De Vaucouleurs Atlas Type: S0o sp
Telescope: UH 2.2-m
North left , East down
Field Dimensions: 4.6 x 3.5 arcminutes
RC3 Type: SA(r)0+: sp
RSA Type: S02(9)
Surface Brightness Range Displayed: 16.0-26.0 mag per square arcsec
Absolute Blue Magnitude: -19.3
De Vaucouleurs Atlas Description:
The central area of NGC 4111 shows three very thin zones, one coincident with the center. De Vaucouleurs interpreted the two zones flanking the center as the edge-on morphology expected for an inner ring . The reason for this was that line of sight effects were expected to be strongest at the ring major axis. However, we use these structures only to set the stage and not the variety. The bulge region shows a ``box/peanut" character and the galaxy may therefore be barred, but not necessarily ringed.
NGC 4111 was one of the first galaxies determined to have a ``thick disk", i.e., a new component of the light distribution of galaxies having a flattening intermediate between a regular thin disk and a typical bulge (Burstein 1979; see also Tsikoudi 1980). Our Galaxy may also have such a feature (Gilmore, King, and van der Kruit 1989).
The origin of thick disks is still under investigation. Various scenarios, including the ideas of a primary or secondary event (i.e., primordial versus post-formation) have been considered.