Adopted Hubble constant:
Ho = 75 km s-1 Mpc-1
Local Group velocity in km/s:
vLG = vsys + 300 sin(l) cos(b)
where l is the Galactic longitude and b the Galactic
latitude, and vsys is the systemic velocity in km/s.
Distance in Mpc:
D = vLG / Ho
We adopt the following distances for galaxies with small Local Group
velocities (vLG < 135 km/s):
NGC6822 0.490 Mpc (Mateo 1998)
DDO210 0.880 Mpc (Mateo 1998)
NGC0055 1.480 Mpc (Mateo 1998)
NGC0300 2.04 Mpc (Willick & Batra 2001)
ESO594-G004 1.060 Mpc (Mateo 1998)
IC5152 1.590 Mpc (Mateo 1998)
WLM 0.925 Mpc (Mateo 1998)
NGC3109 1.250 Mpc (Mateo 1998)
SextansA 1.440 Mpc (Mateo 1998).
HI Mass:
MHI = 2.36 105 D2 FHI
where D is the distance in Mpc and
FHI is the HI flux in Jy km/.s.
apparent blue magnitude, mb (= bt in LEDA)
estimated Galactic extinction, ag
estimated internal extinction, ai
(here currently neglected)
absolute blue magnitude:
MB,0 = mb - ag - 5 log D + 25
with D in Mpc.
Blue Luminosity in Lsun:
LB = D2 1010 - 0.4 (mb -
ag - MB,sun)
= 100.4 (MB,sun - MB,0)
with MB,sun = 5.37???, the solar blue absolute magnitude.
=> MHI/LB =
1.5 10-7 FHI
100.4*(mb-ag)