|
|
Q:
Can Chandra calculate red shift data of objects?
A:
Yes. The ability of the transmission gratings on Chandra to make
fine distinctions between the energies of the X-rays from an
object makes it possible to identify sharp peaks or lines in the
spectrum due to ions of oxygen, silicon, iron, etc. if they are
present. By comparing the observed energy or wavelength of these
peaks with the corresponding values observed in the laboratory,
the red shift can be measured.
A rough measurement (within 5 or 10%) of the red shift can be
made with the Advanced CCD Imaging Spectrometer (ACIS) without
the gratings. In practice the red shifts determined by Chandra
are used as a confirmation of the red shifts measured by optical
telescopes. A notable exception is the red shift measured from
the X-ray afterglow of the gamma ray burst GRB
991216.
Back | Index | Next
|
