1. Finding the next Galactic extragalactic FRB
Dan Maoz
Tel-Aviv University
with Avi Loeb

3. WRONG!

4. All-sky rate of FRBs with flux >0.3 Jy:
~10,000 day/sky (Scholz+16) or
~3.65 million FRBs/year from volume within 2.4 Gpc (median z=0.64)
that includes
600 million L* galaxies.
If FRBs do not avoid L* galaxies, Milky Way should host one every 150 years (or years considering rate uncertainty).

5. FRB121102 has repeated for >4 years.
Is its persistence special? Probably not!
FRB and FRB appeared in same 14 arcmin-diameter Parkes beam.
Petroff+15: 32% random probability  unrelated FRBs

6. FRB121102 has repeated for >4 years.
Is its persistence special? Probably not!
FRB and FRB appeared in same 14 arcmin-diameter Parkes beam.
Petroff+15: 32% random probability  unrelated FRBs
Maoz+15: 1%  % it’s the same source, repeating >3 yrs
DM goes from 945  562 pc/cm3

7. FRB from NS inside expanding SNR  changing DM

8. If FRBs persist for decades or centuries, an active FRB could be repeating in the Milky Way now. It is BRIGHT:
4 Gpc  10 kpc
0.3 Jy  30 GJy

9. Challenge: detect a ~30 GJy, ~1 ms, dispersed pulse that occurs somewhere in the sky, maybe once a week or month?
Thornton+13
t ~ f-2

10. If FRBs repeat for decades or centuries, an active FRB could be repeating in the Milky Way now
4 Gpc  10 kpc
0.3 Jy  30 GJy
Flux levels and frequencies (e.g. 2.4 GHz) of cellular communication

11. Option 1:
Use some of 7 billion cellphones on Earth as receivers.
*Free downloadable Citizen Science application listens in background for FRB-like signal by analyzing raw radio signal. Can do efficient real-time de-dispersion search (Zackay & Ofek 2017) over cellphone bandpass.
*GPS time-stamp and record candidate events.
*Upload list of candidate events and the phone’s location to central website.

12. dt ET events will be detected near-simultaneously by many receivers.
Arrival-time differences  triangulation of source direction
GPS time accuracy: 100 ns
Earth light-crossing time : ~20 ms
Localization precision: 5x10-6 ~ 1 asec
DM compared to Galactic DM model
 Source distance dt
Problem: raw signal may be inaccessible to applications

13. Option 2:
Analyze raw broad-band signal from cell-phone’s FM tuner
Problem: ~100 MHz probably not a good place for FRB search

14. Option 3:
Deploy global network of software defined radios (SDRs)

20. STARE results:
18 months: 4 million pulses at 611 MHz.
Only 4000 coincident among the 3 receivers.
Associated with 99 events.
All associated with solar flares.
 Concept works (GPS time stamp, localization)
 RFI is manageable (at least was, 20 yrs ago, at 600 MHz)

21. Conclusions
If FRBs do not avoid Milky-Way-like galaxies, MW hosts a 30 GJy FRB every yrs (and Local Group galaxies host MJy FRBs).
If some or all FRBs repeat for decades-centuries, a MW FRB may be active now.
Simple and cheap networks of cellular devices (phones, PCs) can detect and localize a MW FRB, which will allow identifying and studying the FRB source in unique detail.