SN 1957D in M83: X-Rays Discovered from Young Supernova Remnant

SN 1957D in M83

Credit: X-ray: NASA/CXC/STScI/K.Long et al.,
Optical: NASA/STScI

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SN 1957D in M83 Animations

Over fifty years ago, a supernova was discovered in M83, a spiral galaxy about 15 million light years from Earth. Astronomers have used NASA's Chandra X-ray Observatory to make the first detection of X-rays emitted by the debris from this explosion.

Named SN 1957D because it was the fourth supernova to be discovered in the year of 1957, it is one of only a few located outside of the Milky Way galaxy that is detectable, in both radio and optical wavelengths, decades after its explosion was observed. In 1981, astronomers saw the remnant of the exploded star in radio waves, and then in 1987 they detected the remnant at optical wavelengths, years after the light from the explosion itself became undetectable.

A relatively short observation -- about 14 hours long -- from NASA's Chandra X-ray Observatory in 2000 and 2001 did not detect any X-rays from the remnant of SN 1957D. However, a much longer observation obtained in 2010 and 2011, totaling nearly 8 and 1/2 days of Chandra time, did reveal the presence of X-ray emission. The X-ray brightness in 2000 and 2001 was about the same as or lower than in this deep image.

This new Chandra image of M83 is one of the deepest X-ray observations ever made of a spiral galaxy beyond our own. This full-field view of the spiral galaxy shows the low, medium, and high-energy X-rays observed by Chandra in red, green, and blue respectively. The location of SN 1957D, which is found on the inner edge of the spiral arm just above the galaxy's center, is outlined in the box (or can be seen by mousing over the image.)

The new X-ray data from the remnant of SN 1957D provide important information about the nature of this explosion that astronomers think happened when a massive star ran out of fuel and collapsed. The distribution of X-rays with energy suggests that SN 1957D contains a neutron star, a rapidly spinning, dense star formed when the core of pre-supernova star collapsed. This neutron star, or pulsar, may be producing a cocoon of charged particles moving at close to the speed of light known as a pulsar wind nebula.

If this interpretation is confirmed, the pulsar in SN 1957D is observed at an age of 55 years, one of the youngest pulsars ever seen. The remnant of SN 1979C in the galaxy M100 contains another candidate for the youngest pulsar, but astronomers are still unsure whether there is a black hole or a pulsar at the center of SN 1979C.

An image from the Hubble Space Telescope (in the box labeled "Optical Close-Up") shows that the debris of the explosion that created SN 1957D is located at the edge of a star cluster less than 10 million years old. Many of these stars are estimated to have masses about 17 times that of the Sun. This is just the right mass for a star's evolution to result in a core-collapse supernova as is thought to be the case in SN 1957D.

Multipanel with Optical, H-alpha & X-ray
Credit: Optical: NASA/STScI)

These results will appear in an upcoming issue of The Astrophysical Journal. The researchers involved with this study were Knox Long (Space Telescope Science Institute), William Blair (Johns Hopkins University), Leith Godfrey (Curtain University, Australia), Kip Kuntz (Johns Hopkins), Paul Plucinsky (Harvard-Smithsonian Center for Astrophysics), Roberto Soria (Curtain University), Christopher Stockdale (University of Oklahoma and the Australian Astronomical Observatory), Bradley Whitmore (Space Telescope Science Institute), and Frank Winkler (Middlebury College).

NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.

Fast Facts for SN 1957D in M83:

Credit: X-ray: NASA/CXC/STScI/K.Long et al., Optical: NASA/STScI
Release Date: July 30, 2012

Scale: 9.5 arcmin on a side (~41,000 light years); Inset image: 1.6 x 1.3 arcsec (~120 x ~100 light years)

Category: Normal Galaxies & Starburst Galaxies
Coordinates: (J2000) RA 13h 37m 00.80s | Dec -29 51 58.60
Constellation: Hydra
Observation Date: 12 pointings between April 29, 2000 and Dec 28, 2011
Observation Time: 219 hours 49 min.
Obs. ID: 793, 2064, 12420, 12992-12996, 13202, 13241, 13248, 14332, 14342
Instrument: ACIS
Also Known As: NGC 5236
References: Long, K. et al, 2012, (in press) arXiv:1207.1555
Color Code: X-ray: (Red, Green, Blue); Optical inset (Red, Green, Blue)

More about → SN 1957D in M83: X-Rays Discovered from Young Supernova Remnant

M83: A Remarkable Outburst from an Old Black Hole

M83

Credit Left image - Optical: ESO/VLT; Close-up - X-ray: NASA/CXC/Curtin University/R.Soria et al., Optical: NASA/STScI/Middlebury College/F.Winkler et al.

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Press Room: M83

NASA's Chandra X-ray Observatory has discovered an extraordinary outburst by a black hole in the spiral galaxy M83, located about 15 million light years from Earth. Using Chandra, astronomers found a new ultraluminous X-ray source (ULX), objects that give off more X-rays than most "normal" binary systems in which a companion star is in orbit around a neutron star or black hole.

On the left is an optical image of M83 from the Very Large Telescope in Chile, operated by the European Southern Observatory. On the right is a composite image showing X-ray data from Chandra in pink and optical data from the Hubble Space Telescope in blue and yellow. The ULX is located near the bottom of the composite image.

In Chandra observations that spanned several years, the ULX in M83 increased in X-ray brightness by at least 3,000 times. This sudden brightening is one of the largest changes in X-rays ever seen for this type of object, which do not usually show dormant periods.

Optical images reveal a bright blue source at the position of the ULX during the X-ray outburst. Before the outburst the blue source is not seen. These results imply that the companion to the black hole in M83 is a red giant star, more than about 500 million years old, with a mass less than about four times the Sun's. According to theoretical models for the evolution of stars, the black hole should be almost as old as its companion.

Before and After Images in X-ray and Optical Light

Astronomers think that the bright, blue optical emission seen during the X-ray outburst must have been caused by a disk surrounding the black hole that brightened dramatically as it gained more material from the companion star.

Another highly variable ULX with an old, red star as a companion to a black hole was found recently in M31. The new ULXs in M83 and M31 provide direct evidence for a population of black holes that are much older and more volatile than those usually considered to be found in these objects.

The researchers estimate a mass range for the M83 ULX from 40 to 100 times that of the Sun. Lower masses of about 15 times the mass of the Sun are possible, but only if the ULX is producing more X-rays than predicted by standard models of how material falls onto black holes.

Evidence was also found that the black hole in this system may have formed from a star surprisingly rich in "metals", as astronomers call elements heavier than helium. The ULX is located in a region that is known, from previous observations, to be rich with metals.

Large numbers of metals increase the mass-loss rate for massive stars, decreasing their mass before they collapse. This, in turn, decreases the mass of the resulting black hole. Theoretical models suggest that with a high metal content only black holes with masses less than about 15 times that of the Sun should form. Therefore, these results may challenge these models.

This surprisingly rich "recipe" for a black hole is not the only possible explanation. It may also be that the black hole is so old that it formed at a time when heavy elements were much less abundant in M83, before seeding by later generations of supernovas. Another explanation is that the mass of the black hole is only about 15 times that of the Sun.

Fast Facts for M83:

Scale: Left image is 17.6 arcmin on a side (~77,000 light years); Close-up: 0.6 x 1.2 arcmin (~2600 x ~5200 light years)

Category: Normal Galaxies & Starburst Galaxies

Coordinates: (J2000) RA 13h 37m 00.80s | Dec -29° 51’ 58.60"
Constellation: Hydra
Observation Dates: 12 pointings between April 29, 2000 and Dec 28, 2011
Observation Time: 219 hours 49 min (9 days 3 hours 49 min)
Obs. IDs: 793, 2064, 12992-12996, 13202, 13241, 13248, 14332, 14342
Instrument: ACIS
Also Known As: NGC 5236
References: Soria, R. et al, 2012, ApJ (in press) arXiv:1203.2335
Kaur, A. et al, 2012, A&A 538, A49 arXiv:1109.1547
Middleton, M.J., et al, 2012, MNRAS, 420, 2969 arXiv:1111.1188
Distance Estimate: About 15 million light years

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