%0 Generic %1 citeulike:12090364 %A Hooper, Dan %A Slatyer, Tracy R. %D 2013 %K imported %T Two Emission Mechanisms in the Fermi Bubbles: A Possible Signal of Annihilating Dark Matter %U http://arxiv.org/abs/1302.6589 %X We study the variation of the spectrum of the Fermi Bubbles with Galactic latitude. Far from the Galactic plane (|b| > 30 degrees), the observed gamma-ray emission is nearly invariant with latitude, and is consistent with arising from inverse Compton scattering of the interstellar radiation field by cosmic-ray electrons with an approximately power-law spectrum. The same electrons in the presence of microgauss-scale magnetic fields can also generate the the observed microwave "haze". At lower latitudes (b < 20 degrees), in contrast, the spectrum of the emission correlated with the Bubbles possesses a pronounced spectral feature peaking at 1-4 GeV (in E^2 dN/dE) which cannot be generated by any realistic spectrum of electrons. Instead, we conclude that a second (non-inverse-Compton) emission mechanism must be responsible for the bulk of the low-energy, low-latitude emission. This second component is spectrally similar to the excess GeV emission previously reported from the Galactic Center (GC), and also appears spatially consistent with a luminosity per volume falling approximately as r^-2.4, where r is the distance from the GC. We argue that the spectral feature visible in the low-latitude Bubbles is the extended counterpart of the GC excess, now detected out to at least 2-3 kpc from the GC. The spectrum and angular distribution of the signal is consistent with that predicted from \~10 GeV dark matter particles annihilating to leptons, or from \~50 GeV dark matter particles annihilating to quarks, following a distribution similar to the canonical Navarro-Frenk-White (NFW) profile. We also consider millisecond pulsars as a possible astrophysical explanation for the signal, as observed millisecond pulsars possess a spectral cutoff at approximately the required energy. Any such scenario would require a large population of unresolved millisecond pulsars extending at least 2-3 kpc from the GC.

@misc{citeulike:12090364, abstract = {{We study the variation of the spectrum of the Fermi Bubbles with Galactic latitude. Far from the Galactic plane (|b| \> 30 degrees), the observed gamma-ray emission is nearly invariant with latitude, and is consistent with arising from inverse Compton scattering of the interstellar radiation field by cosmic-ray electrons with an approximately power-law spectrum. The same electrons in the presence of microgauss-scale magnetic fields can also generate the the observed microwave "haze". At lower latitudes (b \< 20 degrees), in contrast, the spectrum of the emission correlated with the Bubbles possesses a pronounced spectral feature peaking at 1-4 GeV (in E^2 dN/dE) which cannot be generated by any realistic spectrum of electrons. Instead, we conclude that a second (non-inverse-Compton) emission mechanism must be responsible for the bulk of the low-energy, low-latitude emission. This second component is spectrally similar to the excess GeV emission previously reported from the Galactic Center (GC), and also appears spatially consistent with a luminosity per volume falling approximately as r^-2.4, where r is the distance from the GC. We argue that the spectral feature visible in the low-latitude Bubbles is the extended counterpart of the GC excess, now detected out to at least 2-3 kpc from the GC. The spectrum and angular distribution of the signal is consistent with that predicted from \~{}10 GeV dark matter particles annihilating to leptons, or from \~{}50 GeV dark matter particles annihilating to quarks, following a distribution similar to the canonical Navarro-Frenk-White (NFW) profile. We also consider millisecond pulsars as a possible astrophysical explanation for the signal, as observed millisecond pulsars possess a spectral cutoff at approximately the required energy. Any such scenario would require a large population of unresolved millisecond pulsars extending at least 2-3 kpc from the GC.}}, added-at = {2019-03-25T08:20:55.000+0100}, archiveprefix = {arXiv}, author = {Hooper, Dan and Slatyer, Tracy R.}, biburl = {https://www.bibsonomy.org/bibtex/226739181de51451b7d8a9265dd7b246c/ericblackman}, citeulike-article-id = {12090364}, citeulike-linkout-0 = {http://arxiv.org/abs/1302.6589}, citeulike-linkout-1 = {http://arxiv.org/pdf/1302.6589}, day = 26, eprint = {1302.6589}, interhash = {1ad42f73c4a036e6b66844ca9b45eb35}, intrahash = {26739181de51451b7d8a9265dd7b246c}, keywords = {imported}, month = feb, posted-at = {2013-03-04 04:44:21}, priority = {2}, timestamp = {2019-03-25T08:20:55.000+0100}, title = {{Two Emission Mechanisms in the Fermi Bubbles: A Possible Signal of Annihilating Dark Matter}}, url = {http://arxiv.org/abs/1302.6589}, year = 2013 }