A search for dark matter in Triangulum II with the MAGIC telescopes

MAGIC Collaboration: et al.
arXiv:2003.05260v1
We present the first results from very-high-energy observations of the dwarf spheroidal satellite candidate Triangulum II with the MAGIC telescopes from 62.4 hours of good-quality data taken between August 2016 and August 2017. We find no gamma-ray excess in the direction of Triangulum II, and upper limits on both the differential and integral gamma-ray flux are presented. Currently, the kinematics of Triangulum II are affected by large uncertainties leading to a bias in the determination of the properties of its dark matter halo. Using a scaling relation between the annihilation J -factor and heliocentric distance of well-known dwarf spheroidal galaxies, we estimate an annihilation J -factor for Triangulum II for WIMP dark matter of log[Jann(0.5◦)/ GeV2cm−5] = 19.35±0.37. We also derive a dark matter density profile for the object relying on results from resolved simulations of Milky Way sized dark matter halos. We obtain 95% confidence-level limits on the thermally averaged annihilation cross section for WIMP annihilation into various Standard Model channels. The most stringent limits are obtained in the τ−τ+final state, where a cross section for annihilation down to hσannvi = 3.05 × 10−24cm3s−1is excluded.
The financial support of the German BMBF and MPG, Germany, the Italian INFN and INAF, Italy, the Swiss National Fund SNF, the ERDF under the Spanish MINECO (FPA2017-87859-P, FPA2017-85668-P, FPA2017-82729-C6-2-R, FPA2017-82729-C6-6-R, FPA2017-82729-C6-5-R, AYA2015-71042-P, AYA2016-76012-C3-1-P, ESP2017-87055-C2-2-P, FPA2017-90566-REDC), the Indian Department of Atomic Energy, the Japanese JSPS, Japan and MEXT, Japan, the Bulgarian Ministry of Education and Science, National RI Roadmap Project DO1-153/28.08.2018 and the Academy of Finland grant nr. 320045 is gratefully acknowledged. This work was also supported by the Spanish Centro de Excelencia “Severo Ochoa” SEV-2016-0588 and SEV-2015-0548, and Unidad de Excelencia “María de Maeztu” MDM-2014-0369, by the Croatian Science Foundation (HrZZ) Project IP-2016-06-9782 and the University of Rijeka, Croatia Project 13.12.1.3.02, by the DFG, Germany Collaborative Research Centers SFB823/C4 and SFB876/C3, the Polish National Research Centre, Polland grant UMO-2016/22/M/ST9/00382 and by the Brazilian MCTIC, CNPq, Brazil and FAPERJ, Brazil .