a not very good rendition of the source
a not very good rendition of the source
a colour rendition
that shows the core colour effects, and some changes in colour in the
hot-spots.
shows hardness
of the core spectrum and some effects in the hot-spots.
shows colour variations in diffuse/faint regions
well, but burns out the core and hot-spots.
another rendition of the source
that shows the colour variations rather better.
a colour rendition after smoothing
.
The halo around the core arises from the energy-dependent point response
function.
The original red, green, and blue images from which these colour images were formed can be found by clicking on the GIFs below. The red image was from data in the energy range 0.50 - 1.25 keV, the green from 1.25 - 2.00 keV, and the blue from 2.00 - 8.00 keV. These bands have about the same number of counts.
Image with 0.123 arcsec pixels
(click to download gzipped FITS file; 132.2 kB).
The FWHM of Chandra is roughly (and I emphasize roughly: the point spread function is not Gaussian) 0.5 arcsec. Since this is quite a bit better than the 0.98 x 0.86 arcsec resolution of the radio data, a convolution by an 0.85 x 0.70 arcsec Gaussian kernel should give a good correspondance of resolutions for direct comparison of the radio and X-ray maps.
Hotspot B:
the spectrum is well fitted by a power-law with photon index
1.44 +/- 0.12 and no additional absorbing column. The spectral
normalization corresponds to a flux density of 5.5 +/- 0.5 nJy at 1
keV. Although this hot-spot has the flattest spectrum, it is also
the weakest and the spectral range in the X-ray is the smallest, so
the spectral difference is marginal.
Hotspot D:
the spectrum is well fitted by a power-law with photon index
1.64 +/- 0.05 and no additional absorbing column. The spectral
normalization corresponds to a flux density of 35.4 +/- 1.4 nJy at 1
keV. This is the brightest of the hot-spots, and so has the best
determined spectrum.
If the hot-spots are generated by inverse-Compton emission, then the radio spectral indices should be 0.68, 0.44, and 0.64 for hotspots A, B, and D respectively in the GHz band.
A synchrotron origin for the hot-spot X-rays is possible if the spectrum is straight from the radio to the X-ray (and the ages of the radiating particles in the X-ray are of order 1 year!). However, this would imply flux densities at 230 GHz for the hotspots of many thousands of Jy. Since this isn't the case, we can safely say that the hot-spot electrons have energy spectra that turn down in the mm/IR range, and then cut off. The X-rays that we see are from the inverse Compton process (see Andy Wilson's Cyg A papers, especially Wilson, A.S., Young, A.J., Shopbell, P.L., 2000; ApJ 544, L27).
