Thursday, April 5, 2018

Dead Star Circled by Light: Data Points to Isolated Neutron Star Beyond Our Galaxy



New images from ESO’s Very Large Telescope in Chile and other telescopes reveal a rich landscape of stars and glowing clouds of gas in one of our closest neighbouring galaxies, the Small Magellanic Cloud. The pictures have allowed astronomers to identify an elusive stellar corpse buried among filaments of gas left behind by a 2000-year-old supernova explosion. The MUSE instrument was used to establish where this elusive object is hiding, and existing Chandra X-ray Observatory data confirmed its identity as an isolated neutron star.

This new picture created from images from telescopes on the ground and in space tells the story of the hunt for an elusive missing object hidden amid a complex tangle of gaseous filaments in one of our nearest neighbouring galaxies, the Small Magellanic Cloud.

The reddish background image comes from the NASA/ESA Hubble Space Telescope and reveals the wisps of gas forming the supernova remnant 1E 0102.2-7219 in green. The red ring with a dark centre is from the MUSE instrument on ESO’s Very Large Telescope and the blue and purple images are from the NASA Chandra X-Ray Observatory. The blue spot at the centre of the red ring is an isolated neutron star with a weak magnetic field, the first identified outside the Milky Way
An isolated neutron star in the Small Magellanic Cloud
Credit: ESO/NASA, ESA and the Hubble Heritage Team (STScI/AURA)/F. Vogt et al.

Spectacular new pictures, created from images from both ground- and space-based telescopes [1], tell the story of the hunt for an elusive missing object hidden amid a complex tangle of gaseous filaments in the Small Magellanic Cloud, about 200 000 light-years from Earth.

New images from ESO’s Very Large Telescope in Chile and other telescopes reveal a rich landscape of stars and glowing clouds of gas in one of our closest neighbouring galaxies, the Small Magellanic Cloud.

The pictures have allowed astronomers to identify an elusive stellar corpse buried among filaments of gas left behind by a 2000-year-old supernova explosion. The MUSE instrument was used to establish where this elusive object is hiding, and existing Chandra X-Ray Observatory data confirmed its identity as an isolated neutron star.
Credit: ESO

New data from the MUSE instrument on ESO’s Very Large Telescope in Chile has revealed a remarkable ring of gas in a system called 1E 0102.2-7219, expanding slowly within the depths of numerous other fast-moving filaments of gas and dust left behind after a supernova explosion. This discovery allowed a team led by Frédéric Vogt, an ESO Fellow in Chile, to track down the first ever isolated neutron star with low magnetic field located beyond our own Milky Way galaxy.

This picture from the NASA/ESA Hubble Space Telescope sets the scene for the story of the hunt for an elusive missing object hidden amid a complex tangle of gaseous filaments in one of our nearest neighbouring galaxies, the Small Magellanic Cloud.

The wisps of gas forming the supernova remnant 1E 0102.2-7219 show up in blue near the centre of the picture. Part of the massive star-forming region, N 76, also known as Henize 1956, appears at the lower right in green and pink.
Hubble view of the surroundings of a hidden neutron star in the Small Magellanic Cloud
Credit: NASA, ESA and the Hubble Heritage Team (STScI/AURA)



The team noticed that the ring was centred on an X-ray source that had been noted years before and designated p1. The nature of this source had remained a mystery. In particular, it was not clear whether p1 actually lies inside the remnant or behind it. It was only when the ring of gas — which includes both neon and oxygen — was observed with MUSE that the science team noticed it perfectly circled p1. The coincidence was too great, and they realised that p1 must lie within the supernova remnant itself. Once p1’s location was known, the team used existing X-ray observations of this target from the Chandra X-ray Observatory to determine that it must be an isolated neutron star, with a low magnetic field.

In the words of Frédéric Vogt: “If you look for a point source, it doesn’t get much better than when the Universe quite literally draws a circle around it to show you where to look.”

This new picture from the MUSE instrument on ESO’s Very Large Telescope in Chile shows how an elusive missing object was found amid a complex tangle of gaseous filaments in one of our nearest neighbouring galaxies, the Small Magellanic Cloud.

The wisps of gas forming the supernova remnant 1E 0102.2-7219 show up in blue, but the red ring in the MUSE data, revealing glowing neon and oxygen forms, is perfectly centred on an X-ray source — an isolated neutron star with a weak magnetic field, the first identified outside the Milky Way.
MUSE view of the surroundings of a hidden neutron star in the Small Magellanic Cloud
Credit: ESO/F. Vogt et al.


When massive stars explode as supernovae, they leave behind a curdled web of hot gas and dust, known as a supernova remnant. These turbulent structures are key to the redistribution of the heavier elements — which are cooked up by massive stars as they live and die — into the interstellar medium, where they eventually form new stars and planets.

Typically barely ten kilometres across, yet weighing more than our Sun, isolated neutron stars with low magnetic fields are thought to be abundant across the Universe, but they are very hard to find because they only shine at X-ray wavelengths [2]. The fact that the confirmation of p1 as an isolated neutron star was enabled by optical observations is thus particularly exciting.

This archival image from the NASA Chandra X-Ray Observatory shows how an elusive missing object was found amid a complex tangle of gaseous filaments in one of our nearest neighbouring galaxies, the Small Magellanic Cloud.

The supernova remnant 1E 0102.2-7219 shows up dramatically, but when combined with data, the blue dot just below centre proves to be an isolated neutron star with a weak magnetic field, the first identified outside the Milky Way.
X-ray view of the surroundings of a hidden neutron star in the Small Magellanic Cloud
Credit: ESO/NASA

Co-author Liz Bartlett, another ESO Fellow in Chile, sums up this discovery: “This is the first object of its kind to be confirmed beyond the Milky Way, made possible using MUSE as a guidance tool. We think that this could open up new channels of discovery and study for these elusive stellar remains.”

This zoom sequence starts with a broad view of the southern skies and then dives towards the Small Magellanic Cloud, a small neighbouring galaxy to the Milky Way. Here we find a rich landscape of stars and glowing gas, including the filamentary remains of a supnova explosion seen about 2000 years ago. New observations from ESO's Very Large Telescopes, along with other telescopes in space, have revealed a stellar corpse, a neutron star, hidden in this region.

Credit: ESO, NASA, ESA and the Hubble Heritage Team (STScI/AURA), N. Risinger (skysurvey.org), DSS. Music: Astral Electronic



Notes

[1] The image combines data from the MUSE instrument on ESO’s Very Large Telescope in Chile and the orbiting the NASA/ESA Hubble Space Telescope and NASA Chandra X-Ray Observatory.

[2] Highly-magnetic spinning neutron stars are called pulsars. They emit strongly at radio and other wavelengths and are easier to find, but they are only a small fraction of all the neutron stars predicted to exist.



Contacts and sources:
Frédéric P. A. Vogt, ESO Fellow
Elizabeth S. Bartlett, ESO Fellow
Richard Hook, ESO  

This research was presented in a paper entitled “Identification of the central compact object in the young supernova remnant 1E 0102.2-7219”, by Frédéric P. A. Vogt et al., in the journal Nature Astronomy.  Research paper in Nature Astronomy

The team is composed of Frédéric P. A. Vogt (ESO, Santiago, Chile & ESO Fellow), Elizabeth S. Bartlett (ESO, Santiago, Chile & ESO Fellow), Ivo R. Seitenzahl (University of New South Wales Canberra, Australia), Michael A. Dopita (Australian National University, Canberra, Australia), Parviz Ghavamian (Towson University, Baltimore, Maryland, USA), Ashley J. Ruiter (University of New South Wales Canberra & ARC Centre of Excellence for All-sky Astrophysics, Australia) and Jason P. Terry (University of Georgia, Athens, USA).


 

No comments:

Post a Comment