Make no mistake. The galactic centre is a fascinating place. Some of the densest interstellar environments in the galaxy, populated by some of the most massive stars. Supernova remnants, strewn about like streamers after a New Year’s celebration, decorate the home of the galaxy’s supermassive black hole, Sagittarius A*. 4 million solar masses, holding our entire galaxy in its gravitational grip.
A nice little picture of this is shown here in an image courtesy of the Chandra X-ray Observatory – as a map. You see, we have no idea what the galactic core actually looks like in visible light. From our vantage point here, adrift in one of the Milky Way’s spiral arms, there’s a thick swathe of dust and stars in our way. That’s where x-rays come in.
X-rays pass through all of that dust as easily as sunlight passes through a window, giving Chandra a nice clear view. Nice and clear, but also quite faint. X-ray astronomers don’t have a lot of photons to work with, so the data that make up this image came from about one million seconds of observation time – it’s effectively a two week exposure!
This gives a lovely view of the galactic centre, showing several of the main features, such as the Arches cluster and, of course, Sagittarius A – with the (much smaller) black hole itself lurking at its heart.
Credit for the awesome image goes to NASA/CXC/MIT/F.K. Baganoff et al. I try not to use the word awesome lightly when writing here, but in this case? Seriously. This image is awe inspiring.
With a tip of the hat to Lauren at the marvellous Science in a Can.