J/ApJ/956/28 Spectral index distrib. of RACS ATNF pulsars (Anumarlapudi+, 2023)
Characterizing pulsars detected in the Rapid ASKAP Continuum Survey.
Anumarlapudi A., Ehlke A., Jones M.L., Kaplan D.L., Dobie D., Lenc E.,
Leung J.K., Murphy T., Pritchard J., Stewart A.J., Sengar R., Anderson C.,
Banfield J., Heald G., Hotan A.W., McConnell D., Moss V.A., Raja W.,
Whiting M.T.
<Astrophys. J., 956, 28 (2023)>
=2023ApJ...956...28A 2023ApJ...956...28A
ADC_Keywords: Pulsars; Radio sources; Surveys; Interferometry
Keywords: Pulsars ; Radio pulsars ; Neutron stars ; Radio interferometry
Abstract:
We present the detection of 661 known pulsars observed with the
Australian SKA Pathfinder (ASKAP) telescope at 888MHz as part of the
Rapid ASKAP Continuum Survey (RACS). Detections were made through
astrometric coincidence and we estimate the false alarm rate of our
sample to be ∼0.5%. Using archival data at 400 and 1400MHz, we
estimate the power-law spectral indices for the pulsars in our sample
and find that the mean spectral index is -1.78±0.6. However, we also
find that a single power law is inadequate for modeling all the
observed spectra. With the addition of flux densities between 150MHz
and 3GHz from various imaging surveys, we find that up to 40% of our
sample show deviations from a simple power-law model. Using Stokes V
measurements from the RACS data, we measured the circular polarization
fraction for 9% of our sample and find that the mean polarization
fraction is ∼10% (consistent between detections and upper limits).
Using the dispersion-measure-derived distance, we estimate the
pseudo-luminosity of the pulsars and do not find any strong evidence
for a correlation with the pulsars' intrinsic properties.
Description:
Data were collected as a part of the Rapid ASKAP Continuum Survey
(RACS; McConnell+ 2020PASA...37...48M 2020PASA...37...48M), an all-sky survey (south of
decl. +51°) initially observing at 888MHz, with a bandwidth of
288MHz. The observations were carried out from 2019 April 21 through
2020 June 21 (constituting the first RACS data set; RACS DR1) and
cover the sky south of +41° decl., with an integration time of
15min, and they were used to generate both Stokes I and Stokes V
images.
The Australian SKA Pathfinder (ASKAP) telescope is an interferometric
array of 36 dish antennas, each 12m in diameter, achieving a
resolution of 15".
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 133 150 Astrometric and spectral measurements for pulsars
in our sample whose spectrum can be described by a
simple power law
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See also:
B/psr : ATNF Pulsar Catalogue (Manchester+, 2005)
J/MNRAS/273/411 : Multifrequency fluxes of 280 pulsars (Lorimer+ 1995)
J/MNRAS/301/235 : Multifrequency polarimetry of 300 pulsars (Gould+, 1998)
J/A+AS/136/571 : Pulsars identified from the NRAO VLA Sky Survey (Han+ 1999)
J/A+AS/147/195 : Pulsar spectra of radio emission (Maron+, 2000)
J/MNRAS/372/777 : Parkes Multibeam Pulsar Survey. VI. (Lorimer+, 2006)
J/ApJ/829/119 : Known pulsars identified in the TGSS ADR (Frail+, 2016)
J/MNRAS/473/4436 : Spectral properties of 441 radio pulsars (Jankowski+, 2018)
J/MNRAS/474/4629 : Polarimetry of pulsars from 1.4GHz obs. (Johnston+, 2018)
J/ApJS/255/30 : VLASS QL Ep.1 Catalog, CIRADA version (Gordon+, 2021)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Pulsar Name
13- 14 I2 h RAh Hour of Right Ascension (J2000)
16- 17 I2 min RAm Minute of Right Ascension (J2000)
19- 22 F4.1 s RAs Second of Right Ascension (J2000)
24 A1 --- DE- Sign of the Declination (J2000)
25- 26 I2 deg DEd Degree of Declination (J2000)
28- 29 I2 arcmin DEm Arcminute of Declination (J2000)
31- 32 I2 arcsec DEs Arcsecond of Declination (J2000)
34- 40 F7.3 mJy S888 [1/373] RACS 888MHz flux density; this work
42- 46 F5.3 mJy e_S888 [0.2/3.1] Uncertainty (1σ) in S888
48- 54 F7.2 mJy S400 [4/1100] ATNF 400MHz flux density from
Manchester+ 2005, B/psr
56- 61 F6.2 mJy e_S400 [0.2/200] Uncertainty (1σ) in S400
63- 69 F7.3 mJy S1400 [0.13/151] ATNF 1.4GHz flux density from
Manchester+ 2005, B/psr
71- 76 F6.3 mJy e_S1400 [0.01/40] Uncertainty (1σ) in S1400
78- 84 F7.3 mJy DSError [0/234] Errors in flux densities due to
diffractive scintillation
86- 91 F6.1 mJy S150 [26/2592]? TIFR GMRT Sky Survey 150MHz flux
density from Frail+ 2016, J/ApJ/829/119
93- 96 F4.1 mJy e_S150 [3.5/30]? Uncertainty (1σ) in S150
98- 103 F6.1 mJy S200 [46/1504]? Murchison Widefield Array 200MHz
flux density from Murphy+ 2017PASA...34...20M 2017PASA...34...20M
105- 109 F5.1 mJy e_S200 [5/269]? Uncertainty (1σ) in S200
111- 115 F5.2 mJy S3000 [0/20.1]? Very Large Array Sky Survey 3GHz
flux density from Gordon+ 2021, J/ApJS/255/30
117- 121 F5.3 mJy e_S3000 [0/0.6]? Uncertainty (1σ) in S3000
123- 127 F5.2 --- alpha [-3.34/-0.3] Spectral index
129- 133 F5.3 --- e_alpha [0.014/0.6] Uncertainty in alpha
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 05-Dec-2025