Search Publications
The glow of axion quark nugget dark matter. Part I. Large scale structures
Dolag, Klaus; Van Waerbeke, Ludovic; Sommer, Julian S. +5 more
Axion quark nuggets (AQN) are hypothetical, macroscopically large objects with a mass greater than a few grams and sub-micrometer size, formed during the quark-hadron transition. Originating from the axion field, they offer a possible resolution of the similarity between visible and dark components of the Universe, i.e. ΩDM ∼ Ωvisi…
Putting all the X in one basket: Updated X-ray constraints on sub-GeV Dark Matter
Pinetti, Elena; Fornengo, Nicolao; Cirelli, Marco +2 more
Sub-GeV dark matter particles can annihilate or decay producing e ± pairs which upscatter the low-energy photon fields in the Galaxy and generate an X-ray emission (via the Inverse Compton effect). Using X-ray data from XMM-NEWTON, INTEGRAL, NUSTAR and SUZAKU, we derive new constraints on this class of dark matter (DM). In the annihilat…
Magnetars and axion-like particles: probes with the hard X-ray spectrum
Sinha, Kuver; Guo, Huai-Ke; Fortin, Jean-François +2 more
Quiescent hard X-ray and soft gamma-ray emission from neutron stars constitute a promising frontier to explore axion-like-particles (ALPs). ALP production in the core peaks at energies of a few keV to a few hundreds of keV; subsequently, the ALPs escape and convert to photons in the magnetosphere. The emissivity goes as T6 while the con…
X-ray shapes of elliptical galaxies and implications for self-interacting dark matter
Jeltema, T.; McDaniel, A.; Profumo, S.
Several proposed models for dark matter posit the existence of self-interaction processes that can impact the shape of dark matter halos, making them more spherical than the ellipsoidal halos of collisionless dark matter. One method of probing the halo shapes, and thus the strength of the dark matter self-interaction, is by measuring the shape of …
A sensitive search for unknown spectral emission lines in the diffuse X-ray background with XMM-Newton
Schmitt, J. H. M. M.; Horns, D.; Gewering-Peine, A.
The Standard Model of particle physics can be extended to include sterile (right-handed) neutrinos or axions to solve the dark matter problem. Depending upon the mixing angle between active and sterile neutrinos, the latter have the possibility to decay into monoenergetic active neutrinos and photons in the keV-range while axions can couple to two…
Where do the 3.5 keV photons come from? A morphological study of the Galactic Center and of Perseus
Profumo, Stefano; Jeltema, Tesla; Carlson, Eric
We test the origin of the 3.5 keV line photons by analyzing the morphology of the emission at that energy from the Galactic Center and from the Perseus cluster of galaxies. We employ a variety of different templates to model the continuum emission and analyze the resulting radial and azimuthal distribution of the residual emission. We then perform…
Observational consistency and future predictions for a 3.5 keV ALP to photon line
Conlon, Joseph P.; Rummel, Markus; Alvarez, Pedro D. +2 more
Motivated by the possibility of explaining the 3.5 keV line through dark matter decaying to axion-like particles that subsequently convert to photons, we study ALP-photon conversion for sightlines passing within 50 pc of the galactic centre. Conversion depends on the galactic centre magnetic field which is highly uncertain. For fields at low or mi…
Unidentified sources in the Fermi-LAT second source catalog: the case for DM subhalos
Horns, Dieter; Zechlin, Hannes-S.
The Large Area Telescope (LAT) aboard the Fermi satellite allows us to study the high-energy γ-ray sky with unprecedented sensitivity. However, the origin of 31% of the detected γ-ray sources remains unknown. This population of unassociated γ-ray sources may contain new object classes, among them sources of photons from self-annihilating or decayi…
The XMM-LSS survey. Survey design and first results
Refregier, Alexandre; Gandhi, Poshak; Mellier, Yannick +36 more
The XMM Large Scale Structure survey (XMM-LSS) is a medium deep large area X-ray survey. Its goal is to extend large scale structure investigations attempted using ROSAT cluster samples to two redshift bins between 0<z<1 while maintaining the precision of earlier studies. Two main goals have constrained the survey design: the evolutionary st…