Showing posts with label molecular clouds. Show all posts
Showing posts with label molecular clouds. Show all posts

Monday, October 27, 2025

Astronomers Share Largest Molecular Survey To-date: GOTHAM Legacy Data Goes Public

The NSF Green Bank Telescope.
Credit: NSF/AUI/NSF NRAO/J.Hellerman



After 1,400+ hours on the NSF Green Bank Telescope, scientists unveil the largest, most sensitive dataset of molecules from deep space’s TMC-1 cloud

A groundbreaking new dataset from the U.S. National Science Foundation Green Bank Telescope (NSF GBT) is now publicly available, opening the door for scientists worldwide to make discoveries in one of the richest molecular clouds in our galaxy, TMC-1. After 1,438 hours of observations and years of data processing pipeline development, 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—including many with complex and aromatic structures—only found in deep space.

TMC-1 is a region within the Taurus Molecular Cloud known for its incredible diversity of interstellar molecules, the perfect “cosmic laboratory” for astrochemistry. Using the GOTHAM survey, researchers identified ten individual aromatic molecules and nearly a hundred other chemical species, helping decode how molecules form and evolve before stars are born. Unlike regions closer to newborn stars, TMC-1’s chemistry is dominated by large hydrocarbons and nitrogen-rich compounds, providing tantalizing clues about the building blocks of planets and organic matter in the universe.

Until now, most telescope data remained inaccessible or too cumbersome for outside researchers to analyze, limiting discoveries to the original teams that collected the data. By releasing a fully-reduced and calibrated dataset, the GOTHAM project invites the global scientific community to pursue new questions, develop advanced chemical models, and potentially uncover phenomena no one expected. For the first time, astronomers everywhere can explore the deepest secrets of TMC-1 without needing advanced computing or data-cleaning skills.

“Sharing GOTHAM’s research in this way allows us to democratize access to big data in astronomy,” shares Brett McGuire, Associate Professor, Department of Chemistry, Massachusetts Institute of Technology (MIT), and an Adjunct Assistant Astronomer with the NSF National Radio Astronomy Observatory (NSF NRAO.) Data sharing efforts have been a mission of collaborative teams producing large datasets using NSF NRAO instruments for nearly two decades.

“It’s a lot of hard work to prepare and package this data for access. We’re really excited to see what the scientific community does next with this, we want to spread word far and wide that it’s available,” adds Ci (Ceci) Xue, co-PI of GOTHAM and lead author of the paper that shares the process behind the automated pipeline her team developed for data reduction and calibration. Xue, formerly a post doc with MIT’s Department of Chemistry, is now a post doc fellow at the NSF-Simons AI Institute for Cosmic Origins, of which the NSF NRAO is a partner.

The GOTHAM dataset is the largest and most comprehensive survey of its kind, setting a new benchmark for astronomical legacy data. Astronomers at MIT, the NSF NRAO, University of British Columbia, and partners are excited for new opportunities for collaboration and cross-disciplinary breakthroughs. The dataset includes calibrated spectra, detailed molecular abundances, and the cutting-edge software used for analysis, all publicly accessible for scientific exploration and innovation.

The release of this GOTHAM dataset is the product of a diverse collaboration spanning multiple institutions and specialties, led by McGuire, and featuring support from the NSF NRAO, NASA Goddard, and the U.S. National Science Foundation. As new molecule discoveries continue to be made in TMC-1, astronomers anticipate more groundbreaking advances in our understanding of how cosmic chemistry shapes our universe.




About NRAO

The National Radio Astronomy Observatory and Green Bank Observatory are major facilities of the U.S. National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.


Wednesday, June 19, 2024

A transformation in progress

Clouds of gas and dust with many stars. The clouds form a flat blue background towards the bottom, and become more thick and smoky towards the top. They are lit on one side by stars in the nebula. A thick arc of gas and dust reaches around from the top, where it is brightly lit by many stars in and around it, to the bottom where it is dark and obscuring. Other large stars lie between the clouds and the viewer. Credit: ESA/Hubble & NASA, J. Tan (Chalmers University & University of Virginia), R. Fedriani (Institute for Astrophysics of Andalusia)

A visually striking collection of interstellar gas and dust is the focus of this week's Hubble Picture of the Week. Named RCW 7, the nebula is located just over 5300 light-years from Earth in the constellation Puppis.

Nebulae are areas of space that are rich in the raw material needed to form new stars. Under the influence of gravity, parts of these molecular clouds collapse until they coalesce into protostars, surrounded by spinning discs of leftover gas and dust. In the case of RCW 7, the protostars forming here are particularly massive, giving off strongly ionising radiation and fierce stellar winds that have transformed it into what is known as a H II region.

H II regions are filled with hydrogen ions — where H I refers to a normal hydrogen atom, H II is hydrogen that has lost its electron. The ultraviolet radiation from the massive protostars excites the hydrogen, causing it to emit light and giving this nebula its soft pinkish glow. Here Hubble is studying a particular massive protostellar binary named IRAS 07299-1651, still in its glowing cocoon of gas in the curling clouds towards the top of the nebula. To expose this star and its siblings, this image was captured using the Wide Field Camera 3 in near-infrared light. The massive protostars here are brightest in ultraviolet light, but they emit plenty of infrared light which can pass through much of the gas and dust around them and be seen by Hubble. Many of the other, larger-looking stars in this image are not part of the nebula, but sit between it and our Solar System.

The creation of an H II region marks the beginning of the end for a molecular cloud. Over only a few million years, the radiation and winds from the massive stars gradually disperse the gas — even more so as the most massive stars come to the end of their lives in supernova explosions. Only a fraction of the gas will be incorporated into new stars in this nebula, with the rest being spread throughout the galaxy to eventually form new molecular clouds.

Links


Monday, June 26, 2023

Milky Way's Central Black Hole Woke Up 200 Years Ago, NASA's IXPE Finds

Sagittarius A*
Credit: Chandra: NASA/CXC/SAO; IXPE: NASA/MSFC/F. Marin et al; Image Processing: L.Frattare, J.Major & K.Arcand;
Sonification Credit: NASA/CXC/SAO/K.Arcand, SYSTEM Sounds (M. Russo, A. Santaguida)




These images show X-ray data of the area around the supermassive black hole at the center of the Milky Way galaxy. New data from NASA’s Imaging X-ray Polarimetry Explorer (IXPE) has provided evidence that this black hole — known as Sagittarius A* (Sgr A*) — had an outburst about 200 years ago after devouring gas and dust within its reach.

The IXPE data are shown in the bottom panel (orange) and have been combined with other X-ray data from NASA’s Chandra X-ray Observatory (blue). The top panel is a much wider field-of-view of the center of the Milky Way from Chandra. In this image, low and high-energy X-rays are represented by blue and purple colors.

The IXPE data was obtained in February and March 2022 and shows X-ray emission from clouds of gas (called “molecular clouds”) near Sgr A*. A team of scientists used the IXPE data to conclude that these molecular clouds, which are usually cold and dark, were bright in X-rays because they were reflecting X-rays generated elsewhere in the past — a phenomenon known as a “light echo”.

By combining the IXPE data with data from Chandra and XMM, the researchers were able to isolate the reflected X-ray signal and track down its source. They determined that the light originated from or near Sgr A* during an outburst approximately 200 years ago. If the outburst came from Sgr A* it may have been caused by the black hole abruptly consuming material from the molecular clouds.

Galactic Center Sonification, Chandra & IXPE.
Sonification Credit: NASA/CXC/SAO/K.Arcand, SYSTEM Sounds (M. Russo, A. Santaguida)


The IXPE team plans to continue its observations of Sgr A*, which will help provide a better understanding of how active the Milky Way’s supermassive black hole was in the past. They are eager to learn the history of such outbursts and whether these are typical events or unique and rare.

These results appear in a paper published in the current issue of the journal Nature by Frederic Marin and colleagues. In addition, a new sonification of these data are being released simultaneously, which translates these new X-ray data from IXPE and Chandra into sounds. This sonification is available at: https://chandra.si.edu/photo/2023/gcenter/animations.html

IXPE is a collaboration between NASA and the Italian Space Agency with partners and science collaborators in 12 countries. IXPE is led by Marshall. Ball Aerospace, headquartered in Broomfield, Colorado, manages spacecraft operations together with the University of Colorado's Laboratory for Atmospheric and Space Physics in Boulder.

NASA's Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory's Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.




Visual Description:

This release features multiple images and sonifications, each focused on molecular clouds near the black hole known as Sagittarius A*.

The primary image features a top panel and a bottom panel. The top panel offers an image of the Milky Way's core, courtesy of Chandra’s X-ray Observatory. In this rendering, the Milky Way resembles layers of neon pink and dark blue clouds, dotted with specks of light in similar colors. Two bright spots in light blue glow to our left of center.

The bottom panel offers a close-up image of the space between the glowing light blue spots, courtesy of Chandra and NASA's Imaging X-ray Polarimetry Explorer (IXPE). Thin white lines layered onto the top panel frame the area being highlighted, and indicate that the perspective in the bottom panel has been rotated approximately 45 degrees to our right. In the bottom panel, dappled orange mist overlaps with cloudy indigo veins, and light purple specks. These patches of veiny mist are molecular clouds. By combining data from IXPE and Chandra, researchers have determined that the X-ray light in the clouds originated from Sagittarius A* during an outburst approximately 200 years ago.

This lower panel image is used in a sonification of the same data sets. In the sonification, an arched line ripples across the image, beginning at our lower right hand corner. As it passes over the dappled orange mist representing IXPE data, sounds like digital winds are triggered. When the mist is bright, the whooshing sounds grow more intense. When the arching line passes the indigo veins and specks representing Chandra data, notes are played resembling steel drums. The brighter the light, the louder the sound.



Fast Facts for Sagittarius A*:

About the Sound :

  • Circular scan, following the path of light emitted in the outburst from SgrA* (out of frame)
  • Horizontal position mapped to stereo position of sound:
  • IXPE: X-ray spectrum (of the echo region) is converted directly to an audio spectrum, 51 and 52 octaves below the true frequencies. Brightness controls the volume
  • Chandra: Brightness controls musical pitch and volume

Scale: Image is about 13 arcmin (100 light-years) across.
Category: Black Holes, Milky Way Galaxy
Coordinates (J2000): RA 17h 45m 23.5s | Dec -29° 02´ 00.1"
Constellation: Sagittarius
Observation Date: 370 observations from Sept 9, 1999 to July 28, 2019
Observation Time: 1555 hours 26 minutes (64 days 19 hours 26 minutes)
Obs. ID: 21581-21628 and 323 others
Instrument: ACIS
Also Known As: Galactic Center
References: F. Marin et al. Nature, 2023, accepted, arXiv:2304.06967
Color Code: Chandra: blue; IXPE: red-orange
Distance Estimate: About 26,000 light-years