The Extended Baryonic Tully-Fisher Relation for SDSS MaNGA Galaxies

TL;DR

This study extends the baryonic Tully-Fisher relation to higher masses using SDSS MaNGA galaxies, comparing observations with Lambda CDM simulations and MOND predictions, and finds consistent slopes across models.

Contribution

It introduces a method to include elliptical galaxies in the BTFR analysis and compares the relation with cosmological simulations and alternative gravity models.

Findings

BTFR slopes between 3.2 and 4.0 for different galaxy types

Good agreement of the joint BTFR slope (~3.54) with TNG100 simulations

Mass range >10^9 Msun shows consistency with Lambda CDM and MOND

Abstract

The baryonic Tully-Fisher relation (BTFR), a relationship between rotational velocity and baryonic mass in spiral galaxies, probes the relative content of baryonic and dark matter in galaxies and thus provides a good test of Lambda CDM. Using H-alpha kinematics to model the rotation curves of spiral galaxies, we construct the BTFR for 5743 SDSS MaNGA DR17 galaxies. To extend the BTFR to higher masses using elliptical galaxies, we estimate their total masses from their stellar velocity dispersions using the virial theorem and define the effective rotational velocity as the velocity a rotation-supported galaxy would exhibit given this mass. The baryonic mass of spiral galaxies is composed of stellar, HI, H2, and He mass, while only the stellar mass is used for the baryonic content of ellipticals. We construct and fit the BTFR for a matched subsample of spiral and elliptical MaNGA and IllustrisTNG 100-1 (TNG100) galaxies, finding BTFR slopes between 3.2 and 4.0. We fit a joint BTFR for the 5743 MaNGA spiral and elliptical galaxies and find a BTFR slope of 3.54 (+0.65/-0.48), which is in good agreement with TNG100 galaxies with baryonic masses greater than 10^9 Msun for which we find a BTFR slope of 3.57 (+0.48/-0.37). Within this mass range, the MaNGA galaxies are consistent with both the Lambda CDM simulation and the prediction from MOND; a sample of lower mass galaxies is necessary to differentiate between the two models.