Search for gamma-ray signatures from dark matter spikes around an intermediate-mass black hole in Omega Centauri

Dark Matter (DM) constitutes 27$\%$ of the total energy density of the Universe, but its precise nature remains unknown. Several DM particles candidates were suggested, such as Weakly Interacting Massive Particles (WIMPs). This particles are supposed to annihilate, and one of the possible final products of that annihilation is gamma rays. Our research focuses on detecting these gamma rays, specifically around Intermediate Mass Black Holes (IMBHs). The strong gravitational potential of IMBHs is believed to attract and accumulate DM in their surroundings, leading to the formation of large DM overdensity known as DM "spikes", which potentially enhances the resulting gamma-ray signal. Recently, evidence was reported for the existence of a black hole with mass of about 8,200 M$_{\odot}$ in $\omega$-Centauri, the most massive globular cluster of the Milky Way, making this a good case for an IMBH in the local universe. We compute the expected gamma-ray signal from WIMP DM annihilation, assuming that the IMBH recently discovered in $\omega$-Centauri hosts an DM "spike", and we compare it with the sensitivity of the H.E.S.S. TeV gamma-ray observatory, which can observe this astrophysical target due to its unique location in Namibia. We compute the expected gamma-ray flux from DM annihilation in the IMBH in Omega Cen for a cross-section of $\langle \sigma v\rangle$ = 3$\times$10$^{-26}cm^{3}s^{-1}$ and a WIMP DM mass $m_{\chi}$ ranging between 10 GeV and 1.5 TeV, for the b-b bar annihilation channel. Our results indicate that the expected signal should be detectable by H.E.S.S. in 50 hours.