20:
884:
462:. They travel in a straight line (in space-time) 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
112:. A high-energy photon produces a cone of light confined to 1° of the original photon direction. About 10,000 m of the Earth's surface is lit by each cone of light. A flux of 10 photons per square meter per second can be detected with current technology, provided the energy is above 0.1 TeV. Instruments include the planned
159:. Only magnetic fields 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 that come through the magnetic window can make a Landau–Pomeranchuk–Migdal shower.
140:
which closed in 2001. Cosmic rays also produce similar flashes of light, but can be distinguished based on the shape of the light flash. Also having more than one telescope simultaneously observing the same spot can help exclude cosmic rays.
148:
Air showers of elementary particles made by gamma rays can also be distinguished from those produced by cosmic rays by the much greater depth of shower maximum, and the much lower quantity of
617:
Neshpor, Yu I.; A. A. Stepanyan; O. P. Kalekin; V. P. Fomin; N. N. Chalenko; V. G. Shitov (March 1998). "Blazar 3C 66A: Another extragalactic source of ultra-high-energy gamma-ray photons".
477:
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 interactions with the
145:
of particles can be detected for gamma rays above 100 TeV. Water scintillation detectors or dense arrays of particle detectors can be used to detect these particle showers.
108:
produced by secondary particles generated from an energetic photon entering the Earth's atmosphere. This method is called imaging atmospheric
Cherenkov technique or
559:
Neshpor, Yu I.; N. N. Chalenko; A. A. Stepanian; O. R. Kalekin; N. A. Jogolev; V. P. Fomin; V. G. Shitov (2001). "BL Lac: A new ultrahigh-energy gamma-ray source".
58:
between 10 and 10 meters, or frequencies of 2 × 10 to 2 × 10 Hz. Such energy levels have been detected from emissions from astronomical sources such as some
829:
797:
156:
117:
822:
482:
815:
507:
Ikhsanov, N. R. (October 1991), "Particle acceleration and main parameters of ultra-high energy gamma-ray binaries",
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93:
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336:
113:
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838:
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142:
92:. Various other sources exist that are not associated with known bodies. For example, the
8:
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121:
24:
458:
Very-high-energy gamma rays are of importance because they may reveal the source of
1250:
1021:
996:
864:
586:
526:
47:
1299:
1212:
1054:
986:
711:
Dar, Arnon (4 June 2009). "High Energy
Phenomena In The Universe". pp. 3–4.
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63:
19:
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125:
774:"Ultra-High Energy Gamma Rays in Geomagnetic Field and Atmosphere"
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1164:
133:
1202:
1197:
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1154:
1149:
1120:
1049:
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82:
16:
Gamma radiation with photon energies between 100GeV and 100TeV
1044:
940:
854:
772:
Vankov, H. P.; Inoue2, N.; Shinozaki, K. (2 February 2008).
1039:
1034:
463:
155:
Very-high-energy gamma rays are too low energy to show the
149:
109:
71:
104:
Instruments to detect this radiation commonly measure the
1059:
771:
1322:
50:) to 100 TeV (teraelectronvolt), i.e., 10 to 10
96:catalog contained 64 sources in November 2011.
823:
27:is used to detect very-high-energy gamma rays
837:
77:-levels. Other astronomical sources include
796:: CS1 maint: numeric names: authors list (
899:
830:
816:
767:
765:
736:
716:
572:
506:
70:has been measured at ranges from GeV to
18:
1323:
762:
658:
552:
379:potential energy of golf ball on a tee
66:. For example, radiation emitted from
811:
732:
730:
728:
706:
704:
502:
500:
498:
612:
610:
608:
710:
13:
882:
725:
701:
637:
495:
54:. This is approximately equal to
14:
1342:
688:"High Energy Stereoscopic System"
605:
328:ping pong ball falling off a bat
473:The ratio of primary cosmic ray
157:Landau–Pomeranchuk–Migdal effect
130:High Energy Stereoscopic System
680:
668:. H.E.S.S. Collaboration. 2011
510:Astrophysics and Space Science
1:
666:"The H.E.S.S. Source Catalog"
488:
483:Greisen–Zatsepin–Kuzmin limit
453:
331:causes nitrogen to fluoresce
161:
645:"Astrophysics with H.E.S.S."
403:penetrate geomagnetic field
337:Ultra-high-energy gamma rays
263:Very-high-energy gamma rays
99:
7:
931:Ultra-high-energy gamma ray
479:cosmic microwave background
10:
1347:
926:Very-high-energy gamma ray
308:air shower reaches ground
32:Very-high-energy gamma ray
1284:
1211:
1140:
1068:
1020:
962:
939:
916:
845:
742:"The Fascinating TeV Sky"
468:ultra-high-energy photons
335:
330:
327:
324:
321:
318:
315:
312:
286:produces Cherenkov light
262:
258:
255:
252:
249:
246:
243:
240:
212:
165:
114:Cherenkov Telescope Array
839:Electromagnetic spectrum
138:Chicago Air Shower Array
523:1991Ap&SS.184..297I
466:which in turn decay to
887:
28:
886:
485:cutoff above 50 EeV.
143:Extensive air showers
62:systems containing a
22:
233:near infrared photon
972:Extreme ultraviolet
631:1998AstL...24..134N
583:2001ARep...45..249N
106:Cherenkov radiation
977:Vacuum ultraviolet
888:
749:WSPC - Proceedings
740:(24 August 2010).
531:10.1007/BF00642978
132:(HESS) in Namibia
29:
1318:
1317:
1022:Visible (optical)
619:Astronomy Letters
591:10.1134/1.1361316
561:Astronomy Reports
450:
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738:Aharonian, Felix
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574:astro-ph/0111448
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325:1.2 × 10 m
319:0.01602 mJ
253:1.2 × 10 m
247:0.01602 μJ
163:
162:
48:gigaelectronvolt
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441:1.2 × 10 m
420:1.2 × 10 m
398:1.2 × 10 m
376:1.2 × 10 m
355:1.2 × 10 m
303:1.2 × 10 m
283:flying mosquito
280:1.2 × 10 m
236:for comparison
102:
44:photon energies
40:gamma radiation
25:MAGIC telescope
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625:(2): 134–138.
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567:(4): 249–254.
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517:(2): 297–311,
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481:by way of the
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64:compact object
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414:0.1602 J
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370:1.602 mJ
369:
366:
363:
362:
359:
357:
354:
351:
348:
345:
342:
341:
338:
334:
322:2.42 × 10 Hz
313:100 TeV
311:
307:
305:
302:
299:
297:1.602 μJ
296:
293:
290:
289:
285:
282:
279:
276:
273:
270:
267:
266:
261:
250:2.42 × 10 Hz
241:100 GeV
239:
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119:
115:
111:
107:
97:
95:
91:
90:Markarian 501
87:
86:Markarian 421
84:
80:
76:
73:
69:
65:
61:
57:
53:
52:electronvolts
49:
45:
41:
37:
33:
26:
21:
925:
890:
780:. Retrieved
752:. Retrieved
748:
691:. Retrieved
682:
670:. Retrieved
660:
639:
622:
618:
564:
560:
554:
514:
508:
472:
457:
438:2.42 × 10 Hz
435:1.602 J
417:2.42 × 10 Hz
395:2.42 × 10 Hz
386:100 PeV
373:2.42 × 10 Hz
352:2.42 × 10 Hz
300:2.42 × 10 Hz
277:2.42 × 10 Hz
154:
147:
103:
75:electronvolt
46:of 100 GeV (
35:
31:
30:
1305:Medium wave
982:Lyman-alpha
964:Ultraviolet
903:wavelengths
896:frequencies
860:Ultraviolet
754:27 November
718:0906.0973v1
693:26 November
672:26 November
650:26 November
460:cosmic rays
429:10 EeV
364:10 PeV
291:10 TeV
187:properties
120:in Crimea,
79:BL Lacertae
60:binary star
56:wavelengths
1331:Gamma rays
1286:Wavelength
1142:Microwaves
954:Hard X-ray
949:Soft X-ray
918:Gamma rays
850:Gamma rays
782:3 December
648:Retrieved
489:References
454:Importance
408:1 EeV
343:1 PeV
268:1 TeV
184:comparison
181:wavelength
68:Cygnus X-3
38:) denotes
1300:Shortwave
1295:Microwave
875:Microwave
599:118955434
547:122089313
539:0004-640X
230:1.2398 μm
227:241.8 THz
178:frequency
100:Detection
1325:Category
1310:Longwave
1070:Infrared
870:Infrared
792:cite web
256:Z boson
126:La Palma
94:H.E.S.S.
901:longer
894:higher
865:Visible
627:Bibcode
579:Bibcode
519:Bibcode
475:hadrons
316:1 × 10
244:1 × 10
221:0.1602
134:VERITAS
1203:L band
1198:S band
1193:C band
1188:X band
1174:K band
1160:Q band
1155:V band
1150:W band
1055:Orange
1050:Yellow
1030:Violet
941:X-rays
855:X-rays
597:
545:
537:
432:1 × 10
411:1 × 10
389:1 × 10
367:1 × 10
346:1 × 10
294:1 × 10
271:1 × 10
204:meters
198:Joules
175:energy
172:energy
169:energy
166:Class
83:3C 66A
1288:types
1213:Radio
1109:Bands
1082:Bands
1045:Green
880:Radio
777:(PDF)
745:(PDF)
713:arXiv
595:S2CID
569:arXiv
543:S2CID
464:pions
201:Hertz
150:muons
122:MAGIC
118:GT-48
42:with
36:VHEGR
1183:band
1169:band
1127:LWIR
1105:MWIR
1100:SWIR
1040:Cyan
1035:Blue
798:link
784:2011
756:2011
695:2011
674:2011
652:2011
535:ISSN
136:and
110:IACT
88:and
23:The
1276:ELF
1271:SLF
1266:ULF
1261:VLF
1241:VHF
1236:UHF
1231:SHF
1226:EHF
1221:THF
1132:FIR
1078:NIR
1060:Red
1012:UVA
1007:UVB
1002:UVC
997:NUV
992:MUV
987:FUV
587:doi
527:doi
515:184
124:on
72:exa
1327::
1256:LF
1251:MF
1246:HF
1119:,
1115:,
1111::
1092:,
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794:}}
790:{{
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585:.
577:.
565:45
563:.
541:,
533:,
525:,
513:,
497:^
470:.
223:aJ
195:eV
192:eV
152:.
128:,
116:,
81:,
1181:u
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1165:K
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1121:N
1117:M
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1107:(
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1094:H
1090:K
1086:J
1080:(
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892:←
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817:v
800:)
786:.
758:.
721:.
715::
697:.
676:.
654:.
633:.
629::
601:.
589::
581::
571::
529::
521::
218:1
215:1
34:(
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
