Generalizations of the Tully‐Fisher Relation for Early‐ and Late‐Type Galaxies

Abstract

We study the locus of dwarf and giant early and late-type galaxies on the Tully-Fisher relation (TFR), the stellar mass Tully-Fisher relation (sTFR) and the so-called baryonic or HI gas+stellar mass Tully-Fisher relation (gsTFR). We show that early-type and late-type galaxies, from dwarfs to giants, trace different yet approximately parallel TFRs. Surprisingly, early-type and late-type galaxies trace a single yet curved sTFR over a range of 3.5 orders of magnitude in stellar mass. Moreover, all galaxies trace a single, linear gsTFR, over 3.5 orders of magnitude in HI gas+stellar mass. Dwarf ellipticals, however, lie slightly below the gsTFR. This may indicate that early-type dwarfs, contrary to the late-types, have lost their gas, e.g. by galactic winds or ram-pressure stripping. Overall, environment only plays a secondary role in shaping these relations, making them a rather ``clean'' cosmological tool. LCDM simulations predict roughly the correct slopes for these relations.