J/ApJ/888/40 Fast radio bursts with AstroSat/CZTI (Anumarlapudi+, 2020)
Prompt X-ray emission from fast radio bursts-upper limits with AstroSat.
Anumarlapudi A., Bhalerao V., Tendulkar S.P., Balasubramanian A.
<Astrophys. J., 888, 40 (2020)>
=2020ApJ...888...40A 2020ApJ...888...40A
ADC_Keywords: Radio lines; X-ray sources; References
Keywords: Radio Bursts ; Radio transient sources ; X-ray bursts
Abstract:
Fast radio bursts (FRBs) are short-lived (∼ms), energetic transients
(having a peak flux density of ∼Jy) with no known prompt emission in
other energy bands. We present results of a search for prompt X-ray
emissions from 41 FRBs using the Cadmium Zinc Telluride Imager (CZTI)
on AstroSat, which continuously monitors ∼70% of the sky. Our searches
on various timescales in the 20-200keV range, did not yield any
counterparts in this hard X-ray band. We calculate upper limits on
hard X-ray flux, in the same energy range and convert them to upper
bounds for η: the ratio of X-ray to radio fluence of FRBs. We find
η≤108-10 for hard X-ray emission. Our results will help
constrain the theoretical models of FRBs as the models become more
quantitative and nearer, brighter FRBs are discovered.
Description:
A total of 85 Fast radio burst (FRB) detections have been publicly
reported until 2019 September (FRBCAT; Petroff+ 2016, J/other/PASA/33.45).
The Cadmium Zinc Telluride Imager (CZTI) on board AstroSat is a coded
aperture mask instrument with a 4.6°x4.6° imaging field of
view in the hard X-ray band from 20keV to 200keV.
For this work, we limit ourselves to the time period from 2015 October 6
(the day CZTI became operational) to 2018 August 31.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 61 7 Parameters used for CZTI search
table2.dat 106 41 Observed parameters of radio bursts
table3.dat 127 123 CZTI fluence limits on X-rays from FRBs
--------------------------------------------------------------------------------
See also:
J/ApJ/812/81 : Arecibo Pulsar-ALFA (PALFA) survey. IV. (Lazarus+, 2015)
J/other/PASA/33.45 : FRBCAT: The Fast Radio Burst (FRB) Cat. (Petroff+, 2016)
J/ApJ/846/44 : Luminous persistent sources in nearby galaxies (Ofek, 2017)
J/ApJ/887/L7 : Faraday rotation of radio sources from THOR (Shanahan+, 2019)
http://www.frbcat.org/ : FRB catalogue
http://astrosat.iucaa.in/czti/?q=grb : CZTI GRB monitor page
http://astronomy.swin.edu.au/research/utmost/?page_id=1910 : All UTMOST FRBs
http://www.wis-tns.org/ : IAU transient name server with FRBs
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 31 A31 --- Parameter Data reduction and Search parameters
33- 59 A27 --- Value Values
61 A1 --- Flag [ab] Flag (1)
--------------------------------------------------------------------------------
Note (1): Flag as follows:
a = Modules with more than 1000 counts in one second are flagged as noisy,
and suppressed for that one second duration. The typical count rates
in each module are ∼5-10 counts per second.
b = Pixels with more than 100 counts in one second are flagged as noisy,
and suppressed for that one second duration.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 A18 --- Name Name designated to FRB
20- 21 I2 h Epoch.h UTC hour of detection
23- 24 I2 min Epoch.m UTC minute of detection
26- 31 F6.3 s Epoch.s UTC second of detection
33- 34 I2 h RAh [0/22] Hour of Right Ascension (J2000)
36- 37 I2 min RAm Minute of Right Ascension (J2000)
39- 43 F5.2 s RAs ? Second of Right Ascension (J2000)
46 A1 --- DE- Sign of the Declination (J2000)
47- 48 I2 deg DEd Degree of Declination (J2000)
50- 51 I2 arcmin DEm Arcminute of Declination (J2000)
53- 57 F5.2 arcsec DEs ? Arcsecond of Declination (J2000)
59- 67 A9 --- Tel Radio Telescope (1)
69- 74 F6.1 MHz Freq [111/1405] Central frequency
76- 82 F7.3 MHz Bandwidth [2.5/400] Bandwidth (2)
84- 89 F6.2 Jy Flux [0.2/666.7] Radio flux
91- 97 F7.2 ms FWHM [0.08/3300] Full Width at Half Maximum
99-106 F8.3 Jy.ms Fluence [1.5/1782] Radio fluence
--------------------------------------------------------------------------------
Note (1): Telescope as follows:
ASKAP = The Australian Square Kilometre Array Pathfinder (18 occurrences)
CHIME/FRB = The Canadian Hydrogen Intensity Mapping Experiment / Fast Radio
Burst Project (see 2018ApJ...863...48C 2018ApJ...863...48C ; 10 occurrences)
UTMOST = The Molonglo Observatory Synthesis Telescope (7 occurrences)
Parkes = Parkes radio telescope (4 occurrences)
Pushchino = Pushchino Radio Astronomy Observatory telescope (1 occurrence)
DSA-10 = The Deep Synoptic Array ten-antenna prototype at Owens Valley
Radio Observatory (1 occurrence)
Note (2): The value of Badwidth for FRB160608 reported is assumed to be 16 on
the basis of previous detection (FRB 160317) since the actual value
is missing from FRBCAT.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 A18 --- Name Name designated to FRB
20- 25 F6.2 Jy RFlux [0.2/666.7] Radio Flux
27- 32 F6.1 Jy.ms RFluence [1.5/1782] Radio Fluence
34- 37 F4.2 s tbin [0.01/1] Binning time for X-ray data
39- 43 F5.2 --- Sp-Index [-1.6/-1] Power law index
45- 53 E9.3 mJ/m2 XFluence-1 [5.9e-8/7e-6] X-ray Fluence; index=-1
55- 63 E9.3 mJ/m2 XFluenceMax [5.9e-8/7.9e-6] X-ray Fluence; index=alpha (1)
65- 69 F5.2 10+9 ratio [0.02/83.7] X-ray/Radio fluence ratio;
index=-1
71- 76 F6.3 10+9 ratioMax [0.02/87.3] X-ray/Radio fluence ratio;
index= alpha (1)
78-107 A30 --- Auth Author's name of the reference to original
detection
109-127 A19 --- BibCode Bibcode of the reference
--------------------------------------------------------------------------------
Note (1): An index of alpha represents the power law index that is consistent
with the radio observations under the assumption of a single source
spectrum from X-ray to radio.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 20-Oct-2021