Andrew Yee[_1_]
January 11th 08, 02:36 AM
Gemini Observatory
Hilo, Hawaii
Media Contact:
Peter Michaud, (808) 974-2510 (desk)
Tuesday, 08 January 200
Supernova Remnants Dance in the LMC
The Gemini South Multi-Object Spectograph (GMOS) recently captured a
dramatic image of a vast cloud complex named DEM L316 located in the Large
Magellanic Cloud. The peanut-shaped nebula appears to be a single object,
but the latest research indicates that it is really comprised of two
distinct gas and dust clouds formed by different types of supernova
explosions.
The new image reveals the intricate tendrils of gas and dust located in the
remnants of the stellar explosions that created the still-expanding cloud
complex. The object was first recognized in the early 1970s as a supernova
remnant, a type of object that is enriched with elements created in stellar
explosions. The nebula was likely created a few tens of thousands of years
ago by more than one type of supernova exploding in this region of the Large
Magellanic Cloud.
"The remarkable clarity of these Gemini-South observations shows the complex
shock structure of these two supernova remnants in impressive detail," said
Dr. Rosa Williams of Columbus State University, an astronomer who has
studied DEM L316 extensively. "It's a great step forward in efforts to
understand this fascinating pair of remnants -- whether they represent only
a chance alignment on the sky or some as-yet uncovered physical
relationship."
Other recent observations of DEM L316 by the Chandra and XMM-Newton X-ray
space telescopes have strengthened the idea that the cloud is actually two
supernova remnants that are aligned in the sky by chance and not a single
remnant with a distorted bi-polar shape. The Chandra observations reveal
that the chemical compositions of the two shells are very different. This is
a strong hint that they were created in very different types of supernova
outbursts. The data show that the smaller shell (lower left in the GMOS
image) contains significantly more iron than the larger one. The high
abundance of iron in the small bubble indicates that the gas is the product
of a Type Ia supernova. This type of explosion is triggered by the infall of
matter from a star onto a white dwarf. Since white dwarf stars are extremely
old objects, the system must have been a few billion years old when this
supernova explosion took place.
By contrast, the larger, less iron-rich bubble is the result of a Type II
supernova that was triggered by the collapse of a massive star (more than
seven times the mass of our Sun) when it was only a few million years old.
Since the two progenitor systems had vastly different ages when they "went
supernova", there is little chance they came from the same system.
Therefore, while the detailed structure seen in the GMOS image makes it look
like the two bubbles are colliding, they only seem to be close together in
the sky because of a chance alignment in our line of sight.
The Large Magellanic Cloud is a sister satellite galaxy to our Milky Way and
lies about 160,000 light-years away in the direction of the constellation
Dorado. The DEM L316 nebula is located within the LMC and its two bubbles
extend over a distance of about 140 light-years (roughly 35 times larger
than the distance between our Sun and its nearest stellar neighbor).
The spectacular x-ray images of DEM L316 obtained with Chandra can be viewed
at:
http://chandra.harvard.edu/photo/2005/d316/
DEM L316 was also imaged as part of The Magellanic Cloud Emission Line
Survey (MCELS) survey. Wide-field images of the target and its surroundings
in the LMC are available here and here.
Rosa Williams of Columbus State University and You-Hua Chu of the University
of Illinois published an extensive study of the double supernova remnant in
the Astrophysical Journal (ApJ, 635, 1077, 2005). In that paper the authors
also review previous work on this target.
[NOTE: Images supporting this release are available at
http://www.gemini.edu/index.php?option=content&task=view&id=265 ]
Hilo, Hawaii
Media Contact:
Peter Michaud, (808) 974-2510 (desk)
Tuesday, 08 January 200
Supernova Remnants Dance in the LMC
The Gemini South Multi-Object Spectograph (GMOS) recently captured a
dramatic image of a vast cloud complex named DEM L316 located in the Large
Magellanic Cloud. The peanut-shaped nebula appears to be a single object,
but the latest research indicates that it is really comprised of two
distinct gas and dust clouds formed by different types of supernova
explosions.
The new image reveals the intricate tendrils of gas and dust located in the
remnants of the stellar explosions that created the still-expanding cloud
complex. The object was first recognized in the early 1970s as a supernova
remnant, a type of object that is enriched with elements created in stellar
explosions. The nebula was likely created a few tens of thousands of years
ago by more than one type of supernova exploding in this region of the Large
Magellanic Cloud.
"The remarkable clarity of these Gemini-South observations shows the complex
shock structure of these two supernova remnants in impressive detail," said
Dr. Rosa Williams of Columbus State University, an astronomer who has
studied DEM L316 extensively. "It's a great step forward in efforts to
understand this fascinating pair of remnants -- whether they represent only
a chance alignment on the sky or some as-yet uncovered physical
relationship."
Other recent observations of DEM L316 by the Chandra and XMM-Newton X-ray
space telescopes have strengthened the idea that the cloud is actually two
supernova remnants that are aligned in the sky by chance and not a single
remnant with a distorted bi-polar shape. The Chandra observations reveal
that the chemical compositions of the two shells are very different. This is
a strong hint that they were created in very different types of supernova
outbursts. The data show that the smaller shell (lower left in the GMOS
image) contains significantly more iron than the larger one. The high
abundance of iron in the small bubble indicates that the gas is the product
of a Type Ia supernova. This type of explosion is triggered by the infall of
matter from a star onto a white dwarf. Since white dwarf stars are extremely
old objects, the system must have been a few billion years old when this
supernova explosion took place.
By contrast, the larger, less iron-rich bubble is the result of a Type II
supernova that was triggered by the collapse of a massive star (more than
seven times the mass of our Sun) when it was only a few million years old.
Since the two progenitor systems had vastly different ages when they "went
supernova", there is little chance they came from the same system.
Therefore, while the detailed structure seen in the GMOS image makes it look
like the two bubbles are colliding, they only seem to be close together in
the sky because of a chance alignment in our line of sight.
The Large Magellanic Cloud is a sister satellite galaxy to our Milky Way and
lies about 160,000 light-years away in the direction of the constellation
Dorado. The DEM L316 nebula is located within the LMC and its two bubbles
extend over a distance of about 140 light-years (roughly 35 times larger
than the distance between our Sun and its nearest stellar neighbor).
The spectacular x-ray images of DEM L316 obtained with Chandra can be viewed
at:
http://chandra.harvard.edu/photo/2005/d316/
DEM L316 was also imaged as part of The Magellanic Cloud Emission Line
Survey (MCELS) survey. Wide-field images of the target and its surroundings
in the LMC are available here and here.
Rosa Williams of Columbus State University and You-Hua Chu of the University
of Illinois published an extensive study of the double supernova remnant in
the Astrophysical Journal (ApJ, 635, 1077, 2005). In that paper the authors
also review previous work on this target.
[NOTE: Images supporting this release are available at
http://www.gemini.edu/index.php?option=content&task=view&id=265 ]