Details

Autor(en) / Beteiligte

• Li, Shang
• Liang, Yun-Feng
• Duan, Kai-Kai
• Shen, Zhao-Qiang
• Huang, Xiaoyuan
• Li, Xiang
• Fan, Yi-Zhong
• Liao, Neng-Hui
• Feng, Lei
• Chang, Jin

Titel

Search for gamma-ray emission from eight dwarf spheroidal galaxy candidates discovered in year two of Dark Energy Survey with Fermi-LAT data

Ist Teil von

• Physical review. D, 2016-02, Vol.93 (4), Article 043518

Erscheinungsjahr

2016

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Very recently the Dark Energy Survey (DES) Collaboration has released their second group of dwarf spheroidal (dSph) galaxy candidates. With the publicly available Pass 8 data of Fermi-LAT we search for gamma -ray emissions from the directions of these eight newly discovered dSph galaxy candidates. No statistically significant gamma -ray signal has been found in the combined analysis of these sources. With the empirically estimated J-factors of these sources, the constraint on the annihilation channel of chi chi arrow right [tau] super(+)[tau] super(-) is comparable to the bound set by the joint analysis of fifteen previously known dSphs with kinematically constrained J-factors for the dark matter mass m sub( chi )>250GeV. In the direction of Tucana III (DES J2356-5935), one of the nearest dSph galaxy candidates that is ~25kpc away, there is a weak gamma -ray signal and its peak test statistic (TS) value for the dark matter annihilation channel chi chi arrow right [tau] super(+)[tau] super(-1) is [approximate] 6.7 at m sub( chi )~15GeV. The significance of the possible signal likely increases with time. More data is highly needed to pin down the physical origin of such a GeV excess.