A5021962612- Dark Matter and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Astrophysics and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- Pulsars and Gravitational Waves Research
- Atomic and Subatomic Physics Research
- Stellar, planetary, and galactic studies
- Particle Detector Development and Performance
- Particle physics theoretical and experimental studies
- Metabolomics and Mass Spectrometry Studies
- Computational Physics and Python Applications
- Astronomy and Astrophysical Research
- Scientific Research and Discoveries
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- History and Developments in Astronomy
- Advancements in Photolithography Techniques
- Space Science and Extraterrestrial Life
- Atomic and Molecular Physics
- Neutrino Physics Research
- Quantum Mechanics and Applications
- Plant Water Relations and Carbon Dynamics
- Spaceflight effects on biology
- Relativity and Gravitational Theory
- Statistical and numerical algorithms
Flatiron Health (United States)
2024-2025
Flatiron Institute
2024-2025
New York University
2024
University of Michigan
2019-2023
Lawrence Berkeley National Laboratory
2020-2023
University of California, Berkeley
2020-2023
Polarization measurements of thermal radiation from magnetic white dwarf (MWD) stars have been proposed as a probe axion-photon mixing. The leaving the surface MWD is unpolarized, but if low-mass axions exist then photons polarized parallel to direction MWD's field may convert into axions, which induces linear polarization dependent on strength coupling $g_{a\gamma\gamma}$. We model this process by using formalism mixing in presence strong-field vacuum birefringence show that all stellar...
The quantum chromodynamics (QCD) axion may modify the cooling rates of neutron stars (NSs). axions are produced within NS cores from nucleon bremsstrahlung and, when nucleons in superfluid states, Cooper pair breaking and formation processes. We show that four nearby isolated magnificent seven NSs along with PSR J0659 prime candidates for studies because they coeval, ages a few hundred thousand years known kinematic considerations, have well-measured surface luminosities. compare these data...
Sterile neutrinos with masses in the keV range are well-motivated extensions to Standard Model that could explain observed neutrino while also making up dark matter (DM) of universe. If sterile DM then they may slowly decay into active and photons, giving rise possibility their detection through narrow spectral features astrophysical x-ray data sets. In this Letter, we perform most sensitive search date for other decaying scenarios across mass from 5 16 using archival XMM-Newton data. We...
Axions may be produced in abundance inside stellar cores and then convert into observable X-rays the Galactic magnetic fields. We focus on Quintuplet Westerlund 1 super star clusters, which host large numbers of hot, young stars including Wolf-Rayet stars; these produce axions efficiently through axion-photon coupling. use field models to calculate expected X-ray flux locally from emitted clusters. combine axion model predictions with archival Nuclear Spectroscopic Telescope Array (NuSTAR)...
Axions with couplings ${g}_{a\ensuremath{\gamma}\ensuremath{\gamma}}\ensuremath{\sim}\mathrm{few}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}\text{ }\text{ }{\mathrm{GeV}}^{\ensuremath{-}1}$ to electromagnetism may resolve a number of astrophysical anomalies, such as unexpected $\ensuremath{\sim}\mathrm{TeV}$ transparency, anomalous stellar cooling, and x-ray excesses from nearby neutron stars. We show, however, that axions are severely constrained by the nonobservation x rays...
The recently launched James Webb Space Telescope can resolve eV-scale emission lines arising from dark matter decay. We forecast the end-of-mission sensitivity to decay of axions, a leading candidate, in Milky Way using blank-sky observations expected during standard operations. Searching for unassociated will constrain axions mass range 0.18 2.6 eV with axion-photon couplings g_{aγγ}≳5.5×10^{-12} GeV^{-1}. In particular, these results nucleophobic QCD masses ≲0.2 eV.
Axions may be produced thermally inside the cores of neutron stars (NSs), escape due to their feeble interactions with matter, and subsequently convert into X-rays in magnetic fields surrounding stars. We show that a recently-discovered excess hard X-ray emission 2 - 8 keV energy range from nearby Magnificent Seven isolated NSs could explained by this mechanism. These are unique they had previously been expected only produce observable flux UV soft bands thermal surface at temperatures ~100...
Abstract The 3.5 keV line is a purported emission observed in galaxies, galaxy clusters, and the Milky Way whose origin inconsistent with known atomic transitions has previously been suggested to arise from dark matter decay. We systematically reexamine bulk of evidence for line, attempting reproduce six previous analyses that found line. only one analyses; other five, we find no significant when following described analysis procedures on original data sets. For example, results claimed 4 σ...
White dwarf (WD) stars may radiate keV-energy axions produced in their stellar cores. This has been extensively studied as an extra channel by which WDs cool, with some analyses even suggesting that can help explain the observed WD luminosity function. We show radiated convert into x rays strong magnetic fields surrounding WDs, leading to observable x-ray signatures. use Suzaku observations of RE J0317-853 set strongest constraints date on combination axion-electron (g_{aee}) times...
Thermal Higgsino dark matter (DM), with mass around 1 TeV, is a well-motivated, minimal DM scenario that arises in supersymmetric extensions of the standard model. Higgsinos may naturally be lightest superpartners split-supersymmetry models decouple scalar while keeping and gauginos close to TeV scale. annihilate today give continuum γ-ray emission at energies less than addition linelike signature equal mass. Previous searches for DM, example H.E.S.S. telescope, have not reached necessary...
Observations of nearby galaxies and galaxy clusters have reported an unexpected x-ray emission line around 3.5 kilo-electron volts (keV). Proposals to explain this include decaying dark matter-in particular, that the decay sterile neutrinos with a mass 7 keV could match available data. If interpretation is correct, 3.5-keV should also be emitted by matter in halo Milky Way. We used more than 30 megaseconds XMM-Newton (X-ray Multi-Mirror Mission) blank-sky observations test hypothesis,...
We report significant hard X-ray excesses in the energy range 2-8 keV for two nearby isolated neutron stars RX J1856.6-3754 and J0420.0-5022. These have previously been observed soft X-rays to nearly thermal spectra at temperatures ~100 eV, which are thought arise from warm star surfaces. find nontrivial well above surface predictions with archival data XMM-Newton Chandra telescopes. analyze possible systematic effects that could generate such spurious signals, as point sources pileup of...
The Hitomi x-ray satellite mission carried unique high-resolution spectrometers that were set to revolutionize the search for sterile neutrino dark matter (DM) by looking narrow lines arising from DM decays. Unfortunately, was lost shortly after launch, and date only analysis using decay used data taken towards Perseus cluster. In this work we present a significantly more sensitive an of archival blank sky locations, searching decaying in our own Milky Way. recently launched XRISM has nearly...
We present a simple model of dark matter that can address astrophysical and cosmological puzzles across wide range scales. The is an application the Secretly Asymmetric Dark Matter mechanism, where several flavors are fully asymmetric despite exact number symmetry $U(1)_{\chi}$. relic abundance arises from these asymmetries, generated in early universe through right-handed neutrino decays. $U(1)_{\chi}$ gauged by massless photon, asymmetries with opposite signs different DM result formation...
We summarize progress made in theoretical astrophysics and cosmology over the past decade areas of interest for coming decade. This Report is prepared as TF09 "Astrophysics Cosmology" topical group summary Theory Frontier part Snowmass 2021 process.
The recently-launched James Webb Space Telescope (JWST) can resolve eV-scale emission lines arising from dark matter (DM) decay. We forecast the end-of-mission sensitivity to decay of axions, a leading DM candidate, in Milky Way using blank-sky observations expected during standard operations. Searching for unassociated will constrain axions mass range $0.18$ eV $2.6$ with axion-photon couplings $g_{a\gamma\gamma}\gtrsim 5.5 \times 10^{-12}$ GeV$^{-1}$. In particular, these results...
We show that macroscopic dark matter (DM) impacts on the degenerate helium cores of red-giant branch (RGB) stars can ignite fusion via DM-baryon elastic scattering. The onset burning leads to a characteristic drop in luminosity and rise temperature marks transition horizontal star. such alter RGB function globular clusters (GCs), focusing particular GC M15. Using models M15 constructed with stellar simulation code MESA, we compute expected DM-ignition event rates theoretical functions under...
The Hitomi X-ray satellite mission carried unique high-resolution spectrometers that were set to revolutionize the search for sterile neutrino dark matter (DM) by looking narrow lines arising from DM decays. Unfortunately, was lost shortly after launch, and to-date only analysis using decay used data taken towards Perseus cluster. In this work we present a significantly more sensitive an of archival blank sky locations, searching decaying in our own Milky Way. soon-to-be-launched XRISM will...
Low mass axion-like particles could be produced in abundance within the cores of hot, compact magnetic white dwarf (MWD) stars from electron bremsstrahlung and converted to detectable X-rays strong fields surrounding these systems. In this work, we constrain existence such axions two dedicated Chandra X-ray observations $\sim$40 ks each energy range $\sim$1 - 10 keV towards dwarfs (MWDs) WD 1859+148 PG 0945+246. We find no evidence for axions, which constrains axion-electron times...