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Title

Exploring the blinking universe with FAST

Speaker: Yi Feng

Lorimer Burst

Lorimer et al. (2007)

Lorimer burst was renamed to Fast Radio Burst (FRB) soon.

Flux: 10 mJy to 100 Jy. Width: 0.1 ms to 10 ms.

Origin

All are out of the Milky Way? (Only one inside the Milky Way)

Fig1

The conjecture on the origin of FRBs Source: Jason Hessels

Fig7
Figure 2 of Li et al. (2021). A bimodal burst energy distribution: diffferent origin?

Repeating FRBs may be pulsar or magnetar in supernova remnant.

Fig8
From Cordes & Chatterjeeet (2019). Schematic diagram of an FRB source engine involving a young, highly magnetized neutron star.

Propagation effects of ISM

Fig2

Depolarization occurs at low frequency

Fig5

Radiation from repeating fast radio burst (FRB) sources appears to rotate as they pass through magnetically active areas in the universe. Variation in this rotation is a result of the different ray paths taken by each burst. A larger variation can mean the FRB source is relatively young and resides in a more turbulent magnetized environment.

From Manisha Caleb (2022)

Fig6
From Yang et al. (2022)
Fig3
Figure 2 from Feng et al. (2022)

RM: Rotation Measure

RM=e32πm2c40dne(s)B(s)ds

Magnetic field can be extremely high: 10911 T.

interstellar Faraday rotation (β) has a simple dependence on the wavelength of light (λ):

β=RMλ2

Lower frequency, higher λ, higher β, and more rotation. If the dispersion of rotation measure σRM is very small or even zero, the radiation from the source will just be rotated by β but the polarization fraction will not be affected. If σRM is large, radiation from different path will be rotated by different β and the radiation from the source will be depolarized.

Repeating or non-repeating FRBs

63 repeating FRBs and 672 non-repeating FRBs BlinkVerse

Confirm a repeating FRB: 3 arcmin, dispersion measure.

Fig4
Figure 3 from Feng et al. (2022)

FRBs with RM>500 rad m2 are more likely to be repeating FRBs. FRBs with RM<500 rad m2 are more likely to be non-repeating FRBs.

Released under the MIT License.