Unidentified line in X-ray spectra of the Andromeda galaxy and Perseus galaxy cluster
Physical review letters, 2014•APS
We report a weak line at 3.52±0.02 keV in x-ray spectra of the Andromeda galaxy and the
Perseus galaxy cluster observed by the metal-oxide-silicon (MOS) and pn (PN) CCD
cameras of the XMM-Newton telescope. This line is not known as an atomic line in the
spectra of galaxies or clusters. It becomes stronger towards the centers of the objects; is
stronger for Perseus than for M31; is absent in the spectrum of a deep “blank sky” data set.
Although for each object it is hard to exclude that the feature is due to an instrumental effect …
Perseus galaxy cluster observed by the metal-oxide-silicon (MOS) and pn (PN) CCD
cameras of the XMM-Newton telescope. This line is not known as an atomic line in the
spectra of galaxies or clusters. It becomes stronger towards the centers of the objects; is
stronger for Perseus than for M31; is absent in the spectrum of a deep “blank sky” data set.
Although for each object it is hard to exclude that the feature is due to an instrumental effect …
We report a weak line at in x-ray spectra of the Andromeda galaxy and the Perseus galaxy cluster observed by the metal-oxide-silicon (MOS) and - (PN) CCD cameras of the XMM-Newton telescope. This line is not known as an atomic line in the spectra of galaxies or clusters. It becomes stronger towards the centers of the objects; is stronger for Perseus than for M31; is absent in the spectrum of a deep “blank sky” data set. Although for each object it is hard to exclude that the feature is due to an instrumental effect or an atomic line, it is consistent with the behavior of a dark matter decay line. Future (non-)detections of this line in multiple objects may help to reveal its nature.
American Physical Society