Dennis Fischer
2014-08-14 17:52:07 UTC
Supernova SN 2014J Explodes
New data from NASAâs Chandra X-ray Observatory has provided stringent
constraints on the environment around one of the closest supernovas discovered
in decades. The Chandra results provide insight into possible cause of the
explosion, as described in our press release.
On January 21, 2014,
astronomers witnessed a supernova soon after it exploded in the Messier 82, or
M82, galaxy. Telescopes across the globe and in space turned their attention to
study this newly exploded star, including Chandra. Astronomers
determined that this supernova, dubbed SN 2014J, belongs to a class of
explosions called âType Iaâ supernovas. These supernovas are used as cosmic
distance-markers and played a key role in the discovery of the Universeâs
accelerated expansion, which has been attributed to the effects of dark
energy. Scientists think that all Type Ia supernovas involve the detonation of
a white dwarf. One important question is whether the fuse on the explosion is
lit when the white dwarf pulls too much material from a companion star like
the Sun, or when two white dwarf stars merge.
This image contains
Chandra data, where low, medium, and high-energy X-rays are red, green, and blue
respectively. The boxes in the bottom of the image show close-up views of the
region around the supernova in data taken prior to the explosion (left), as well
as data gathered on February 3, 2014, after the supernova went off (right). The
lack of the detection of X-rays detected by Chandra is an important clue for
astronomers looking for the exact mechanism of how this star
exploded.
The non-detection of X-rays reveals that the region around the
site of the supernova explosion is relatively devoid of material. This finding
is a critical clue to the origin of the explosion. Astronomers expect that if a
white dwarf exploded because it had been steadily collecting matter from a
companion star prior to exploding, the mass transfer process would not be 100%
efficient, and the white dwarf would be immersed in a cloud of gas.
If a
significant amount of material were surrounding the doomed star, the blast wave
generated by the supernova would have struck it by the time of the
Chandra observation, producing a bright X-ray source. Since they do not detect
any X-rays, the researchers determined that the region around SN 2014J
is exceptionally clean.
A viable candidate for the cause of SN 2014J
must explain the relatively gas-free environment around the star prior to the
explosion. One possibility is the merger of two white dwarf stars, in which
case there might have been little mass transfer and pollution of the environment
before the explosion. Another is that several smaller eruptions on the surface
of the white dwarf cleared the region prior to the supernova. Further
observations a few hundred days after the explosion could shed light on the
amount of gas in a larger volume, and help decide between these and
other scenarios.
A paper describing these results was published in the
July 20 issue of The Astrophysical Journal and is available online. The first
author is Raffaella Margutti from the Harvard-Smithsonian Center for
Astrophysics (CfA) in Cambridge, MA, and the co-authors are Jerod Parrent (CfA),
Atish Kamble (CfA), Alicia Soderberg (CfA), Ryan Foley (University of Illinois
at Urbana-Champaign), Dan Milisavljevic (CfA), Maria Drout (CfA), and Robert
Kirshner (CfA).
New data from NASAâs Chandra X-ray Observatory has provided stringent
constraints on the environment around one of the closest supernovas discovered
in decades. The Chandra results provide insight into possible cause of the
explosion, as described in our press release.
On January 21, 2014,
astronomers witnessed a supernova soon after it exploded in the Messier 82, or
M82, galaxy. Telescopes across the globe and in space turned their attention to
study this newly exploded star, including Chandra. Astronomers
determined that this supernova, dubbed SN 2014J, belongs to a class of
explosions called âType Iaâ supernovas. These supernovas are used as cosmic
distance-markers and played a key role in the discovery of the Universeâs
accelerated expansion, which has been attributed to the effects of dark
energy. Scientists think that all Type Ia supernovas involve the detonation of
a white dwarf. One important question is whether the fuse on the explosion is
lit when the white dwarf pulls too much material from a companion star like
the Sun, or when two white dwarf stars merge.
This image contains
Chandra data, where low, medium, and high-energy X-rays are red, green, and blue
respectively. The boxes in the bottom of the image show close-up views of the
region around the supernova in data taken prior to the explosion (left), as well
as data gathered on February 3, 2014, after the supernova went off (right). The
lack of the detection of X-rays detected by Chandra is an important clue for
astronomers looking for the exact mechanism of how this star
exploded.
The non-detection of X-rays reveals that the region around the
site of the supernova explosion is relatively devoid of material. This finding
is a critical clue to the origin of the explosion. Astronomers expect that if a
white dwarf exploded because it had been steadily collecting matter from a
companion star prior to exploding, the mass transfer process would not be 100%
efficient, and the white dwarf would be immersed in a cloud of gas.
If a
significant amount of material were surrounding the doomed star, the blast wave
generated by the supernova would have struck it by the time of the
Chandra observation, producing a bright X-ray source. Since they do not detect
any X-rays, the researchers determined that the region around SN 2014J
is exceptionally clean.
A viable candidate for the cause of SN 2014J
must explain the relatively gas-free environment around the star prior to the
explosion. One possibility is the merger of two white dwarf stars, in which
case there might have been little mass transfer and pollution of the environment
before the explosion. Another is that several smaller eruptions on the surface
of the white dwarf cleared the region prior to the supernova. Further
observations a few hundred days after the explosion could shed light on the
amount of gas in a larger volume, and help decide between these and
other scenarios.
A paper describing these results was published in the
July 20 issue of The Astrophysical Journal and is available online. The first
author is Raffaella Margutti from the Harvard-Smithsonian Center for
Astrophysics (CfA) in Cambridge, MA, and the co-authors are Jerod Parrent (CfA),
Atish Kamble (CfA), Alicia Soderberg (CfA), Ryan Foley (University of Illinois
at Urbana-Champaign), Dan Milisavljevic (CfA), Maria Drout (CfA), and Robert
Kirshner (CfA).