SN 2010jl: A Supernova Cocoon Breakthrough

SN 2010jl

Credit X-ray: NASA/CXC/Royal Military College of Canada/P.Chandra et al); Optical: NASA/STScI

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Observations with NASA's Chandra X-ray Observatory have provided the first X-ray evidence of a supernova shock wave breaking through a cocoon of gas surrounding the star that exploded. This discovery may help astronomers understand why some supernovas are much more powerful than others.

On November 3, 2010, a supernova was discovered in the galaxy UGC 5189A, located about 160 million light years away. Using data from the All Sky Automated Survey telescope in Hawaii taken earlier, astronomers determined this supernova exploded in early October 2010 (in Earth's time-frame).

This composite image of UGC 5189A shows X-ray data from Chandra in purple and optical data from Hubble Space Telescope in red, green and blue. SN 2010jl is the very bright X-ray source near the top of the galaxy.

A team of researchers used Chandra to observe this supernova in December 2010 and again in October 2011. The supernova was one of the most luminous that has ever been detected in X-rays.

In optical light, SN 2010jl was about ten times more luminous than a typical supernova resulting from the collapse of a massive star, adding to the class of very luminous supernovas that have been discovered recently with optical surveys. Different explanations have been proposed to explain these energetic supernovas including (1) the interaction of the supernova's blast wave with a dense shell of matter around the pre-supernova star, (2) radioactivity resulting from a pair-instability supernova (triggered by the conversion of gamma rays into particle and anti-particle pairs), and (3) emission powered by a neutron star with an unusually powerful magnetic field.

In the first Chandra observation of SN 2010jl, the X-rays from the explosion's blast wave were strongly absorbed by a cocoon of dense gas around the supernova. This cocoon was formed by gas blown away from the massive star before it exploded.

In the second observation taken almost a year later, there is much less absorption of X-ray emission, indicating that the blast wave from the explosion has broken out of the surrounding cocoon. The Chandra data show that the gas emitting the X-rays has a very high temperature -- greater than 100 million degrees Kelvin - strong evidence that it has been heated by the supernova blast wave.

The energy distribution, or spectrum, of SN 2010jl in optical light reveals features that the researchers think are explained by the following scenario: matter around the supernova has been heated and ionized (electrons stripped from atoms) by X-rays generated when the blast wave plows through this material. While this type of interaction has been proposed before, the new observations directly show, for the first time, that this is happening.

This discovery therefore supports the idea that some of the unusually luminous supernovas are caused by the blast wave from their explosion ramming into the material around it.

In a rare example of a cosmic coincidence, analysis of the X-rays from the supernova shows that there is a second unrelated source at almost the same location as the supernova. These two sources strongly overlap one another as seen on the sky. This second source is likely to be an ultraluminous X-ray source, possibly containing an unusually heavy stellar-mass black hole, or an intermediate mass black hole.

These results were published in a paper appearing in the May 1st, 2012 issue of The Astrophysical Journal Letters. The authors were Poonam Chandra (Royal Military College of Canada, Kingston, Canada), Roger Chevalier and Christopher Irwin (University of Virginia, Charlottsville, VA), Nikolai Chugai (Institute of Astronomy of Russian Academy of Sciences, Moscow, Russia), Claes Fransson (Stockholm University, Sweden), and Alicia Soderberg (Harvard-Smithsonian Center for Astrophysics, Cambridge, MA).

Fast Facts for SN 2010jl:

Scale: 46 arcsec across (36,000 light years)
Category: Supernovas & Supernova Remnants
Coordinates: (J2000) RA 09h 42m 53.33s | Dec +09° 29' 41.80"
Constellation: Leo
Observation Date: 3 pointings between 7 Dec 2010 and 17 Oct 2011
Observation Time: 22 hours 13 min.
Obs. ID: 11122, 13199, 13781
Color Code: X-ray (Purple); Optical (Red, Green, Blue)
Instrument: ACIS
References: Chandra, P. et al, 2012 ApJ 750:L2; arXiv:1203.1614
Distance Estimate: 163 million light years

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IGR J17091-3624: NASA'S Chandra Finds Fastest Wind From Stellar-Mass Black Hole

IGR J17091-3624
Credit Illustration: NASA/CXC/M.Weiss

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Press Room: IGR J17091-3624

This artist's impression shows a binary system containing a stellar-mass black hole called IGR J17091-3624, or IGR J17091 for short. The strong gravity of the black hole, on the left, is pulling gas away from a companion star on the right. This gas forms a disk of hot gas around the black hole, and the wind is driven off this disk.

New observations with NASA's Chandra X-ray Observatory have clocked the fastest wind ever seen blowing off a disk around this stellar-mass black hole. Stellar-mass black holes are born when extremely massive stars collapse and typically weigh between five and 10 times the mass of the Sun.

The record-breaking wind is moving about twenty million miles per hour, or about three percent the speed of light. This is nearly ten times faster than had ever been seen from a stellar-mass black hole, and matches some of the fastest winds generated by supermassive black holes, objects millions or billions of times more massive.

Another unanticipated finding is that the wind, which comes from a disk of gas surrounding the black hole, may be carrying away much more material than the black hole is capturing.

The high speed for the wind was estimated from a spectrum made by Chandra in 2011. A spectrum shows how intense the X-rays are at different energies. Ions emit and absorb distinct features in spectra, which allow scientists to monitor them and their behavior. A Chandra spectrum of iron ions made two months earlier showed no evidence of the high-speed wind, meaning the wind likely turns on and off over

time.

Fast Facts for IGR J17091-3624:

Category: Black Holes
Coordinates: (J2000) RA 17h 09m 07.92s | Dec -36° 24' 25.20"
Constellation: Scorpius
Observation Dates: 2 pointings on Aug 1 and Oct 6, 2011
Observation Time: 16 hours 40 min
Obs. IDs: 12405, 12406
Instrument: ACIS
References: King, A. et al, 2012, ApJ, 746, L20; arXiv:1112.3648
Distance Estimate: About 28,000 light years

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Cygnus X-1: NASA's Chandra Adds to Black Hole Birth Announcement

Credit: Optical: DSS; Illustration: NASA/CXC/M.Weiss

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On the left, an optical image from the Digitized Sky Survey shows Cygnus X-1, outlined in a red box. Cygnus X-1 is located near large active regions of star formation in the Milky Way, as seen in this image that spans some 700 light years across. An artist's illustration on the right depicts what astronomers think is happening within the Cygnus X-1 system. Cygnus X-1 is a so-called stellar-mass black hole, a class of black holes that comes from the collapse of a massive star. The black hole pulls material from a massive, blue companion star toward it. This material forms a disk (shown in red and orange) that rotates around the black hole before falling into it or being redirected away from the black hole in the form of powerful jets.

A trio of papers with data from radio, optical and X-ray telescopes, including NASA's Chandra X-ray Observatory, has revealed new details about the birth of this famous black hole that took place millions of years ago. Using X-ray data from Chandra, the Rossi X-ray Timing Explorer, and the Advanced Satellite for Cosmology and Astrophysics, scientists were able to determine the spin of Cygnus X-1 with unprecedented accuracy, showing that the black hole is spinning at very close to its maximum rate. Its event horizon -- the point of no return for material falling towards a black hole -- is spinning around more than 800 times a second.

Chandra X-ray Image of Cygnus X-1

Over three decades ago, Stephen Hawking placed -- and eventually lost - a bet against the existence of a black hole in Cygnus X-1. Today, astronomers are confident the Cygnus X-1 system contains a black hole. In fact, a team of scientists has combined data from radio, optical, and X-ray telescopes including Chandra to determine the black hole's spin, mass, and distance more precisely than ever before. With these key pieces of information, the history of the black hole has been reconstructed. This new information gives astronomers strong clues about how the black hole was born, how much it weighed, and how fast it was spinning. This is important because scientists still would like to know much more about the birth of black holes. (Credit: NASA/CXC)

Using optical observations of the companion star and its motion around its unseen companion, the team also made the most precise determination ever for the mass of Cygnus X-1, of 14.8 times the mass of the Sun. It was likely to have been almost this massive at birth, because of lack of time for it to grow appreciably.

The researchers also announced that they have made the most accurate distance estimate yet of Cygnus X-1 using the National Radio Observatory's Very Long Baseline Array (VLBA). The new distance is about 6,070 light years from Earth. This accurate distance was a crucial ingredient for making the precise mass and spin determinations.

Fast Facts for Cygnus X-1:

Scale: Wide field optical image is 4x5 degrees (560x700 light years)
Category: Black Holes
Coordinates (J2000): RA 19h 58m 21.70s | Dec +35° 12' 05.80"
Constellation: Cygnus
Color Code: Intensity Map
Distance Estimate : About 8,000 light years

More about → Cygnus X-1: NASA's Chandra Adds to Black Hole Birth Announcement