YOU ARE HERE: Home > News & Press > Cosmic “dust factory” reveals clues to how stars are born

I want information on:

Information for:

NEWS & PRESS

Cosmic “dust factory” reveals clues to how stars are born

Last Updated on Monday, 10 July 2017 15:05
Published on Monday, 10 July 2017 15:00

A group of scientists led by researchers at Cardiff University have discovered a rich inventory of molecules at the centre of an exploded star for the very first time. The findings are published today in the journal Monthly Notices of the Royal Astronomical Society.

thumb SN1987A Illustration FINAL-1This artist's illustration of Supernova 1987A reveals the cold, inner regions of the exploded star's remnants (red) where tremendous amounts of dust were detected and imaged by ALMA. This inner region is contrasted with the outer shell (blue), where the energy from the supernova is colliding (green) with the envelope of gas ejected from the star prior to its powerful detonation. Credit: A. Angelich / NRAO / AUI / NSF

 

Two previously undetected molecules, formylium (HCO+) and sulphur monoxide (SO), were found in the cooling aftermath of Supernova 1987A, located 163,000 light years away in a nearby neighbour of our own Milky Way galaxy. The explosion was originally witnessed in February 1987, hence its name.

 

These newly identified molecules were accompanied by previously detected compounds such as carbon monoxide (CO) and silicon oxide (SiO). The researchers estimate that about 1 in 1000 silicon atoms from the exploded star can be found in SiO molecules and only a few out of every million carbon atoms are in HCO+ molecules.

 

It was previously thought that the massive explosions of supernovae would completely destroy any molecules and dust that may have been already present.

 

However, the detection of these unexpected molecules suggests that the explosive death of stars could lead to clouds of molecules and dust at extremely cold temperatures, which are similar conditions to those seen in a stellar nursery where stars are born. 

 

Lead author of the study Dr Mikako Matsuura, from Cardiff University’s School of Physics and Astronomy, said: “This is the first time that we’ve found these species of molecules within supernovae, which questions our long held assumptions that these explosions destroy all molecules and dust that are present within a star.”

 

“Our results have shown that as the leftover gas from a supernova begins to cool down to below  200°C, the many heavy elements that are synthesised can begin to harbour rich molecules, creating a dust factory.”

 

“What is most surprising is that this factory of rich molecules is usually found in conditions where stars are born. The deaths of massive stars may therefore lead to the birth of a new generation.”

 

The team arrived at their findings using the Atacama Large Millimeter/submillimeter Array (ALMA) to probe the heart of Supernova 1987A in remarkably fine detail.

 

Astronomers have been studying Supernova 1987A since it was first discovered over 30 years ago, but have found it difficult to analyse the supernova’s innermost core. ALMA’s ability to observe at millimetre wavelengths – a region of the electromagnetic spectrum between infrared and radio light – made it possible to see through the intervening dust and gas and study the abundance and location of the newly formed molecules.

 thumb nrao17cb12 still1-1170x600Remnant of Supernova 1987A as seen by ALMA. Purple area indicates emission from SiO molecules. Yellow area is emission from CO molecules. The blue ring is Hubble data that has been artificially expanded into 3-D. Credit: ALMA (ESO/NAOJ/NRAO) / R. Indebetouw / NASA / ESA Hubble

Prof Mike Barlow, from University College London, one of the team members involved in the observations, commented that, “The ALMA observations of molecules such as silicon monoxide in Supernova 1987A have enabled isotopic abundance ratios to be measured for the first time in supernova material, allowing comparisons to be made with models for the explosive nuclear reactions that take place in such supernovas.’’

 

In an accompanying paper, a second research team have used ALMA’s data to create the first 3D model of Supernova 1987A, revealing important insights into the original star itself and the way supernovae create the basic building blocks of planets.

 

It is well understood that massive stars, those more than 10 times the mass of our Sun, end their lives in spectacular fashion. When such a star runs out of fuel, there is no longer enough heat and energy to fight back against the force of their own gravity. The outer reaches of the star, once held up by the power of nuclear fusion, then come crashing down on the core with tremendous force. The rebound from this collapse triggers an explosion that blasts material into space.

 

Prof Pat Roche, another team member, from the University of Oxford, said he was excited to see the ALMA observations. These trace the emission from cold silicon monoxide and carbon monoxide molecules almost 30 years after he first detected warm SiO at infrared wavelengths, when the supernova remnant was still very compact, hot and young. 

 

Prof Roche added, “The detailed structure seen in the molecular gas helps refine our understanding of supernova explosions and the formation of molecules, dust and heavy elements in the ejected material as it hurtles through interstellar space, eventually to be recycled into new stars, planets and other astronomical bodies.”

 

Building on their current findings, the team hope to use ALMA to find out exactly how abundant the molecules of HCO+ and SO are, and to see if there are there any other molecules within the supernova that have yet to be detected.

 


Media contacts

 

Michael Bishop

Communications & Marketing

Cardiff University

Tel: +44 (0)2920 874499

Mob : +44 (0)7713 325300

This email address is being protected from spambots. You need JavaScript enabled to view it.

 

Robert Massey
Royal Astronomical Society
Mob: +44 (0)7802 877699
This email address is being protected from spambots. You need JavaScript enabled to view it.

 

Morgan Hollis

Royal Astronomical Society

This email address is being protected from spambots. You need JavaScript enabled to view it.

 


Science contacts

 

Mikako Matsuura

Cardiff University

Mob : +44 (0)7815 607025

This email address is being protected from spambots. You need JavaScript enabled to view it.

 


Images and captions

 

This artist's illustration of Supernova 1987A reveals the cold, inner regions of the exploded star's remnants (red) where tremendous amounts of dust were detected and imaged by ALMA. This inner region is contrasted with the outer shell (blue), where the energy from the supernova is colliding (green) with the envelope of gas ejected from the star prior to its powerful detonation. Credit: A. Angelich / NRAO / AUI / NSF

 

Remnant of Supernova 1987A as seen by ALMA. Purple area indicates emission from SiO molecules. Yellow area is emission from CO molecules. The blue ring is Hubble data that has been artificially expanded into 3-D. Credit: ALMA (ESO/NAOJ/NRAO) / R. Indebetouw / NASA / ESA Hubble

 


Further information

 

The new work appears in: “ALMA spectral survey of supernova 1987A — molecular inventory, chemistry, dynamics and explosive nucleosynthesis,” M. Matsuura, R. Indebetouw, et al., Monthly Notices of the Royal Astronomical Society (2017) 469 (3): 3347-3362. 

A copy of the paper is available from: https://academic.oup.com/mnras/article/469/3/3347/3103046/ALMA-spectral-survey-of-Supernova-1987A-molecular?guestAccessKey=c44e79c6-1faf-440d-be8d-b85aa2317806

 

The second paper is published as: "Very deep inside the SN 1987 A core ejecta: Molecular structures seen in 3D," F. J. Abellán, R. Indebetouw, et al., Astrophysical Journal Letters (2017) 842 (2).

A copy of the paper is available from: https://arxiv.org/abs/1706.04675

 


Notes for editors

 

The Royal Astronomical Society (RAS, www.ras.org.uk), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organises scientific meetings, publishes international research and review journals, recognizes outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 4000 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.

T: https://twitter.com/royalastrosoc

F: https://facebook.com/royalastrosoc

 

Cardiff University is recognised in independent government assessments as one of Britain’s leading teaching and research universities and is a member of the Russell Group of the UK’s most research intensive universities. The 2014 Research Excellence Framework ranked the University 5th in the UK for research excellence. Among its academic staff are two Nobel Laureates, including the winner of the 2007 Nobel Prize for Medicine, University Chancellor Professor Sir Martin Evans.  Founded by Royal Charter in 1883, today the University combines impressive modern facilities and a dynamic approach to teaching and research. The University’s breadth of expertise encompasses: the College of Arts, Humanities and Social Sciences; the College of Biomedical and Life Sciences; and the College of Physical Sciences and Engineering, along with a longstanding commitment to lifelong learning. Cardiff’s flagship Research Institutes are offering radical new approaches to pressing global problems. www.cardiff.ac.uk

 

Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Southern Observatory (ESO; representing its member states, including UK), 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 Council of Taiwan (NSC) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

 

This project is supported by an STFC Ernest Rutherford fellowship (ST/L003597/1), and the European Research Council (ERC) in the forms of Consolidator Grant COSMICDUST (ERC-2014-CoG-647939) and Advanced Grant SNDUST (ERC-2015-AdG-694520).