Properties of barred spiral galaxies.

Blue and near-infrared surface photometry of 15 barred spiral galaxies, combined with results from photometric and kinematic studies of barred galaxies, reveals that: (1) early Hubble types have flat bars with uniform intensities along their lengths and stellar spiral arms with amplitudes that decrease with radius, and (2) late Hubble types have bars with exponential-like intensity profiles and spiral arm amplitudes that increase or remain constant with radius. Relative bar luminosities are derived using Fourier decompositions of the bar azimuthal profiles. It is concluded that bars in early-type galaxies probably contain highly elongated stellar orbits out to the corotation vicinity and also stimulate stellar spiral structure either by continuously growing, in the case of a non-self-gravitating stellar disk, or by exciting a wave mode at a resonance, in the case of a strongly self-gravitating stellar disk. It is shown that bars in some late-type galaxies may extend out only to the inner Lindbald resonances and that they appear to be too short or too weak to drive prominent stellar spirals because the spirals in these galaxies are often irregular.