605:
47:. Discounting the relatively weak effect of gravity, they travel in a straight line from their source to an observer. This is unlike cosmic rays which have their direction of travel scrambled by magnetic fields. Sources that produce cosmic rays will almost certainly produce gamma rays as well, as the cosmic ray particles interact with nuclei or electrons to produce photons or neutral
35:(LHAASO) reported the detection of a dozen ultra-high-energy gamma rays with energies exceeding 1 peta-electron-volt (quadrillion electron-volts or PeV), including one at 1.4 PeV, the highest energy photon ever observed. The authors of the report have named the sources of these PeV gamma rays PeVatrons.
69:
Ultra-high-energy gamma rays interact with magnetic fields to produce positron-electron pairs. In the Earth's magnetic field, a 10 eV photon is expected to interact about 5000 km above the Earth's surface. The high-energy particles then go on to produce more lower energy photons that can suffer
74:. Only magnetic field perpendicular to the path of the photon causes pair production, so that photons coming in parallel to the geomagnetic field lines can survive intact until they meet the atmosphere. These photons coming through the magnetic window can produce Landau–Pomeranchuk–Migdal showers.
70:
the same fate. This effect creates a beam of several 10 eV gamma ray photons heading in the same direction as the original UHE photon. This beam is less than 0.1 m wide when it strikes the atmosphere. These gamma rays are too low-energy to show the
30:
higher than 100 TeV (0.1 PeV). They have a frequency higher than 2.42 × 10 Hz and a wavelength shorter than 1.24 × 10 m. The existence of these rays was confirmed in 2019. In a 18 May 2021 press release, China's
58:
to gamma rays also gives a clue as to the origin of cosmic rays. Although gamma rays could be produced near the source of cosmic rays, they could also be produced by interaction with
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Ultra-high-energy gamma rays are of importance because they may reveal the source of
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Search for
Galactic PeV Gamma Rays with the IceCube Neutrino Observatory
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492:"Ultra-High Energy Gamma Rays in Geomagnetic Field and Atmosphere"
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397:"Highest energy photons ever recorded coming from Crab Nebula"
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Vankov, H. P.; Inoue, N.; Shinozaki, K. (2 February 2008).
48:
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Gamma rays with photon energies higher than 100 TeV
51:which in turn decay to ultra-high-energy photons.
1043:
524:Air shower detection of diffuse PeV gamma-rays
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558:
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33:Large High Altitude Air Shower Observatory
485:
483:
420:
365:explosion of a car tank full of gasoline
1044:
480:
270:potential energy of golf ball on a tee
532:
394:
433:The Twelfth Marcel Grossmann Meeting
13:
603:
414:
14:
1063:
512:
221:ping pong ball falling off a bat
72:Landau–Pomeranchuk–Migdal effect
54:The ratio of primary cosmic ray
476:– via WSPC - Proceedings.
388:
1:
381:
229:Ultra-high-energy gamma rays
224:causes nitrogen to fluoresce
76:
64:Greisen–Zatsepin–Kuzmin limit
38:
395:Yrika, Bob (June 26, 2019).
20:Ultra-high-energy gamma rays
7:
652:Ultra-high-energy gamma ray
155:Very-high-energy gamma rays
60:cosmic microwave background
10:
1068:
647:Very-high-energy gamma ray
449:10.1142/9789814374552_0016
201:air shower reaches ground
1005:
932:
861:
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426:"The Fascinating TeV Sky"
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179:produces Cherenkov light
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560:Electromagnetic spectrum
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319:10 000 000
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298:1 000 000
255:10 000 TeV
66:cutoff above 50 EeV.
435:. pp. 368–380.
124:near infrared photon
693:Extreme ultraviolet
441:2012mgm..conf..368A
698:Vacuum ultraviolet
609:
424:(24 August 2010).
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1038:
743:Visible (optical)
458:978-981-4374-51-4
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127:(for comparison)
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461:. Archived from
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176:flying mosquito
96:wavelength (am)
93:frequency (YHz)
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28:photon energies
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513:External links
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62:by way of the
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468:on 2012-05-29
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374:
373:Planck energy
371:
370:
362:1.61623 × 10
356:1.95611 × 10
353:1.22091 × 10
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277:100 000
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498:. Retrieved
470:. Retrieved
463:the original
432:
416:
406:December 20,
404:. Retrieved
400:
390:
84:energy (TeV)
68:
53:
42:
19:
18:
1026:Medium wave
703:Lyman-alpha
685:Ultraviolet
624:wavelengths
617:frequencies
581:Ultraviolet
472:27 November
359:1.855 × 10
121:1.2398 × 10
102:properties
90:energy (μJ)
87:energy (eV)
45:cosmic rays
1052:Gamma rays
1007:Wavelength
863:Microwaves
675:Hard X-ray
670:Soft X-ray
639:Gamma rays
571:Gamma rays
500:3 December
382:References
325:1.602 × 10
304:1.602 × 10
283:1.602 × 10
215:2.42 × 10
118:2.418 × 10
115:1.602 × 10
99:comparison
39:Importance
24:gamma rays
1021:Shortwave
1016:Microwave
596:Microwave
328:2.42 × 10
307:2.42 × 10
286:2.42 × 10
264:2.42 × 10
243:2.42 × 10
193:2.42 × 10
1046:Category
1031:Longwave
791:Infrared
591:Infrared
401:phys.org
331:1.2 × 10
310:1.2 × 10
289:1.2 × 10
267:1.2 × 10
246:1.2 × 10
147:Z boson
138:0.01602
622:longer
615:higher
586:Visible
437:Bibcode
209:1 × 10
135:1 × 10
56:hadrons
924:L band
919:S band
914:C band
909:X band
895:K band
881:Q band
876:V band
871:W band
776:Orange
771:Yellow
751:Violet
662:X-rays
576:X-rays
455:
322:1 × 10
301:1 × 10
280:1 × 10
258:1 × 10
237:1 × 10
218:0.012
212:16.02
187:1 × 10
167:0.1602
164:1 × 10
81:Class
1009:types
934:Radio
830:Bands
803:Bands
766:Green
601:Radio
495:(PDF)
466:(PDF)
429:(PDF)
342:1.220
240:160.2
190:1.602
141:24.2
49:pions
26:with
904:band
890:band
848:LWIR
826:MWIR
821:SWIR
761:Cyan
756:Blue
502:2011
474:2011
453:ISBN
408:2019
261:1602
234:1000
206:100
196:0.12
132:0.1
22:are
997:ELF
992:SLF
987:ULF
982:VLF
962:VHF
957:UHF
952:SHF
947:EHF
942:THF
853:FIR
799:NIR
781:Red
733:UVA
728:UVB
723:UVC
718:NUV
713:MUV
708:FUV
445:doi
173:1.2
170:242
144:12
1048::
977:LF
972:MF
967:HF
840:,
836:,
832::
813:,
809:,
805::
482:^
451:.
443:.
431:.
399:.
349:10
344:91
184:10
109:10
902:u
900:K
888:a
886:K
844:)
842:N
838:M
834:L
828:(
817:)
815:H
811:K
807:J
801:(
627:→
613:←
552:e
545:t
538:v
504:.
447::
439::
410:.
347:×
161:1
112:1
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.