Decaying dark matter in the Draco dwarf galaxy

Free access article

Issue		A&A Volume 500, Number 2, June III 2009


Page(s)		L37 - L40
Section		Letters
DOI		http://dx.doi.org/10.1051/0004-6361/200912430
Published online		19 May 2009

A&A 500, L37-L40 (2009)
DOI: 10.1051/0004-6361/200912430

Letter

Decaying dark matter in the Draco dwarf galaxy

S. Riemer-Sørensen and S. H. Hansen

Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen, Denmark (The Dark Cosmology Centre is funded by the Danish National Research Foundation.)
e-mail: signe@dark-cosmology.dk

Received 6 May 2009 / Accepted 13 May 2009

Abstract
Context. The sterile neutrino is an excellent dark matter candidate, which can be searched for in a wide range of astrophysical sites. It has previously been shown that the optimal search strategy is to consider dwarf galaxies belonging to the Milky Way.
Aims. We search for line emission from decaying dark matter.
Methods. We analyse publicly available Chandra X-ray observations of the dwarf galaxy Draco.
Results. The Draco and blank sky (background) spectra are nearly identical in shape, which allows us to conclude: i) dwarf spheroidals are ideal for studying dark matter X-ray emission since the baryonic noise is impressively low; ii) there is very little room for line emission, which leads to constraints in the mass-mixing angle parameter space of the sterile neutrino. We compare the standard flux derivation method to a very conservative rebinning approach. The resulting constraints are strongly dependent on the chosen method.

Key words: cosmology: dark matter -- X-rays: general

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.