The LITTLE THINGS sample includes 42 dwarf irregular (dIm)
and Blue Compact Dwarf (BCD) galaxies.
We will obtain new VLA HI-line observations of 21 galaxies; the other
21 have data in the NRAO archives.
The galaxies are listed in Table 1 and the datasets in Table 2.
The LITTLE THINGS sample was drawn from a larger multi-wavelength
survey that includes
94 dIm, 24 BCDs, and 18 Sm galaxies
(Hunter & Elmegreen 2004,
2006),
the result of 15 years of observations.
The HI sample covers the entire range of dIm parameter space of the full survey
(see Figure 1), including
the extremes---from high star formation rate BCDs to low
surface brightness dwarfs without any current star formation.
aRH is the Holmberg radius, the radius of the galaxy at a B-band isophote, corrected for reddening, of 26.7 mag of one arcsec2.
bSFRD is the star formation rate, measured from
Halpha, normalized to the pi×RD2,
where RD is the disk
scale length measured from V-band images.
A galaxy without any detectable Halpha emission is listed as
having a SFR of 0.
References for published datasets:
Halpha images (Hunter & Elmegreen 2004);
UBVJHK images (Hunter & Elmegreen 2006);
Spitzer IRAC images (Hunter, Elmegreen, & Martin 2006);
Spitzer IRS spectra (Hunter & Kaufman 2006, AJ, submitted);
individual HI studies (Hunter, Elmegreen, & van Woerden 2001;
Simpson, Hunter, & Knezek 2005;
Simpson, Hunter, & Nordgren 2005;
Kepley, Wilcots, Hunter, & Nordgren 2007).
Figure 1: Properties of the LITTLE THINGS HI sample
(new observations [hashed +45° ]+archive
[hashed -45°])
compared to the entire optical survey (open) of
Hunter & Elmegreen (2004,
2006).
The HI sample covers the range of parameters of the full survey.
dIm and BCD galaxies have been combined. A star formation rate (SFR) of 0 is
plotted as a log of -6. SFRD is the SFR
normalized to pi×RD2, where
RD is the disk scale length.