Saved in:
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2024
|
| Subjects: | |
| Online Access: | https://arxiv.org/abs/2411.08191 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866911007969902592 |
|---|---|
| author | Geiger, Abra Cordes, James M. Lam, Michael T. Ocker, Stella Koch Chatterjee, Shami Arzoumanian, Zaven Battaglia, Ava L. Blumer, Harsha Brook, Paul R. Combs, Olivia A. Cromartie, H. Thankful DeCesar, Megan E. Demorest, Paul B. Dolch, Timothy Ellis, Justin A. Ferdman, Robert D. Ferrara, Elizabeth C. Fonseca, Emmanuel Garver-Daniels, Nate Gentile, Peter A. Good, Deborah C. Jones, Megan L. Lorimer, Duncan R. Luo, Jing Lynch, Ryan S. McLaughlin, Maura A. Ng, Cherry Nice, David J. Pennucci, Timothy T. Pol, Nihan S. Ransom, Scott M. Spiewak, Renée Stairs, Ingrid H. Stovall, Kevin Swiggum, Joseph K. Vigeland, Sarah J. |
| author_facet | Geiger, Abra Cordes, James M. Lam, Michael T. Ocker, Stella Koch Chatterjee, Shami Arzoumanian, Zaven Battaglia, Ava L. Blumer, Harsha Brook, Paul R. Combs, Olivia A. Cromartie, H. Thankful DeCesar, Megan E. Demorest, Paul B. Dolch, Timothy Ellis, Justin A. Ferdman, Robert D. Ferrara, Elizabeth C. Fonseca, Emmanuel Garver-Daniels, Nate Gentile, Peter A. Good, Deborah C. Jones, Megan L. Lorimer, Duncan R. Luo, Jing Lynch, Ryan S. McLaughlin, Maura A. Ng, Cherry Nice, David J. Pennucci, Timothy T. Pol, Nihan S. Ransom, Scott M. Spiewak, Renée Stairs, Ingrid H. Stovall, Kevin Swiggum, Joseph K. Vigeland, Sarah J. |
| contents | Free electrons in the interstellar medium refract and diffract radio waves along multiple paths, resulting in angular and temporal broadening of radio pulses that limits pulsar timing precision. We determine multifrequency, multi-epoch scattering times for the large dispersion measure millisecond pulsar J1903+0327 by developing a three component model for the emitted pulse shape that is convolved with a best fit pulse broadening function (PBF) identified from a family of thin-screen and extended-media PBFs. We show that the scattering time, $τ$, at a fiducial frequency of 1500 MHz changes by approximately 10% over a 5.5yr span with a characteristic timescale of approximately 100 days. We also constrain the spectral index and inner scale of the wavenumber spectrum of electron density variations along this line of sight. We find that the scaling law for $τ$ vs. radio frequency is strongly affected by any mismatch between the true and assumed PBF or between the true and assumed intrinsic pulse shape. We show using simulations that refraction is a plausible cause of the epoch dependence of $τ$, manifesting as changes in the PBF shape and $1/e$ time scale. Finally, we discuss the implications of our scattering results on pulsar timing including time of arrival delays and dispersion measure misestimation. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2411_08191 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | The NANOGrav 12.5-Year Data Set: Probing Interstellar Turbulence and Precision Pulsar Timing with PSR J1903+0327 Geiger, Abra Cordes, James M. Lam, Michael T. Ocker, Stella Koch Chatterjee, Shami Arzoumanian, Zaven Battaglia, Ava L. Blumer, Harsha Brook, Paul R. Combs, Olivia A. Cromartie, H. Thankful DeCesar, Megan E. Demorest, Paul B. Dolch, Timothy Ellis, Justin A. Ferdman, Robert D. Ferrara, Elizabeth C. Fonseca, Emmanuel Garver-Daniels, Nate Gentile, Peter A. Good, Deborah C. Jones, Megan L. Lorimer, Duncan R. Luo, Jing Lynch, Ryan S. McLaughlin, Maura A. Ng, Cherry Nice, David J. Pennucci, Timothy T. Pol, Nihan S. Ransom, Scott M. Spiewak, Renée Stairs, Ingrid H. Stovall, Kevin Swiggum, Joseph K. Vigeland, Sarah J. High Energy Astrophysical Phenomena Free electrons in the interstellar medium refract and diffract radio waves along multiple paths, resulting in angular and temporal broadening of radio pulses that limits pulsar timing precision. We determine multifrequency, multi-epoch scattering times for the large dispersion measure millisecond pulsar J1903+0327 by developing a three component model for the emitted pulse shape that is convolved with a best fit pulse broadening function (PBF) identified from a family of thin-screen and extended-media PBFs. We show that the scattering time, $τ$, at a fiducial frequency of 1500 MHz changes by approximately 10% over a 5.5yr span with a characteristic timescale of approximately 100 days. We also constrain the spectral index and inner scale of the wavenumber spectrum of electron density variations along this line of sight. We find that the scaling law for $τ$ vs. radio frequency is strongly affected by any mismatch between the true and assumed PBF or between the true and assumed intrinsic pulse shape. We show using simulations that refraction is a plausible cause of the epoch dependence of $τ$, manifesting as changes in the PBF shape and $1/e$ time scale. Finally, we discuss the implications of our scattering results on pulsar timing including time of arrival delays and dispersion measure misestimation. |
| title | The NANOGrav 12.5-Year Data Set: Probing Interstellar Turbulence and Precision Pulsar Timing with PSR J1903+0327 |
| topic | High Energy Astrophysical Phenomena |
| url | https://arxiv.org/abs/2411.08191 |