The Turndown of the Baryonic Tully-Fisher Relation and Changing Baryon Fraction at Low Galaxy Masses

Kristen B.W. McQuinn, Elizabeth A.K. Adams, John M. Cannon, Jackson Fuson, Evan D. Skillman, Alyson Brooks, Katherine L. Rhode, Martha P. Haynes, John L. Inoue, Joshua Marine, John J. Salzer, Anjana K. Talluri

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

The ratio of baryonic-to-dark matter in present-day galaxies constrains galaxy formation theories and can be determined empirically via the baryonic Tully-Fisher relation (BTFR), which compares a galaxy’s baryonic mass (M bary) to its maximum rotation velocity (V max). The BTFR is well determined at M bary > 108 M , but poorly constrained at lower masses due to small samples and the challenges of measuring rotation velocities in this regime. For 25 galaxies with high-quality data and M bary ≲ 108 M , we estimate M bary from infrared and H i observations and V max from the H i gas rotation. Many of the V max values are lower limits because the velocities are still rising at the edge of the detected H i disks (R max); consequently, most of our sample has lower velocities than expected from extrapolations of the BTFR at higher masses. To estimate V max, we map each galaxy to a dark matter halo assuming density profiles with and without cores. In contrast to noncored profiles, we find the cored profile rotation curves are still rising at R max values, similar to the data. When we compare the V max values derived from the cored density profiles to our M bary measurements, we find a turndown of the BTFR at low masses that is consistent with Λ cold dark matter predictions and implies baryon fractions of 1%-10% of the cosmic value.

Original languageEnglish (US)
Article number8
JournalAstrophysical Journal
Volume940
Issue number1
DOIs
StatePublished - Nov 1 2022

Bibliographical note

Funding Information:
K.B.W.M. thanks Yao-Yuan Mao for helpful discussions on dark matter density profiles. E.A.K.A. is supported by the Wide-field Infrared Survey Explorer research program, which is financed by the Dutch Research Council (NWO). J.M.C., J.F., and J.L.I. are supported by NSF/AST-2009894. M.P.H. acknowledges support from NSF/AST-1714828 and grants from the Brinson Foundation. This research has made use of NASA Astrophysics Data System Bibliographic Services and the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

Funding Information:
K.B.W.M. thanks Yao-Yuan Mao for helpful discussions on dark matter density profiles. E.A.K.A. is supported by the Wide-field Infrared Survey Explorer research program, which is financed by the Dutch Research Council (NWO). J.M.C., J.F., and J.L.I. are supported by NSF/AST-2009894. M.P.H. acknowledges support from NSF/AST-1714828 and grants from the Brinson Foundation. This research has made use of NASA Astrophysics Data System Bibliographic Services and the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.

Fingerprint

Dive into the research topics of 'The Turndown of the Baryonic Tully-Fisher Relation and Changing Baryon Fraction at Low Galaxy Masses'. Together they form a unique fingerprint.

Cite this