Yan Wang1,2,3, James M. Cordes4, Fredrick A. Jenet2,3, Shami Chatterjee4, Paul B. Demorest5,
Timothy Dolch6, Justin A. Ellis7, Michael T. Lam4, Dustin R. Madison5, Maura A. McLaughlin8,
Delphine Perrodin9, Joanna Rankin10, Xavier Siemens11 and Michele Vallisneri7
1 MOE Key Laboratory of Fundamental Physical Quantities Measurements, School of Physics, Huazhong
University of Science and Technology,Wuhan 430074, China; ywang12@hust.edu.cn
2 Center for Advanced Radio Astronomy, University of Texas at Brownsville, 1 West University Boulevard,
Brownsville, TX 78520, USA
3 Department of Physics and Astronomy, University of Texas at Brownsville, 1 West University Boulevard,
Brownsville, TX 78520, USA
4 Department of Astronomy, Cornell University, Ithaca, NY 14853, USA
5 National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA
6 Department of Physics, Hillsdale College, 33 E. College Street, Hillsdale, MI 49242, USA
7 Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91106, USA
8 Department of Physics, West Virginia University, P.O. Box 6315,Morgantown,WV 26505, USA
9 INAF-Osservatorio Astronomico di Cagliari, Via della Scienza 5, 09047 Selargius (CA), Italy
10 Department of Physics, University of Vermont, Burlington, VT 05405, USA
11 Center for Gravitation, Cosmology and Astrophysics, Department of Physics, University of
Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201, USA
Abstract In pulsar timing, timing residuals are the differences between the observed times of arrival and predictions from the timing model. A comprehensive timing model will produce featureless residuals, which are presumably composed of dominating noise and weak physical effects excluded from the timing model (e.g. gravitational waves). In order to apply optimal statistical methods for detecting weak gravitational wave signals, we need to know the statistical properties of noise components in the residuals. In this paper we utilize a variety of non-parametric statistical tests to analyze the whiteness and Gaussianity of the NorthAmerican NanohertzObservatory for GravitationalWaves (NANOGrav) 5-year timing data, which are obtained from Arecibo Observatory and Green Bank Telescope from 2005 to 2010. We find that most of the data are consistent with white noise; many data deviate from Gaussianity at different levels, nevertheless, removing outliers in some pulsars will mitigate the deviations.
RAA 2017 Vol. 17 No. 2, 19 (14pp) doi: 10.1088/1674–4527/17/2/19
