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Sculpting a Galaxy

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in Sculptor

Wow!  Take a look at this beauty of an image from the European Southern Observatory’s VISTA telescope.

ESO VISTA's view of the galaxy NGC 253, which lies about 13 million light-years from Earth. Click to massively galacticate. Courtesy ESO/J. Emerson/VISTA. Acknowledgment: Cambridge Astronomical Survey Unit.

What you’re seeing here is a VISTA view of the galaxy NGC 253, a.k.a. the Sculptor Galaxy, found in the constellation Sculptor (visible in Southern Hemisphere skies).  VISTA looked at this galaxy in infrared light, which gave it a great view of the rich collection of dust clouds that thread through the spiral arms of the galaxy. These dust clouds are where star formation takes place.  In fact, NGC 253 is a starburst galaxy, one that has undergone waves of star formation.  Tracing the dust clouds and bursts of starbirth allows astronomers to understand the formation history of the galaxy and the actions that have shaped it into the barred spiral we see today.

The telescope also was able to see a population of cool, red stars that aren’t very visible (if at all) in optical wavelengths of light (which are the main wavelengths our eyes can see).    This is what infrared viewing allows astronomers to do — that is, to peer through the veils of dust that hide the details of the Sculptor Galaxy. Now they can study in deeper detail the myriad of cool red giant stars in the halo that surrounds the galaxy, and measure the composition of some of NGC 253’s small dwarf satellite galaxies. And, they can search for new objects such as globular clusters and ultra-compact dwarf galaxies that would otherwise be invisible without the deep VISTA infrared images.

I remember some years ago when we first started seeing boasts by ground-based observatories that, using new (at the time) technologies such as adaptive optics, astronomers would be able to achieve “near-Hubble” quality observations of such things as the Sculptor Galaxy.  Images like this, from a ground-based observatory in Chile, show that it can be done.  And, the exciting part is that using observatories like this and the newly improved Hubble Space Telescope, our view of the cosmos is only going to get better!

astronomy, evolution of galaxies, galaxies, galaxy interactions, galaxy shapes

View from a Distance

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Galaxy Beauty

What if you could move anywhere in the cosmos just to get a good view? Where would you go? The view from our own planet takes in the interior of our own galaxy, plus a healthy look out to intergalactic space. We can see, literally, for billions of  light-years, provided we use the right instruments.  But, what if you could live on a world at the rim of a distant galaxy that was overlooking a pair of interacting galaxies?  What you like this to be your view?

NGC 1532/1 as seen by ESOs 1.5-meter Danish Telescope. (Click to embiggen.)
NGC 1532/1 as seen by ESO's 1.5-meter Danish Telescope. (Click to embiggen.)

This is a pair of galaxies called NGC 1531/2 and they lie about 70 million light-years away from Earth. From this point of view, we can tell they are interacting in a sort of spirited galactic waltz. The spiral galaxy in the foreground is being warped by its dance with the smaller galaxy just above it. The cosmic dance leads to another dramatic effect: a whole new generation of massive stars that were created in the chaos of collision during the dance.  They are visible as the purple objects in the spiral arms.

This view from your living room window on that distant planet I mentioned above is really an exquisite image from the European Southern Observatory. It was made by R. Gendler and J.-E. Ovaldsen who used the 1.5-meter Danish telescope to capture the image.

I often wish we had dramatic views like this from our own back yards here on Earth rather than the skies we do have. On the other hand, using telescopes like the ones at ESO, we really kinda do.  So, enjoy!!