RT Journal Article T1 Upper limits on the VHE gamma-ray emission from the Willman 1 satellite galaxy with the Magic telescope A1 Antoranz Canales, Pedro A1 Barrio Uña, Juan Abel A1 Contreras González, José Luis A1 Fonseca González, Mª Victoria A1 Miranda Pantoja, José Miguel A1 Nieto, Daniel AB We present the result of the observation of the ultrafaint dwarf galaxy Willman 1 performed with the 17 m MAGIC telescope during 15.5 hr between March and May 2008. No significant gamma-ray emission was found. We derived upper limits of the order of 10(-12) ph cm(-2) s(-1) on the integral flux above 100 GeV, which we compare with predictions from several of the established neutralino benchmark models in the mSUGRA parameter space. The neutralino annihilation spectra are defined after including the recently quantified contribution of internal bremsstrahlung from the virtual sparticles that mediate the annihilation. 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NO © The American Astronomical Society. We thank the Instituto de Astrofisica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The support of the German BMBF and MPG, the Italian INFN, and Spanish MCINN is gratefully acknowledged. This work was also supported by ETH Research grant TH 34/043, by the Polish MNiSzW grant N N203 390834, and by the YIP of the Helmholtz Gemeinschaft. Finally, we thank the anonymous referees for useful comments. NO ETH Research NO Polish MNiSzW NO German BMBF NO MPG NO Italian INFN NO Spanish MCINN DS Docta Complutense RD 6 may 2024