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 data astronomers 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

Multi-Wavelength Astronomy


These four images show the Whirlpool Galaxy (aka M51) in different wavelengths of light.

View A uses visible light data from the 2.1-m telescope at the Kitt Peak National Observatory. View B combines two visible light wavelengths, 400 nm (blue) and 700 nm (green) with infrared data from the Spitzer Space Telescope. The IR data is shown in red.

Views C and D are false color images assembled using more IR data from Spitzer. C uses data from three wavelengths—8 µm (red), 4.5 µm (green), and 3.6 µm (blue). The galaxy’s stars shine brightly in the shorter (“blue”) IR wavelengths, while the cooler interstellar dust glows red in the false color image. D add longer 24 µm data (also in red).

Image Credit: NASA

Serpens Cloud Core


Serpens Cloud CoreStars that are just beginning to coalesce out of cooling swaths of dust and gas can be seen in this image from the Spitzer Space Telescope and the Two Micron All Sky Survey (2MASS). Different wavelengths of infrared light has been color-coded, revealing young stars in orange and yellow, and a central cloud of gas in blue. This area is obscured in visible-light, but infrared light can travel through the dust, allowing a peek inside the stellar hatchery, but the dark region to the left of center is surrounded by so much dust that the infrared light is blocked also. Stars are just beginning to form in such dark spaces.

This star-forming region is called the Serpens Cloud Core. It’s located about 750 light-years away in Serpens (the Serpent), a constellation named after its resemblance to a snake. The region is noteworthy because it only contains stars of relatively low to moderate mass and lacks any of the massive and incredibly bright stars found in larger star-forming regions like the Orion nebula. The Sun is a moderate-mass star.

Image Credit: NASA

W40


This red butterfly in space is a nebula, a giant cloud of gas and dust officially cataloged as W40. The “wings” of the butterfly are giant bubbles of gas being blown out by massive stars. The formation of those stars resulted in the destruction of the very cloud that helped create them. Stars form inside giant clouds of gas and dust as the force of gravity pulls material together into dense clumps. When a clump of matter reaches a critical density a star is born. Radiation and winds coming from the massive stars in W40 have blow  cosmic bubbles dispersing the gas and dust, breaking up smaller clumps of matter, and reducing or halting new star formation.

Image Credit: NASA

The Crab Nebula


In 1054, observers around the world reported the appearance of a “new star” in the direction of the constellation Taurus. The remnant of that supernova is called the Crab Nebula, and it is powered by a quickly spinning, highly magnetized neutron star called a pulsar. The pulsar was formed when the massive star ran out of its nuclear fuel and collapsed. The combination of rapid rotation and a strong magnetic field in the Crab generates an intense electromagnetic field that creates jets of matter and anti-matter moving away from both the north and south poles of the pulsar and an intense wind flowing out in the equatorial direction.

This composite image of the nebula was created with data from the Chandra X-ray Observatory (blue and white), the Hubble Space Telescope (purple), and the Spitzer Space Telescope (pink).

Image Credit: NASA

A Magnetic Cigar


This is a composite image of the Cigar Galaxy (aka M82), a starburst galaxy about 12 million light-years away in the constellation Ursa Major. It combines visible starlight (gray) and a tracing of hydrogen gas (red) from the Kitt Peak Observatory, with near-infrared and mid-infrared starlight and dust (yellow) from SOFIA (a NASA telescope mounted on 747 which does infrared astronomy flying above most of the atmosphere) and the Spitzer Space Telescope.. A magnetic field detected by SOFIA shows up in the image as streamlines which seem to follow the outflows (red) generated by the burst of star formation in the nucleus of the galaxy.

Image Credits: NASA / SOFIA / E. Lopez-Rodriguez and Spitzer / J. Moustakas et al.