2016-07-26

Some terrific images of galaxies have appeared recently in various media, providing an opportunity to share a few with SpaceRip visitors.

Meet “Mike”

The Hubble Space Telescope has produced countless photos of galaxies large and small, spirals and ellipticals, deep in space and drifting relatively nearby.  The one below, released last Friday, presents the striking visage of an interesting spiral.



Galaxy MCG+07-33-027 creates stars at a prodigious pace. [Image credit: ESA/Hubble & NASA and N. Grogin (STScI)]

The galaxy is catalogued as MCG+07-33-027, but let’s just call it “Mike.”  Located roughly 300 million light years from here, Mike is categorized as a “starburst” galaxy, because, for reasons not clearly understood, it is producing new stars perhaps a hundred times faster than an average galaxy.  Its many star-forming regions (in blue) are wrapped tightly around the bright core and extend out through the galaxy’s spiral arms.  The foreground star from the Milky Way and the numerous background galaxies add to the image’s appeal.

Call the Cosmic Cops

Somebody’s getting robbed!  The victim, LEDA 677373 (below), is a dwarf galaxy on the edge of the Local Group lying about 14 million light years from Earth.



LEDA 677373 is a victim of cosmic theft. (Image credit: ESA/Hubble & NASA)

Using Hubble to study LEDA’s individual stars at different wavelengths of light, astronomers have calculated that the galaxy is approximately six billion years old.  They also know that it has plenty of gas to have created many more stars than have actually ignited during that time.  So, the question is what has held LEDA up?  Investigators have now pointed their fingers at a prime suspect, Messier 83, a giant spiral galaxy (not shown) that skulks nearby and absconds with enough of LEDA’s gas to prevent it from forming the stars to which it is entitled.

A 3-D Road Map of Galaxies

What would happen if you were to combine the artistic tenets of pointillism and abstract expressionism with the scientific rigor of astronomy?  Maybe something like this:



48,741 galaxies are mapped in this image. (Image credit: Daniel Eisenstein & the SDSS-III Collaboration)

As part of an effort to better understand dark energy and how it might be accelerating the expansion of the Universe, more than 100 astronomers from the Sloan Digital Sky Survey III and the Max Planck Institutes for Extraterrestrial Physics and Astrophysics have plotted the positions of over one million galaxies up to six billion light years away.  One slice of the survey – galaxies occupying approximately 5% of the night sky – is represented in the astonishing image that the collaborators released last week.  The different colors of the dots represent the galaxies’ relative distance from Earth, thus suggesting a three-dimensional view:  yellow dots are closer, red are at an intermediate distance, and purple are up to six billion light years away.

“We have spent a decade collecting measurements of 1.2 million galaxies over one quarter of the sky to map out the structure of the universe over a volume of 650 cubic billion light-years.” – Dr. Jeremy Tinker, New York University

Hubble Takes a Deep View into Leo

Finally, let’s open the aperture and take a very deep field view into the constellation Leo.  Over 10,000 galaxies appear in a Hubble image (below) from the Frontier Fields campaign.  To snap the picture, astronomers aimed Hubble’s cameras at galaxy cluster MACS J1149.5+2223.  One camera focused on the cluster itself, while another captured this “parallel field” image that astronomers will use as a reference to compare to other field views, which will help clarify how the Universe looks from different directions.  As for us, we can just sit back and enjoy the view at our leisure.

Galaxy cluster viewed through the constellation Leo. (Image credit: ESA/Hubble & NASA, Acknowledgement: Judy Schmidt)

The post Galaxies on Parade! appeared first on SpaceRip: Fresh Perspectives on Space & Astronomy.

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