RIT: Crash with Dark Galaxy Gave Milky Way Ripples in Outer Disc

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RIT: Crash with Dark Galaxy Gave Milky Way Ripples in Outer Disc

Post by bystander » Fri Jun 14, 2019 3:32 pm

Crash with Antlia 2 Gave Milky Way Ripples in Outer Disc
Rochester Institute of Technology | 2019 Jun 12
RIT scientist Sukanya Chakrabarti developing methods to hunt for the darkest dwarf galaxies

The newly-discovered dark dwarf galaxy Antlia 2’s collision with the Milky Way may be responsible for our galaxy’s characteristic ripples in its outer disc, according to a study led by Rochester Institute of Technology Assistant Professor Sukanya Chakrabarti.

The Antlia 2 dwarf galaxy was discovered from the second data release of the European Space Agency’s Gaia mission, which aims to chart a three-dimensional map of our galaxy. Antlia 2’s current location closely matches the location of a dark-matter dominated dwarf galaxy that Chakrabarti predicted in 2009 through a dynamical analysis. Using the Gaia data, Chakrabarti calculated its past trajectory and found that Antlia 2 would have crashed into the Milky Way and produced the large ripples that we see in the outer gas disc of our galaxy.

Upcoming additional data releases from Gaia will provide further clarity, and Chakrabarti said that she and her team have made “a hand-on-the-cutting-board kind of prediction of what to expect for the motion of the stars in the Antlia 2 dwarf galaxy in future Gaia data releases.” Chakrabarti said the discovery could help develop methods to hunt for dark galaxies and ultimately solve the long-standing puzzle of what dark matter is. ...

Antlia 2's Role in Driving the Ripples in the Outer Gas Disk of the Galaxy ~ Sukanya Chakrabarti et al
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