Repeating fast radio bursts with WSRT/Apertif
Journal article, 2020

Context. Repeating fast radio bursts (FRBs) present excellent opportunities to identify FRB progenitors and host environments as well as to decipher the underlying emission mechanism. Detailed studies of repeating FRBs might also hold clues as to the origin of FRBs as a population.
Aims. We aim to detect bursts from the first two repeating FRBs, FRB 121102 (R1) and FRB 180814.J0422+73 (R2), and to characterise their repeat statistics. We also want to significantly improve the sky localisation of R2 and identify its host galaxy.
Methods. We used the Westerbork Synthesis Radio Telescope to conduct extensive follow-up of these two repeating FRBs. The new phased-array feed system, Apertif, allows one to cover the entire sky position uncertainty of R2 with fine spatial resolution in a single pointing. The data were searched for bursts around the known dispersion measures of the two sources. We characterise the energy distribution and the clustering of detected R1 bursts. Results. We detected 30 bursts from R1. The non-Poissonian nature is clearly evident from the burst arrival times, which is consistent with earlier claims. Our measurements indicate a dispersion measure (DM) of 563.5(2) pc cm(-3), suggesting a significant increase in DM over the past few years. Assuming a constant position angle across the burst, we place an upper limit of 8% on the linear polarisation fraction for the brightest burst in our sample. We did not detect any bursts from R2.
Conclusions. A single power-law might not fit the R1 burst energy distribution across the full energy range or widely separated detections. Our observations provide improved constraints on the clustering of R1 bursts. Our stringent upper limits on the linear polarisation fraction imply a significant depolarisation, either intrinsic to the emission mechanism or caused by the intervening medium at 1400 MHz, which is not observed at higher frequencies. The non-detection of any bursts from R2, despite nearly 300 h of observations, implies either a highly clustered nature of the bursts, a steep spectral index, or a combination of the two assuming that the source is still active. Another possibility is that R2 has turned off completely, either permanently or for an extended period of time.

stars

general

general

radio continuum

pulsars

neutron

Author

L. C. Oostrum

Netherlands Institute for Radio Astronomy (ASTRON)

University of Amsterdam

Y. Maan

Netherlands Institute for Radio Astronomy (ASTRON)

J. van Leeuwen

Netherlands Institute for Radio Astronomy (ASTRON)

University of Amsterdam

L. Connor

University of Amsterdam

Netherlands Institute for Radio Astronomy (ASTRON)

E. Petroff

University of Amsterdam

J. J. Attema

Netherlands eSci Ctr

J. E. Bast

Netherlands Institute for Radio Astronomy (ASTRON)

D. W. Gardenier

University of Amsterdam

Netherlands Institute for Radio Astronomy (ASTRON)

J. E. Hargreaves

Netherlands Institute for Radio Astronomy (ASTRON)

E. Kooistra

Netherlands Institute for Radio Astronomy (ASTRON)

D. van der Schuur

Netherlands Institute for Radio Astronomy (ASTRON)

A. Sclocco

Netherlands eSci Ctr

R. Smits

Netherlands Institute for Radio Astronomy (ASTRON)

S. M. Straal

NYU Abu Dhabi

S. ter Veen

Netherlands Institute for Radio Astronomy (ASTRON)

D. Vohl

Netherlands Institute for Radio Astronomy (ASTRON)

E. A. K. Adams

Kapteyn Astronomical Institute

Netherlands Institute for Radio Astronomy (ASTRON)

B. Adebahr

AIRUB

W. J. G. de Blok

Kapteyn Astronomical Institute

Netherlands Institute for Radio Astronomy (ASTRON)

University of Cape Town

R. H. van den Brink

Netherlands Institute for Radio Astronomy (ASTRON)

Tricas Ind Design & Engn

W. A. van Cappellen

Netherlands Institute for Radio Astronomy (ASTRON)

A. H. W. M. Coolen

Netherlands Institute for Radio Astronomy (ASTRON)

S. Damstra

Netherlands Institute for Radio Astronomy (ASTRON)

G. N. J. van Diepen

Netherlands Institute for Radio Astronomy (ASTRON)

B. S. Frank

South African Radio Astron Observ

University of Cape Town

K. M. Hess

Netherlands Institute for Radio Astronomy (ASTRON)

Kapteyn Astronomical Institute

J. M. van der Hulst

Kapteyn Astronomical Institute

B. Hut

Netherlands Institute for Radio Astronomy (ASTRON)

Marianna Ivashina

Chalmers, Electrical Engineering, Communication and Antenna Systems, Antennas

G. M. Loose

Netherlands Institute for Radio Astronomy (ASTRON)

D. M. Lucero

Virginia Polytechnic Institute and State University

A. Mika

Netherlands Institute for Radio Astronomy (ASTRON)

R. H. Morganti

Kapteyn Astronomical Institute

Netherlands Institute for Radio Astronomy (ASTRON)

V. A. Moss

Netherlands Institute for Radio Astronomy (ASTRON)

The University of Sydney

Australia Telescope National Facility

H. Mulder

Netherlands Institute for Radio Astronomy (ASTRON)

M. J. Norden

Netherlands Institute for Radio Astronomy (ASTRON)

T. A. Oosterloo

Kapteyn Astronomical Institute

Netherlands Institute for Radio Astronomy (ASTRON)

E. Orru

Netherlands Institute for Radio Astronomy (ASTRON)

J. P. R. de Reijer

Netherlands Institute for Radio Astronomy (ASTRON)

M. Ruiter

Netherlands Institute for Radio Astronomy (ASTRON)

N. J. Vermaas

Netherlands Institute for Radio Astronomy (ASTRON)

S. J. Wijnholds

Netherlands Institute for Radio Astronomy (ASTRON)

J. Ziemke

University of Groningen

Netherlands Institute for Radio Astronomy (ASTRON)

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 635 A61

Subject Categories

Astronomy, Astrophysics and Cosmology

Electrical Engineering, Electronic Engineering, Information Engineering

DOI

10.1051/0004-6361/201937422

More information

Latest update

8/6/2020 5