López Sanjuan, C., Fíaz García, L. A., Cenarro, A. J., Fernández Soto, A., Viironen, K., Molino, A., Benitez, N., Cristobal Hornillos, D., Moles, M., Varela, J., Arnalte Mur, P., Ascaso, B., Castander, F. J., Cervino, M., Delgado, R. M. G., Husillos, C., Márquez, I., Masegosa, J., Del Olmo, A., Povic, M., Perea, J. 2019. The ALHAMBRA survey: tight dependence of the optical mass-to-light ratio on galaxy colour up to z=1.5. Astronomy and Astrophysics 622, DOI: 10.1051/0004-6361/201833402
Our goal is to characterise the dependence of the optical mass-to-light ratio on galaxy colour up to z = 1.5, expanding the redshift range explored in previous work.
Methods. From the redshifts, stellar masses, and rest-frame luminosities of the ALHAMBRA multi-filter survey, we derive the mass-to-light ratio versus colour relation for quiescent and for star-forming galaxies. The intrinsic relation and its physical dispersion are derived with a Bayesian inference model.
Results. The rest-frame i-band mass-to-light ratio of quiescent and star-forming galaxies presents a tight correlation with the rest-frame (g – i) colour up to z = 1.5. The mass-to-light ratio versus colour relation is linear for quiescent galaxies and quadratic for star-forming galaxies. The intrinsic dispersion in these relations is 0.02 dex for quiescent galaxies and 0.06 dex for star-forming ones. The derived relations do not present a significant redshift evolution and are compatible with previous local results in the literature. Finally, these tight relations also hold for g- and r-band luminosities.
Conclusions. The derived mass-to-light ratio versus colour relations in ALHAMBRA can be used to predict the mass-to-light ratio from a rest-frame optical colour up to z = 1.5. These tight correlations do not change with redshift, suggesting that galaxies have evolved along the derived relations during the last 9 Gyr.