From ALMA (CL): “Undergraduate Researcher Captures Young Galaxy’s ‘Coming of Age’ and Finds Evidence That Early Galaxies May Be Bigger and More Complex Than We Thought” Revised to add link to science paper

From ALMA (CL)

Nicolás Lira
Education and Public Outreach Coordinator
Joint ALMA Observatory, Santiago – Chile
Phone: +56 2 2467 6519
Cell phone: +56 9 9445 7726

Junko Ueda
Public Information Officer

Bárbara Ferreira
ESO Public Information Officer
Garching bei München, Germany
Phone: +49 89 3200 6670

Amy C. Oliver
Public Information & News Manager
National Radio Astronomical Observatory (NRAO), USA
Phone: +1 434 242 9584

All general references:
ALMA Observatory (CL)

European Southern Observatory(EU)

National Astronomical Observatory of Japan(JP)

National Radio Astronomy Observatory(US)
Full identification of an astronomical asset will be presented once in the first instance of that asset.

A1689-zD1 is a star-forming galaxy located in the Virgo constellation cluster. It was first observed thanks to gravitational lensing from the Abell 1689 galaxy, which made the young galaxy appear nine times more luminous. New observations made using the Atacama Large Millimeter/submillimeter Array (ALMA) are revealing to scientists that the young galaxy, and others like it, may be bigger and more complex than originally thought. Credit: ALMA (ESO/NAOJ/NRAO)/H. Akins (Grinnell College), B. Saxton (NRAO/AUI/NSF)

This composite combines radio images of A1689-zD1, captured using the Atacama Large Millimeter/submillimeter Array (ALMA), shown in orange/red, with optical images from the Hubble Space Telescope (HST), shown in blue/white. In the context of its surroundings, it becomes clear how A1689-zD1 managed to “hide out” behind Abell 1689, and why gravitational lensing— the magnification of the young galaxy— are critical to studying its behaviors and processes. Credit: ALMA (ESO/NAOJ/NRAO)/H. Akins (Grinnell College), HST, B. Saxton (NRAO/AUI/NSF)

This artist’s conception illustrates the previously unknown complexity of the young galaxy, A1689-zD1. Reaching far beyond the center of the galaxy, shown here in pink, is an abundant halo of cold carbon gas. For scientists, this uncommon feature indicates that the galaxy may be much larger than previously believed and that early stages of normal galaxy formation may have been more active and dynamic than theorized. To the upper left and lower right are outflows of hot, ionized gas pushing outward from the center of the galaxy, shown here in red. Scientists believe it is possible that these outflows have something, though they don’t yet know what, to do with the presence of cold carbon gas in the outer reaches of the galaxy. Credit: ALMA (ESO/NAOJ/NRAO), B. Saxton (NRAO/AUI/NSF)

A1689-zD1 is a young, star-forming galaxy located in the Virgo constellation cluster, roughly 13 billion light-years away from Earth. Credit: IAU/Sky & Telescope

Scientists using the Atacama Large Millimeter/submillimeter Array (ALMA) have observed a significant amount of cold, neutral gas in the outer regions of the young galaxy A1689-zD1, as well as outflows of hot gas coming from the galaxy’s center. These results may shed light on a critical stage of galactic evolution for early galaxies, where young galaxies begin the transformation to be increasingly like their later, more structured cousins. The observations were presented today in a press conference at the 240th meeting of the American Astronomical Society (AAS) in Pasadena, California. They will be published in an upcoming edition of The Astrophysical Journal.

A1689-zD1— a young, active, star-forming galaxy slightly less luminous and less massive than the Milky Way— is located roughly 13 billion light-years away from Earth in the Virgo constellation cluster. It was discovered hiding out behind the Abell 1689 galaxy cluster in 2007 and confirmed in 2015 thanks to gravitational lensing, which amplified the brightness of the young galaxy by more than 9x. Since then, scientists have continued to study the galaxy as a possible analog for the evolution of other “normal” galaxies. That label— normal— is an important distinction that has helped researchers divide A1689-zD1’s behaviors and characteristics into two buckets: typical and uncommon, with the uncommon characteristics mimicking those of later and more massive galaxies.

“A1689-zD1 is located in the very early Universe— only 700 million years after the Big Bang. This is the era where galaxies were just beginning to form,” said Hollis Akins, an undergraduate student in astronomy at Grinnell College and the lead author of the research. “What we see in these new observations is evidence of processes that may contribute to the evolution of what we call normal galaxies as opposed to massive galaxies. More importantly, these processes are ones we did not previously believe applied to these normal galaxies.”

One of these uncommon processes is the galaxy’s production and distribution of star-forming fuel, potentially a lot of it. The team used ALMA’s highly-sensitive Band 6 receiver to home in on a halo of carbon gas that extends far beyond the center of the young galaxy. This could be evidence of ongoing star formation in the same region or the result of structural disruptions, such as mergers or outflows, in the earliest stages of the galaxy’s formation.

According to Akins, this is unusual for early galaxies. “The carbon gas we observed in this galaxy is typically found in the same regions as neutral hydrogen gas, which is also where new stars tend to form. If that is the case with A1689-zD1, the galaxy is likely much larger than previously thought. It’s also possible that this halo is a remnant of previous galactic activity, like mergers that exerted complex gravitational forces on the galaxy leading to the ejection of a lot of neutral gas out to these large distances. In either case, the early evolution of this galaxy was likely active and dynamic, and we’re learning that this may be a common, although previously unobserved, theme in early galaxy formation.”

More than just uncommon, the discovery could have significant implications for the study of galactic evolution, particularly as radio observations uncover details unseen at optical wavelengths. Seiji Fujimoto, a postdoctoral researcher at the Niels Bohr Institute’s Cosmic Dawn Center and co-author of the research, said, “The emission from the carbon gas in A1689-zD1 is much more extended than what was observed with Hubble Space Telescope, and this could mean that early galaxies are not as small as they appear. If, in fact, early galaxies are larger than we previously believed, this would have a major impact on the theory of galaxy formation and evolution in the early Universe.”

Led by Akins, the team also observed outflows of hot, ionized gas— commonly caused by violent galactic activity like supernovae— pushing outward from the galaxy’s center. Given their potentially explosive nature, the outflows may have something to do with the carbon halo. “Outflows occur as a result of violent activity, such as the explosion of supernovae— which blast nearby gaseous material out of the galaxy— or black holes in the centers of galaxies— which have strong magnetic effects that can eject material in powerful jets. Because of this, there’s a strong possibility that the hot outflows have something to do with the presence of the cold carbon halo,” said Akins. “And that further highlights the importance of the multiphase, or hot to cold, nature of the outflowing gas.”

Darach Watson, an associate professor at the Niels Bohr Institute’s Cosmic Dawn Center and co-author of the new research, confirmed A1689-zD1 as a high-redshift galaxy in 2015, the most distant dusty galaxy known. “We have seen this type of extended gas halo emission from galaxies that formed later in the Universe, but seeing it in such an early galaxy means that this behavior is universal even in the more modest galaxies that formed most of the stars in the early Universe. Understanding how these processes occurred in such a young galaxy is critical to understanding how star-formation happens in the early Universe.”

Kirsten Knudsen, a professor of astrophysics in the Department of Space, Earth, and Environment at the Chalmers University of Technology and co-author of the research, found evidence of A1689-zD1’s dust continuum in 2017. Knudsen pointed out the fortunate role of extreme gravitational lensing in making each discovery in the research possible. “Because A1689-zD1 is magnified more than nine times, we can see critical details that are otherwise difficult to observe in ordinary observations of such distant galaxies. Ultimately, we see here that early Universe galaxies are very complex, and this galaxy will continue to present new research challenges and results for some time.”

Dr. Joe Pesce, NSF program officer for ALMA, added, “This fascinating ALMA research adds to a growing body of results indicating that things aren’t quite as we expected in the early Universe, but they are really interesting and exciting nonetheless!”

Spectroscopy and infrared observations of A1689-zD1 are planned for January 2023, using the NIRSpec Integral Field Unit (IFU) and NIRCam on the James Webb Space Telescope. The new observations will complement previous HST and ALMA data, offering a deeper and more complete multi-wavelength look at the young galaxy.

See the full article here .


Please help promote STEM in your local schools.

Stem Education Coalition

The Atacama Large Millimeter/submillimeter Array (ALMA) (CL) , an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO) (EU), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) (CA) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

ALMA construction and operations are led on behalf of Europe by European Southern Observatory(EU), on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (US) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.
NRAO Small
ESO 50 Large

The antennas can be moved across the desert plateau over distances from 150 m to 16 km, which will give ALMA a powerful variable “zoom”, similar in its concept to that employed at the centimetre-wavelength Very Large Array (VLA) site in New Mexico, United States.

The high sensitivity is mainly achieved through the large numbers of antenna dishes that will make up the array.

The telescopes were provided by the European, North American and East Asian partners of ALMA. The American and European partners each provided twenty-five 12-meter diameter antennas, that compose the main array. The participating East Asian countries are contributing 16 antennas (four 12-meter diameter and twelve 7-meter diameter antennas) in the form of the Atacama Compact Array (ACA), which is part of the enhanced ALMA.

By using smaller antennas than the main ALMA array, larger fields of view can be imaged at a given frequency using ACA. Placing the antennas closer together enables the imaging of sources of larger angular extent. The ACA works together with the main array in order to enhance the latter’s wide-field imaging capability.

ALMA has its conceptual roots in three astronomical projects — the Millimeter Array (MMA) of the United States, the Large Southern Array (LSA) of Europe, and the Large Millimeter Array (LMA) of Japan.

The first step toward the creation of what would become ALMA came in 1997, when the National Radio Astronomy Observatory (NRAO) and the European Southern Observatory (ESO) agreed to pursue a common project that merged the MMA and LSA. The merged array combined the sensitivity of the LSA with the frequency coverage and superior site of the MMA. ESO and NRAO worked together in technical, science, and management groups to define and organize a joint project between the two observatories with participation by Canada and Spain (the latter became a member of ESO later).

A series of resolutions and agreements led to the choice of “Atacama Large Millimeter Array”, or ALMA, as the name of the new array in March 1999 and the signing of the ALMA Agreement on 25 February 2003, between the North American and European parties. (“Alma” means “soul” in Spanish and “learned” or “knowledgeable” in Arabic.) Following mutual discussions over several years, the ALMA Project received a proposal from the National Astronomical Observatory of Japan (NAOJ) whereby Japan would provide the ACA (Atacama Compact Array) and three additional receiver bands for the large array, to form Enhanced ALMA. Further discussions between ALMA and NAOJ led to the signing of a high-level agreement on 14 September 2004 that makes Japan an official participant in Enhanced ALMA, to be known as the Atacama Large Millimeter/submillimeter Array. A groundbreaking ceremony was held on November 6, 2003 and the ALMA logo was unveiled.

During an early stage of the planning of ALMA, it was decided to employ ALMA antennas designed and constructed by known companies in North America, Europe, and Japan, rather than using one single design. This was mainly for political reasons. Although very different approaches have been chosen by the providers, each of the antenna designs appears to be able to meet ALMA’s stringent requirements. The components designed and manufactured across Europe were transported by specialist aerospace and astrospace logistics company Route To Space Alliance, 26 in total which were delivered to Antwerp for onward shipment to Chile.


European Southern Observatory (EU) and the European Regional Support Centre
National Science Foundation (US) via the National Radio Astronomy Observatory (US) and the North American ALMA Science Center (US)
National Research Council Canada [Conseil national de recherches Canada] (CA)
National Astronomical Observatory of Japan (JP) under the National Institute of Natural Sciences (自然科学研究機構, Shizenkagaku kenkyuukikou) (JP)
ALMA-Taiwan at the Academia Sinica Institute of Astronomy & Astrophysics [中央研究院天文及天文物理研究所](TW)
Republic of Chile

ALMA is a time machine!

ALMA-In Search of our Cosmic Origins