Hostname: page-component-848d4c4894-mwx4w Total loading time: 0 Render date: 2024-07-03T13:13:32.796Z Has data issue: false hasContentIssue false

Search for Ultralight Scalar Dark Matter from Pulsar Timing

Published online by Cambridge University Press:  27 October 2016

Konstantin Postnov
Affiliation:
M.V. Lomonosov Moscow State University, Faculty of Physics, and Sternberg Astronomical Institute email: pk@sai.msu.ru
Nataliya Porayko
Affiliation:
M.V. Lomonosov Moscow State University, Faculty of Physics, and Max Planck Institute for Radio Astronomy, Bonn email: porayko.nataliya@gmail.com
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We perform a Bayesian analysis of pulsar-timing residuals from the NANOGrav pulsar-timing array to search for a specific form of stochastic narrow-band signal produced by oscillating gravitational potential (Gravitational Potential Background) in the Galactic halo. Such oscillations arise in models of warm dark matter composed of an ultralight massive scalar field (m ≃ 10−23 eV). The propagation of an electromagnetic signal from a pulsar through the time-dependent spacetime will leave an imprint in the pulsar timing, much like a gravitational wave. From the physical point of view, this is the classical Sachs-Wolfe effect. A distinctive feature of the pulsar-timing residuals due to GBP produced by a variable scalar field is that the amplitude of the TOA residuals should be independent of the pulsar location in the sky. In the monochromatic approximation, the stringent upper limit (95% C.L.) on the variable gravitational potential amplitude is found to be (Ψc<1.14 × 10−15), corresponding to the characteristic strain hc = 2$\sqrt{3}$Ψc < 4 × 10−15 at f=1.75 × 10−8 Hz. In the narrow-band approximation, the upper limit of this background energy density is ΩGPB < 1.27 × 10−9 at f=1.75 × 10−8 Hz. These limits are an order of magnitude higher than the expected signal amplitude assuming all Galactic dark matter is made of such scalar particles. The applied analysis of the pulsar-timing residuals can be used to search for any narrow-band stochastic signals with different correlation properties. As a by-product, parameters of the red noise present in four NANOGrav pulsars were found.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2016 

References

Demorest, P. B., Ferdman, R. D., Gonzalez, M. E., et al. 2013, ApJ, 762, 94 CrossRefGoogle Scholar
Detweiler, S. 1979, ApJ, 234, 1100 Google Scholar
Foster, R. S. & Backer, D. C. 1990, ApJ, 361, 300 Google Scholar
Khmelnitsky, A. & Rubakov, V. 2014, J. Cosmol. Astropart. Phys., 2, 019 Google Scholar
Porayko, N. & Postnov, K., 2014, Phys. Rev. D., 90, 062008 Google Scholar
Sazhin, M. V. 1978, SvA, 22, 36 Google Scholar
Tiburzi, C., Hobbs, G., Kerr, M., et al. 2015, MNRAS, in press; arXiv:1510.02363Google Scholar
van Haasteren, R. & Levin, Y. 2013, MNRAS, 428, 1147 Google Scholar