Signatures of stellar accretion in MaNGA early-type galaxies

Understand

The late assembly of massive galaxies is thought to be dominated by stellar accretion in their outskirts (beyond 2 effective radii Re) due to dry, minor galaxy mergers.

• We use observations of 1010 passive early-type galaxies (ETGs) within z<0.15 from SDSS IV MaNGA to search for evidence of this accretion.
• The outputs from the stellar population fitting codes FIREFLY, pPXF, and Prospector are compared to control for systematic errors in stellar metallicity (Z) estimation.
• We find that the average radial logZ/Zsun profiles of ETGs in various stellar mass (M) bins are not linear.