Chandra HETG

HETG Principal Investigator: Prof. Claude R. Canizares

E0102 spectrum image

E0102 model spectrum

Chandra High Energy Transmission Grating (HETG)

HETG Analysis & Software

Overview -- The main HETG-related software are briefly described below. The various s/w are related through the common data products of FITS event files (either from a real observation or from a MARX simulation) and PHA, ARF, and RMF files. A rough summary of the flow is given here:

Observation --> FITS events --> CIAO, --> PHA,ARF,RMF -->  ISIS,  <-- models
 or MARX                         TGCat       & evt2       Other s/w

CIAO, Chandra Interactive Analysis of Observations, is the comprehensive software provided by the CXC for user data processing and analysis, including HETG observations. See, for example, the Analysis Guide for Chandra High Resolution Spectroscopy and the Data Preparation (for ACIS) and Grating Spectroscopy Threads.

_ TGCat allows browsing the Chandra grating observations, interactive plotting of their spectra, and provides nominally processed PHAs, ARFs, and RMFs for futher analysis. A set of TGCat software scripts have been created to facilitate custom (re-)processing using files from the Chandra archive.

ISIS, is an interactive and scriptable (by virtue of S-Lang) platform that supports the display, measurement, and identification of features in high-resolution spectra. ISIS can load HETG PHA spectra (and corresponding ARFs and RMFs) and interfaces with ATOMDB, a database of atomic structure and plasma emission models. ISIS can also import the XSPEC library of X-ray source models. ISIS lovers are using ISIS for a wide range of analyses.

ISIS allows the user to add (with a little programming effort) their own custom models; see the simple isis-3D example.

Other Analysis Software -- Other common X-ray analysis software can be used to analyze the main HETG data products (PHAs, ARFs and RMFs), e.g., XSPEC, Sherpa, PINTofALE, etc.

Event-2D software is available for the case of spatially extended sources observed with the HETG. This custom software requires only the evt2 file and ARFs, taken directly from TGCat or from user reprocessing.

MARX, is a ray-trace simulator for Chandra including the HETG. MARX is useful for HETG simulations especially for extended sources and those with spatial-spectral complexity. The source modeling capabilities of MARX are extended with the MARX-S-Lang-User model which can make use of the simple V3D volumetric modeling primatives.

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