[2] The galaxy has a small and bright nucleus and tightly wound multiple spiral arms.

It is considered the best candidate to be a true type II Seyfert galaxy,[4] galaxies which feature optical/UV spectrum lacking broad emission lines due to the lack of the broad line region rather than its obscuration, since the nucleus is simultaneously seen unobscured in the X-rays.

[6] Birghtman et al. confirmed their findings and also noted that the hard X-ray flux dropped by a factor of ~2 between the observation by Chandra (2001) and XMM-Newton (2006).

[5] Bianchi et al. rejected the presence of a Compton thick column on the grounds of low-equivalent width of the iron Kα line (≃130 eV), and of the large ratio between hard X-ray and [O III] fluxes.

[5] In July 2019 researchers using the Hubble Space Telescope Imaging Spectrograph reported the presence of a thin disk of material around a supermassive black hole at the center of NGC 3147.

The disk is also unusual because it is deep within the gravitational well of the black hole and rotates around it at more than 10% of the speed of light.