Supernova Remnant N132D

Description:

Simulated HETG observation of N132D, the brightest supernova remnant in the Large Magellanic Cloud. This MARX simulation is based on Einstein FPCS observations by Hwang, Hughes, Canizares & Markert (1993) [ApJ 414, 219], which detected individual emission lines from OVII, OVIII, NeIX, NeX and Fe XVII. The model spectrum consists of a single component non-equilibrium ionization model from SPEX .

Figure 1. - A MARX simulation of the supernova remnant N132D as observed with the ACIS imager. The input to MARX consisted of a deconvolved ROSAT HRI FITS image. AXAF's superioir spatial resolution will actually be capable of resolving finer structure in the remnant than this image depicts.

Figure 2. - A simulation of the same supernova remnant as observed with the HETGS. The image shows a section of the full ACIS-S image which is obtained. The zeroth spectral order is seen in the left of the image while the broad bands extending to the right represent the dispersed MEG (top) and HEG (bottom) spectra. Images of the remnant are also visible in the MEG and HEG spectra due to bright emission lines in the spectrum.

Figure 3. - This figure shows a portion of the detected MEG spectrum with each event color coded according to its energy as detected by the ACIS-S spectrometer. Photons from strong lines show up clearly as images of the SNR at a given color. Higher energy photons have bluer colors while lower energy photons are redder. Click on the image to see a larger version.

Figure 4. - This figure shows a portion of the detected HEG spectrum with each event color coded according to its energy as detected by the ACIS-S spectrometer. Photons from strong lines show up clearly as images of the SNR at a given color. Higher energy photons have bluer colors while lower energy photons are redder. Click on the image to see a larger version.

Figure 5. - A plot of the detected pulse height spectrum from ACIS for all positive order events. The spectrum was binned using 10 eV bins. The color scale corresponding to Figures 3 and 4 has been overlaid.

Simulation details:

• Input data was taken from ROSAT HRI observation
• Lx = 6.0e37 erg/s (0.2-4.0 keV)
• LMC distance = 55 kpc
• Exposure time = 100 ksec

Spectral parameters:

• Spectrum created using SPEX NEI model
• Nh = 6.25e20 cm**-2
• kT = 8.4e6 K = 0.72 keV
• Ionization parameter = ne * t = 6.1e3 yr/cm**3
• Abundances relative to solar:
  Oxygen = 1.9
  Neon = 2.5
  All other elements fixed at solar abundance
  
  

Simulation courtesy of John Houck (MIT/ASC)
Additional images created by Dan Dewey (MIT/ASC)