Hubble’s New Infrared Mosaic is the Best Picture of Our Galactic Center Ever

Behold, your galactic center. This Hubble image, captured with the space telescope’s Near Infrared Camera and Multi-Object Spectrometer (NICMOS), is the highest-resolution pic of the Milky Way’s galactic center taken to date, taking in a newly discovered group of massive stars, lots of super-hot gas, and roughly 35,000 square light years of space in one sweeping mosaic.
But naturally this image goes far beyond simply being aesthetically pleasing. The galactic center is obscured from our view by gas and dust, but Hubble’s infrared camera can peer through that dense, swirling detritus and focus in on the various structures and processes taking place at our galaxy’s core. That in turn makes it a kind of laboratory in which astronomers can observe and draw conclusions about what’s happening not just in the Milky Way but in other galactic hubs around the universe.
The ambient red glow is produced by ionized hydrogen gas, but amidst that you can clearly see plenty of massive stars distributed across the panorama—a finding that is relatively new for astronomers who thought most of the massive stars at the galaxy’s center were confined into three general clusters. And if you look really hard, you can see the supermassive black hole that sits at the very center of our galaxy, surrounded by a spiral of swirling gas.
See it? Maybe you need the super-enlarged wallpaper quality version.

Source: Popsci.com

Hubble’s New Infrared Mosaic is the Best Picture of Our Galactic Center Ever

Behold, your galactic center. This Hubble image, captured with the space telescope’s Near Infrared Camera and Multi-Object Spectrometer (NICMOS), is the highest-resolution pic of the Milky Way’s galactic center taken to date, taking in a newly discovered group of massive stars, lots of super-hot gas, and roughly 35,000 square light years of space in one sweeping mosaic.

But naturally this image goes far beyond simply being aesthetically pleasing. The galactic center is obscured from our view by gas and dust, but Hubble’s infrared camera can peer through that dense, swirling detritus and focus in on the various structures and processes taking place at our galaxy’s core. That in turn makes it a kind of laboratory in which astronomers can observe and draw conclusions about what’s happening not just in the Milky Way but in other galactic hubs around the universe.

The ambient red glow is produced by ionized hydrogen gas, but amidst that you can clearly see plenty of massive stars distributed across the panorama—a finding that is relatively new for astronomers who thought most of the massive stars at the galaxy’s center were confined into three general clusters. And if you look really hard, you can see the supermassive black hole that sits at the very center of our galaxy, surrounded by a spiral of swirling gas.

See it? Maybe you need the super-enlarged wallpaper quality version.

Source: Popsci.com

This zoom video sequence starts with the spectacular view of the central parts of the Milky Way. As we close in on the constellation of Scorpius, one of the richest parts of the sky, many clusters and nebula appear. The final sequence closes in on an apparently unremarkable star, IRAS 17163-3907, which has been found by recent VLT observations to be a rare yellow hypergiant star, surrounded by two shells.

VISTA Finds 96 Star Clusters Hidden Behind Dust
ESO’s infrared survey telescope digs deep into star-forming regions in our Milky Way
Using data from the VISTA infrared survey telescope at ESO’s Paranal Observatory, an international team of astronomers has discovered 96 new open star clusters hidden by the dust in the Milky Way. These tiny and faint objects were invisible to previous surveys, but they could not escape the sensitive infrared detectors of the world’s largest survey telescope, which can peer through the dust. This is the first time so many faint and small clusters have been found at once.
Keep reading.

VISTA Finds 96 Star Clusters Hidden Behind Dust

ESO’s infrared survey telescope digs deep into star-forming regions in our Milky Way

Using data from the VISTA infrared survey telescope at ESO’s Paranal Observatory, an international team of astronomers has discovered 96 new open star clusters hidden by the dust in the Milky Way. These tiny and faint objects were invisible to previous surveys, but they could not escape the sensitive infrared detectors of the world’s largest survey telescope, which can peer through the dust. This is the first time so many faint and small clusters have been found at once.

Keep reading.

APOD: Kona Galaxy Garden
Credit & Copyright: Garden by Jon Lomberg; Kite Aerial Photography by Pierre and Heidy Lesage
Explanation: How does your galaxy grow? Quite contrary to a typical galaxy, this one needs water to flourish. Pictured above as it appears at the Paleaku Peace Gardens Sanctuary in Kona, Hawaii, USA, a meticulously planned garden spanning about 30 meters provides a relatively accurate map of our Milky Way Galaxy. Different plants depict stars, globular clusters, and even nebulas. Many bright stars visible in Earth’s night sky are depicted on leaves surrounding the marked location of the Sun. Plant rows were placed to represent arms of our Galaxy, including the Sun’s Orion Arm, the impressive Sagittarius Arm, and the little discussed Norma Arm. A small bar runs through our Galaxy’s center, while a fountain has been built to represent represents the central black hole. What a stellar use of space!
Vitor/bumerangue: Is this awesome or what? Official Galaxy Garden website here.

APOD: Kona Galaxy Garden

Credit & Copyright: Garden by Jon Lomberg; Kite Aerial Photography by Pierre and Heidy Lesage

Explanation: How does your galaxy grow? Quite contrary to a typical galaxy, this one needs water to flourish. Pictured above as it appears at the Paleaku Peace Gardens Sanctuary in Kona, Hawaii, USA, a meticulously planned garden spanning about 30 meters provides a relatively accurate map of our Milky Way Galaxy. Different plants depict stars, globular clusters, and even nebulas. Many bright stars visible in Earth’s night sky are depicted on leaves surrounding the marked location of the Sun. Plant rows were placed to represent arms of our Galaxy, including the Sun’s Orion Arm, the impressive Sagittarius Arm, and the little discussed Norma Arm. A small bar runs through our Galaxy’s center, while a fountain has been built to represent represents the central black hole. What a stellar use of space!

Vitor/bumerangue: Is this awesome or what? Official Galaxy Garden website here.

Expanding on a News Story: Fermi Bubbles

Recently, there’s been a lot of buzz in the astronomy community about the recent discovery of gamma-ray bubbles over the center of our galaxy. Above is an illustration from the press release depicting the bubbles, which were discovered by NASA’s Fermi space telescope. [See the original IFOS post here. See the paper for this discovery here.] The discovery was made by using the highest-resolution gamma-ray detectors ever created, and exposing them to the center of the Milky Way for a total of 1.6 years (done in shifts). Below is the sciencey photo:

There are a few problems, though, that have people scratching their heads. First of all, according to the paper, the “bubbles” are of uniform density. This is a problem because when you look at a sphere, there is more matter in the center and less at the edges, just because of how spheres are shaped.

You’d expect to see a concentration of density near the center, but such a thing is not present in the Fermi bubbles. So what does this mean? Either the gas “bubble” happens to grow more diffuse (the opposite of dense) near the center (which is a convoluted but completely possible theory) or the “bubbles” are in fact flat discs. Why would two flat discs be positioned so perfectly that they are exactly perpendicular to our line of sight? It’s possible that that could happen, but the chances are so unlikely that it’s hard to believe. Those who made the discovery are not sure why the data shows this. [If you’re interested in reading more, check out Section 3 in the paper, specifically pp. 11-13 and Fig. 10.]

There are a few plausible theories as to what these structures could possibly be. When matter falls into an active black hole, relativistic jets shoot out of either one or both of the black hole’s rotational poles.

This happens because when matter is falling into a black hole, it circles the black hole in a thing called an accretion disc, which is not unlike when water circles the drain in your sink. This whole process creates a massive amount of energy due to friction, which escapes in the form of the relativistic jets. Not all black holes have relativistic jets, though. They can enter a state called “quiescence”, where the matter in the accretion disc reaches a kind of uniformity of flow that allows for the energy to stay in the disc instead of escaping.

The black hole supposedly at the center of our galaxy is expected to be quiescent, which is why we wouldn’t expect to find any structures like the Fermi bubbles hovering over the center. It’s been suggested [source] that these bubbles are a remnant of former jets from our black hole, which is quite possible. The structures are very faint; it took 1.6 years worth of exposure to find them.

Another possible explanation is that they’re the remnant of a period of rapid star formation, which releases a lot of energy. The structures have sharp edges [as per the paper and the press release], meaning that the energy was released around the same time. A burst of star formation would explain this well.

At this point, we can only speculate about the Fermi bubbles, but they and their implications will surely be highly studied in years to come.

[By Carly; email me here or drop a line in the ask box.]

Using data from NASA’s Fermi Gamma-ray Space Telescope, scientists have recently discovered a gigantic, mysterious structure in our galaxy. This feature looks like a pair of bubbles extending above and below our galaxy’s center. Each lobe is 25,000 light-years tall and the whole structure may be only a few million years old.
Read more and watch animation here.
Click image for larger version.

Using data from NASA’s Fermi Gamma-ray Space Telescope, scientists have recently discovered a gigantic, mysterious structure in our galaxy. This feature looks like a pair of bubbles extending above and below our galaxy’s center. Each lobe is 25,000 light-years tall and the whole structure may be only a few million years old.

Read more and watch animation here.

Click image for larger version.