By Stacy Palen
It’s that time of the semester when we are talking about galaxies, galactic structure, and supermassive black holes. Fortunately, Chandra has our back and has released a new image of a superbubble in NGC3079. The picture is sufficiently spectacular that I want to let you know about it right now!
1. Along the bottom of the composite image on the website, there are tabs that allow you to switch back and forth between the composite image, the X-ray image and the optical image. Compare the X-ray image and the optical image.
Answer: The X-ray image contains mostly just point sources, as well as two larger fuzzy patches. One of these fuzzy patches is shaped like a ring. The optical image, however, shows the entire galaxy, including dark lanes of dust and gas and bright light from stars and emission nebulae.
2. How big are the superbubbles, compared to the diameter of the disk of the Milky Way Galaxy?
Answer: The superbubbles have diameters of a few thousand light years. The disk of the Milky Way has a diameter of a few hundred thousand light years. So, these bubbles are about 1/100 (0.01 or 1%) the size of the Milky Way’s disk.
3. What is a cosmic ray?
Answer: A high energy positively charged particle traveling through space. Note: they will have to click through to find this answer, if they don’t already know it! Let’s encourage that behavior!
4. Humans also accelerate particles, in particle accelerators, funny enough. How much more energy do the particles in these bubbles have than those accelerated by humans?
Answer: These particles have 100 times more energy than those in particle accelerators.
5. Run your mouse over the composite image to see it with labels on it. Why do astronomers think these superbubbles are associated with a supermassive black hole?
Answer: Because they are located together in space.
X-ray: NASA/CXC/University of Michigan/J-T Li et al.; Optical: NASA/STScI