NEW LIMITS ON STERILE NEUTRINOS FROM SUZAKU OBSERVATIONS OF THE URSA MINOR DWARF SPHEROIDAL GALAXY

Journal Article · Mon Jul 20 04:00:00 EDT 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/700/1/426; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21313870

Loewenstein, Michael ^[1]; Kusenko, Alexander ^[2]; Biermann, Peter L ^[3]

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1. Department of Astronomy, University of Maryland, College Park, MD (United States)
2. Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States)
3. Max-Planck-Institut fuer Radioastronomie, Bonn (Germany)

We present results of our search for X-ray line emission associated with the radiative decay of the sterile neutrino, a well motivated dark matter candidate, in Suzaku Observatory spectra of the Ursa Minor dwarf spheroidal galaxy. These data represent the first deep observation of one of these extreme mass-to-light systems and the first dedicated dark matter search using an X-ray telescope. No such emission line is positively detected, and we place new constraints on the combination of the sterile neutrino mass, m{sub st}, and the active-sterile neutrino oscillation mixing angle, {theta}. Line flux upper limits are derived using a maximum-likelihood-based approach that, along with the lack of intrinsic X-ray emission, enables us to minimize systematics and account for those that remain. The limits we derive match or approach the best previous results over the entire 1-20 keV mass range from a single Suzaku observation. These are used to place constraints on the existence of sterile neutrinos with given parameters in the general case and in the case where they are assumed to constitute all of the dark matter. The range allowed implies that sterile neutrinos remain a viable candidate to make up some-or all-of the dark matter and also explain pulsar kicks and various other astrophysical phenomena.

• OSTI ID: 21313870
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 700; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS
ASTROPHYSICS
COSMIC NEUTRINOS
EMISSION
GALAXIES
MASS
MAXIMUM-LIKELIHOOD FIT
NEUTRINO OSCILLATION
NONLUMINOUS MATTER
PULSARS
RADIATIVE DECAY
SPECTRA
TELESCOPES
WEINBERG ANGLE
X RADIATION