Showing posts with label ALMA Observatory. Show all posts
Showing posts with label ALMA Observatory. Show all posts

Tuesday, July 18, 2023

ALMA Unveils Cosmic Nursery and Stellar Graveyard in Most Remote Galaxy Ever Observed


The ALMA image of the galaxy MACS0416_Y1 located 13.2 billion light-years away, harboring the farthest ever dark nebula. The image spans approximately 15,000 light-years on each side. (Left) Radio images captured by ALMA depicting the dark nebula (emitting radio waves from dust, shown in red) and the emission nebula (emitting radio waves from oxygen, green), along with the image of stars captured by the Hubble Space Telescope (blue). Credit: ALMA (ESO/NAOJ/NRAO), Y. Tamura et al., NASA/ESA Hubble Space Telescope. (Right) Image captured by ALMA, only showing the radio waves emitted by the dust within the dark nebula. A vertically elongated elliptical cavity, a candidate for a superbubble, is visible in the central region." Credit: ALMA (ESO/NAOJ/NRAO), Y. Tamura et al.


The ALMA image of the galaxy MACS0416_Y1 located 13.2 billion light-years away, harboring the farthest ever dark nebula. The image spans approximately 15,000 light-years on each side. Radio images captured by ALMA depicting the dark nebula (emitting radio waves from dust, shown in red) and the emission nebula (emitting radio waves from oxygen, green), along with the image of stars captured by the Hubble Space Telescope (blue). Credit: ALMA (ESO/NAOJ/NRAO), Y. Tamura et al., NASA/ESA Hubble Space Telescope. Credit: ALMA (ESO/NAOJ/NRAO), Y. Tamura et al.


The ALMA image of the galaxy MACS0416_Y1 located 13.2 billion light-years away, harboring the farthest ever dark nebula. The image spans approximately 15,000 light-years on each side. Image captured by ALMA, only showing the radio waves emitted by the dust within the dark nebula. A vertically elongated elliptical cavity, a candidate for a superbubble, is visible in the central region." Credit: ALMA (ESO/NAOJ/NRAO), Y. Tamura et al.




Astronomers glean vital insights into the birth and death of stars through unprecedented high-resolution imaging of an ancient galaxy.

An international team of astronomers, spearheaded by Professor Yoichi Tamura of Nagoya University, has achieved an astronomical tour de force by capturing high-resolution images of a fledgling galaxy that existed a mere 600 million years after the Big Bang. These groundbreaking images, obtained with the Atacama Large Millimeter/submillimeter Array (ALMA), have shed light on previously unseen structures formed through the interplay of dark and emission nebulae.

The ALMA radio images paint a captivating tapestry where these nebulae coalesce to form a gargantuan cavity reminiscent of a ‘superbubble’. This superbubble is believed to have been formed by the birth of vibrant stars and the subsequent shockwaves created by supernova explosions. These revelations are paramount for understanding the enigmatic processes associated with the formation of galaxies and the cycles of stellar birth and death.

The team commenced its pioneering exploration into ultra-distant galaxies with ALMA in 2012 and achieved a major breakthrough in 2016 by detecting radio waves from oxygen in a record-setting distant galaxy. They continued to push the envelope, identifying the most distant galaxy ever known by detecting radio waves emitted by oxygen 13.28 billion light-years away in 2018.

In 2019, the researchers further refined their discoveries by detecting radio waves emitted by both oxygen and dust in another galaxy called MACS0416_Y1, located 13.2 billion light-years away. The detection of dust in the early Universe, where the cycle of the reincarnation of stars had not yet repeated extensively, was a remarkable finding that marked a milestone in our understanding of the Universe.

One of the remarkable findings from these observations is the presence of dark nebulae in the early universe. Dark nebulae are dense clouds of cold dust and gas that obscure starlight and are known to be the crucibles where stars are born. The team’s intricate observations reveal the life cycle within these dark nebulae; stars are born, they live, and they die, giving rise to new stars.

In their most recent endeavor, the research team achieved unparalleled high-resolution images of MACS0416_Y1. By configuring ALMA’s antennas akin to a zoom lens and employing a 28-hour-long exposure, they were able to discern the origins of radio waves emitted by dust and oxygen, depicting how emission and dark nebulae are closely intertwined, each carving out its own space. This delicate dance is indicative of a process where new stars born within the dark nebulae ionize the surrounding gas.

Moreover, the images reveal a colossal cavity, spanning approximately 1,000 light-years, at the center of the galaxy, which is possibly a superbubble. Prior studies indicated that MACS0416_Y1 was producing stars at an astonishing rate, about 100 times higher than that of the Milky Way. This frenzied pace of star formation likely led to the creation of this superbubble through consecutive supernova explosions.

The team was also able to analyze the motion of gas within the nebulae, finding it to be in a turbulent state, with speeds reaching up to an astounding 200,000 kilometers per hour. “Under such turbulent conditions, it is suggested that stars may form as massive clusters,” remarks Professor Tamura. He further noted that these massive star clusters are characteristic of galaxies in the early Universe. Dr. Takuya Hashimoto from the University of Tsukuba lauded ALMA’s performance, stating, “It corresponds to capturing the extremely weak light emitted by two fireflies located 3 centimeters apart on the summit of Mount Fuji as seen from Tokyo, and being able to distinguish between those two fireflies. The significance of this study lies in bringing out the ultimate performance of ALMA, leading to an understanding of the formation of early galaxies, the life and death of stars, and the ecocycle of matter in the Universe.”




Additional Information

These observation results were published as Yoichi Tamura et al. "The 300-parsec resolution imaging of a z = 8.31 galaxy: Turbulent ionized gas and potential stellar feedback 600 million years after the Big Bang" in the Astrophysical Journal on July 13, 2023 (DOI: 10.3847/1538-4357/acd637).

This work is supported by a Grant-in-Aid from the Japan Society for the Promotion of Science (17H06130, 19H01931, 20H01951, 20H05861, 20K22358, 21H01128, 21H04496, 22J21948, 22H01258, 22H04939), NAOJ ALMA Scientific Research Grant (2018-09B, 2020-16B), and Leading Initiative for Excellent Young Researchers, MEXT, Japan (HJH02007).

This Press Releases is adapted from the original text released by the
National Astronomical Observatory of Japan, an ALMA partner on behalf of East Asia.

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Organization for Astronomical Research in the Southern Hemisphere (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science and Technology Council (NSTC) in Taiwan and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.




Contacts:

Valeria Foncea
Education and Public Outreach Manager
Joint ALMA Observatory Santiago - Chile
Phone: +56 2 2467 6258
Cel: +56 9 7587 1963
Email:
valeria.foncea@alma.cl

Naoko Inoue
EPO officer, ALMA Project
National Astronomical Observatory of Japan (NAOJ)
Email:
naoko.inoue@nao.ac.jp



Friday, December 03, 2021

Stellar Cocoon with Organic Molecules at the Edge of our Galaxy


Top: Radio spectrum of a protostar in the extreme outer Galaxy discovered with ALMA. Bottom: Distributions of radio emissions from the protostar. Emissions from dust, formaldehyde (H2CO), ethynylradical (CCH), carbon monosulfide (CS), sulfur monoxide (SO), silicon monoxide (SiO), acetonitrile (CH3CN), formamide (NH2CHO), propanenitrile (C2H5CN), methyl formate (HCOOCH3), ethanol (C2H5OH), acetaldehyde (CH3CHO), deuterated water (HDO), and methanol (CH3OH) are shown as examples. In the bottom right panel, an infrared 2-color composite image of the surrounding region is shown (red: 2.16 m and blue: 1.25 m, based on 2MASS data). Credit: ALMA (ESO/NAOJ/NRAO), T. Shimonishi (Niigata University)

Artist’s conceptual image of the protostar discovered in the extreme outer Galaxy
Credit: Niigata University

For the first time, astronomers have detected a newborn star and the surrounding cocoon of complex organic molecules at the edge of our Galaxy, which is known as the extreme outer Galaxy. The discovery, which revealed the hidden chemical complexity of our Universe, appears in a paper in The Astrophysical Journal.

The scientists from Niigata University (Japan), Academia Sinica Institute of Astronomy and Astrophysics (Taiwan), and the National Astronomical Observatory of Japan, used the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile to observe a newborn star (protostar) in the WB89-789 region, located in the extreme outer Galaxy. A variety of carbon-, oxygen-, nitrogen-, sulfur-, and silicon-bearing molecules, including complex organic molecules containing up to nine atoms, were detected. Such a protostar, as well as the associated cocoon of chemically-rich molecular gas, were for the first time detected at the edge of our Galaxy.

The ALMA observations reveal that various kinds of complex organic molecules, such as methanol (CH3OH), ethanol (C2H5OH), methyl formate (HCOOCH3), dimethyl ether (CH3OCH3), formamide (NH2CHO), propanenitrile (C2H5CN), etc., are present even in the primordial environment of the extreme outer Galaxy. Such complex organic molecules potentially act as the feedstock for larger prebiotic molecules.

Interestingly, the relative abundances of complex organic molecules in this newly discovered object resemble remarkably well what is found in similar objects in the inner Galaxy. The observations suggest that complex organic molecules are formed with similar efficiency even at the edge of our Galaxy, where the environment is very different from the solar neighborhood.

It is believed that the outer part of our Galaxy still harbors a primordial environment that existed in the early epoch of galaxy formation. The environmental characteristics of the extreme outer Galaxy, e.g., low abundance of heavy elements, small or no perturbation from Galactic spiral arms, are very different from those seen in the present-day solar neighborhood. Because of its unique characteristics, the extreme outer Galaxy is an excellent laboratory to study star formation and the interstellar medium in the past Galactic environment.

“With ALMA we were able to see a forming star and the surrounding molecular cocoon at the edge of our Galaxy,” says Takashi Shimonishi, an astronomer at Niigata University, Japan, and the paper’s lead author. “To our surprise, a variety of abundant complex organic molecules exists in the primordial environment of the extreme outer Galaxy. The interstellar conditions to form the chemical complexity might have persisted since the early history of the Universe,” Shimonishi adds.

“These observations have revealed that complex organic molecules can be efficiently formed even in low-metallicity environments like the outermost regions of our Galaxy. This finding provides an important piece of the puzzle to understand how complex organic molecules are formed in the Universe,” says Kenji Furuya, an astronomer at the National Astronomical Observatory of Japan, and the paper’s co-author.

It is not yet clear, however, if such a chemical complexity is common in the outer part of the Galaxy. Complex organic molecules are of special interest, because some of them are connected to prebiotic molecules formed in space. The team is planning to observe a larger number of star-forming regions in the future, and hopes to clarify whether chemically-rich systems, as seen in our Solar System, are ubiquitous through the history of the Universe.




Additional Information

These observation results were published as Takashi Shimonishi et al. “The detection of a hot molecular core in the extreme outer Galaxy” in the Astrophysical Journal on December 1, 2021 (doi: 10.3847/1538-4357/ac289b).

This work is supported by a Grant-in-Aid from the Japan Society for the Promotion of Science (19H05067, 21H00037, 21H01145).

The original image release was published by the National Astronomical Observatory of Japan (NAOJ) an ALMA partner on behalf of East Asia.

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Organisation for Astronomical Research in the Southern Hemisphere (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the Ministry of Science and Technology (MOST) in Taiwan and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI). ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.



Contacts:

Nicolás Lira
Education and Public Outreach Coordinator
Joint ALMA Observatory, Santiago - Chile
Phone: tel+56 2 2467 6519
Cell phone: +56 9 9445 7726
Email:
nicolas.lira@alma.cl

Masaaki Hiramatsu
Education and Public Outreach Officer, NAOJ Chile
Observatory, Tokyo - Japan
Phone: tel+81 422 34 3630
Email:
hiramatsu.masaaki@nao.ac.jp

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

Bárbara Ferreira
ESO Public Information Officer
Garching bei München, Germany
Phone: tel+49 89 3200 6670
Email:
pio@eso.org