Axion spectra and the associated x-ray spectra of low-mass stars

Abstract

For the first time, we predict the axion spectra and their associated luminosities for several low-mass stars -- one and two solar masses stars in the main sequence and post-main sequence stages of evolution. Equally, we also compute the x-ray excess emission resulting from the conversion of axions back to photons in the presence of a strong magnetic field in the envelope of these stars. Hence, a given star will have a unique axion spectrum and $L_a$ axion luminosity. And if such star has a strong magnetic field in its stellar envelope, it will also show a characteristic x-ray spectrum and $L_{a\gamma }$ x-ray luminosity. Such radiation will add up to the x-ray electromagnetic spectrum and $L_X$ luminosity of the star. The present study focuses on axion models with an axion-photon coupling constant, $510^{-11}{\mathrm{GeV}}^{-1}$, a value just below the most recent upper limit of $6.610^{-11}{\mathrm{GeV}}^{-1}$ found by CAST and IAXO helioscopes. The range of axion parameters discussed here spans many axion models' parameter space, including the DFSZ and KSVZ models. We found that axions with a mass in the range $10^{-7}$ to $10^{-5}\mathrm{eV}$ and an axion-photon coupling constant of $510^{-11}{\mathrm{GeV}}^{-1}$ produce an axion emission spectra with an averaged axion energy that varies from 1 to 5 KeV, and an $L_a$ ranging from $10^{-6}$ to $710^{-3}{L}_{\odot }$. We also predict that $L_{a\gamma }$ varies from $510^{-8}$ to $10^{-5}{L}_{\odot }$ for stars with an averaged magnetic field of $310^4\mathrm{G}$ in their atmospheres. Most of these $L_{a\gamma }$ predictions are larger than the $L_X$ observed in some stars. Therefore, such preliminary results show the potential of the next generation of stellar x-ray missions to constrain several classes of axion models.

arXiv comment12 pages, 1 table, 4 figures, published in PRD

References in corpus (60)

• The chemical composition of the Sun
• Modules for Experiments in Stellar Astrophysics (MESA)
• Modules for Experiments in Stellar Astrophysics (MESA): Giant Planets, Oscillations, Rotation, and Massive Stars
• Modules for Experiments in Stellar Astrophysics (MESA): Binaries, Pulsations, and Explosions
• The Nuclear Spectroscopic Telescope Array (NuSTAR) Mission
• Modules for Experiments in Stellar Astrophysics (MESA): Convective Boundaries, Element Diffusion, and Massive Star Explosions
• Axion Cosmology
• The PLATO 2.0 Mission
• Kepler Mission Design, Realized Photometric Performance, and Early Science
• New CAST Limit on the Axion-Photon Interaction
• Solar Models with Helium and Heavy Element Diffusion
• New experimental approaches in the search for axion-like particles
• Magnetic fields of non-degenerate stars
• The landscape of QCD axion models
• Astrophysical Axion Bounds
• Revisiting the SN1987A gamma-ray limit on ultralight axion-like particles
• An improved limit on the axion-photon coupling from the CAST experiment
• Conceptual Design of the International Axion Observatory (IAXO)
• The solar magnetic field
• 10,000 Standard Solar Models: a Monte Carlo Simulation
• Searching for WISPy Cold Dark Matter with a Dish Antenna
• Neutrino and axion bounds from the globular cluster M5 (NGC 5904)
• Constraining the mass of dark photons and axion-like particles through black-hole superradiance
• Tunable axion plasma haloscopes
• Probing eV-scale axions with CAST
• Dilute and dense axion stars
• Axion and hidden photon dark matter detection with multilayer optical haloscopes
• Cool WISPs for stellar cooling excesses
• Stellar Recipes for Axion Hunters
• A Proposal to Detect Dark Matter Using Axionic Topological Antiferromagnets
• Phase transitions between dilute and dense axion stars
• The connection between stellar activity cycles and magnetic field topology
• X-ray Searches for Axions from Super Star Clusters
• Magnetic Field Generation in Stars
• Three-dimensional simulations of near-surface convection in main-sequence stars. III. The structure of small-scale magnetic flux concentrations
• The meV mass frontier of axion physics
• Directional axion detection
• X-ray Signatures of Axion Conversion in Magnetic White Dwarf Stars
• An X-ray activity cycle on the young solar-like star $\epsilon \mathrm{Eridani}$
• Magnetic field topologies of the bright, weak-field Ap stars theta Aurigae and epsilon Ursae Majoris
• Revisiting longitudinal plasmon-axion conversion in external magnetic fields
• Axion Searches with Helioscopes and astrophysical signatures for axion(-like) particles
• Formation of Relativistic Axion Stars
• Axion helioscopes as solar magnetometers
• Future cosmological sensitivity for hot dark matter axions
• Almost-Goldstone Bosons from Extra-Dimensional Gauge Theories
• Signatures of photon-axion conversion in the thermal spectra and polarization of neutron stars
• Weighing the Solar Axion
• Hydrogen Axion Star: Metallic Hydrogen Bound to a QCD Axion BEC
• Inflection point in the power spectrum of stellar brightness variations. I. The model
• Long-term variations in sunspot magnetic field - area relation
• Production of axion-like particles from photon conversions in large-scale solar magnetic fields
• Oscillator models of the solar cycle: Towards the development of inversion methods
• A review on axions and the strong CP problem
• A first proof of principle booster setup for the MADMAX dielectric haloscope
• Planetary influence on the young Sun's evolution: the solar neutrino probe
• The impact of composition choices on solar evolution: age, helio- and asteroseismology, and neutrinos
• Photon-Dark Photon Conversions in Background Electromagnetic Fields
• X-rays from magnetic intermediate mass Ap/Bp stars
• Acoustic modes of pulsating axion stars: Non-radial oscillations

Cited by in corpus (1)

• Axion Astrophysics