A 3D View of a Galactic Merger

This animation shows a #D rendering of a gas halo observed by ESO’s Very Large Telescope superimposed over an older image of a galaxy merger obtained with ESO’s Atacama Large Millimeter Array. The halo of hydrogen gas is shown in blue, and the ALMA data is shown in orange. The halo is bound to the galaxy, which contains a quasar at its center. The gas in the halo provides the perfect food source for the supermassive black hole at the centre of the quasar.

The redshift on these objects is 6.2, meaning we see them as they were 12.8 billion years ago.

Video Credit: ESO

A Cosmic Pretzel

The Atacama Large Millimeter/submillimeter Array (ALMA) has obtained an extremely high-resolution image showing two disks in which young stars are growing, fed by a complex pretzel-shaped filaments of gas and dust. The two baby stars which will likely wind up as a binary system were found in the [BHB2007] 11 system which is part of the clouds of interstellar dust called the Pipe Nebula.

Image Credit: ESO

A Protostar

Infant Star’s First StepsThis false color image from the Atacama Large Millimeter/submillimeter Array shows a pair of immense jets of dense gas with near-perfect symmetry radiating from a single source at the center of the picture. They’re coming from an extremely young star—a protostar—that is in the early stages of becoming a star much like the Sun. The baby star, known as CARMA-7, and its jets are located around 1,400 light-years from Earth in the Serpens South star cluster. That dense cluster is home to at least 30 more protostars that are being formed in close proximity to one another.

Image Credit: ESO

NGC 1433

Composite_NGC_1433This detailed view shows the central parts of the nearby active galaxy NGC 1433. The dim blue background image, showing the central dust lanes of this galaxy, comes from the Hubble Space Telescope. The other colored structures near the middle of the image are from ALMA observations. ALMA is the Atacama Large Millimeter/sub-millimeter Array, an astronomical interferometer of radio telescopes in the Atacama desert of northern Chile.

Image Credit: ESO / NASA / ESA

A Microquasar

This is SS 433, a microquasar located about 18,000 light-years away in the constellation Aquila. This image at submillimeter wavelengths is special because it shows the jets emitted by a hot, swirling disc of material around the black hole at SS 433’s center. The jets’ corkscrew shapes are created by a phenomenon known as precession. The two jets are slowly wobbling about their spin axes in the same manner as a spinning top as it slows down. The corkscrew is enormous—5000 times the size of the Solar System.

Image Credit: ESO


Seeing into the Heart of Mira A and its PartnerMain sequence stars such as the Sun wind up as red giants. Studying red giant stars tells astronomers about the future of the Sun (in a few billion years). It also tells us about how previous generations of stars spread the elements needed for life across the Universe. One of the most famous red giants in the sky is called Mira A, part of the binary system Mira about 400 light-years from Earth.

Mira A is an old star, already spewing out the products of its life’s work into space for recycling. Mira B, Mira A’s companion, orbits A at twice the distance from the Sun to Neptune.

Mira A is known to have a slow stellar wind which gently moulds the surrounding material. Mira B is a hot, dense white dwarf with a fierce and fast stellar wind. Recent observations at millimeter wavelengths show how the interaction of the stellar winds from the two stars have created a complex nebula. The bubble at the centre is created by Mira B’s energetic wind inside Mira A’s more relaxed outflow. The heart-shaped bubble, formed some time in the last 400 years or so, is a relatively young object in astronomical terms.

Image Credit: ESO / S. Ramstedt (Uppsala University, Sweden) & W. Vlemmings (Chalmers University of Technology, Sweden)

HH 46/47

HH 46:47This picture was assembled from combined observations from NASA’s Spitzer Space Telescope and ESO’s Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. It reveals the throes of stellar birth in an object known as HH 46/47.

HH or Herbig-Haro objects form when particle jets shot out by newborn stars collide with surrounding matter, producing small, bright, nebulous regions. The dynamics within many HH objects are obscured from observation with visible light by the enveloping gas and dust, but the infrared and submillimeter light seen by Spitzer and ALMA, respectively, cuts through the cloud around HH 46/47. (Infrared light has longer wavelengths than what we see with our eyes, and submillimeter wavelengths are longer still.)

In this false-color image the shorter-wavelength light appears blue and longer-wavelength light, red. Blue shows gas energized by the outflowing jets. Green traces a combination of hydrogen gas molecules and dust that follows the boundary of the gas cloud surrounding the young star. The red areas are excited carbon monoxide gas.

Image Credit: NASA / ESO

The Heart of the Galaxy

This image resembles red ink filtering through water or a crackling stream of electricity, but it is actually a view of our cosmic home. It’s the central plane of the Milky Way as seen by ESA’s Planck satellite and the Atacama Pathfinder Experiment (APEX) operated at an altitude of around 5100m in the Chilean Andes by the European Southern Observatory. While APEX is best at viewing small patches of sky in great detail, Planck data is ideal for studying areas of sky at the largest scales. The two data sets complement each other and offer a unique perspective on the sky.

The bright pockets scattered along the galactic plane this view are compact sources of submillimetre radiation: very cold, clumpy, dusty regions that may are being studied for information on multiple questions ranging from how individual stars form to how the entire Universe is structured. From right to left, notable sources include NGC 6334 (the rightmost bright patch), NGC 6357 (just to the left of NGC 6334), the galactic core itself (the central, most extended, and brightest patch in this image), M8 (the bright lane branching from the plane to the bottom left), and M20 (visible to the upper left of M8).

Image Credit: ESA / ESO

Making Planets

ALMA image of the protoplanetary disc around HL TauriThis image from the Atacama Large Millimeter/submillimeter Array at the European Souther Observatory in Chile reveals extraordinarily fine detail that has never been seen before in the planet-forming disc around a young star, in this case, HL Tauri. This is one of the sharpest pictures ever made at submillimetre wavelengths. It’s an enormous step forward in the observation of how protoplanetary discs develop and how planets form.

HL Tauri’s disc appears much more developed than would be expected from the age of the system, suggesting that the planet-formation process may be faster than previously thought. Young stars are born in clouds of gas and fine dust which have collapsed under the effects of gravitation. The dense hot cores eventually ignite to become young stars. These young stars are initially cocooned in the remaining gas and dust, which eventually settles into a protoplanetary disc.

Image Credit: ESO

Acquisitions and Mergers

This video starts with data from a survey of galaxies (blue and green) done by ESA’s Herschel Space Observatory and zooms in on a source that astronomers found interesting. The zooming in continues using observations performed with the Atacama Pathfinder Experiment (APEX; red). Finally, the video shows further observations obtained with the Atacama Large Millimeter/submillimeter Array (ALMA) at higher resolution. Those observations revealed that the interesting source isn’t an ancient, massive galaxy, but of a pair of distinct massive galaxies about to merge. These two galaxies, each roughly as massive as our Milky Way, were informally dubbed the ‘Horse’ and the ‘Dragon’.

Video Credit: ESA

Stellar Explosions in Orion

Stellar explosions are usually associated with supernovae, the spectacular deaths of stars. New ALMA observations of the Orion Nebula provide insights into explosions at the other end of the stellar life cycle, star birth. This image shows the remains of a 500-year-old explosion from the birth of a group of massive stars; star formation can be a violent and explosive process too.

The colors in the ALMA data represent the relative Doppler shifting of the millimetre-wavelength light emitted by carbon monoxide gas. Blue data represents gas approaching at the highest speeds; the red data is from gas moving toward us more slowly.

The millimetre wave data is superimposed over optical and near-infrared images from the Gemini South and the ESO Very Large Telescope. The famous Trapezium Cluster of hot young stars appears towards the bottom of this image. The ALMA data only covers the central portion of the picture.

Image Credit: ESO

A Hole in the Cosmic Microwave Background

The Cosmic Microwave Background (CMB) in the afterglow of the Big Bang. Why would this cluster of galaxies punch a hole in it? The CMB flows right through most of the gas and dust in the universe. It is all around us. However, large clusters of galaxies have enough gravity to contain gas hot enough to up-scatter the CMB photons into light of significantly higher energy, creating “holes” in the CMB. This is known as the Sunyaev–Zel’dovich (SZ) effect, and it’s used for decades to study the hot gas in clusters. This picture combines CMB data from ESO’s ALMA with imagery from the Hubble Space Telescope to measure the galaxies in the massive galaxy cluster RX J1347.5-1145. False-color blue shows light from the CMB; almost every yellow object is a galaxy. The shape of the SZ hole indicates not only that hot gas is present in this galaxy cluster, but also that it is distributed in a surprisingly uneven manner.

Image Credit: ESO / ESA / NASA