FRB20201124A the final location sprint.

[Michiel Klaassen]

Hi All,

Because FRB 2020201124a is a repeater, a lot of observatories are scrambling to pinpoint the correct location.

Further, note the end conclusion of the Effelsberg observers.

Regards

Michiel

parac.eu

"""

ATEL #14529                                                          ATEL #14529

Title:  uGMRT detection of a persistent radio source coincident with

                FRB20201124A

Author: Robert Wharton (MPIfR), Suryarao Bethapudi (MPIfR), Tasha

                Gautam (MPIfR), Dongzi Li (Caltech), Hsiu-Hsien Lin (CITA), Robert

                Main (MPIfR), Viswesh Marthi (NCRA), Laura Spitler (MPIfR), Ue-Li

                Pen (CITA)

Queries:        wha...@mpifr-bonn.mpg.de

Posted: 8 Apr 2021; 14:39 UT

Subjects:Radio, Fast Radio Burst

Based on the initial ASKAP localization of the newly active repeater FRB20201124A

(ATels #14497, #14508), we conducted observations with the upgraded Giant

Metrewave Radio Telescope (uGMRT) at 550-750 MHz between UTC 2021-04-05T12:30:00

and 2021-04-05T16:45:00 with a total on-source exposure of 3.0 hr. We have

analyzed 40 min of data starting from UTC 2021-04-05T13:46:33.2. An unresolved

persistent radio source with a 650 MHz flux density of  0.7 +/- 0.1 mJy

is found at a position (epoch J2000) of (RA, Dec) = (05:08:03.43, +26:03:38.5)

with a 5 sigma positional uncertainty of about 0.9 arcsec.  This persistent

radio source is coincident with both the VLA/realfast burst position (ATel

#14526) and the location of the galaxy SDSS J050803.48+260338.0 (ATel #14516),

but offset by about 3.5 arcsec from the latest ASKAP burst position (ATel

#14515). Since the source was not detected at 1400 MHz in the VLA/realfast

image (3 sigma upper limit of 0.5 mJy), the spectral index of the source

must be steeper than -0.4.  We encourage higher resolution interferometric

observations of this source to better determine its relationship to the

bursts and the SDSS galaxy. 

In addition to standard interferometric visibilities, we also recorded

channelized time series data from the incoherently summed array to search

for bursts.  The incoherent beam data from this observation yielded many

(>30) burst detections. Analysis of the localization, TOAs, and fluences

of these bursts is in progress. 

Below is a link to our 650 MHz map showing the persistent radio source

with the 5 sigma source position uncertainty (black), the ASKAP (green)

and VLA/realfast (cyan) burst localizations, the location of SDSS J050803.48+260338.0

(blue cross), and the uGMRT synthesized beam shape (white). 

Image of Persistent Source: http://www.ncra.tifr.res.in/~viswesh/gmrt_loc_prs.pdf

"""

"""

Title:  Radio observations of FRB20201124a at 4-8 GHz with the 100-m

                Effelsberg Radio Telescope

Author: Laura Spitler (MPIfR), Henning Hilmarsson (MPIfR)

Queries:        lspi...@mpifr-bonn.mpg.de

Posted: 9 Apr 2021; 13:45 UT

Subjects:Radio, Fast Radio Burst

We report observations with the 100-m Effelsberg radio telescope at 4-8

GHz of FRB20201124a (ATel #14497). The observations began at 15:32:36 UTC

on 7 April 2021 (MJD 58946) and continued for a total of 21600 s. The telescope

was pointed at the interferometrically determined source position from

ASKAP (ATel #14515). Total intensity filterbank data were recorded in two

adjacent 2 GHz bands with 2048 channels each and a time resolution of 131

us.  

The data were searched for single pulses using HEIMDALL and PRESTO with

a S/N threshold of 8 over a DM range between 400 and 430 pc/cc. Candidates

were classified using FETCH as well as being visually inspected. No single

pulses were found in the data.  

We place a fluence upper limit of  0.07 Jy ms, assuming a minimum S/N threshold

of 8, 4 GHz of bandwidth, and a fiducial burst duration of 1 ms. Previous

observations placed a fluence limit of 5.4 Jy ms at 2.26 GHz (ATel #14519).

Our observations significantly deepen the fluence limit on emission at

higher radio frequencies and suggest that bursts with fluences greater

than roughly 0.1 Jy ms in the 4-8 GHz band are rare. Therefore, we recommend

that future observations searching for bursts will be more fruitful at

lower radio frequencies. 

"""