Radial gradients of CO absorptions and abundance ratios in the bulge of M31 F. La Barbera, A. Vazdekis, A. Pasquali, J. Heidt, A. Gargiulo and E. Eftekhari A&A, 687 (2024) A156 Published online: 05 July 2024 DOI: 10.1051/0004-6361/202348990