Visions of Future Past

ngc2207Over next couple of billion years, these two spiral galaxies will end up in a complete galactic merger—the two galaxies will become a single, larger one. They’re about 150 million light-years away in the constellation of Canis Major (the Great Dog), so what we can see now is what was happening 150 million years ago.

The gravitational attraction of NGC 2207, the larger of the pair, is already stirring things up throughout its smaller partner, distorting IC 2163’s shape and throwing stars and gas into long streamers that extend over 100,000 light-years. However, most of the space between stars in a galaxy is empty. When these galaxies collide, almost none of the stars in them will crash into another star.

This 150 million old image is a vision of the Milky Way’s future. About the time NGC 2207 and IC 2163 have finished their merger, the Milky Way will begin colliding with the Andromeda Galaxy.

Image Credit: ESO

Cool Andromeda

Cool_AndromedaThis view of the Andromeda galaxy from the Herschel space observatory shows relatively cool lanes of forming stars. Herschel was sensitive to the far-infrared light from cool dust mixed in with the gas where stars are born. This image reveals some of the very coldest dust in the galaxy (colored red here) that is only a few tens of degrees above absolute zero. Warmer regions such as the densely populated central bulge, home to older stars, appear as blue. Star-formation zones are in the spiral arms with several concentric rings interspersed with dark gaps where star formation is absent.

Andromeda (aka M31) is the nearest major galaxy to our own Milky Way about 2.5 million light-years away. Herschel was a European Space Agency mission active from 2009 to 2013.

Image Credit: ESA

Andromeda in UV

AndromedaGalex_900Andromeda Galaxy (aka M31) is just next door as large galaxies go, only about 2.5 million light-years. So close and spanning some 260,000 light-years, it took 11 images from the Galaxy Evolution Explorer (GALEX) satellite’s telescope to produce this portrait of the spiral galaxy in ultraviolet light. While its spiral arms stand out in visible light images, they look like rings in UV because the image is dominated by light from hot, young, massive stars. As sites of intense star formation, the rings have been interpreted as evidence Andromeda collided with its smaller neighboring elliptical galaxy M32 more than 200 million years ago.

Image Credit: NASA

A UV View of Andromeda

This mosaic of M31 merges 330 individual images taken by the Ultraviolet/Optical Telescope aboard the Swift spacecraft. It is the highest-resolution image of the galaxy ever recorded in the ultraviolet. Also known as the Andromeda Galaxy, M31 is more than 220,000 light-years across and lies 2.5 million light-years away. On a clear, dark night, the galaxy is faintly visible as a misty patch to the naked eye.

The irregular shape of the image results when the more than 300 images were assembled to make the final image.

There are three instruments on Swift—a UV telescope, an X-ray telescope, and the Burst Alert Telescope which serves as the gamma ray burst detector for the spacecraft. I contributed to the design of the ultra-quiet regulators powering the detector blocks in the BAT.

Image Credit: NASA /Swift / Stefan Immler (GSFC) and Erin Grand (UMCP)

Andromeda (1899)

Andromeda_1899This picture of the Andromeda galaxy (also known as Messier 31 or M31) was made by astronomer Isaac Roberts in 1899. The first photographs of that galaxy were taken a couple of years earlier in 1887 by Roberts from his private observatory in Sussex, England. At the end of the 19th-century, M31 was still commonly believed to be a nebula within the Milky Way, and Roberts mistakenly believed that it and similar spiral nebulae were actually solar systems being formed.

Image Credit: Public Domain

X-ray Sources in Andromeda

Andromeda NUSTARThe Nuclear Spectroscopic Telescope Array (or NuSTAR) has captured the best high-energy X-ray view yet of a band across Andromeda, our nearest large, neighboring galaxy. The satellite has observed 40 “X-ray binaries,” intense sources of X-rays comprised of a black hole or neutron star that feeds off a stellar companion.

Image Credit: NASA

Andromeda in UV

AndromedaGalex_900Andromeda Galaxy (aka M31) is just next door as large galaxies go, only about 2.5 million light-years. So close and spanning some 260,000 light-years, it took 11 images from the Galaxy Evolution Explorer (GALEX) satellite’s telescope to produce this portrait of the spiral galaxy in ultraviolet light. While its spiral arms stand out in visible light images, they look like rings in UV because the image is dominated by light from hot, young, massive stars. As sites of intense star formation, the rings have been interpreted as evidence Andromeda collided with its smaller neighboring elliptical galaxy M32 more than 200 million years ago.

Image Credit: NASA

Mergers and Acquistions

This animation depicts the predicted collision between our galaxy (The Milky Way) and our larger neighbor, the Andromeda galaxy. The two are being pulled together by their mutual gravity, and will crash together about 4 billion years from now. Later, around 6 billion years from now, the two galaxies will merge. The video also shows a third galaxy (the Triangulum) which will join in the pill up and may wind up merging with the Andromeda/Milky Way pair.

[youtube http://www.youtube.com/watch?v=fMNlt2FnHDg]

Video Credit: NASA

Infrared Andromeda

infrared_andromedaThe Andromeda galaxy is the largest nearby galaxy. It’s about twice the diameter of our Milky Way and only about 2.5 million light years away. Given a dark, clear sky, it’s visible to the naked eye. This false-color image is from infrared data taken by the Spitzer Space Telescope. It was assembled from around 3,000 separate frames.

Image Credit: NASA

A Journey to the Center of a Galaxy

This video contains with the sharpest visible-light image ever made of the nucleus of an external galaxy. Beginning with a naked eye sky view, the zoom goes into the nucleus of our neighbor, the Andromeda Galaxy and ends with a Hubble Space Telescope image that centers on the 100-million-solar-mass black hole at the core of the galaxy with its collection of young blue stars.

[youtube http://www.youtube.com/watch?v=tsTODjZGM58]

Video Credit: NASA

Cool Andromeda

Cool_AndromedaThis view of the Andromeda galaxy from the Herschel space observatory shows relatively cool lanes of forming stars. Herschel is sensitive to the far-infrared light from cool dust mixed in with the gas where stars are born. This image reveals some of the very coldest dust in the galaxy (colored red here) that is only a few tens of degrees above absolute zero. Warmer regions such as the densely populated central bulge, home to older stars, appear as blue. Star-formation zones are in the spiral arms with several concentric rings interspersed with dark gaps where star formation is absent.

Andromeda (aka M31) is the nearest major galaxy to our own Milky Way about 2.5 million light-years away. Herschel is a European Space Agency mission.

Image Credit: ESA