Willman 1: An X-ray shot in the dark with Chandra
| dc.contributor.author | Nieto, D. | |
| dc.contributor.author | Mirabal, N. | |
| dc.date.accessioned | 2020-09-04T16:53:25Z | |
| dc.date.available | 2020-09-04T16:53:25Z | |
| dc.date.issued | 2010-03-19 | |
| dc.description.abstract | The sterile neutrino is a weakly-interacting particle that emerges in the framework of certain extensions of standard particle physics and that fits naturally with the properties of a warm dark matter particle candidate. We present an analysis of a deep archival Chandra observation of Willman 1, one of the darkest purported ultra-faint dwarf galaxies, that excludes the presence of sterile neutrinos in the 1.6-16 keV mass range within 55 pc of its centre down to the limits of the observation. Spectral analysis of the Chandra data fails to find any non-instrumental spectral feature possibly connected with the radiative decay of a dark matter particle. Accordingly, we establish upper bounds on the sterile neutrino parameter space and discuss it in the context of previous measurements. Regarding the point source population, we identify a total of 26 sources within the central 5 arcminutes to a limiting 0.5-2.0 keV X-ray flux of 6 x 10⁻¹⁶ erg cm-2 s⁻¹. While some of these sources could be formal members of Willman 1, we find no outstanding evidence for either an unusual population of bright X-ray sources or a densely populated cluster core. In fact, the entire X-ray population could be explained by background active galactic nuclei and/or foreground stars unrelated to Willman 1. Finally, possible associations of the X-ray point like population with optical sources from the SDSS DR7 catalogue are discussed. | en_US |
| dc.description.sponsorship | We are indebted to an anonymous colleague for careful reading of the original version. We thank all the members of Grupo de Altas Energ´ıas (GAE) at the Universidad Complutense de Madrid for stimulating discussions. N.M. acknowledges support from the Spanish Ministry of Science and Innovation through a Ram´on y Cajal fellowship. We also acknowledge support from the Consolider-Ingenio 2010 Programme under grant MULTIDARK CSD2009-00064 | en_US |
| dc.description.uri | https://arxiv.org/abs/1003.3745v3 | en_US |
| dc.format.extent | 14 pages | en_US |
| dc.genre | journal articles preprints | en_US |
| dc.identifier | doi:10.13016/m2t73v-8rvy | |
| dc.identifier.citation | D. Nieto and N. Mirabal, Willman 1: An X-ray shot in the dark with Chandra, https://arxiv.org/abs/1003.3745v3 | en_US |
| dc.identifier.uri | http://hdl.handle.net/11603/19589 | |
| dc.language.iso | en_US | en_US |
| dc.relation.isAvailableAt | The University of Maryland, Baltimore County (UMBC) | |
| dc.relation.ispartof | UMBC Physics Department Collection | |
| dc.relation.ispartof | UMBC Joint Center for Earth Systems Technology (JCET) | |
| dc.relation.ispartof | UMBC Center for Space Sciences and Technology (CSST) / Center for Research and Exploration in Space Sciences & Technology II (CRSST II) | |
| dc.rights | This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author. | |
| dc.title | Willman 1: An X-ray shot in the dark with Chandra | en_US |
| dc.type | Text | en_US |