Products Overview

The webpage for each sequence number and each Obs ID is identified at the top of the webpage by the source name, sequence number, and Obs ID.

Note: The first thing that you should do for a particular sequence number and Obs ID that you are interested in, is to check the link "Known Problems", situated just below the page title, to the left. The user should also consult the literature (for example, the Chandra Bibliography Database) for work which may already have been done on the data set(s) in question. Below is a brief description of all the other data products available from the webpage for each sequence and Obs ID. Further descriptions of the data products are available by clicking on the name of the data product from the webpage for every data set.

Information Table This contains a number of useful information items for the particular astrophysical source in question, such as coordinates, exposure time, count rates, fluxes, and the Galactic column density.

Level 2 Events file Clean level 2 events file from which lightcurves, spectra, and cross-dispersion profiles are derived.

Effective Area Plots "At-a-glance" first-order effective areas, with and without the ACIS QE degradation correction. Plots compare the - and + first orders with each other and with the combined - and + first orders. A tar file can be obtained from the "Downloads" table which contains the actual ascii files corresponding to the these plots.

Effective Area and Response Files A tar file can be obtained from the "Downloads" table which contains the actual telescope response files (ARFs) corresponding to the above plots, as well as spectral redistribution matrices (RMFs). In addition, second and third order files are also included, as well as the so-called "pha2" file, which is a "Type II" FITS spectral file containing 12 spectra (the - and + 1st, 2nd, and 3rd orders for the MEG and HEG). Again, ARF files are available both with and without the ACIS QE degradation correction.

Lightcurve Plots "At-a-glance" first-order lightcurves, from the MEG, HEG and also combined MEG and HEG. The lightcurves for the separate - and + orders, as well as combined - and + orders are available.

Lightcurve Files A tar file can be obtained from the "Downloads" table which contains the actual data in ascii format corresponding to the above plots.

Cross-dispersion Profiles "At-a-glance" first-order cross-dispersion profiles from the MEG and HEG. Profiles for the separate - and + orders, as well as the combined - and + orders are available.

Cross-dispersion Profile Files A tar file can be obtained from the "Downloads" table which contains the actual data in ascii format corresponding to the above plots.

Rest-frame Flux Spectra "At-a-glance" first-order spectra for the MEG and HEG (separately), at two different bin sizes. Plots are available with the photon flux plotted against energy as well as wavelength. The spectra are NOT corrected for Galactic absorption but are corrected for cosmological redshift.

Observed-frame Flux Spectra & Very Simple XSPEC Model Files "At-a-glance" first-order coarsely binned spectral plots for the MEG and HEG (separately). A very simple model (fitted in XSPEC) is also shown in some of the plots, and the XSPEC model file is downloadable. These models principally serve to calculate the observed fluxes, and are not meant to be serious physical models of the data. It is the responsibility of the user to fit detailed physical models to the data and consult the literature (e.g. the Chandra Bibliographical Database) for work which may already have been done in this respect for the data set in question.

Flux Spectral Files A tar file can be obtained from the "Downloads" table (by clicking in "Ascii Spectra"), which contains the actual data in ascii format corresponding to the above plots, as well as the XSPEC model files.

FITS Spectra and Responses #1 A tar file can be obtained from the "Downloads" table which contains "Type I" FITS spectral files and response files for the 1st order MEG and HEG data, with various bin sizes. The response files have the RMFs and ARFs combined into one file. The spectra have the - and + orders combined, except for 4 files corresponding to the separate - and + orders for the HEG and MEG.

FITS Spectra and Responses #2 A tar file can be obtained from the "Downloads" table which contains the so-called "pha2" file, which is a "Type II" FITS spectral file containing 12 spectra (the - and + 1st, 2nd, and 3rd orders for the MEG and HEG). Also included in this tar file are the 1st, 2nd, and 3rd order spectral redistribution matrices (RMFs) and the telescope response files (ARFs). An additional 4 spectral FITS files are included which have the - and + 1st orders separated for the MEG and HEG.