Kilonova

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Artist's impression of neutron stars merging, producing gravitational waves and resulting in a kilonova Eso1733s Artist's impression of merging neutron stars.jpg
Artist's impression of neutron stars merging, producing gravitational waves and resulting in a kilonova
Kilonova illustration Kilonova illustration.png
Kilonova illustration

A kilonova (also called a macronova) is a transient astronomical event that occurs in a compact binary system when two neutron stars or a neutron star and a black hole merge. [1] These mergers are thought to produce gamma-ray bursts and emit bright electromagnetic radiation, called "kilonovae", due to the radioactive decay of heavy r-process nuclei that are produced and ejected fairly isotropically during the merger process. [2] [3] The measured high sphericity of the kilonova AT2017gfo at early epochs was deduced from the blackbody nature of its spectrum. [4] [5]

Contents

History

Animation showing two small, very dense neutron stars merge via gravitational wave radiation and explode as a kilonova

The existence of thermal transient events from neutron star mergers was first introduced by Li & Paczyński in 1998. [1] The radioactive glow arising from the merger ejecta was originally called mini-supernova, as it is 110 to 1100 the brightness of a typical supernova, the self-detonation of a massive star. [6] The term kilonova was later introduced by Metzger et al. in 2010 [7] to characterize the peak brightness, which they showed reaches 1000 times that of a classical nova.

The first candidate kilonova to be found was detected as a short gamma-ray burst, GRB 130603B, by instruments on board the Swift Gamma-Ray Burst Explorer and KONUS/WIND spacecraft and then observed using the Hubble Space Telescope 9 and 30 days after burst. [8]

This artist's impression shows a kilonova produced by two colliding neutron stars. Noirlab2228a - Artist's impression of colliding neutron stars.jpg
This artist's impression shows a kilonova produced by two colliding neutron stars.

On October 16, 2017, the LIGO and Virgo collaborations announced the first simultaneous detections of gravitational waves (GW170817) and electromagnetic radiation (GRB 170817A and AT 2017gfo) [9] and demonstrated that the source was a binary neutron star merger. [10] This merger was followed by a short GRB (GRB 170817A) and a longer lasting transient visible for weeks in the optical and near-infrared electromagnetic spectrum (AT 2017gfo) located in a relatively nearby galaxy, NGC 4993. [11] Observations of AT 2017gfo confirmed that it was the first conclusive observation of a kilonova. [12] Spectral modelling of AT2017gfo identified the r-process elements strontium and yttrium, which conclusively ties the formation of heavy elements to neutron-star mergers. [13] [14] Further modelling showed the ejected fireball of heavy elements was highly spherical in early epochs. [4] [15] It has been suggested that "Thanks to this work, astronomers could use kilonovae as a standard candle to measure cosmic expansion. Since kilonovae explosions are spherical, astronomers could compare the apparent size of a supernova explosion with its actual size as seen by the gas motion, and thus measure the rate of cosmic expansion at different distances." [16]

Theory

The inspiral and merging of two compact objects are a strong source of gravitational waves (GW). [7] The basic model for thermal transients from neutron star mergers was introduced by Li-Xin Li and Bohdan Paczyński in 1998. [1] In their work, they suggested that the radioactive ejecta from a neutron star merger is a source for powering thermal transient emission, later dubbed kilonova. [17]

Observations

First kilonova observations by the Hubble Space Telescope Hubble observes first kilonova.jpg
First kilonova observations by the Hubble Space Telescope

A first observational suggestion of a kilonova came in 2008 following the gamma-ray burst GRB 080503, [19] where a faint object appeared in optical light after one day and rapidly faded. However, other factors such as the lack of a galaxy and the detection of X-rays were not in agreement with the hypothesis of a kilonova. Another kilonova was suggested in 2013, in association with the short-duration gamma-ray burst GRB 130603B, where the faint infrared emission from the distant kilonova was detected using the Hubble Space Telescope. [8]

In October 2017, astronomers reported that observations of AT 2017gfo showed that it was the first secure case of a kilonova following a merger of two neutron stars. [12]

Fading kilonova in GRB160821B seen by the Hubble Space Telescope. GRB160821B.gif
Fading kilonova in GRB160821B seen by the Hubble Space Telescope.

In October 2018, astronomers reported that GRB 150101B, a gamma-ray burst event detected in 2015, may be analogous to the historic GW170817. The similarities between the two events, in terms of gamma ray, optical and x-ray emissions, as well as to the nature of the associated host galaxies, are considered "striking", and this remarkable resemblance suggests the two separate and independent events may both be the result of the merger of neutron stars, and both may be a hitherto-unknown class of kilonova transients. Kilonova events, therefore, may be more diverse and common in the universe than previously understood, according to the researchers. [20] [21] [22] [23] In retrospect, GRB 160821B, a gamma-ray burst detected in August 2016, is now believed to also have been due to a kilonova, by its resemblance of its data to AT2017gfo. [24]

A kilonova was also thought to have caused the long gamma-ray burst GRB 211211A, discovered in December 2021 by Swift’s Burst Alert Telescope (BAT) and the Fermi Gamma-ray Burst Monitor (GBM). [25] [26] These discoveries challenge the formerly prevailing theory that long GRBs exclusively come from supernovae, the end-of-life explosions of massive stars. [27] GRB 211211A lasted 51s; [28] [29] GRB 191019A (2019) [30] and GRB 230307A (2023), [31] [32] with durations of around 64s and 35s respectively, have been also argued to belong to this class of long GBRs from neutron star mergers. [33]

In 2023, GRB 230307A was observed and associated with tellurium and lanthanides. [34]

See also

Related Research Articles

<span class="mw-page-title-main">Neutron star</span> Collapsed core of a massive star

A neutron star is a collapsed core of a massive supergiant star. The stars that later collapse into neutron stars have a total mass of between 10 and 25 solar masses (M), possibly more if the star was especially rich in elements heavier than hydrogen and helium. Except for black holes, neutron stars are the smallest and densest known class of stellar objects. Neutron stars have a radius on the order of 10 kilometers (6 mi) and a mass of about 1.4 M. They result from the supernova explosion of a massive star, combined with gravitational collapse, that compresses the core past white dwarf star density to that of atomic nuclei.

<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, described by NASA as "the most powerful class of explosions in the universe". They are the most energetic and luminous electromagnetic events since the Big Bang. Bursts can last from ten milliseconds to several hours. After an initial flash of gamma rays, a longer-lived "afterglow" is usually emitted at longer wavelengths.

<i>r</i>-process Nucleosynthesis pathway

In nuclear astrophysics, the rapid neutron-capture process, also known as the r-process, is a set of nuclear reactions that is responsible for the creation of approximately half of the atomic nuclei heavier than iron, the "heavy elements", with the other half produced by the p-process and s-process. The r-process usually synthesizes the most neutron-rich stable isotopes of each heavy element. The r-process can typically synthesize the heaviest four isotopes of every heavy element; of these, the heavier two are called r-only nuclei because they are created exclusively via the r-process. Abundance peaks for the r-process occur near mass numbers A = 82, A = 130 and A = 196.

<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.

Nial Rahil Tanvir is a British astronomer at the University of Leicester. His research specialisms are the Extragalactic distance scale, Galaxy evolution and Gamma ray bursts. Tanvir has featured in various TV programs, including The Sky at Night hosted by Sir Patrick Moore, and Horizon

<span class="mw-page-title-main">Stellar collision</span> Coming together of two stars

A stellar collision is the coming together of two stars caused by stellar dynamics within a star cluster, or by the orbital decay of a binary star due to stellar mass loss or gravitational radiation, or by other mechanisms not yet well understood.

<span class="mw-page-title-main">GRB 101225A</span> Gamma-ray burst event of December 25, 2010

GRB 101225A, also known as the "Christmas burst", was a cosmic explosion first detected by NASA's Swift observatory on Christmas Day 2010. The gamma-ray emission lasted at least 28 minutes, which is unusually long. Follow-up observations of the burst's afterglow by the Hubble Space Telescope and ground-based observatories were unable to determine the object's distance using spectroscopic methods.

<span class="mw-page-title-main">Tsvi Piran</span> Israeli theoretical physicist and astrophysicist (born 1949)

Tsvi Piran is an Israeli theoretical physicist and astrophysicist, best known for his work on Gamma-ray Bursts (GRBs) and on numerical relativity. The recipient of the 2019 EMET prize award in Physics and Space Research.

<span class="mw-page-title-main">Neutron star merger</span> Type of stellar collision

A neutron star merger is the stellar collision of neutron stars.

Multi-messenger astronomy is astronomy based on the coordinated observation and interpretation of signals carried by disparate "messengers": electromagnetic radiation, gravitational waves, neutrinos, and cosmic rays. They are created by different astrophysical processes, and thus reveal different information about their sources.

<span class="mw-page-title-main">Hypernova</span> Supernova that ejects a large mass at unusually high velocity

A hypernova is a very energetic supernova which is believed to result from an extreme core-collapse scenario. In this case, a massive star 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 so much of gamma rays they usually 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.

<span class="mw-page-title-main">GW170817</span> Gravitational-wave signal detected in 2017

GW 170817 was a gravitational wave (GW) signal observed by the LIGO and Virgo detectors on 17 August 2017, originating from the shell elliptical galaxy NGC 4993. The signal was produced by the last moments of the inspiral process of a binary pair of neutron stars, ending with their merger. It is the first GW observation that has been confirmed by non-gravitational means. Unlike the five previous GW detections—which were of merging black holes and thus not expected to produce a detectable electromagnetic signal—the aftermath of this merger was seen across the electromagnetic spectrum by 70 observatories on 7 continents and in space, marking a significant breakthrough for multi-messenger astronomy. The discovery and subsequent observations of GW 170817 were given the Breakthrough of the Year award for 2017 by the journal Science.

<span class="mw-page-title-main">NGC 4993</span> Galaxy in the constellation of Hydra

NGC 4993 is a lenticular galaxy located about 140 million light-years away in the constellation Hydra. It was discovered on 26 March 1789 by William Herschel and is a member of the NGC 4993 Group.

<span class="mw-page-title-main">GRB 150101B</span>

GRB 150101B is a gamma-ray burst (GRB) that was detected on 1 January 2015 at 15:23 UT by the Burst Alert Telescope (BAT) on board the Swift Observatory Satellite, and at 15:23:35 UT by the Gamma-ray Burst Monitor (GBM) on board the Fermi Gamma-ray Space Telescope. The GRB was determined to be 1.7 billion light-years (0.52 Gpc) from Earth near the host galaxy 2MASX J12320498-1056010 in the constellation Virgo. The characteristics of GRB 150101B are remarkably similar to the historic event GW170817, a merger of neutron stars.

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

GRB 190114C was an extreme gamma-ray burst explosion from a galaxy 4.5 billion light years away (z=0.4245; magnitude=15.60est) near the Fornax constellation, that was initially detected in January 2019. The afterglow light emitted soon after the burst was found to be tera-electron volt radiation from inverse Compton emission, identified for the first time. According to the astronomers, "We observed a huge range of frequencies in the electromagnetic radiation afterglow of GRB 190114C. It is the most extensive to date for a gamma-ray burst." Also, according to other astronomers, "light detected from the object had the highest energy ever observed for a GRB: 1 Tera electron volt (TeV) -- about one trillion times as much energy per photon as visible light"; another source stated, "the brightest light ever seen from Earth [to date].".

<span class="mw-page-title-main">Fast blue optical transient</span> Astronomical observation

In astronomy, a fast blue optical transient (FBOT), or more specifically, luminous fast blue optical transient (LFBOT), is an explosive transient event similar to supernovae and gamma-ray bursts with high optical luminosity, rapid evolution, and predominantly blue emission. The origins of such explosions are currently unclear, with events occurring at not more than 0.1% of the typical core-collapse supernova rate. This class of transients initially emerged from large sky surveys at cosmological distances, yet in recent years a small number have been discovered in the local Universe, most notably AT 2018cow.

<span class="mw-page-title-main">GRB 221009A</span> Gamma-ray burst

GRB 221009A, also known as Swift J1913.1+1946, was an extraordinarily bright and long-lasting gamma-ray burst (GRB) jointly discovered by the Neil Gehrels Swift Observatory and the Fermi Gamma-ray Space Telescope on October 9, 2022. The gamma-ray burst was around seven minutes long, but was detectable for more than ten hours following initial detection. Despite being around two billion light-years away, it was powerful enough to affect Earth's atmosphere, having the strongest effect ever recorded by a gamma-ray burst on the planet. The peak luminosity of GRB 221009A was measured by Konus-Wind to be ~ 2.1 × 1047 W and by Fermi Gamma-ray Burst Monitor to be ~ 1.0 × 1047 W over its 1.024s interval. A burst as energetic and as close to Earth as 221009A is thought to be a once-in-10,000-year event. It was the brightest and most energetic gamma-ray burst ever recorded, with some dubbing it the BOAT, or Brightest Of All Time.

<span class="mw-page-title-main">GRB 230307A</span>

GRB 230307A was an extremely bright, long duration gamma-ray burst (GRB), likely produced as a consequence of a neutron star merger or black hole - neutron star merger event. The gamma-ray burst was observed to have a gamma ray fluence of 3×10-4 erg cm-2 in the 10 to 1000 KeV (electronvolt) range making it second only to GRB 221009A, which was an extremely bright and long duration gamma ray burst deemed to be the Brightest Of All Time (B.O.A.T.). This also means that it is 1000 times more powerful than a typical gamma-ray burst. The burst had the second-highest gamma-ray fluence ever recorded. The James Webb Space Telescope (JWST) detected the chemical signature for tellurium (Te). The neutron stars were once part of a spiral galaxy (host galaxy) but were kicked out via gravitational interactions. Then while outside of the main galaxy at a distance of 120,000 light years, they merged, creating GRB 230307A.

<span class="mw-page-title-main">GRB 200522A</span> An extremely rare and bright kilanova

GRB 200522A is a large kilonova in the Constellation Pisces. It was first observed in May 2020 by the Hubble Space Telescope. It is the result of the largest neutron star explosion ever recorded, and was bright enough to be visible by Hubble 5.4 billion light years away.

References

  1. 1 2 3 Li, L.-X.; Paczyński, B.; Fruchter, A. S.; Hjorth, J.; Hounsell, R. A.; Wiersema, K.; Tunnicliffe, R. (1998). "Transient Events from Neutron Star Mergers". The Astrophysical Journal. 507 (1): L59–L62. arXiv: astro-ph/9807272 . Bibcode:1998ApJ...507L..59L. doi:10.1086/311680. S2CID   3091361.
  2. Metzger, Brian D. (2019-12-16). "Kilonovae". Living Reviews in Relativity. 23 (1): 1. Bibcode:2019LRR....23....1M. doi:10.1007/s41114-019-0024-0. ISSN   1433-8351. PMC   6914724 . PMID   31885490.
  3. Rosswog, Stephan (2015-04-01). "The multi-messenger picture of compact binary mergers". International Journal of Modern Physics D. 24 (5): 1530012–1530052. arXiv: 1501.02081 . Bibcode:2015IJMPD..2430012R. doi:10.1142/S0218271815300128. ISSN   0218-2718. S2CID   118406320.
  4. 1 2 Sneppen, Albert; Watson, Darach; Bauswein, Andreas; Just, Oliver; Kotak, Rubina; Nakar, Ehud; Poznanski, Dovi; Sim, Stuart (February 2023). "Spherical symmetry in the kilonova AT2017gfo/GW170817". Nature. 614 (7948): 436–439. arXiv: 2302.06621 . Bibcode:2023Natur.614..436S. doi:10.1038/s41586-022-05616-x. ISSN   1476-4687. PMID   36792736. S2CID   256846834.
  5. Sneppen, Albert (2023-09-01). "On the Blackbody Spectrum of Kilonovae". The Astrophysical Journal. 955 (1): 44. arXiv: 2306.05452 . Bibcode:2023ApJ...955...44S. doi: 10.3847/1538-4357/acf200 . ISSN   0004-637X.
  6. "Hubble captures infrared glow of a kilonova blast". spacetelescope.org. 5 August 2013. Retrieved 28 February 2018.
  7. 1 2 Metzger, B. D.; Martínez-Pinedo, G.; Darbha, S.; Quataert, E.; Arcones, A.; Kasen, D.; Thomas, R.; Nugent, P.; Panov, I. V.; Zinner, N. T. (August 2010). "Electromagnetic counterparts of compact object mergers powered by the radioactive decay of r-process nuclei". Monthly Notices of the Royal Astronomical Society. 406 (4): 2650. arXiv: 1001.5029 . Bibcode:2010MNRAS.406.2650M. doi:10.1111/j.1365-2966.2010.16864.x. S2CID   118863104.
  8. 1 2 Tanvir, N. R.; Levan, A. J.; Fruchter, A. S.; Hjorth, J.; Hounsell, R. A.; Wiersema, K.; Tunnicliffe, R. L. (2013). "A 'kilonova' associated with the short-duration γ-ray burst GRB 130603B". Nature. 500 (7464): 547–549. arXiv: 1306.4971 . Bibcode:2013Natur.500..547T. doi:10.1038/nature12505. PMID   23912055. S2CID   205235329.
  9. Abbott, B. P.; Abbott, R.; Abbott, T. D.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; et al. (LIGO Scientific Collaboration & Virgo Collaboration) (16 October 2017). "GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral". Physical Review Letters. 119 (16): 161101. arXiv: 1710.05832 . Bibcode:2017PhRvL.119p1101A. doi:10.1103/PhysRevLett.119.161101. PMID   29099225. S2CID   217163611.
  10. Miller, M. Coleman (16 October 2017). "Gravitational waves: A golden binary". Nature. News and Views (7678): 36. Bibcode:2017Natur.551...36M. doi: 10.1038/nature24153 .
  11. Berger, E. (16 October 2017). "Focus on the Electromagnetic Counterpart of the Neutron Star Binary Merger GW170817". Astrophysical Journal Letters. Retrieved 16 October 2017.
  12. 1 2 Abbott, B. P.; Abbott, R.; Abbott, T. D.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Afrough, M.; Agarwal, B.; Agathos, M.; Agatsuma, K. (2017-10-16). "Multi-messenger Observations of a Binary Neutron Star Merger". The Astrophysical Journal. 848 (2): L12. arXiv: 1710.05833 . Bibcode:2017ApJ...848L..12A. doi: 10.3847/2041-8213/aa91c9 . ISSN   2041-8213. S2CID   217162243.
  13. Watson, Darach; Hansen, Camilla J.; Selsing, Jonatan; Koch, Andreas; Malesani, Daniele B.; Andersen, Anja C.; Fynbo, Johan P. U.; Arcones, Almudena; Bauswein, Andreas; Covino, Stefano; Grado, Aniello; Heintz, Kasper E.; Hunt, Leslie; Kouveliotou, Chryssa; Leloudas, Giorgos (October 2019). "Identification of strontium in the merger of two neutron stars". Nature. 574 (7779): 497–500. arXiv: 1910.10510 . Bibcode:2019Natur.574..497W. doi:10.1038/s41586-019-1676-3. ISSN   1476-4687. PMID   31645733. S2CID   204837882.
  14. Sneppen, Albert; Watson, Darach (2023-07-01). "Discovery of a 760 nm P Cygni line in AT2017gfo: Identification of yttrium in the kilonova photosphere". Astronomy & Astrophysics. 675: A194. arXiv: 2306.14942 . Bibcode:2023A&A...675A.194S. doi:10.1051/0004-6361/202346421. ISSN   0004-6361.
  15. "What happens when two neutron stars collide? A 'perfect' explosion". Washington Post. ISSN   0190-8286 . Retrieved 2023-02-18.
  16. "When Neutron Stars Collide, the Explosion is Perfectly Spherical". 17 February 2023.
  17. Metzger, Brian D. (2019-12-16). "Kilonovae". Living Reviews in Relativity. 23 (1): 1. arXiv: 1910.01617 . Bibcode:2019LRR....23....1M. doi:10.1007/s41114-019-0024-0. ISSN   1433-8351. PMC   6914724 . PMID   31885490.
  18. "Hubble observes source of gravitational waves for the first time". www.spacetelescope.org. Retrieved 18 October 2017.
  19. Perley, D. A.; Metzger, B. D.; Granot, J.; Butler, N. R.; Sakamoto, T.; Ramirez-Ruiz, E.; Levan, A. J.; Bloom, J. S.; Miller, A. A. (2009). "GRB 080503: Implications of a Naked Short Gamma-Ray Burst Dominated by Extended Emission". The Astrophysical Journal. 696 (2): 1871–1885. arXiv: 0811.1044 . Bibcode:2009ApJ...696.1871P. doi:10.1088/0004-637X/696/2/1871. S2CID   15196669.
  20. University of Maryland (16 October 2018). "All in the family: Kin of gravitational wave source discovered - New observations suggest that kilonovae -- immense cosmic explosions that produce silver, gold and platinum--may be more common than thought". EurekAlert! . Retrieved 17 October 2018.
  21. Troja, E.; et al. (16 October 2018). "A luminous blue kilonova and an off-axis jet from a compact binary merger at z = 0.1341". Nature Communications . 9 (1): 4089. arXiv: 1806.10624 . Bibcode:2018NatCo...9.4089T. doi:10.1038/s41467-018-06558-7. PMC   6191439 . PMID   30327476.
  22. Mohon, Lee (16 October 2018). "GRB 150101B: A Distant Cousin to GW170817". NASA . Retrieved 17 October 2018.
  23. Wall, Mike (17 October 2018). "Powerful Cosmic Flash Is Likely Another Neutron-Star Merger". Space.com . Retrieved 17 October 2018.
  24. Strickland, Ashley (2019-08-27). "This is what it looks like when an explosion creates gold in space". CNN. Retrieved 2022-12-11.
  25. Reddy, Francis (2022-10-13). "NASA's Swift, Fermi Missions Detect Exceptional Cosmic Blast". NASA. Retrieved 2022-12-11.
  26. "Kilonova Discovery Challenges our Understanding of Gamma-Ray Bursts". Gemini Observatory. 2022-12-07. Retrieved 2022-12-11.
  27. Troja, Eleonora; Dichiara, Simone (21 December 2022). "Unusual, long-lasting gamma-ray burst challenges theories about these powerful cosmic explosions that make gold, uranium and other heavy metals". The Conversation. Retrieved 2022-12-27.
  28. Rastinejad, Jillian C.; Gompertz, Benjamin P.; Levan, Andrew J.; Fong, Wen-fai; Nicholl, Matt; Lamb, Gavin P.; Malesani, Daniele B.; Nugent, Anya E.; Oates, Samantha R.; Tanvir, Nial R.; de Ugarte Postigo, Antonio; Kilpatrick, Charles D.; Moore, Christopher J.; Metzger, Brian D.; Ravasio, Maria Edvige (2022-12-08). "A kilonova following a long-duration gamma-ray burst at 350 Mpc". Nature. 612 (7939): 223–227. arXiv: 2204.10864 . Bibcode:2022Natur.612..223R. doi:10.1038/s41586-022-05390-w. ISSN   0028-0836. PMID   36477128. S2CID   248376822.
  29. Troja, E.; Fryer, C. L.; O’Connor, B.; Ryan, G.; Dichiara, S.; Kumar, A.; Ito, N.; Gupta, R.; Wollaeger, R. T.; Norris, J. P.; Kawai, N.; Butler, N. R.; Aryan, A.; Misra, K.; Hosokawa, R. (2022-12-08). "A nearby long gamma-ray burst from a merger of compact objects". Nature. 612 (7939): 228–231. arXiv: 2209.03363 . Bibcode:2022Natur.612..228T. doi:10.1038/s41586-022-05327-3. ISSN   0028-0836. PMC   9729102 . PMID   36477127.
  30. Levan, Andrew J.; Malesani, Daniele B.; Gompertz, Benjamin P.; Nugent, Anya E.; Nicholl, Matt; Oates, Samantha R.; Perley, Daniel A.; Rastinejad, Jillian; Metzger, Brian D.; Schulze, Steve; Stanway, Elizabeth R.; Inkenhaag, Anne; Zafar, Tayyaba; Agüí Fernández, J. Feliciano; Chrimes, Ashley A. (2023-06-22). "A long-duration gamma-ray burst of dynamical origin from the nucleus of an ancient galaxy". Nature Astronomy. 7 (8): 976–985. arXiv: 2303.12912 . Bibcode:2023NatAs...7..976L. doi:10.1038/s41550-023-01998-8. ISSN   2397-3366. S2CID   257687190.
  31. "GCN - Circulars - 33410: Solar Orbiter STIX observation of GRB 230307A".
  32. "GCN - Circulars - 33412: GRB 230307A: AGILE/MCAL detection".
  33. Wodd, Charlie (11 December 2023). "Extra-Long Blasts Challenge Our Theories of Cosmic Cataclysms". Quanta magazine .
  34. Levan, Andrew; Gompertz, Benjamin P.; Salafia, Om Sharan; Bulla, Mattia; Burns, Eric; Hotokezaka, Kenta; Izzo, Luca; Lamb, Gavin P.; Malesani, Daniele B.; Oates, Samantha R.; Ravasio, Maria Edvige; Rouco Escorial, Alicia; Schneider, Benjamin; Sarin, Nikhil; Schulze, Steve (2023-10-25). "Heavy element production in a compact object merger observed by JWST". Nature. 626 (8000): 737–741. arXiv: 2307.02098 . doi:10.1038/s41586-023-06759-1. ISSN   0028-0836. PMC   10881391 . PMID   37879361. S2CID   264489953.