PIRSA:26050054 Scientific Series Cosmology

DOI10.48660/26050054

Series: Cosmology and Gravitation

Tsai, A. (2026). Reaching diffraction-limited localization with coherent PTAs. Perimeter Institute. https://pirsa.org/26050054

Tsai, Anna. Reaching diffraction-limited localization with coherent PTAs. Perimeter Institute, May. 12, 2026, https://pirsa.org/26050054 

@misc{ pirsa_PIRSA:26050054,
  doi = {10.48660/26050054},
  url = {https://pirsa.org/26050054},
  author = {Tsai, Anna},
  keywords = {Cosmology},
  language = {en},
  title = {Reaching diffraction-limited localization with coherent PTAs},
  publisher = {Perimeter Institute},
  year = {2026},
  month = {may},
  note = {PIRSA:26050054 see, \url{https://pirsa.org}}
}

Abstract

Current pulsar timing array (PTA) analyses do not take full advantage of pulsar distance information, thereby missing out on improved angular resolution and on a potential factor-of-two gain in detection sensitivity for individual gravitational-wave (GW) sources. In this work, we investigate the impact of precise pulsar distance measurements on angular resolution as an extension to previous work measuring the angular resolution of a dense, isotropic PTA [Jow et al., 2025]. We present a coherent map-making technique that utilizes precise pulsar distance measurements to reach the diffraction-limited resolution of an individual source: δθdiff ∼ (1/SNR)(λGW/r) ≈ 2 arcmin, where the SNR refers to the detection strength of the source. With this level of angular resolution, identifying an EM counterpart may become feasible, enabling multi-messenger follow-up. We show that for SNR = 10, which may be the current sensitivity level using a coherent analysis, the diffraction limit is reached with roughly 9 pulsars. Moreover, angular resolution scales sharply with the number of known pulsar distances as ∼ (1/SNR)Ndist/2 . Thus, each additional pulsar with high signal-to-noise timing and precise distance measurement can improve PTA resolution by an order of magnitude. The distance to the best-timed millisecond pulsar (PSR J0437−4715) is already constrained to subparsec levels. We argue, therefore, that a coherent analysis of PTA data, fully incorporating pulsar distance information, is timely.

Resources

1/21
1/21
2/21
2/21
3/21
3/21
4/21
4/21
5/21
5/21
6/21
6/21
7/21
7/21
8/21
8/21
9/21
9/21
10/21
10/21
11/21
11/21
12/21
12/21
13/21
13/21
14/21
14/21
15/21
15/21
16/21
16/21
17/21
17/21
18/21
18/21
19/21
19/21
20/21
20/21
21/21
21/21

Next talk

Related Talks