The rotation curves shapes of late-type dwarf galaxies

By R. Swaters, R. Sancisi, T. S. Albada, van der Thijs Hulst. 2009

163 citations recorded by the source corpus.

We present rotation curves derived from H i observations for a sample of 62 galaxies that have been observed as part of the Westerbork H i Survey of Spiral and Irregular Galaxies (WHISP) project. These rotation curves have been derived by interactively fitting model data cubes to the observed cubes. This procedure takes the rotation curve shape, the H i distribution, the inclination, and the size of the beam into account, and makes it possible to correct for the effects of beam smearing. A comparison with higher spatial resolution Hα rotation curves available in the literature shows that there is general agreement between the two. The late-type dwarf galaxies in our sample have rotation-curve shapes that are similar to those of late-type spiral galaxies, in the sense that their rotation curves, when expressed in units of disk scale lengths, rise as steeply in the inner parts and start to flatten at two disk scale lengths. None of the galaxies in our sample have solid-body rotation curves that extend beyond three disk scale lengths. The logarithmic slopes between two disk scale lengths and the last measured point on the rotation curve is similar between late-type dwarf and spiral galaxies. Thus, whether the flat part of the rotation curve is reached or not seems to depend more on the extent of the rotation curve than on its amplitude. We also find that the outer rotation curve shape does not strongly depend on luminosity, at least for galaxies fainter than MR ∼− 19. We find that in spiral galaxies and even in the central regions of late-type dwarf galaxies, the shape of the central distribution of light and the inner rise of the rotation curve are related. This implies that galaxies with stronger central concentrations of light also have higher central mass densities, and it suggests that the luminous mass dominates the gravitational potential in the central regions, even in low surface brightness dwarf galaxies.

Subfields: Astronomy and Astrophysics, Instrumentation, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/4c252c225c219e9f9e02d3f195253afbe31c2937

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Citations in the corpus

The unexpected diversity of dwarf galaxy rotation curves (2015, background): “The baryon distribution is at least partly responsible, since it is well documented that high surface brightness galaxies have more steeply rising rotation curves than low surface brightness systems (see e.g. McGaugh & de Blok 1998; Swaters et al. 2009, and references therein).”
THE VELOCITY WIDTH FUNCTION OF GALAXIES FROM THE 40% ALFALFA SURVEY: SHEDDING LIGHT ON THE COLD DARK MATTER OVERABUNDANCE PROBLEM (2011, background): “The dwarf galaxy samples of Spekkens et al. (2005) and Swaters et al. (2009), suggest that the effect becomes more dramatic at the lowest velocities (see Figure 3 & Figure 4 in the respective references).”
THE VELOCITY FUNCTION IN THE LOCAL ENVIRONMENT FROM ΛCDM AND ΛWDM CONSTRAINED SIMULATIONS (2009, methodology): “A recent analysis by Swaters et al. (2009) indi- cates that the rotation curves for late-type dwarf galaxies are similar to those of more massive galaxies, starting to flatten at two disk scale lengths, thus, W50 would not underestimate strongly the value of Vmax for these galaxies since the HI gas…”
Fitting the radial acceleration relation to individual SPARC galaxies (2018, background): “…the errors on the rotation velocities are not expected to be Gaussian because they are obtained by summing two different contributors (see Swaters et al. 2009; Lelli et al. 2016): the formal error from fitting the whole disk (driven by data quality and random non-circular motions) and…”
THE SMALL SCATTER OF THE BARYONIC TULLY–FISHER RELATION (2015, methodology): “For some low-mass, gasdominated galaxies, these radii may occur along the rising part of the RC (Swaters et al. 2009).”
One Law to Rule Them All: The Radial Acceleration Relation of Galaxies (2016, methodology): “Several works try to parametrize this baryon−DM coupling using different approaches (Sanders 1990; Persic & Salucci 1991; McGaugh 1999, 2004, 2014; Swaters et al. 2009, 2014; Lelli et al. 2013, 2016a; Walker & Loeb 2014).”
Is there a "too big to fail" problem in the field? (2014, background): “…from Sanders (1996),30 galaxies from Verheijen & Sancisi (2001), 19 galaxies from the The HI Nearby Galaxy Survey (THINGS; de Blok et al. 2008; Oh et al. 2011a), 54 galaxies from the Westerbork HI Survey of Spiral and Irregular Galaxies (WHISP; Swaters et al. 2009, 3 Including scatter in Eqn.”
THE BARYONIC TULLY–FISHER RELATION OF GAS-RICH GALAXIES AS A TEST OF ΛCDM AND MOND (2011, background): “Stark et al. (2009) required resolved rotation curves that were observed to flatten sufficiently that the logarithmic slope became < 0.1 in their outer parts (see Swaters et al. 2009, from which much of this sample originates).”
SPARC: MASS MODELS FOR 175 DISK GALAXIES WITH SPITZER PHOTOMETRY AND ACCURATE ROTATION CURVES (2016, methodology): “…175 rotation curves are drawn from the following publications (in parenthesis we provide the corresponding number of objects excluding duplicates): Swaters et al. (2009, 32), Sanders & Verheijen (1998, 30), Sanders (1996, 17), Noordermeer et al. (2007, 12), de Blok et al. (2001, 10), Begeman et…”