During the early stages of star formation, material is ejected at high speed from near the forming star forming a bipolar structure referred to as protostellar outflow. Credit: NASA, ESA, CSA, STScI
A study led by the Center for Astrochemical Studies (CAS) at MPE has revealed an unexpectedly rich chemical inventory in the outflow of the young, Sun-like protostar IRAS 4B1, located about 300 parsecs away in the star-forming region NGC 1333 in the Perseus molecular cloud. So far, there is only one low-mass protostellar outflow in which emission of complex organic molecules has been studied extensively, making IRAS 4B1 a rare and valuable laboratory for exploring how these molecules behave under extreme conditions.
One of the central questions in astrochemistry is how simple interstellar molecules grow into more complex species during the process of star and planet formation. As these processes unfold over millions of years, astronomers rely on snapshots of many systems at different evolutionary stages, using comparisons with theoretical models to trace the chemical evolution.
Protostellar outflows offer a unique window into these transformations. In the earliest stages of star formation, material is ejected from the young forming star at high speed. When this gas collides with the surrounding cloud, it generates shock waves that compress and briefly heat the gas and dust, rapidly altering the chemistry. These shocks can release complex organic molecules - defined as carbon-bearing species containing at least six atoms - that were previously frozen onto dust grains, injecting a burst of rich chemistry into the surrounding region.
Despite their importance, such detections are rare. “While working on a separate PRODIGE project mapping methyl cyanide (CH₃CN) toward IRAS 4B1, I noticed emission that appeared to trace the outflow rather than the hot surroundings of the forming star,” says Laura Busch, a postdoctoral researcher at MPE who led the study. “This made me search the data for more complex molecules – and I found them.”
The PRODIGE observations, carried out with the Northern Extended Millimeter Array (NOEMA), reveal a surprisingly diverse chemical composition in the outflow. “The combination of high sensitivity and broad spectral coverage makes PRODIGE ideally suited to this kind of study,” adds Jaime Pineda, scientist at MPE. “It allows us to detect and map multiple complex molecules simultaneously — something that would otherwise be extremely difficult.”
Maps of molecular emission show that different molecules trace distinct regions within the outflow, indicating variations in temperature and density. Some species are brightest where temperatures are highest, while others originate in cooler zones, reflecting different chemical pathways. These findings provide fresh insight into how complex organic molecules — the precursors of prebiotic chemistry — are processed by shocks during the earliest phases of star formation.
A study led by the Center for Astrochemical Studies (CAS) at MPE has revealed an unexpectedly rich chemical inventory in the outflow of the young, Sun-like protostar IRAS 4B1, located about 300 parsecs away in the star-forming region NGC 1333 in the Perseus molecular cloud. So far, there is only one low-mass protostellar outflow in which emission of complex organic molecules has been studied extensively, making IRAS 4B1 a rare and valuable laboratory for exploring how these molecules behave under extreme conditions.
One of the central questions in astrochemistry is how simple interstellar molecules grow into more complex species during the process of star and planet formation. As these processes unfold over millions of years, astronomers rely on snapshots of many systems at different evolutionary stages, using comparisons with theoretical models to trace the chemical evolution.
Protostellar outflows offer a unique window into these transformations. In the earliest stages of star formation, material is ejected from the young forming star at high speed. When this gas collides with the surrounding cloud, it generates shock waves that compress and briefly heat the gas and dust, rapidly altering the chemistry. These shocks can release complex organic molecules - defined as carbon-bearing species containing at least six atoms - that were previously frozen onto dust grains, injecting a burst of rich chemistry into the surrounding region.
Despite their importance, such detections are rare. “While working on a separate PRODIGE project mapping methyl cyanide (CH₃CN) toward IRAS 4B1, I noticed emission that appeared to trace the outflow rather than the hot surroundings of the forming star,” says Laura Busch, a postdoctoral researcher at MPE who led the study. “This made me search the data for more complex molecules – and I found them.”
The PRODIGE observations, carried out with the Northern Extended Millimeter Array (NOEMA), reveal a surprisingly diverse chemical composition in the outflow. “The combination of high sensitivity and broad spectral coverage makes PRODIGE ideally suited to this kind of study,” adds Jaime Pineda, scientist at MPE. “It allows us to detect and map multiple complex molecules simultaneously — something that would otherwise be extremely difficult.”
Maps of molecular emission show that different molecules trace distinct regions within the outflow, indicating variations in temperature and density. Some species are brightest where temperatures are highest, while others originate in cooler zones, reflecting different chemical pathways. These findings provide fresh insight into how complex organic molecules — the precursors of prebiotic chemistry — are processed by shocks during the earliest phases of star formation.
Source: Max Planck Institute for Extraterrestrial Physics (MPE)/Paper of the Month
The PROtostars & DIsks: Global Evolution (PRODIGE; PIs: P. Caselli and Th. Henning) is a collaboration between the Max Planck Society and the Institut de Radioastromie Millimétrique (IRAM) located in France. The project targeted a total of 30 Class 0/I protostellar systems in the Perseus molecular cloud, with the main goal of studying the kinematics of star formation. The observations cover a broad spectral bandwidth of 16GHz, a unique treat of the NOrthern Extended Millimeter Array (NOEMA) located in the French Alpes and run by IRAM that was used to observe the data, is essential for identifying molecules and study their emission spectra.
Contacts:
Dr. Laura Busch
Post-Doc
lbusch@mpe.mpg.de
Max Planck Institute for Extraterrestrial Physics, Garching
Center for Astrochemical Studies
Dr. Jaime Pineda Fornerod
Scientist
Tel: +49 (0)89 30000-3610
Fax: +49 (0)89 30000-3950
jpineda@mpe.mpg.de
Max Planck Institute for Extraterrestrial Physics, Garching
Center for Astrochemical Studies
Publication
Source | DOI
Contacts:
Dr. Laura Busch
Post-Doc
lbusch@mpe.mpg.de
Max Planck Institute for Extraterrestrial Physics, Garching
Center for Astrochemical Studies
Dr. Jaime Pineda Fornerod
Scientist
Tel: +49 (0)89 30000-3610
Fax: +49 (0)89 30000-3950
jpineda@mpe.mpg.de
Max Planck Institute for Extraterrestrial Physics, Garching
Center for Astrochemical Studies
Publication
L. A. Busch, J. E. Pineda, P. Caselli, D. M. Segura-Cox, S. Narayanan, C. Gieser, M. J. Maureira, T.-H. Hsieh, Y. Lin, M. T. Valdivia-Mena, L. Bouscasse, Th. Henning, D. Semenov, A. Fuente, Y.-R. Chou, L. Mason, P. C. Cortés, L. W. Looney, I. W. Stephens, M. Tafalla, A. Dutrey, W. Kwon, P. Saha
PRODIGE - envelope to disk with NOEMA: VII. (Complex) organic molecules in the NGC1333 IRAS4B1 outflow: A new laboratory for shock chemistry
arXivPRODIGE - envelope to disk with NOEMA: VII. (Complex) organic molecules in the NGC1333 IRAS4B1 outflow: A new laboratory for shock chemistry
Source | DOI
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