THE LOCAL TULLY–FISHER RELATION FOR DWARF GALAXIES
- Special Astrophysical Observatory, Nizhniy Arkhyz, Karachai-Cherkessia 369167 (Russian Federation)
We study different incarnations of the Tully–Fisher (TF) relation for the Local Volume (LV) galaxies taken from Updated Nearby Galaxy Catalog. The UNGC sample contains 656 galaxies with W{sub 50} H i-line-width estimates, mostly belonging to low-mass dwarfs. Of them, 296 objects have distances measured with accuracies better than 10%. For the sample of 331 LV galaxies having baryonic masses logM{sub bar}>5.8log M{sub ⊙}, we obtain a relation logM{sub bar}=2.49logW{sub 50}+3.97 with an observed scatter of 0.38 dex. The largest factors affecting the scatter are observational errors in K-band magnitudes and W{sub 50} line widths for the tiny dwarfs, as well as uncertainty of their inclinations. We find that accounting for the surface brightness of the LV galaxies or their gas fraction, specific star-formation rate, or isolation index does not essentially reduce the observed scatter on the baryonic TF diagram. We also notice that a sample of 71 dSph satellites of the Milky Way and M31 with a known stellar velocity dispersion σ* tends to follow nearly the same bTF relation, having slightly lower masses than that of late-type dwarfs.
- OSTI ID:
- 22863095
- Journal Information:
- The Astronomical Journal (Online), Vol. 153, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1538-3881
- Country of Publication:
- United States
- Language:
- English
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