The U.S. National Science Foundation National Radio Astronomy Observatory (NSF NRAO), in partnership with several leading Mexican universities and research institutes, has announced a series of landmark agreements and meetings aimed at advancing Mexico’s role in the Next Generation Very Large Array (ngVLA) project.
Recent News
Astronomers Discover a Superheated Star Factory in the Early Universe
Astronomers have uncovered a previously unknown, extreme kind of star factory by taking the temperature of a distant galaxy using the ALMA telescope. The galaxy is glowing intensely in superheated cosmic dust while forming stars 180 times faster than our own Milky Way.
Astronomers Share Largest Molecular Survey To-date: GOTHAM Legacy Data Goes Public
Astronomers in the “GBT Observations of TMC-1: Hunting Aromatic Molecules” research survey, known as GOTHAM, have released a spectral line survey with largest amount of telescope time ever conducted, charting more than 100 molecular species only found in deep space.
Stellar Explosions and Cosmic Chemistry
NGC 253. Credit: ALMA
Unveiling the Secrets of Starburst Galaxies with ALMA
Astronomers have discovered the secrets of a starburst galaxy producing new stars at a rate much faster than our Milk Way. This research revealed many different molecules, more than ever seen before in a galaxy like this.
This international research team used the Atacama Large Millimeter/submillimeter Array (ALMA) to observe the center of starburst galaxy NGC 253. Through ALMA’s high sensitivity and angular resolution, the team detected over one hundred molecular species in NGC 253, far more than previously observed in galaxies beyond the Milky Way.
This research was assembled from several papers from the ALMA Comprehensive High-resolution Extragalactic Molecular Inventory (ALCHEMI),a large program led by Sergio Martín of the European Southern Observatory/Joint ALMA Observatory, Nanase Harada of the National Astronomical Observatory of Japan, and Jeff Mangum of the National Radio Astronomy Observatory.
The astronomers found that the center of NGC 253 has a lot of dense gas, which helps make stars. This molecular gas is more than ten times as dense as the gas found in the center of our own Milky Way galaxy. Astronomers also discovered an abundance of complex organic molecules around regions of active star formation. When clouds of gas collide, they create shock waves that make certain molecules easier to see with telescopes like ALMA. The ALCHEMI survey expanded the molecular species atlas outside the Milky Way, doubling the number of identified species.
Excerpts from the ALCHEMI atlas of the center of NGC 253. The different colors represent the distribution of molecular gas (blue), shocked regions (red), relatively high-density regions (orange), young starbursts (yellow), developed starbursts (magenta), and molecular gas affected by cosmic-ray ionization (cyan). Credit: ALMA (ESO/NAOJ/NRAO), N. Harada et al.
By employing machine learning, astronomers identified molecules effectively tracing various stages of star formation. This research also observed enhanced species like H3O+ and HOC+ in developed starburst regions, indicating energy output from massive stars, which could inhibit future star formation. NGC 253 has had a lot of stars explode as supernovae, and these powerful bursts of energy make it harder for gas to come together to form new stars.
The ALCHEMI survey provided an atlas of 44 molecular species. By applying a machine-learning technique to this atlas, the researchers were able to identify which molecules are present at specific stages of star formation. Identifying tracers can help guide future ALMA observations, particularly with the anticipated wideband sensitivity upgrade. This upgrade, outlined in the ALMA 2030 Development roadmap, will allow for the simultaneous tracking of multiple tracer molecules, further advancing astronomers understanding of how stars form.
(Top) Spectra from the ALCHEMI survey. (Bottom) A schematic image of the center of the starburst galaxy, NGC 253, describing locations where various tracer molecular species are enhanced according to the ALCHEMI survey. Credit: ALMA (ESO/NAOJ/NRAO), N. Harada et al.
This news article was originally published on the NRAO website on April 1, 2024.
Recent News
NSF National Radio Astronomy Observatory and Mexican Institutions Sign Historic Agreements to Advance ngVLA Collaboration
The U.S. National Science Foundation National Radio Astronomy Observatory (NSF NRAO), in partnership with several leading Mexican universities and research institutes, has announced a series of landmark agreements and meetings aimed at advancing Mexico’s role in the Next Generation Very Large Array (ngVLA) project.
Astronomers Discover a Superheated Star Factory in the Early Universe
Astronomers have uncovered a previously unknown, extreme kind of star factory by taking the temperature of a distant galaxy using the ALMA telescope. The galaxy is glowing intensely in superheated cosmic dust while forming stars 180 times faster than our own Milky Way.
Astronomers Share Largest Molecular Survey To-date: GOTHAM Legacy Data Goes Public
Astronomers in the “GBT Observations of TMC-1: Hunting Aromatic Molecules” research survey, known as GOTHAM, have released a spectral line survey with largest amount of telescope time ever conducted, charting more than 100 molecular species only found in deep space.