Velocity pattern at centre of NGC 7782

This image shows the velocity pattern of the gas in the inner region of the spiral galaxy NGC 7782, as visualized by the [NII] emission line (rest wavelength 658.3 nm). The north and south sides of the galaxy correspond to the left and right of the spectrum. At the distance of this galaxy, 1 arcsec = 1,182 light-years. The original UVES spectrum was exposed during 30 min, with an average seeing of 0.7 arcsec. The full wavelength range is 476 - 684 nm in the red arm of the instrument. The spectrum pixel size is 0.027 Å x 0.18 arcsec (1.2 km/sec x 215 light-years).