The Bimodal Galaxy Stellar Mass Function in the COSMOS Survey to z~1: A Steep Faint End and a New Galaxy Dichotomy

Understand

We present a new analysis of stellar mass functions (MF) in the COSMOS field to fainter limits than has been previously probed to z~1.

• Neither the total nor the passive or star-forming MF can be well fit with a single Schechter function once one probes below 3e9 Msun.
• We observe a dip or plateau at masses ~1e10 Msun, and an upturn towards a steep faint-end slope of -1.7 at lower mass at any z<1.
• This bimodal nature of the MF is not solely a result of the blue/red dichotomy.