J/MNRAS/527/5183 Galactic distribution of pulsar scattering (He+, 2024)
The Galactic distribution of pulsar scattering and the tau-DM relation.
He Q.Y., Shi X.
<Mon. Not. R. Astron. Soc. 527, 5183-5191 (2024)>
=2024MNRAS.527.5183H 2024MNRAS.527.5183H (SIMBAD/NED BibCode)
ADC_Keywords: Interstellar medium ; Pulsars ; Galactic plane
Keywords: scattering - methods: data analysis - pulsars: general - galaxies: ISM
Abstract:
Interstellar radio-wave scattering leads to flux density fluctuations
and pulse broadening of pulsar signals. However, Galactic distribution
and the structure of the scattering medium are still poorly
understood. Pulsar pulse broadening data available for a relatively
large number of pulsars is well-suited for such investigations. We
collected an up-to-date sample of publicly-available pulsar scattering
data and introduced a new quantity - the reduced scattering strength
to study the Galactic distribution of pulsar scattering in the Milky
Way. We show that the current observations are dominated by two
distinct pulsar populations: a local and an inner-Galactic one
separated by ∼τ=10-5.1s.cm6/pc. The stronger electron
density fluctuations associated with the inner-Galactic population
naturally explain the observed steepening of pulsar scattering time -
dispersion measure (DM) relation. We measure an inner disk region with
3kpc<r<5.5kpc from the Galactic center to have a scattering scale
height of about 0.28kpc, supporting a correlation between interstellar
radio scattering and structures associating with the ionized gas and
stellar activities.
Description:
Our data collection is based on the publicly available pulsar
scattering time data from the ATNF website (Catalogue Version: 1.70).
We traced back to the original references and obtained the
corresponding scattering time values at the observed frequencies.
Multiple frequencies were all included when available. We also
supplemented our data collection by searching for additional pulsar
observation data mentioned in each reference. Next, we included
additional data mentioned in Cordes et al. (2016,
10.48550/arXiv.1605.05890). Finally, we added results from a recently
published article and some articles not included on the ATNF website.
We finally formed a database with 1110 pulsar scattering time
observations obtained by measuring 473 pulsars at different
observation frequencies from 54 papers. This is the most complete
multi-frequency data of τ measurements compiled to date. Among
them, 244 pulsars have scattering time data at a single frequency,
and 229 pulsars have multi-frequency data.
The X,Y,Z coordinates included in previous versions of this dataset
were calculated based on the Sun's position parameter (0, 8.5, 0),
which differs from the standard parameters used by the ATNF pulsar
catalog and other sources. To avoid position errors, X,Y,Z coordinate
columns have been removed in this version. Researchers can calculate
the X,Y,Z coordinates of pulsars in the Galaxy themselves using the
Galactic longitude (l), Galactic latitude (b), and distance (d) values
provided in the table, according to their preferred Sun position
parameters.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 85 1110 Pulsar scattering data and their sources
(corrected version, 27-Feb-2025)
refs.dat 210 54 References
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See also:
http://www.atnf.csiro.au/research/pulsar/psrcat : PSR cat Home page
Byte-by-byte Description of file: tableb1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- BName Pulsar BName (or JName if no BName)
13- 23 A11 --- JName Pulsar JName
25- 31 F7.3 deg GLON Galactic longitude
33- 39 F7.3 deg GLAT Galactic latitude
41- 46 F6.3 kpc Dist Distance
48- 58 F11.6 pc/cm3 DM Dispersion measure
60- 65 F6.1 MHz Freq Observation frequency
67- 78 E12.7 s tau Scattering time
80- 81 I2 --- Ref [1/54] Original reference of this data
(in refs.dat file)
83- 85 A3 --- Parallax [yes/no] Indicates whether we correct the
pulsar position according to the pulsar
parallax (1)
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Note (1): Parallax code as follows:
yes = the Dist value is derived from the measured parallax
no = The position information of the pulsar comes from the results on the
ATNF catalogue (version 1.70).
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Byte-by-byte Description of file: refs.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Ref Reference number
4- 22 A19 --- BibCode BibCode
24- 54 A31 --- Aut Author's name
56-210 A155 --- Com Comments
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Acknowledgements:
Qiuyi He, qiuyi981022(at)gmail.com
Xun Shi, xun(at)ynu.edu.cn
History:
07-Dec-2023: on-line version
27-Feb-2025: corrected version
(End) Patricia Vannier [CDS] 27-Feb-2025