Credit Wide Field Optical: Focal Pointe Observatory/B.Franke,
Inset: X-ray: NASA/CXC/MSFC/D.Swartz et al,
Inset: Optical: DSS, SARA
The Jellyfish Nebula, also known by its official name IC 443, is the remnant of a supernova lying 5,000 light years from Earth. New Chandra observations show that the explosion that created the Jellyfish Nebula may have also formed a peculiar object located on the southern edge of the remnant, called CXOU J061705.3+222127, or J0617 for short. The object is likely a rapidly spinning neutron star, or pulsar.
When a massive star runs out of thermonuclear fuel, it implodes, forming a dense stellar core called a neutron star.
The outer layers of the star collapse toward the neutron star then
bounce outward in a supernova explosion. A spinning neutron star that
produces a beam of radiation is called a pulsar. The radiation sweeps by
like a beacon of light from a lighthouse and can be detected as pulses
of radio waves and other types of radiation.
This new composite image includes a wide-field view from an
astrophotographer that shows the spectacular filamentary structure of IC
443. Within the inset box, another optical image from the Digitized Sky
Survey (red, green, orange, and cyan) has been combined with X-ray data from Chandra (blue). The inset shows a close-up view of the region around J0617.
The Chandra image reveals a small, circular structure (or ring)
surrounding the pulsar and a jet-like feature pointing roughly in an
up-down direction that passes through the pulsar. It is unclear if the
long, pink wisp of optical emission is related to the pulsar, as similar
wisps found in IC 443 are unrelated to X-ray features from the pulsar.
The ring may show a region where a high speed wind of particles flowing
away from the pulsar, is slowing down abruptly. Alternately, the ring
may represent a shock wave, similar to a sonic boom, ahead of the pulsar
wind. The jet could be particles that are being fired away from the
pulsar in a narrow beam at high speed.
The X-ray brightness of J0617 and its X-ray spectrum, or the amount
of X-rays at different wavelengths, are consistent with the profiles
from known pulsars. The spectrum and shape of the diffuse, or spread
out, X-ray emission surrounding J0617 and extending well beyond the ring
also match with expectations for a wind flowing from a pulsar.
X-ray close-up
(Credit: Wide Field Optical: Focal Pointe
Observatory/B.Franke,
Inset: X-ray: NASA/CXC/MSFC/D.Swartz et al,
Inset: Optical: DSS, SARA)
Inset: X-ray: NASA/CXC/MSFC/D.Swartz et al,
Inset: Optical: DSS, SARA)
The comet-like shape of the diffuse X-ray emission suggests motion
towards the lower right of the image. As pointed out in previous
studies, this orientation is about 50 degrees away from the direction
expected if the pulsar was moving away from the center of the supernova
remnant in a straight line. This misalignment has cast some doubt on the
association of the pulsar with the supernova remnant. However, this
misalignment could also be explained by movement towards the left of
material in the supernova remnant pushing J0617's cometary tail aside.
This latest research points to an estimate for the age of the
supernova remnant to be tens of thousands of years. This agrees with
previous work that pegged IC 443's age to be about 30,000 years.
However, other scientists have inferred much younger ages of about 3,000
years for this supernova remnant, so its true age remains in question.
These findings are available in a paper published in The Astrophysical Journal and is available online.
The authors are Douglas Swartz (Marshall Space Flight Center), George
Pavlov (Penn State University), Tracy Clarke (Naval Research
Laboratory), Gabriela Castelletti (IAEF, Argentina), Vyacheslav Zavlin
(MSFC), Niccolo Bucciantini (INAF, Italy), Margarita Karovska
(Smithsonian Astrophysical Observatory), Alexander van der Horst (George
Washington University), Mihoko Yukita (Goddard Space Flight Center),
and Martin Weisskopf (MSFC).
NASA's Marshall Space Flight Center in Huntsville, Alabama, manages
the Chandra program for NASA's Science Mission Directorate in
Washington. The Smithsonian Astrophysical Observatory in Cambridge,
Massachusetts, controls Chandra's science and flight operations.
Fast Facts for IC 443:
Scale: Wide Field: 1.2 deg (about 100 light years); Inset: 7 arcmin (about 10 light years)
Category: Neutron Stars/X-ray Binaries, Supernovas & Supernova Remnants
Coordinates (J2000): RA 06h 17m 05.00s | Dec +22° 21' 30.00"
Constellation: Gemini
Observation Date: 06 and 08 Feb 2012
Observation Time: 42 hours 13 min (1 day 18 hours 13 min).
Obs. ID: 13736, 14385
Instrument: ACIS
References: Swartz, D. et al, 2015, ApJ, 808, 84; arXiv:1506.05507
Color Code: Wide Field Optical (Red, Green, Blue); Inset: Optical (Red, Green, Orange, Cyan), Inset: X-ray (Blue)
Distance Estimate: About 5,000 light years
Source: NASA’s Chandra X-ray Observatory
