THE BARYONIC TULLY-FISHER RELATION OF GAS-RICH GALAXIES AS A TEST OF {Lambda}CDM AND MOND
- Department of Astronomy, University of Maryland College Park, MD 20742-2421 (United States)
The baryonic Tully-Fisher relation (BTFR) is an empirical relation between baryonic mass and rotation velocity in disk galaxies. It provides tests of galaxy formation models in {Lambda}CDM and of alternative theories like modified Newtonian dynamics (MOND). Observations of gas-rich galaxies provide a measure of the slope and normalization of the BTFR that is more accurate (if less precise) than that provided by star-dominated spirals, as their masses are insensitive to the details of stellar population modeling. Recent independent data for such galaxies are consistent with M{sub b} = AV{sup 4}{sub f} with A = 47 {+-} 6 M{sub Sun} km{sup -4} s{sup 4}. This is equivalent to MOND with a{sub 0} = 1.3 {+-} 0.3 Angstrom-Sign s{sup -2}. The scatter in the data is consistent with being due entirely to observational uncertainties. It is unclear why the physics of galaxy formation in {Lambda}CDM happens to pick out the relation predicted by MOND. We introduce a feedback efficacy parameter E to relate halo properties to those of the galaxies they host. E correlates with star formation rate and gas fraction in the sense that galaxies that have experienced the least star formation have been most impacted by feedback.
- OSTI ID:
- 22034712
- Journal Information:
- Astronomical Journal (New York, N.Y. Online), Vol. 143, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1538-3881
- Country of Publication:
- United States
- Language:
- English
Similar Records
LOCAL GROUP DWARF SPHEROIDALS: CORRELATED DEVIATIONS FROM THE BARYONIC TULLY-FISHER RELATION
FORMING REALISTIC LATE-TYPE SPIRALS IN A {Lambda}CDM UNIVERSE: THE ERIS SIMULATION