VictorBorun wrote: ↑
Wed Jan 27, 2021 4:55 am
Knowing that dust is visible in front of galaxy bulge backlight, what can we think about dust lanes here?
Is Cen A realy a dark olive tyre, shown almost edge-on at 15° to our line of sight, with radius of 4 times the width, centered around a shining ivory ball with dense core radius of 1/4 tyre's radius and the pale halo radius of 1 tyre's radius?
Is NGC 1316 really a latte-colored shining ball with long chestnut streacks all over the surface and volume, that are quite dark at the very surface and gradually get lost to our eyes before they sink any deeper than R/10 from the surface?
As for the dust disk of Cen A, ESO has revealed it to us. They describe it as the shape of a parallelogram. No doubt the twisted shape of the dust lane (or rather, dust disk) reflects the tidal forces tearing at the spiral as it is being absorbed into the larger elliptical galaxy.
The galaxy at right is the remarkable polar ring galaxy NGC 660.
NGC 660 is a peculiar and unique polar-ring galaxy located approximately 45 million light-years from Earth in the Pisces constellation. It is the only such galaxy having, as its host, a "late-type lenticular galaxy". It was probably formed when two galaxies collided a billion years ago. However, it may have first started as a disk galaxy that captured matter from a passing galaxy. This material could have, over time, become "strung out" to form a rotating ring.
As for NGC 1316, I think of it as a cross between elliptical shell galaxy NGC 474 and active galaxy NGC 1275.
NGC 474 has probably absorbed smaller galaxies in the past and developed shells - think of the small galaxies as "pebbles splashing into the larger galaxy" and causing "ripples in a pond" - and now NGC 474 is interacting with a close spiral companion, which is further messing up its outer structures.
NGC 1275 has collided with and is absorbing a spiral galaxy. The dusty remnants of the spiral are still forming stars.
As for NGC 1316, note that it has shells somewhat similar to the shells of NGC 474, and note that it has a small spiral companion very nearby, just like NGC 474.
Note that the dust structures in NGC 1316 are quite small, compared with the full extent of the galaxy. Note that the shape of the tattered dust structures are somewhat similar to the tattered dust structures in NGC 1275. But unlike the dust in NGC 1275, the dust in NGC 1316 is not forming stars.
And that is really all I can say about the dust in NGC 1316!