Multi-messenger astronomy explained

Multi-messenger astronomy is the coordinated observation and interpretation of multiple signals received from the same astronomical event. Many types of cosmological events involve complex interactions between a variety of astrophysical processes, each of which may independently emit signals of a characteristic "messenger" type: electromagnetic radiation (including visible light), gravitational waves, neutrinos, and cosmic rays. When received on Earth, identifying that disparate observations were generated by the same source can allow for improved reconstruction or a better understanding of the event, and reveals more information about the source.

The main multi-messenger sources outside the heliosphere are expected to be compact binary pairs (black holes and neutron stars), supernovae, irregular neutron stars, gamma-ray bursts, active galactic nuclei, and relativistic jets.^{[1] [2] [3]} The table below lists several types of events and expected messengers.

Detection from one messenger and non-detection from a different messenger can also be informative.^[4] Lack of any electromagnetic counterpart, for example, could be evidence in support of the remnant being a black hole.

Event type	Electromagnetic	Cosmic rays		Neutrinos	Example
	yes	yes	-	-	SOL1942-02-28
	yes	-	predicted^[5]	yes	SN 1987A
	yes	-	yes	predicted^[6]	GW170817
	yes	possible	-	yes	TXS 0506+056 (IceCube)
Active galactic nucleus	yes	possible		yes	Messier 77^[7] ^[8] (IceCube)
	yes	possible	possible	yes	AT2019dsg (IceCube)AT2019fdr^[9] (IceCube)

Networks

The Supernova Early Warning System (SNEWS), established in 1999 at Brookhaven National Laboratory and automated since 2005, combines multiple neutrino detectors to generate supernova alerts. (See also neutrino astronomy).

The Astrophysical Multimessenger Observatory Network (AMON),^[10] created in 2013,^[11] is a broader and more ambitious project to facilitate the sharing of preliminary observations and to encourage the search for "sub-threshold" events which are not perceptible to any single instrument. It is based at Pennsylvania State University.

Milestones

• 1940s: Some cosmic rays are identified as forming in solar flares.^[12]
• 1987: Supernova SN 1987A emitted neutrinos that were detected at the Kamiokande-II, IMB and Baksan neutrino observatories, a couple of hours before the supernova light was detected with optical telescopes.
• August 2017: A neutron star collision in the galaxy NGC 4993 produced the gravitational wave signal GW170817, which was observed by the LIGO/Virgo collaboration. After 1.7 seconds, it was observed as the gamma ray burst GRB 170817A by the Fermi Gamma-ray Space Telescope and INTEGRAL, and its optical counterpart SSS17a was detected 11 hours later at the Las Campanas Observatory, then by the Hubble Space Telescope and the Dark Energy Camera. Ultraviolet observations by the Neil Gehrels Swift Observatory, X-ray observations by the Chandra X-ray Observatory and radio observations by the Karl G. Jansky Very Large Array complemented the detection. This was the first gravitational wave event observed with an electromagnetic counterpart, thereby marking a significant breakthrough for multi-messenger astronomy.^[13] Non-observation of neutrinos was attributed to the jets being strongly off-axis.^[14] In October 2020, astronomers reported lingering X-ray emission from GW170817/GRB 170817A/SSS17a.^[15]
• September 2017 (announced July 2018): On September 22, the extremely-high-energy^[16] (about 290 TeV) neutrino event IceCube-170922A^[17] was recorded by the IceCube Collaboration,^{[18] [19]} which sent out an alert with coordinates for the possible source. The detection of gamma rays above 100 MeV by the Fermi-LAT Collaboration^[20] and between 100 GeV and 400 GeV by the MAGIC Collaboration^[21] from the blazar TXS 0506+056 (reported September 28 and October 4, respectively) was deemed positionally consistent with the neutrino signal. The signals can be explained by ultra-high-energy protons accelerated in blazar jets, producing neutral pions (decaying into gamma rays) and charged pions (decaying into neutrinos).^[22] This is the first time that a neutrino detector has been used to locate an object in space and a source of cosmic rays has been identified.^{[23] [24] [25] [26] [27]}
• October 2019 (announced February 2021): On October 1, a high energy neutrino was detected at IceCube and follow-up measurements in visible light, ultraviolet, x-rays and radio waves identified the tidal disruption event AT2019dsg as possible source.^[28]
• November 2019 (announced June 2022): A second high energy neutrino detected by IceCube associated with a tidal disruption event AT2019fdr.^[29]
• June 2023: Astronomers used a new cascade neutrino technique^[30] to detect, for the first time, the release of neutrinos from the galactic plane of the Milky Way galaxy, creating the first neutrino-based galactic map.^{[31] [32]}

External links

• AMON website

Notes and References

1. Book: Bartos. Imre. Kowalski. Marek. Multimessenger Astronomy. 2017. IOP Publishing. 10.1088/978-0-7503-1369-8. 2017muas.book.....B. 978-0-7503-1369-8.
2. Multimessenger Astronomy with Neutrinos. Anna. Franckowiak. Journal of Physics: Conference Series. 888. 12009. 012009. 10.1088/1742-6596/888/1/012009. 2017JPhCS.888a2009F. 2017. free.
3. Marica. Branchesi. 2016. Multi-messenger astronomy: gravitational waves, neutrinos, photons, and cosmic rays. Journal of Physics: Conference Series. 718. 22004. 022004. 10.1088/1742-6596/718/2/022004. 2016JPhCS.718b2004B. free.
4. J.. Abadie. The LIGO Collaboration. 2012. Implications for the origins of GRB 051103 from the LIGO observations. The Astrophysical Journal. 755. 2. 1. 10.1088/0004-637X/755/1/2. 1201.4413. 2012ApJ...755....2A. 15494223.
5. Supernova Theory Group: Core-Collapse Supernova Gravitational Wave Signature Catalog
6. Web site: No neutrino emission from a binary neutron star merger. 16 October 2017. 20 July 2018.
7. IceCube Collaboration*† . Abbasi . R. . Ackermann . M. . Adams . J. . Aguilar . J. A. . Ahlers . M. . Ahrens . M. . Alameddine . J. M. . Alispach . C. . Alves . A. A. . Amin . N. M. . Andeen . K. . Anderson . T. . Anton . G. . Argüelles . C. . 2022-11-04 . Evidence for neutrino emission from the nearby active galaxy NGC 1068 . Science . en . 378 . 6619 . 538–543 . 10.1126/science.abg3395 . 36378962 . 2211.09972 . 2022Sci...378..538I . 1854/LU-01GSA90WVKWXWD30RYFKKK1XC6 . 253320297 . 0036-8075.
8. Web site: Staff . IceCube neutrinos give us first glimpse into the inner depths of an active galaxy . 2022-11-23 . IceCube . 3 November 2022 . en-US.
9. Reusch . Simeon . Stein . Robert . Kowalski . Marek . van Velzen . Sjoert . Franckowiak . Anna . Lunardini . Cecilia . Murase . Kohta . Winter . Walter . Miller-Jones . James C. A. . Kasliwal . Mansi M. . Gilfanov . Marat . 2022-06-03 . Candidate Tidal Disruption Event AT2019fdr Coincident with a High-Energy Neutrino . Physical Review Letters . 128 . 22 . 221101 . 10.1103/PhysRevLett.128.221101. 35714251 . 2111.09390 . 2022PhRvL.128v1101R . 20.500.11937/90027 . 244345574 .
10. http://amon.gravity.psu.edu/ AMON home page
11. The Astrophysical Multimessenger Observatory Network (AMON) . M.W.E. . Smith . etal . Astroparticle Physics . 45 . May 2013 . 56–70 . 10.1016/j.astropartphys.2013.03.003 . 1211.5602 . 2013APh....45...56S . 2060/20140006956 . 55937718 .
12. Book: Spurio, Maurizio . Particles and Astrophysics: A Multi-Messenger Approach. 2015. Springer. 46. 978-3-319-08050-5 . 10.1007/978-3-319-08051-2. Astronomy and Astrophysics Library .
13. News: Landau . Elizabeth . Chou . Felicia . Washington . Dewayne . Porter . Molly . NASA Missions Catch First Light from a Gravitational-Wave Event. 16 October 2017 . . 17 October 2017 .
14. Search for high-energy neutrinos from binary neutron star merger GW170817 with ANTARES, IceCube, and the Pierre Auger Observatory. The Astrophysical Journal. 850. 2. L35. Albert. A.. ANTARES, IceCube, and the Pierre Auger Observatory. 16 Oct 2017. 1710.05839. 10.3847/2041-8213/aa9aed. 2017ApJ...850L..35A. 217180814. free.
15. Web site: Starr . Michelle . 2020-10-12 . Astronomers Detect Eerie Glow Still Radiating From Neutron Star Collision Years Later . 2023-01-04 . ScienceAlert . en-US.
16. The New Era of Multimessenger Astronomy . 318 . 5 . 36–41 . 10.1038/scientificamerican0518-36 . 29672499 . Scientific American . 2017-09-22 . Finkbeiner . A. .
17. https://gcn.gsfc.nasa.gov/gcn/gcn3/21916.gcn3
18. Ghostly particle caught in polar ice ushers in new way to look at the universe. Cleary. D.. Science. 2018-07-12. 10.1126/science.aau7505. 126347626.
19. IceCube Collaboration. Neutrino emission from the direction of the blazar TXS 0506+056 prior to the IceCube-170922A alert. Science. 361. 6398. 2018-07-12. 147–151. 10.1126/science.aat2890. 30002248. 1807.08794. 2018Sci...361..147I. 133261745.
20. Web site: ATel #10791: Fermi-LAT detection of increased gamma-ray activity of TXS 0506+056, located inside the IceCube-170922A error region.
21. Web site: Razmik . Mirzoyan . ATel #10817: First-time detection of VHE gamma rays by MAGIC from a direction consistent with the recent EHE neutrino event IceCube-170922A . Astronomerstelegram.org . 2017-10-04 . 2018-07-16.
22. Book: Introduction to particle and astroparticle physics (multimessenger astronomy and its particle physics foundations). Alessandro . De Angelis . Mario . Pimenta . 2018. Springer. 978-3-319-78181-5. 10.1007/978-3-319-78181-5.
23. Multimessenger observations of a flaring blazar coincident with high-energy neutrino IceCube-170922A . The IceCube Collaboration, Fermi-LAT, MAGIC, AGILE, ASAS-SN, HAWC, H.E.S.S., INTEGRAL, Kanata, Kiso, Kapteyn, Liverpool Telescope, Subaru, Swift/NuSTAR, VERITAS, VLA/17B-403 teams. Aartsen . . 12 July 2018 . 361 . 6398 . eaat1378 . 10.1126/science.aat1378. 30002226. 1807.08816 . 2018Sci...361.1378I. 49734791.
24. Neutrino emission from the direction of the blazar TXS 0506+056 prior to the IceCube-170922A alert . IceCube Collaboration . Aartsen . Science . 12 July 2018 . 361 . 6398 . 147–151 . 10.1126/science.aat2890. 30002248 . 1807.08794 . 2018Sci...361..147I . 133261745 .
25. News: Overbye . Dennis . Dennis Overbye . It Came From a Black Hole, and Landed in Antarctica - For the first time, astronomers followed cosmic neutrinos into the fire-spitting heart of a supermassive blazar. . July 12, 2018 . . July 13, 2018 .
26. Web site: Neutrino that struck Antarctica traced to galaxy 3.7bn light years away . The Guardian . July 12, 2018 . July 12, 2018 .
27. Web site: Source of cosmic 'ghost' particle revealed . BBC . July 12, 2018 . 12 July 2018 .
28. https://www.nature.com/articles/s41550-020-01295-8 A tidal disruption event coincident with a high-energy neutrino
29. Buchanan . Mark . 2022-06-03 . Neutrinos from a Black Hole Snack . Physics . en . 15. 77 . 10.1103/Physics.15.77 . 2022PhyOJ..15...77B . 251078776 . free .
30. Wright . Katherine . Milky Way Viewed through Neutrinos . Physics . 2023 . 16 . 115 . Physics 16, 115 (29 June 2023) . 10.1103/Physics.16.115 . Kurahashi Neilson first came up with the idea to use cascade neutrinos to map the Milky Way in 2015.. free . 2023PhyOJ..16..115W .
31. News: Chang . Kenneth . Neutrinos Build a Ghostly Map of the Milky Way - Astronomers for the first time detected neutrinos that originated within our local galaxy using a new technique. . . 29 June 2023 . live . https://archive.today/20230629182106/https://www.nytimes.com/2023/06/29/science/neutrinos-milky-way-map.html . 29 June 2023 . 30 June 2023 .
32. IceCube Collaboration . Observation of high-energy neutrinos from the Galactic plane . 29 June 2023 . Science . 380 . 6652 . 1338–1343 . 10.1126/science.adc9818 . 37384687 . live . https://archive.today/20230630042539/https://www.science.org/doi/10.1126/science.adc9818 . 30 June 2023 . 30 June 2023 . 2307.04427 .