Hypernova

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ESO image of hypernova SN 1998bw in a spiral arm of galaxy ESO 184-G82 SN 1998bw.jpg
ESO image of hypernova SN 1998bw in a spiral arm of galaxy ESO 184-G82

A hypernova is a very energetic supernova which is believed to result from an extreme core collapse scenario. In this case, a massive star (>30 solar masses) collapses to form a rotating black hole emitting twin astrophysical jets and surrounded by an accretion disk. It is a type of stellar explosion that ejects material with an unusually high kinetic energy, an order of magnitude higher than most supernovae, with a luminosity at least 10 times greater. Hypernovae release such intense gamma rays that they often appear similar to a type Ic supernova, but with unusually broad spectral lines indicating an extremely high expansion velocity. Hypernovae are one of the mechanisms for producing long gamma ray bursts (GRBs), which range from 2 seconds to over a minute in duration. They have also been referred to as superluminous supernovae, though that classification also includes other types of extremely luminous stellar explosions that have different origins.

Contents

History

In the 1980s, the term hypernova was used to describe a theoretical type of supernova now known as a pair-instability supernova. It referred to the extremely high energy of the explosion compared to typical core collapse supernovae. [1] [2] [3] The term had previously been used to describe hypothetical explosions from diverse events such as hyperstars, extremely massive population III stars in the early universe, [4] or from events such as black hole mergers. [5]

In February 1997, Dutch-Italian satellite BeppoSAX was able to trace GRB 970508 to a faint galaxy roughly 6 billion light years away. [6] From analyzing the spectroscopic data for both the GRB 970508 and its host galaxy, Bloom et al. concluded in 1998 that a hypernova was the likely cause. [6] That same year, hypernovae were hypothesized in greater detail by Polish astronomer Bohdan Paczyński as supernovae from rapidly spinning stars. [7]

The usage of the term hypernova from the late 20th century has since been refined to refer to those supernovae with unusually large kinetic energy. [8] The first hypernova observed was SN 1998bw, with a luminosity 100 times higher than a standard Type Ib. [9] This supernova was the first to be associated with a gamma-ray burst (GRB) and it produced a shockwave containing an order of magnitude more energy than a normal supernova. Other scientists prefer to call these objects simply broad-lined type Ic supernovae. [10] Since then the term has been applied to a variety of objects, not all of which meet the standard definition; for example ASASSN-15lh. [11]

In 2023, the observation of the highly energetic, non-quasar transient event AT2021lwx was published with an extremely strong emission from mid-infrared to X-ray wavelengths and an overall energy of 1.5 1046  Joule. [12] This object is not thought to be a hypernova; instead, it is likely to be a huge gas cloud being absorbed by a massive black hole. The event was also assigned the random name "ZTF20abrbeie" by the Zwicky Transient Facility. This name and the seeming ferocity of the event led to nickname "Scary Barbie", drawing the attention of the mainstream press.

Properties

Hypernovae are thought to be supernovae with ejecta having a kinetic energy larger than about 1045  joule , an order of magnitude higher than a typical core collapse supernova. The ejected nickel masses are large and the ejection velocity up to 99% of the speed of light. These are typically of type Ic, and some are associated with long-duration gamma-ray bursts. The electromagnetic energy released by these events varies from comparable to other type Ic supernova, to some of the most luminous supernovae known such as SN 1999as. [13] [14]

The archetypal hypernova, SN 1998bw, was associated with GRB 980425. Its spectrum showed no hydrogen and no clear helium features, but strong silicon lines identified it as a type Ic supernova. The main absorption lines were extremely broadened and the light curve showed a very rapid brightening phase, reaching the brightness of a type Ia supernova at day 16. The total ejected mass was about 10 M☉ and the mass of nickel ejected about 0.4 M☉. [13] All supernovae associated with GRBs have shown the high-energy ejecta that characterises them as hypernovae. [15]

Unusually bright radio supernovae have been observed as counterparts to hypernovae, and have been termed "radio hypernovae". [16]

Astrophysical models

Models for hypernova focus on the efficient transfer of energy into the ejecta. In normal core collapse supernovae, 99% of neutrinos generated in the collapsing core escape without driving the ejection of material. It is thought that rotation of the supernova progenitor drives a jet that accelerates material away from the explosion at close to the speed of light. Binary systems are increasingly being studied as the best method for both stripping stellar envelopes to leave a bare carbon-oxygen core, and for inducing the necessary spin conditions to drive a hypernova.

Collapsar model

The collapsar model describes a type of supernova that produces a gravitationally collapsed object, or black hole. The word "collapsar", short for "collapsed star", was formerly used to refer to the end product of stellar gravitational collapse, a stellar-mass black hole. The word is now sometimes used to refer to a specific model for the collapse of a fast-rotating star. When core collapse occurs in a star with a core at least around fifteen times the Sun's mass (M☉) — though chemical composition and rotational rate are also significant — the explosion energy is insufficient to expel the outer layers of the star, and it will collapse into a black hole without producing a visible supernova outburst.

A star with a core mass slightly below this level — in the range of 5–15 M☉ — will undergo a supernova explosion, but so much of the ejected mass falls back onto the core remnant that it still collapses into a black hole. If such a star is rotating slowly, then it will produce a faint supernova, but if the star is rotating quickly enough, then the fallback to the black hole will produce relativistic jets. Those powerful jets plough through stellar material produce strong shock waves, with the vigorous winds of newly-formed 56Ni blowing off the accretion disk, detonating the hypernova explosion. The ejected radioactive decay of 56Ni renders the visible outburst substantially more luminous than a standard supernova. [17] The jets also beam high energy particles and gamma rays directly outward and thereby produce x-ray or gamma-ray bursts; the jets can last for several seconds or longer and correspond to long-duration gamma-ray bursts, but they do not appear to explain short-duration gamma-ray bursts. [18] [19]

Binary models

The mechanism for producing the stripped progenitor, a carbon-oxygen star lacking any significant hydrogen or helium, of type Ic supernovae was once thought to be an extremely evolved massive star, for example a type WO Wolf-Rayet star whose dense stellar wind expelled all its outer layers. Observations have failed to detect any such progenitors. It is still not conclusively shown that the progenitors are actually a different type of object, but several cases suggest that lower-mass "helium giants" are the progenitors. These stars are not sufficiently massive to expel their envelopes simply by stellar winds, and they would be stripped by mass transfer to a binary companion. Helium giants are increasingly favoured as the progenitors of type Ib supernovae, but the progenitors of type Ic supernovae is still uncertain. [20]

One proposed mechanism for producing gamma-ray bursts is induced gravitational collapse, where a neutron star is triggered to collapse into a black hole by the core collapse of a close companion consisting of a stripped carbon-oxygen core. The induced neutron star collapse allows for the formation of jets and high-energy ejecta that have been difficult to model from a single star. [21]

See also

Related Research Articles

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A supernova is a powerful and luminous explosion of a star. A supernova occurs during the last evolutionary stages of a massive star, or when a white dwarf is triggered into runaway nuclear fusion. The original object, called the progenitor, either collapses to a neutron star or black hole, or is completely destroyed to form a diffuse nebula. The peak optical luminosity of a supernova can be comparable to that of an entire galaxy before fading over several weeks or months.

<span class="mw-page-title-main">SN 1987A</span> 1987 supernova event in the constellation Dorado

SN 1987A was a type II supernova in the Large Magellanic Cloud, a dwarf satellite galaxy of the Milky Way. It occurred approximately 51.4 kiloparsecs from Earth and was the closest observed supernova since Kepler's Supernova in 1604. Light and neutrinos from the explosion reached Earth on February 23, 1987 and was designated "SN 1987A" as the first supernova discovered that year. Its brightness peaked in May of that year, with an apparent magnitude of about 3.

<span class="mw-page-title-main">Gamma-ray burst</span> Flashes of gamma rays from distant galaxies

In gamma-ray astronomy, gamma-ray bursts (GRBs) are immensely energetic explosions that have been observed in distant galaxies, being the brightest and most extreme explosive events in the entire universe, as NASA describes the bursts as the "most powerful class of explosions in the universe". They are the most energetic and luminous electromagnetic events since the Big Bang. Gamma-ray bursts can last from ten milliseconds to several hours. After the initial flash of gamma rays, an "afterglow" is emitted, which is longer lived and usually emitted at longer wavelengths.

<span class="mw-page-title-main">Superluminous supernova</span> Supernova at least ten times more luminous than a standard supernova

A super-luminous supernova is a type of stellar explosion with a luminosity 10 or more times higher than that of standard supernovae. Like supernovae, SLSNe seem to be produced by several mechanisms, which is readily revealed by their light-curves and spectra. There are multiple models for what conditions may produce an SLSN, including core collapse in particularly massive stars, millisecond magnetars, interaction with circumstellar material, or pair-instability supernovae.

In astrophysics, silicon burning is a very brief sequence of nuclear fusion reactions that occur in massive stars with a minimum of about 8–11 solar masses. Silicon burning is the final stage of fusion for massive stars that have run out of the fuels that power them for their long lives in the main sequence on the Hertzsprung–Russell diagram. It follows the previous stages of hydrogen, helium, carbon, neon and oxygen burning processes.

<span class="mw-page-title-main">Messier 74</span> Face-on spiral galaxy in the constellation Pisces

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<span class="mw-page-title-main">W49B</span> Supernova remnant nebula in the constellation Aquila

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<span class="mw-page-title-main">Type Ia supernova</span> Type of supernova in binary systems

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<span class="mw-page-title-main">SN 1998bw</span>

SN 1998bw was a rare broad-lined Type Ic gamma ray burst supernova detected on 26 April 1998 in the ESO 184-G82 spiral galaxy, which some astronomers believe may be an example of a collapsar (hypernova). The hypernova has been linked to GRB 980425, which was detected on 25 April 1998, the first time a gamma-ray burst has been linked to a supernova. The hypernova is approximately 140 million light years away, very close for a gamma ray burst source.

<span class="mw-page-title-main">Type Ib and Ic supernovae</span> Types of supernovae caused by a star collapsing

Type Ib and Type Ic supernovae are categories of supernovae that are caused by the stellar core collapse of massive stars. These stars have shed or been stripped of their outer envelope of hydrogen, and, when compared to the spectrum of Type Ia supernovae, they lack the absorption line of silicon. Compared to Type Ib, Type Ic supernovae are hypothesized to have lost more of their initial envelope, including most of their helium. The two types are usually referred to as stripped core-collapse supernovae.

<span class="mw-page-title-main">Type II supernova</span> Explosion of a star 8 to 45 times the mass of the Sun

A Type II supernova or SNII results from the rapid collapse and violent explosion of a massive star. A star must have at least eight times, but no more than 40 to 50 times, the mass of the Sun (M☉) to undergo this type of explosion. Type II supernovae are distinguished from other types of supernovae by the presence of hydrogen in their spectra. They are usually observed in the spiral arms of galaxies and in H II regions, but not in elliptical galaxies; those are generally composed of older, low-mass stars, with few of the young, very massive stars necessary to cause a supernova.

<span class="mw-page-title-main">Pair-instability supernova</span> Type of high-energy supernova in very large stars

A pair-instability supernova is a type of supernova predicted to occur when pair production, the production of free electrons and positrons in the collision between atomic nuclei and energetic gamma rays, temporarily reduces the internal radiation pressure supporting a supermassive star's core against gravitational collapse. This pressure drop leads to a partial collapse, which in turn causes greatly accelerated burning in a runaway thermonuclear explosion, resulting in the star being blown completely apart without leaving a stellar remnant behind.

<span class="mw-page-title-main">Photodisintegration</span> Disintegration of atomic nuclei from high-energy EM radiation

Photodisintegration is a nuclear process in which an atomic nucleus absorbs a high-energy gamma ray, enters an excited state, and immediately decays by emitting a subatomic particle. The incoming gamma ray effectively knocks one or more neutrons, protons, or an alpha particle out of the nucleus. The reactions are called (γ,n), (γ,p), and (γ,α).

<span class="mw-page-title-main">Gamma-ray burst progenitors</span> Types of celestial objects that can emit gamma-ray bursts

Gamma-ray burst progenitors are the types of celestial objects that can emit gamma-ray bursts (GRBs). GRBs show an extraordinary degree of diversity. They can last anywhere from a fraction of a second to many minutes. Bursts could have a single profile or oscillate wildly up and down in intensity, and their spectra are highly variable unlike other objects in space. The near complete lack of observational constraint led to a profusion of theories, including evaporating black holes, magnetic flares on white dwarfs, accretion of matter onto neutron stars, antimatter accretion, supernovae, hypernovae, and rapid extraction of rotational energy from supermassive black holes, among others.

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<span class="mw-page-title-main">GRB 190114C</span> Notable high energy gamma ray burst explosion

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Ken'ichi Nomoto is a Japanese astrophysicist and astronomer, known for his research on stellar evolution, supernovae, and the origin of heavy elements.

References

  1. ↑ Woosley, S. E.; Weaver, T. A. (1981). "Theoretical models for supernovae". NASA Sti/Recon Technical Report N. 83: 16268. Bibcode:1981STIN...8316268W.
  2. ↑ Janka, Hans-Thomas (2012). "Explosion Mechanisms of Core-Collapse Supernovae". Annual Review of Nuclear and Particle Science . 62 (1): 407–451. arXiv: 1206.2503 . Bibcode:2012ARNPS..62..407J. doi: 10.1146/annurev-nucl-102711-094901 . S2CID   118417333.
  3. ↑ Gass, H.; Liebert, James; Wehrse, R. (1988). "Spectrum analysis of the extremely metal-poor carbon dwarf star G 77-61". Astronomy and Astrophysics. 189: 194. Bibcode:1988A&A...189..194G.
  4. ↑ Barrington, R. E.; Belrose, J. S. (1963). "Preliminary Results from the Very-Low Frequency Receiver Aboard Canada's Alouette Satellite". Nature. 198 (4881): 651–656. Bibcode:1963Natur.198..651B. doi:10.1038/198651a0. S2CID   41012117.
  5. ↑ Park, Seok J.; Vishniac, Ethan T. (1991). "Are Hypernovae Detectable?". The Astrophysical Journal. 375: 565. Bibcode:1991ApJ...375..565P. doi:10.1086/170217.
  6. 1 2 Bloom (1998). "The Host Galaxy of GRB 970508". The Astrophysical Journal. 507 (507): L25–28. arXiv: astro-ph/9807315 . Bibcode:1998ApJ...507L..25B. doi:10.1086/311682. S2CID   18107687.
  7. ↑ Paczynski (1997). GRBs as Hypernovae. Huntsville Gamma-Ray Burst Symposium. arXiv: astro-ph/9712123 . Bibcode:1997astro.ph.12123P.
  8. ↑ David S. Stevenson (5 September 2013). Extreme Explosions: Supernovae, Hypernovae, Magnetars, and Other Unusual Cosmic Blasts. Springer Science & Business Media. ISBN   978-1-4614-8136-2. Archived from the original on 25 January 2022. Retrieved 18 August 2019.
  9. ↑ Woosley (1999). "Gamma-Ray Bursts and Type Ic Supernovae: SN 1998bw". The Astrophysical Journal. 516 (2): 788–796. arXiv: astro-ph/9806299 . Bibcode:1999ApJ...516..788W. doi:10.1086/307131. S2CID   17690696.
  10. ↑ Moriya, Takashi J.; Sorokina, Elena I.; Chevalier, Roger A. (2018). "Superluminous Supernovae". Space Science Reviews. 214 (2): 59. arXiv: 1803.01875 . Bibcode:2018SSRv..214...59M. doi:10.1007/s11214-018-0493-6. S2CID   119199790.
  11. ↑ Jessica Orwig (January 14, 2016). "Astronomers are baffled by a newly discovered cosmic explosion that shines 570 billion times brighter than the sun". Business Insider . Archived from the original on April 2, 2016. Retrieved March 22, 2016.
  12. ↑ Wiseman, P.; et al. (2023). ""Multiwavelength observations of the extraordinary accretion event AT2021lwx"". Monthly Notices of the Royal Astronomical Society. 522 (3): 3992–4002. arXiv: 2303.04412 . doi: 10.1093/mnras/stad1000 .
  13. 1 2 Nomoto, Ken'Ichi; Maeda, Keiichi; Mazzali, Paolo A.; Umeda, Hideyuki; Deng, Jinsong; Iwamoto, Koichi (2004). "Hypernovae and Other Black-Hole-Forming Supernovae". Stellar Collapse. Astrophysics and Space Science Library. Vol. 302. pp. 277–325. arXiv: astro-ph/0308136 . Bibcode:2004ASSL..302..277N. doi:10.1007/978-0-306-48599-2_10. ISBN   978-90-481-6567-4. S2CID   119421669.
  14. ↑ Mazzali, P. A.; Nomoto, K.; Deng, J.; Maeda, K.; Tominaga, N. (2005). "The Properties of Hypernovae in Gamma Ray Bursts". 1604-2004: Supernovae as Cosmological Lighthouses. 342: 366. Bibcode:2005ASPC..342..366M.
  15. ↑ Mösta, Philipp; Richers, Sherwood; Ott, Christian D.; Haas, Roland; Piro, Anthony L.; Boydstun, Kristen; Abdikamalov, Ernazar; Reisswig, Christian; Schnetter, Erik (2014). "Magnetorotational Core-Collapse Supernovae in Three Dimensions". The Astrophysical Journal. 785 (2): L29. arXiv: 1403.1230 . Bibcode:2014ApJ...785L..29M. doi:10.1088/2041-8205/785/2/L29. S2CID   17989552.
  16. ↑ Nakauchi, Daisuke; Kashiyama, Kazumi; Nagakura, Hiroki; Suwa, Yudai; Nakamura, Takashi (2015). "Optical Synchrotron Precursors of Radio Hypernovae". The Astrophysical Journal. 805 (2): 164. arXiv: 1411.1603 . Bibcode:2015ApJ...805..164N. doi:10.1088/0004-637X/805/2/164. S2CID   118228337.
  17. ↑ "Hypernova | COSMOS". astronomy.swin.edu.au. Retrieved 2024-07-05.
  18. ↑ Nomoto, Ken'Ichi; Moriya, Takashi; Tominaga, Nozomu (2009). "Nucleosynthesis of the Elements in Faint Supernovae and Hypernovae". Proceedings of the International Astronomical Union. 5: 34–41. doi: 10.1017/S1743921310000128 .
  19. ↑ Fujimoto, S. I.; Nishimura, N.; Hashimoto, M. A. (2008). "Nucleosynthesis in Magnetically Driven Jets from Collapsars". The Astrophysical Journal. 680 (2): 1350–1358. arXiv: 0804.0969 . Bibcode:2008ApJ...680.1350F. doi:10.1086/529416. S2CID   118559576.
  20. ↑ Tauris, T. M.; Langer, N.; Moriya, T. J.; Podsiadlowski, Ph.; Yoon, S.-C.; Blinnikov, S. I. (2013). "ULTRA-STRIPPED TYPE Ic SUPERNOVAE FROM CLOSE BINARY EVOLUTION". The Astrophysical Journal. 778 (2): L23. arXiv: 1310.6356 . Bibcode:2013ApJ...778L..23T. doi:10.1088/2041-8205/778/2/L23. S2CID   50835291.
  21. ↑ Ruffini, R.; Karlica, M.; Sahakyan, N.; Rueda, J. A.; Wang, Y.; Mathews, G. J.; Bianco, C. L.; Muccino, M. (2018). "A GRB Afterglow Model Consistent with Hypernova Observations". The Astrophysical Journal. 869 (2): 101. arXiv: 1712.05000 . Bibcode:2018ApJ...869..101R. doi: 10.3847/1538-4357/aaeac8 . S2CID   119449351.

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