Cunnington, StevenStevenCunningtonLi, YichaoYichaoLiSantos, Mario G.Mario G.SantosWang, JingyingJingyingWangCARUCCI, Isabella PaolaIsabella PaolaCARUCCIIrfan, Melis O.Melis O.IrfanPourtsidou, AlkistisAlkistisPourtsidouSPINELLI, MARTAMARTASPINELLIWolz, LauraLauraWolzSoares, Paula S.Paula S.SoaresBlake, ChrisChrisBlakeBULL, PHILIPPHILIPBULLEngelbrecht, BrandonBrandonEngelbrechtFonseca, JoséJoséFonsecaGrainge, KeithKeithGraingeMa, Yin-ZheYin-ZheMa2025-02-172025-02-1720230035-8711http://hdl.handle.net/20.500.12386/35990We present a detection of correlated clustering between MeerKAT radio intensity maps and galaxies from the WiggleZ Dark Energy Survey. We find a $7.7\sigma$ detection of the cross-correlation power spectrum, the amplitude of which is proportional to the product of the HI density fraction ($\Omega_{\rm HI}$), HI bias ($b_{\rm HI}$) and the cross-correlation coefficient ($r$). We therefore obtain the constraint $\Omega_{\rm HI} b_{\rm HI} r\,{=}\,[0.86\,{\pm}\,0.10\,({\rm stat})\,{\pm}\,0.12\,({\rm sys})]\,{\times}\,10^{-3}$, at an effective scale of $k_{\rm eff}\,{\sim}\,0.13\,h\,{\rm Mpc}^{-1}$. The intensity maps were obtained from a pilot survey with the MeerKAT telescope, a 64-dish pathfinder array to the SKA Observatory (SKAO). The data were collected from 10.5 hours of observations using MeerKAT's L-band receivers over six nights covering the 11hr field of WiggleZ, in the frequency range $1015-973\,{\rm MHz}$ (0.400$\,{<}\,z\,{<}\,$0.459 in redshift). This detection is the first practical demonstration of the multi-dish auto-correlation intensity mapping technique for cosmology. This marks an important milestone in the roadmap for the cosmology science case with the full SKAO.STAMPAenArticle10.1093/mnras/stac30602-s2.0-85149777190http://arxiv.org/abs/2206.01579v2https://academic.oup.com/mnras/article/518/4/6262/67831692023MNRAS.518.6262CFIS/05 - ASTRONOMIA E ASTROFISICA