Galaxy Crashes Through Another. Loses Spirals, Steals Hydrogen!

What the heck? A strange thing this is.

Usually labeled Bode's Nebula (M82), the  body is also called the Cigar Galaxy, It is 12 million light years away.

This odd shaped galaxy has been distorted by its passage through a nearby galaxy conveniently numbered M81, and Cigar had most of its spirals pulled away during the passage. But it also grabbed some of M81's own intergalactic mass in a kind of equivalent exchange.

(See M81 at https://astrob.in/z91ugi/0/ Note a gap in the bottom spiral arm)

(And here's both galaxies in one image https://astrob.in/2nceb2/0/ )

While most of the original outer spirals are gone from Cigar, the latest astronomical technology has detected remaining faint spirals by looking at nearly invisible wavelengths of light. It's possible they are just very slight remnants after the other galaxy pulled most of their material away.

Or, maybe they are new ones being formed.

The features noticed most immediately are the curly red ribbons radiating around Cigar's center. These are those clouds of intergalactic hydrogen gas stolen from the other galaxy. They are irradiated red by the incredibly bright stars swirling around the nucleus. The ribbons were pulled from M81 by the gravitational pull from the super massive black hole in Cigar's nucleus, so they are being sucked into this galaxy, not spewed outward. 

It is thought Cigar was quiet and dim until a billion years ago, when star formation was triggered from the interaction with its much bigger neighbor.

The friction from the turbulence caused by the encounter with M81 has caused this galaxy to create new stars 10 times more frequently than the Milky Way. As a result, Cigar is about 5 times more luminous than the Milky Way, and its central region is 100 times brighter!

The galaxy was discovered by Johann Elert Bode in 1774. it was just a soft blurry patch in his scope, but he did notice its close proximity to the other galaxy. During this first golden era of telescopes, Johann had no idea what is was or how far away it was. "Galaxy" had yet to be defined, so he simply called anything that was soft and bright a "nebula."

Because they were, well, nebulous.

And now a new mystery! In 2010, radio astronomers detected  radio waves coming from Cigar with an unrecognized combination of frequencies and patterns. So far, despite careful analysis, the signals do not look like anything else seen in the entire universe.

Is it an accident of physics? Or, is it intentional? Hmmm.

Tonight's log was written to Avishai Cohen's jazz tune appropriately called, 𝘚𝘮𝘢𝘴𝘩.

An amazing closeup and detailed image from Hubble at https://en.wikipedia.org/wiki/Messier_82#/media/File:M82_HST_ACS_2006-14-a-large_web.jpg