Constraining sterile neutrino warm dark matter with Chandra observations of the Andromeda galaxy

Journal Article · Thu Mar 01 04:00:00 EST 2012 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2012/03/018· OSTI ID:22280089

Watson, Casey R.; Polley, Nicholas K. ^[1]; Li, Zhiyuan ^[2]

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1. Department of Physics and Astronomy, Millikin University, Decatur, Illinois 62522 (United States)
2. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

We use the Chandra unresolved X-ray emission spectrum from a 12'–28' (2.8–6.4 kpc) annular region of the Andromeda galaxy to constrain the radiative decay of sterile neutrino warm dark matter. By excising the most baryon-dominated, central 2.8 kpc of the galaxy, we reduce the uncertainties in our estimate of the dark matter mass within the field of view and improve the signal-to-noise ratio of prospective sterile neutrino decay signatures relative to hot gas and unresolved stellar emission. Our findings impose the most stringent limit on the sterile neutrino mass to date in the context of the Dodelson-Widrow model, m{sub s} < 2.2 keV (95% C.L.). Our results also constrain alternative sterile neutrino production scenarios at very small active-sterile neutrino mixing angles.

• OSTI ID: 22280089
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 03 Vol. 2012; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTROPHYSICS
BARYONS
COSMIC NEUTRINOS
COSMIC PHOTONS
COSMOLOGY
EMISSION SPECTRA
GALAXIES
KEV RANGE
MASS
NONLUMINOUS MATTER
PARTICLE PRODUCTION
RADIATIVE DECAY
SIGNAL-TO-NOISE RATIO
WEINBERG ANGLE
X RADIATION