors

  • XEUS - output is the XEUS count rate calculated from the input source. Note: Observation efficiency is expected to be ~30%

  • XMM - output is the XMM count rate calculated from the input source.
    For the RGS, the default energy ranges are:
    Order 1: 0.35 - 2.5 keV
    Order 2: 0.62 - 2.5 keV
    Order 3: 1.20 - 2.5 keV

  • Flux - output is in flux, not folded through any instrument in ergs/cm^2/s. Output Energy Range is a required field with this selection.

Model of Source

Specifies the spectral shape to be folded with the effective area curve of the instrument. Currently four simple, one-parameter models plus a gaussian are recognized with a fixed absorption model (due to Morrison & McCammon),

  • Power Law - Parameter is photon index.
    (Flux in photons/cm2/s is E[-(index)]).
    A power-law photon spectrum that increases with increasing energy can be specified by entering a negative number as the index.

  • Black Body - Parameter is temperature (keV).

  • Therm. Bremss. - Parameter is temperature (keV).
    The model includes the Gaunt factor.

  • Raymond Smith - Parameter is plasma temperature (keV).
    WebPIMMS uses one of 59 pre-calculated models (see pull down menu) that cover a range of values between 0.0343 keV - 27.25 keV.
    Allowed Values:

    Note: If a different value is entered WebPIMMS uses the closest allowed value. Abundance is assumed to be Solar, as defined by Allen.

    Additional Raymond Smith Model Selection The user also has the option of selecting a Solar Abundance fraction and a Log T. If these values are set, they will override the keV entered previously.

  • Gaussian - Parameters are:
    • line center energy (kev);
    • line width (kev);
    • equivalent width relative to base model (eV).

    This model takes the central energy and physical width (in keV) as parameters. A physical width of 0 is allowed, which is interpreted as a delta function (integrations of the delta function is treated appropriately, although it may look incorrect in the differential form, which is what is saved by the OUTPUT command).

    Note:Gaussian is primarily intended as a second (etc.) component in addition to a continuum model, with the same nH as the primary component. In such cases, specify the equivalent width in eV rather than the 'relative strength'

Multiple Models

Up to 3 model components can be added together to represent multi-temperature plasma, power law plus Gaussian emission line, partial-covering absorber etc. Only a limited combinations of models have been rigorously tested. When selecting multiple models, in addition to the standard model parameters, the user needs to input:

  • Normalization - Always relative to the base model. NOT equivalent to the XSPEC normalization

  • Energy - At which the models are normalized (keV).

Energy Range

  • Input Energy Range - When a specific mission is selected (i.e. ASCA, RXTE...) the user can specify the energy range of the satellite response to be used in the calculations. If left BLANK, or UNCHANGED from the default value, it uses the instrument default values.

    - When 'Flux' or 'Unabsorbed Flux' is selected the energy range of the source MUST be set by the user. This will then be folded through the model and then the output mission. This can be entered in either keV or Angstroms by selecting the appropriate unit.

    - When 'Flux Density' is selected a SINGLE energy value MUST be set by the user. This will then be folded through the model and then the output mission. This can be entered in either keV or Angstroms by selecting the appropriate unit.

  • Output Energy Range - When a specific mission is selected (i.e. ASCA, RXTE...) the user can specify the energy range of the satellite response to be used in the calculations. If left BLANK, or UNCHANGED from the default value, it uses the instrument default values.

    -When 'Flux' is selected in "Into" WebPIMMS will convert the input source value into energy (ergs/cm2/s). The energy range of the source MUST be set by the user. Both absorbed and unabsorbed flux (nH = 0) are calculated simultaneously. This can be entered in either keV or Angstroms by selecting the appropriate unit.



Source Parameters


Values pertaining to the source.
  • Flux/Count Rate - The source energy. If the user is converting from 'Flux' the units are (erg/cm2/s), if converting from a mission, the units are (counts/second) for that mission.

  • Galactic nH - The neutral Hydrogen column density, within the Milkyway, along the line-of-sight to the source. H program.
    The program does NOT allow for a decimal exponent to be entered, and will give an erroneous answer if used.

  • Photon index/kT - The model dependent parameter. If the 'Power Law' model is selected then value is the photon index, i.e [E^-(index)], for all other models the value is temperature in keV.


Redshift


Optionally, all components may be redshifted using a common z; in which case, all optional nH values are interpreted as an intrinsic absorber with the same z, in addition to the required Galactic nH.

Mission Dependent Parameters

Go back to the Pimms web interface.
Go back to the Multi-component/Gaussian Pimms web interface.

For help in the use of PIMMS, see the PIMMS User Guide

WebPIMMS is a Web version of the PIMMS (v4.5) tool. PIMMS was developed by Koji Mukai at the HEASARC. The first Web version was developed at the SAX Data Center. The SAX PIMMS package was ported to and modified for the HEASARC Web site by Michael Arida.
This file was last modified on Tuesday, 31-Jan-2012 07:54:58 EST

For feedback or questions on WebPIMMS, please contact Michael Arida. arida@milkyway.gsfc.nasa.gov