Fast radio burst

A Fast Radio Burst  ( FRB ), Schneller Radioblitz or Extragalactic Fast Radio Transient is a one-off, short burst in the field of radio radiation lasting a few milliseconds at (presumably) extragalactic distances. It is also known as Blitzar, Millisecond Radio Burst, Extragalactic Radio Burst or Cosmological Fast Radio Burst . So far there are only hypotheses about their origin and cause .

properties

The rapid radio flashes were discovered during renewed analyzes of surveys of the sky for millisecond pulsars . The first was received at the Parkes Radio Telescope in Australia in August 2001 , but was not discovered in archival data until 2006.

While pulsars show repetitive signals, most fast radio bursts only detected a single pulse lasting a few milliseconds. The pulse profile is symmetrical in the shape of an isosceles triangle . For the duration of the eruption , the Fast Radio Bursts are strong radiation sources with intensities of up to 30  Jansky . The outbreaks have not yet been observed outside the radio range, and there are no cataloged astronomical sources in their locations . Usually only one outbreak has been detected at the location of a burst.

The frequency of the outbreaks in an FRB is said to be every 10 seconds over the entire sky, although the value is very uncertain.

After around 25 FRB were known by  2017, many more have been discovered since the Canadian Hydrogen Intensity Mapping Experiment (CHIME) went into operation at the end of 2017, including a second repeater (see below).

Dispersion

The Lorimer Burst, the first proven fast radio burst. The dispersion is shown as the time delay of the arrival time as a function of the frequency.

The distance can be deduced from the dispersion (see Fig.), Since free electrons slow down the radio signal (influence on the group speed of the signal). In this case, electromagnetic radiation of low frequency or high wavelength strongly influenced.

The free charge carriers , especially the free electrons , in the interstellar matter of the Milky Way can only cause 3 to 6 percent of the observed dispersion, the rest must be of extragalactic origin. Therefore, the distance of the previously known millisecond radio bursts should be between 1.7 and 3.3 Giga parsec . Assuming a distance of one gigaparsec, the energy released results in the order of magnitude of 10 ³³  joules .

The delay at a frequency is ${\displaystyle \nu }$

${\displaystyle t=k_{\mathrm {DM} }\cdot {\frac {\mathrm {DM} }{\nu ^{2}}}}$

With

• the dispersion constant ${\displaystyle k_{\mathrm {DM} }={\frac {e^{2}}{2\,\pi \,m_{\mathrm {e} }\,c}}\simeq 4,149\,\mathrm {GHz} ^{2}\,\mathrm {pc} ^{-1}\,\mathrm {cm} ^{3}\,\mathrm {ms} }$
  • the elementary charge ${\displaystyle e}$
  • the electron mass ${\displaystyle m_{\mathrm {e} }}$
  • the speed of light ${\displaystyle c}$
• the dispersion measure  (DM), d. H. the particle density  n _{e of} the electrons (in electrons / cm ³ ) integrated along the distance traveled by the photons from the pulsar to the earth:

${\displaystyle \mathrm {DM} =\int _{0}^{d}{n_{e}\;dl}}$

in units of parsecs per cm ³ (1 pc / cm ³ = 30.857 × 10 ²¹  m ⁻² ).

Since the particle densities along the routes covered in the interstellar or intergalactic medium are not constant, the degree of dispersion of an observed FRB is not proportional to its distance.

As is often the case with astronomical observations, the delay t cannot be measured directly because the radiation time is not known. Instead, the time delay  Δ t of the signal arrival between a high frequency of a pulse and a low one can be determined: ${\displaystyle \nu _{\mathrm {hi} }}$ ${\displaystyle \nu _{\mathrm {lo} }}$

${\displaystyle \Delta t=t_{\mathrm {lo} }-t_{\mathrm {hi} }=k_{\mathrm {DM} }\cdot \mathrm {DM} \cdot \left({\frac {1}{\nu _{\mathrm {lo} }^{2}}}-{\frac {1}{\nu _{\mathrm {hi} }^{2}}}\right)>0}$

After rearranging the above equation, the measure of dispersion can be determined by measuring pulse arrival times at several frequencies:

${\displaystyle \Leftrightarrow \mathrm {DM} ={\frac {\Delta t}{k_{\mathrm {DM} }\cdot \left({\frac {1}{\nu _{\mathrm {lo} }^{2}}}-{\frac {1}{\nu _{\mathrm {hi} }^{2}}}\right)}}}$

This can be used to study the interstellar medium; in addition, the observations of pulsars at different frequencies can be combined.

Theories

Since the description of the Extragalactic Fast Radio Transients in 2007, many hypotheses have been developed:

Neutron star -based

• The Millisecond Extragalactic Radio Bursts are particularly strong bursts from soft gamma repeaters . There could be  a weaker form of the Extragalactic Fast Radio Transient in the Andromeda Galaxy M31, of which multiple bursts in the radio range have been observed.
• The Fast Radio Bursts are a phenomenon similar to the giant pulses in extragalactic pulsars , whose repetitive bursts, similar to the Rotating Radio Transients, occur very rarely and have not been observed as repetitive in previous surveys . Part of the dispersion can possibly be caused by the former shell of the star in the form of a supernova remnant . In the first 60 to 200 years after the supernova explosion, the envelope is still too tight to allow a radio burst to pass, only after that the FRBs can be observed.
• They arise when two neutron stars merge in a close binary star system when the magnetic fields of the individual stars collapse. This means that Extragalactic Fast Radio Transient would be closely related to the short duration gamma ray bursts .
• As a result of the collapse of the magnetic field of a neutron star due to a nearby supernova explosion.
• The model by Luciano Rezzolla and Heino Falcke (Blitzar). The collapse of a massive neutron star over the Tolman-Oppenheimer-Volkoff boundary into a black hole destroys the neutron star's magnetic field. This magnetic field, which was decoupled from the star during the collapse, runs through the universe as an electromagnetic wave and is observed as an Extragalactic Fast Radio Transient. Such a collapse would happen in a supernova a few thousand to millions of years after the birth of a neutron star. Alternatively, a fast radio burst could also be coupled to a gamma ray burst if, as a result of the collapsar model or the merging of two neutron stars, a rapidly rotating supermassive neutron star initially emerges. Part of the matter of the previous star or stars has not been accelerated to the escape speed and therefore falls back on the neutron star. Through an interaction with the magnetic field of the neutron star, both the rotation speed and the magnetic field are reduced and the neutron star collapses a few minutes after the gamma ray burst, emitting a fast radio burst to form a black hole. This model has received possible confirmation through follow-up observations of long gamma-ray bursts. During one of the breaks in the X-ray light curve of two gamma ray bursts, a cosmological fast radio burst was detected in the radio range. The breaks are transitions in the light curve from which the course of the brightness is described with another power law . If this model is confirmed, the Fast Radio Bursts are likely also a source of highly relativistic cosmic rays . During follow-up observations with radio telescopes at the location of gamma ray bursts within a period of 140 seconds after an outbreak, no fast radio burst could be detected.

Further

• As a result of a merger of two white dwarfs , whereby the observed radio emission should come from the region of the magnetic pole of a newly formed massive and rapidly rotating white dwarf. According to this hypothesis, a type Ia supernova should be detectable at the location of some fast radio bursts .
• The Fast Radio Bursts could also be a brief eruption on a flare star near the Sun. According to this interpretation, the measured dispersion is not the result of a cosmological distance, but is generated by a dense envelope of plasma in the corona of the star. The outbreaks occur in the lower chromosphere , which is why the radio radiation is bent on the way through the corona. A magnetically active W Ursae Majoris star was discovered in the field of FRB110703, which could be the source of the observed fast radio burst.
• For the FRB010621 near the galactic plane , the observed dispersion could also have been caused by diffuse ionized gas and the object causing it to lie within the Milky Way. The outbreak in the range of radio emissions could be an extreme form of a giant pulse in a pulsar or it could have been caused by the evaporation of a black hole .
• In Fast Extragalactic Radio Bursts, all of the energy is released in a very short period of time, suggesting that the source is highly relativistic. But even if the plasma emitting the radiation moves in a highly relativistic manner, a coherent emission mechanism is required. According to a modified hypothesis on radio emission from gamma ray bursts, this mechanism could arise from a spontaneous maser emission in a strongly magnetized wind accelerated to almost the speed of light .
• The radiation is created when a black hole evaporates .
• It could be some kind of beacon signal from extraterrestrial technology .
• According to speculative consideration, Kardaschow II civilizations could operate solar sail transporters with a megaton payload with repeatedly generated FRBs .

Repeated Fast Radio Bursts: Repeater

Starting in 2012, researchers at Cornell University in the United States discovered repeated fast radio bursts in a dwarf galaxy in the constellation Fuhrmann , 972 mega parsec or around three billion light years away . In an observation of the area using the Very Large Array - interferometer , they identified nine fast radio burst. Radiation bursts from a massive star or an extremely massive black hole are suspected to be the explanation .

FRB 121102 was the first fast radio burst with repetitive outbreaks to be observed and intensively investigated in 2014. Using Very Long Baseline Interferometry , the origin was determined to be a dwarf galaxy with a redshift of  . However, FRB 121102 is not a typical fast radio burst, as long observation series at the locations of other FRBs have not shown any further outbreaks. ${\displaystyle z=0{,}193}$

The home galaxy of FRB 121102 is a metal-poor dwarf galaxy and shows signs of an Extreme Emission-Line Galaxy . The radiation source is 0.2  arc seconds away from the center of this galaxy in a star formation region that is also a permanent radio source . Parallel observations in the optical, ultraviolet , X-ray and gamma ray range show no outbreaks or other abnormalities compared to other metal-poor dwarf galaxies. The bursts are non-periodic and show no memory of earlier bursts due to their time interval, their shape, the emitted energy or the amplitude .

The distribution of the outbreaks of FRB 121102 corresponds in its energy-time distribution to the Gutenberg-Richter relationship for earthquakes . This is a small deviation from a power law , with weak tremors occurring a little more frequently and strong tremors with a slightly lower frequency than would be expected according to a simple power law. As in seismology , the waiting times between the bursts follow a Gaussian normal distribution . These properties are also observed in soft gamma repeaters , so the breakout mechanism of the crustal breakage of a neutron star with a strong magnetic field could be. Alternative hypotheses are a relaxation process in a quark star or a magnetic cycle on a neutron star with a kind of superflare .

Further examples

See also List of fast radio bursts

The name contains the day of occurrence in the form YYMMDD; z. B. FRB 010125 appeared on January 25, 2001 in the earthly sky.

designation	Intensity in  Jansky	Duration in ms	Dispersion measure in pc / cm 3	annotation
FRB 010125	0.3	9	790	2015 found, wrongly z. Partly still published as FRB 011025
FRB 010724	30th	5	375	"Lorimer Burst", first proven FRB (found 2007)
FRB 121002	0.4	5	1629	Double burst every 5 ms
FRB 121102	0.4	3	557	Arecibo observation in a dwarf galaxy 3 billion light years away in the galactic anticenter , first repeater observed
Location of FRB 121102	2.2	0.8	776	Multiple outbreaks again in 2015
FRB 131104	1.1	2	779	from the neighboring Carina dwarf galaxy , 300,000 ly away
FRB 180924				from a source that is around 13,000 light years away from the center of a galaxy around 3.6 billion light years away with around 22 billion solar masses and a low star formation rate

Web links

• FRB catalog Swinburne University of Technology, Australia
• Mysterious radio waves: code from space

Individual evidence

1. ↑ There are weird bursts of energy coming from deep space. At: bbc.com. Retrieved June 9, 2016.
2. ↑ DR Lorimer, M. Bailes, MA McLaughlin, DJ Narkevic, F. Crawford: A bright millisecond radio burst of extragalactic origin . In: Astrophysics. Solar and Stellar Astrophysics . 2007, doi : 10.1126 / science.1147532 , arxiv : 0709.4301v1 .
3. ↑ D. Thornton et al: A Population of Fast Radio Bursts at Cosmological Distances . In: Science . tape 341 , 2013, p. 53-56 , doi : 10.1126 / science.1236789 .
4. ↑ DR Lorimer, A. Karastergiou, MA McLaughlin, S. Johnston: On the detectability of extragalactic fast radio transients . In: Astrophysics. Solar and Stellar Astrophysics . 2013, arxiv : 1307.1200v1 .
5. ↑ Single-Dish Radio Astronomy: Techniques and Applications, ASP Conference Proceedings, Vol. 278. Edited by Snezana Stanimirovic, Daniel Altschuler, Paul Goldsmith, and Chris Salter. ISBN 1-58381-120-6 San Francisco: Astronomical Society of the Pacific, 2002, p. 251-269
6. ↑ Lorimer, DR, and Kramer, M., Handbook of Pulsar Astronomy , vol. 4 of Cambridge Observing Handbooks for Research Astronomers, ( Cambridge University Press , Cambridge, UK; New York, USA, 2005), 1st edition.
7. ↑ SB Popov, KA Postnov: hyperflare of SGRs as to engine for millisecond extragalactic radio bursts . In: Astrophysics. Solar and Stellar Astrophysics . 2007, arxiv : 0710.2006v1 .
8. ↑ SB Popov, KA Postnov: Millisecond extragalactic radio bursts as magnetar flares . In: Astrophysics. Solar and Stellar Astrophysics . 2013, arxiv : 1307.4924v1 .
9. ↑ LG Spitler include: fast radio burst Discovered in the Arecibo Pulsar ALFA Survey . In: Astrophysics. Solar and Stellar Astrophysics . 2014, arxiv : 1404.2934v1 .
10. ↑ Michael F. Bietenholz, Norbert Bartel: On the Possibility of Fast Radio Bursts from Inside Supernovae: The Case of SN 1986J . In: Astrophysics. Solar and Stellar Astrophysics . 2017, arxiv : 1707.07746v1 .
11. ↑ MS Pshirkov, KA Postnov: Radio precursors to neutron star binary mergings . In: Astrophysics. Solar and Stellar Astrophysics . 2010, arxiv : 1004.5115v1 .
12. ↑ Tomonori Totani: Cosmological Fast Radio Bursts from Binary Neutron Star Mergers . In: Astrophysics. Solar and Stellar Astrophysics . 2013, arxiv : 1307.4985v1 .
13. ↑ AE Egorov, K .A. Postnov: On the possible observational manifestation of supernova shock impact on the neutron star magnetosphere . In: Astrophysics. Solar and Stellar Astrophysics . 2008, arxiv : 0810.2219v1 .
14. ↑ Heino Falcke, Luciano Rezzolla: Fast radio bursts: the last sign of supramassive neutron stars . In: Astrophysics. Solar and Stellar Astrophysics . 2013, arxiv : 1307.1409v1 .
15. ↑ Bing Zhang: A possible FRB / GRB connection: towards a multi-wavelength campaign to unveil the nature of Fast Radio Bursts . In: Astrophysics. Solar and Stellar Astrophysics . 2013, arxiv : 1310.4893v1 .
16. ↑ Xiang Li, Bei Zhou, Hao-Ning He, Yi-Zhong Fan, Da-Ming Wei: Cosmological fast radio bursts and ultra-high energy cosmic rays . In: Astrophysics. Solar and Stellar Astrophysics . 2013, arxiv : 1312.5637v1 .
17. ↑ Divya Palaniswamy, Randall B. Wayth, Cathryn M. Trott, Jamie N. McCallum, Steven J. Tingay, Cormac Reynolds: A Search for Fast Radio Bursts Associated with Gamma-Ray Bursts . In: Astrophysics. Solar and Stellar Astrophysics . 2014, arxiv : 1406.1850v1 .
18. ↑ Kazumi Kashiyama, Kunihito Ioka, Peter Mészáros: Cosmological Fast Radio Bursts from Binary White Dwarf Mergers . In: Astrophysics. Solar and Stellar Astrophysics . 2013, arxiv : 1307.7708v1 .
19. ↑ Abraham Loeb, Yossi Shvartzvald, Dan Maoz: Fast radio bursts may originate from nearby flaring stars . In: Astrophysics. Solar and Stellar Astrophysics . 2013, arxiv : 1310.2419v1 .
20. ↑ KW Bannister, GJ Madsen: A Galactic Origin for the Fast Radio Burst FRB010621 . In: Astrophysics. Solar and Stellar Astrophysics . 2014, arxiv : 1402.0268v1 .
21. ↑ YE Lyubarsky: A model for almost extragalactic radio bursts . In: Astrophysics. Solar and Stellar Astrophysics . 2014, arxiv : 1401.6674v1 .
22. ↑ EF Keane et al .: On the origin of a highly-dispersed coherent radio burst . In: Astrophysics. Solar and Stellar Astrophysics . 2012, arxiv : 1206.4135v1 .
23. ↑ Is this ET? Mystery of strange radio bursts from space. At: newscientist.com.
24. ↑ Fast Radio Bursts: SETI Implications? At: centauri-dreams.org.
25. ↑ Manasvi Lingam, Abraham Loeb: Fast Radio Bursts from Extragalactic Light Sails . In: The Astrophysical Journal Letters . January 2, 2017, arxiv : 1701.01109 .
26. ↑ Dwarf galaxy creates mysterious radio flashes. At: Spiegel.de. 5th January 2017.
27. ↑ LG Spitler include: fast radio burst Discovered in the Arecibo Pulsar ALFA Survey . In: Astrophysics. Solar and Stellar Astrophysics . 2014, arxiv : 1404.2934v1 .
28. ↑ P. Scholz et al: The repeating Fast Radio Burst FRB 121102: Multi-wavelength observations and additional bursts . In: Astrophysics. Solar and Stellar Astrophysics . 2016, arxiv : 1603.08880v1 .
29. ↑ Divya Palaniswamy, Bing Zhang: Is the repeating FRB 121102 representative of FRBs? In: Astrophysics. Solar and Stellar Astrophysics . 2017, arxiv : 1703.09232v1 .
30. ↑ S. Chatterjee et al: The direct localization of a fast radio burst and its host . In: Astrophysics. Solar and Stellar Astrophysics . 2017, arxiv : 1701.01098v1 .
31. ↑ P. Scholz et al .: Simultaneous X-ray, gamma-ray, and Radio Observations of the repeating Fast Radio Burst FRB 121102 . In: Astrophysics. Solar and Stellar Astrophysics . 2017, arxiv : 1705.07824v1 .
32. ↑ P. Scholz et al: The repeating Fast Radio Burst FRB 121102: Multi-wavelength observations and additional bursts . In: Astrophysics. Solar and Stellar Astrophysics . 2016, arxiv : 1603.08880v1 .
33. ↑ Weiyang Wang, Rui Luo, Han Yue, Kejia Lee, Xuelei Chen, Renxin Xu: FRB121102: a star quake-induced repeater? In: Astrophysics. Solar and Stellar Astrophysics . 2017, arxiv : 1710.00541v1 .
34. ↑ Origin of rapid radio burst identified. Max Planck Institute for Radio Astronomy , January 4, 2017, accessed on February 27, 2017 .