Southern Galaxies. III. Isophotometry of the Large Barred Spiral NGC 1313.
Abstract
Isophotes and photometric parameters of the SB(s)d spiral NGC 1313 are derived from photographs taken with the Mount Stromlo 30- and 74-inch reflectors. The total apparent photographic magnitude = 9.74 (with provisional zero point) and maximum dimensions 14' ?( 10' (at the threshold p = 27.3mag = 0.95 C/pc2) correspond to MT = -18.7 and Dm = 18.3 kpc, if m - M = 28.55 and A = 4.5 Mpc. The major axis is in position angle 0 40" at j# 25 mag , and 0 15" at p 27 mag (including a peculiar appendage 6' X 5' at 6 1 in p.a. 185"); the mean axis ratio of the outer regions q = (b/a = 0.80 corresponds to an incllnation i = 39". The equivalent effective radius is - 1 `44 - 1.9 kpc, the effective surface brightness = 22.32 mag = 91 0/pc2, and the mean luminosity gradient of the exponential component contributing 70 per cent of the total luminosity is G(a) = -0.36 = -0.275 . The radial velocity of the brightest H ii region is V = +254 + 10 (p.e.) km .
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 1963
- DOI:
- 10.1086/147550
- Bibcode:
- 1963ApJ...137..720D