The Galactic Core

galactic coreWhen we look inward toward the center of the Milky Way, the galactic core is obscured in visible light by intervening dust clouds, but infrared light penetrates the dust. This composite false-color infrared image of the center of our galaxy reveals a new population of massive stars and new details in complex structures in the hot ionized gas swirling around the central 300 light-years.It combines the sharp imaging of the Hubble Space Telescope‘s Near Infrared Camera and Multi-Object Spectrometer (NICMOS) with color imagery from a previous Spitzer Space Telescope survey done with its Infrared Astronomy Camera (IRAC).

In this new data astronomers now see that the massive stars are not confined to one of the three known clusters of massive stars in the Galactic Center, known as the Central cluster, the Arches cluster, and the Quintuplet cluster. These three clusters are easily seen as tight concentrations of bright, massive stars in the image. The unattached stars may have formed in isolation, or they may have originated in clusters that have been disrupted by strong gravitational tidal forces.

The winds and radiation from these stars form the complex structures seen in the core, and in some cases, they may be triggering new generations of stars. IN the upper left large arcs of ionized gas form linear filaments suggesting the influence of locally strong magnetic fields.

The lower left region shows pillars of gas sculpted by winds from hot massive stars in the Quintuplet cluster.

Near the center of the image ionized gas surrounding the supermassive black hole at the center of the galaxy is confined to a bright spiral embedded in a circum-nuclear dusty donut-shaped torus.

Image Credit: NASA / ESA

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