Related papers: X-ray Searches for Axions from Super Star Clusters
Axion-like particles (ALPs) coupled to nucleons can be efficiently produced in the interior of protoneutron stars (PNS) during supernova (SN) explosions. If these ALPs are also coupled to photons they can convert into gamma rays in the…
We propose a new method to search for axion-like particles (ALPs) based on the gamma-rays produced concomitant with high-energy astrophysical neutrinos. The existence of high-energy neutrinos implies production of gamma-rays in the same…
We relate the star formation from cold baryons in virialized structures to the X-ray properties of the associated diffuse, hot baryonic component. Our computations use the standard ``semi-analytic'' models to describe i) the evolution of…
Light axion fields, if they exist, can be sourced by neutron stars due to their coupling to nuclear matter, and play a role in binary neutron star mergers. We report on a search for such axions by analysing the gravitational waves from the…
In this work, we studied ten nearby ($z$$ \leq$0.038) galaxy clusters to understand possible interactions between hot plasma and member galaxies. A multi-band source detection was applied to detect point-like structures within the…
We present recent results from a GALEX investigation of star formation in 16 cooling core clusters of galaxies, selected to span a broad range in both redshift and central cooling time. Initial results demonstrate clear UV excesses in most,…
If the dark matter particles are axions, gravity can cause them to coalesce into axion stars, which are stable gravitationally bound systems of axions. In the previously known solutions for axion stars, gravity and the attractive force…
We have searched for solar axions or similar particles that couple to two photons by using the CERN Axion Solar Telescope (CAST) setup with improved conditions in all detectors. From the absence of excess X-rays when the magnet was pointing…
Elemental abundances hold important information about the star formation history in the Galactic Center. The thermal X-ray spectra of certain stars can provide a robust probe of elemental abundances, mainly through the presence of K-shell…
Star-forming regions have been the targets of X-ray observations since the dawn of satellite X-ray astronomy. The increase in sensitivity and/or spatial resolution offered by XMM-Newton and Chandra allows a dramatic improvement, both…
We present a novel approach to investigating axions and axion-like particles (ALPs) by studying their potential conversion into X-rays within the Sun's atmospheric magnetic field. Utilizing high-sensitivity data from the Nuclear…
Axion-photon conversion is a prime mechanism to detect axion-like particles that share a coupling to the photon. We point out that in the vicinity of neutron stars with strong magnetic fields, magnetars, the effective photon mass receives…
Axion dark matter or any ultralight bosonic dark matter can go through Bose-Einstein condensation due to the large phase density, leading to the formation of axion stars or solitons in dark matter halo centers. The formation rate is…
We present the results of a high-resolution X-ray imaging study of the stellar population in the Galactic massive star-forming region RCW49 and its central OB association Westerlund 2. We obtained a 40 ks X-ray image of a 17'x17' field…
Protons can be plausibly accelerated to $\sim 10^{18}$-$10^{19}$ eV in strong accretion shocks surrounding massive clusters of galaxies. Such protons efficiently produce very high energy pairs through interactions with the CMB, which then…
The Orion Nebula Cluster and the molecular cloud in its vicinity have been observed with the ACIS-I detector on board the Chandra X-ray Observatory with 23 hours exposure. We detect 1075 X-ray sources: 91% are spatially associated with…
We report the Chandra/ACIS-S detection of more than 20 ultraluminous X-ray sources (ULXs, L_{0.5-10 keV} >~ 3 x 10^{39} ergs/sec) in the Cartwheel collisional ring galaxy system, of which over a dozen are located in the outer active…
A finite axion-nucleon coupling, nearly unavoidable for QCD axions, leads to the production of axions via the thermal excitation and subsequent de-excitation of Fe-57 isotopes in the sun. We revise the solar bound on this flux adopting the…
We present the most comprehensive and deepest X-ray study to date of the properties of the richest Wolf-Rayet (WR) population observed in a single stellar cluster, Westerlund 1 (Wd1). This work is based on 36 Chandra observations obtained…
Polarization measurements of thermal radiation from magnetic white dwarf (MWD) stars have been proposed as a probe of axion-photon mixing. The radiation leaving the surface of the MWD is unpolarized, but if low-mass axions exist then…