Science Using Single-Pulse Exploration with Combined Telescopes: II. Pulse profile evolution and single-pulse modulation
Abstract
Aims. We aim to illuminate how the pulsars' integrated pulse profiles and single-pulse modulation evolve with radio frequency, while separating intrinsic and propagation effects. Methods. We present integrated pulse profiles and phase-resolved modulation indices for 12 radio pulsars at up to five frequency bands. Our wideband dataset was systematically acquired with the Nancay Radio Observatory telescopes and the uGMRT, covering the frequency range 10 MHz to 2.8 GHz, including NenuFAR, LOFAR FR606, uGMRT, and NRT observations. We carefully measured the pulse widths and scattering times using multi-component profile fitting. We employed a profile width scaling model to separate the profile evolution into scattering and intrinsic contributions. We quantified the pulsars' single-pulse variability across frequency. Results. We describe the pulse profile evolution. Two pulsars have scattering indices compatible with Kolmogorov turbulence, while the majority have flatter scattering indices. This suggests complex scattering environments, dominated by localised turbulence. Complex scattering behaviour is seen in some pulsars, and most profiles are scattering-dominated below 200 MHz. The measured intrinsic power law indices are small, with absolute values between 0 and 0.3. Five pulsars exhibit decreasing intrinsic widths, two or three pulsars show flat behaviour, and four pulsars have increasing profile widths with frequency. Accounting for biases, most pulsar modulation parameters decrease with frequency, while three pulsars show flat behaviour. Conclusions. The pulse width evolution is explained by intrinsic radio beam narrowing, the emergence of profile components, and the balance between the two. Our modulation analysis indicates that the single-pulse emission from most of our pulsars becomes more erratic towards lower radio frequencies, consistent with increasing amplitude modulation.
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BibTeX
@misc{jankowski2026science,
title = {{Science Using Single-Pulse Exploration with Combined Telescopes: II. Pulse profile evolution and single-pulse modulation}},
author = {F. Jankowski and Jean-Mathias Griessmeier and T Roy and M Surnis and G Theureau and L Bondonneau and P Noe and J Petri and Lucas Guillemot and Ismaël Cognard and M Serylak and I Kravtsov and V Zakharenko and O Ulyanov},
howpublished = {HAL},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.38039},
eprint = {2609.38039},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05835188v1},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Science Using Single-Pulse Exploration with Combined Telescopes: II. Pulse profile evolution and single-pulse modulation
AU - F. Jankowski
AU - Jean-Mathias Griessmeier
AU - T Roy
AU - M Surnis
AU - G Theureau
AU - L Bondonneau
AU - P Noe
AU - J Petri
AU - Lucas Guillemot
AU - Ismaël Cognard
AU - M Serylak
AU - I Kravtsov
AU - V Zakharenko
AU - O Ulyanov
PY - 2026
DA - 2026/09/29
PB - HAL
DO - 10.48550/arxiv.2609.38039
UR - https://hal.science/hal-05835188v1
AB - Aims. We aim to illuminate how the pulsars' integrated pulse profiles and single-pulse modulation evolve with radio frequency, while separating intrinsic and propagation effects. Methods. We present integrated pulse profiles and phase-resolved modulation indices for 12 radio pulsars at up to five frequency bands. Our wideband dataset was systematically acquired with the Nancay Radio Observatory telescopes and the uGMRT, covering the frequency range 10 MHz to 2.8 GHz, including NenuFAR, LOFAR FR606, uGMRT, and NRT observations. We carefully measured the pulse widths and scattering times using multi-component profile fitting. We employed a profile width scaling model to separate the profile evolution into scattering and intrinsic contributions. We quantified the pulsars' single-pulse variability across frequency. Results. We describe the pulse profile evolution. Two pulsars have scattering indices compatible with Kolmogorov turbulence, while the majority have flatter scattering indices. This suggests complex scattering environments, dominated by localised turbulence. Complex scattering behaviour is seen in some pulsars, and most profiles are scattering-dominated below 200 MHz. The measured intrinsic power law indices are small, with absolute values between 0 and 0.3. Five pulsars exhibit decreasing intrinsic widths, two or three pulsars show flat behaviour, and four pulsars have increasing profile widths with frequency. Accounting for biases, most pulsar modulation parameters decrease with frequency, while three pulsars show flat behaviour. Conclusions. The pulse width evolution is explained by intrinsic radio beam narrowing, the emergence of profile components, and the balance between the two. Our modulation analysis indicates that the single-pulse emission from most of our pulsars becomes more erratic towards lower radio frequencies, consistent with increasing amplitude modulation.
ER -