%0 Generic %1 arzoumanian2020nanograv %A Arzoumanian, Zaven %A Baker, Paul T. %A Blumer, Harsha %A Becsy, Bence %A Brazier, Adam %A Brook, Paul R. %A Burke-Spolaor, Sarah %A Chatterjee, Shami %A Chen, Siyuan %A Cordes, James M. %A Cornish, Neil J. %A Crawford, Fronefield %A Cromartie, H. Thankful %A DeCesar, Megan E. %A Demorest, Paul B. %A Dolch, Timothy %A Ellis, Justin A. %A Ferrara, Elizabeth C. %A Fiore, William %A Fonseca, Emmanuel %A Garver-Daniels, Nathan %A Gentile, Peter A. %A Good, Deborah C. %A Hazboun, Jeffrey S. %A Holgado, A. Miguel %A Islo, Kristina %A Jennings, Ross J. %A Jones, Megan L. %A Kaiser, Andrew R. %A Kaplan, David L. %A Kelley, Luke Zoltan %A Key, Joey Shapiro %A Laal, Nima %A Lam, Michael T. %A Lazio, T. Joseph W. %A Lorimer, Duncan R. %A Luo, Jing %A Lynch, Ryan S. %A Madison, Dustin R. %A McLaughlin, Maura A. %A Mingarelli, Chiara M. F. %A Ng, Cherry %A Nice, David J. %A Pennucci, Timothy T. %A Pol, Nihan S. %A Ransom, Scott M. %A Ray, Paul S. %A Shapiro-Albert, Brent J. %A Siemens, Xavier %A Simon, Joseph %A Spiewak, Renee %A Stairs, Ingrid H. %A Stinebring, Daniel R. %A Stovall, Kevin %A Sun, Jerry P. %A Swiggum, Joseph K. %A Taylor, Stephen R. %A Turner, Jacob E. %A Vallisneri, Michele %A Vigeland, Sarah J. %A Witt, Caitlin A. %D 2020 %K tifr %T The NANOGrav 12.5-year Data Set: Search For An Isotropic Stochastic Gravitational-Wave Background %U http://arxiv.org/abs/2009.04496 %X We search for an isotropic stochastic gravitational-wave background (GWB) in the $12.5$-year pulsar timing data set collected by the North American Nanohertz Observatory for Gravitational Waves (NANOGrav). Our analysis finds strong evidence of a stochastic process, modeled as a power-law, with common amplitude and spectral slope across pulsars. The Bayesian posterior of the amplitude for a $f^-2/3$ power-law spectrum, expressed as characteristic GW strain, has median $1.92 10^-15$ and $5\%$--$95\%$ quantiles of $1.37$--$2.67 10^-15$ at a reference frequency of $f_yr = 1 ~yr^-1$. The Bayes factor in favor of the common-spectrum process versus independent red-noise processes in each pulsar exceeds $10,000$. However, we find no statistically significant evidence that this process has quadrupolar spatial correlations, which we would consider necessary to claim a GWB detection consistent with General Relativity. We find that the process has neither monopolar nor dipolar correlations, which may arise from, for example, reference clock or solar-system ephemeris systematics, respectively. The amplitude posterior has significant support above previously reported upper limits; we explain this in terms of the Bayesian priors assumed for intrinsic pulsar red noise. We examine potential implications for the supermassive black hole binary population under the hypothesis that the signal is indeed astrophysical in nature.

@misc{arzoumanian2020nanograv, abstract = {We search for an isotropic stochastic gravitational-wave background (GWB) in the $12.5$-year pulsar timing data set collected by the North American Nanohertz Observatory for Gravitational Waves (NANOGrav). Our analysis finds strong evidence of a stochastic process, modeled as a power-law, with common amplitude and spectral slope across pulsars. The Bayesian posterior of the amplitude for a $f^{-2/3}$ power-law spectrum, expressed as characteristic GW strain, has median $1.92 \times 10^{-15}$ and $5\%$--$95\%$ quantiles of $1.37$--$2.67 \times 10^{-15}$ at a reference frequency of $f_\mathrm{yr} = 1 ~\mathrm{yr}^{-1}$. The Bayes factor in favor of the common-spectrum process versus independent red-noise processes in each pulsar exceeds $10,000$. However, we find no statistically significant evidence that this process has quadrupolar spatial correlations, which we would consider necessary to claim a GWB detection consistent with General Relativity. We find that the process has neither monopolar nor dipolar correlations, which may arise from, for example, reference clock or solar-system ephemeris systematics, respectively. The amplitude posterior has significant support above previously reported upper limits; we explain this in terms of the Bayesian priors assumed for intrinsic pulsar red noise. We examine potential implications for the supermassive black hole binary population under the hypothesis that the signal is indeed astrophysical in nature.}, added-at = {2020-09-11T08:02:09.000+0200}, author = {Arzoumanian, Zaven and Baker, Paul T. and Blumer, Harsha and Becsy, Bence and Brazier, Adam and Brook, Paul R. and Burke-Spolaor, Sarah and Chatterjee, Shami and Chen, Siyuan and Cordes, James M. and Cornish, Neil J. and Crawford, Fronefield and Cromartie, H. Thankful and DeCesar, Megan E. and Demorest, Paul B. and Dolch, Timothy and Ellis, Justin A. and Ferrara, Elizabeth C. and Fiore, William and Fonseca, Emmanuel and Garver-Daniels, Nathan and Gentile, Peter A. and Good, Deborah C. and Hazboun, Jeffrey S. and Holgado, A. Miguel and Islo, Kristina and Jennings, Ross J. and Jones, Megan L. and Kaiser, Andrew R. and Kaplan, David L. and Kelley, Luke Zoltan and Key, Joey Shapiro and Laal, Nima and Lam, Michael T. and Lazio, T. Joseph W. and Lorimer, Duncan R. and Luo, Jing and Lynch, Ryan S. and Madison, Dustin R. and McLaughlin, Maura A. and Mingarelli, Chiara M. F. and Ng, Cherry and Nice, David J. and Pennucci, Timothy T. and Pol, Nihan S. and Ransom, Scott M. and Ray, Paul S. and Shapiro-Albert, Brent J. and Siemens, Xavier and Simon, Joseph and Spiewak, Renee and Stairs, Ingrid H. and Stinebring, Daniel R. and Stovall, Kevin and Sun, Jerry P. and Swiggum, Joseph K. and Taylor, Stephen R. and Turner, Jacob E. and Vallisneri, Michele and Vigeland, Sarah J. and Witt, Caitlin A.}, biburl = {https://www.bibsonomy.org/bibtex/23e8fe3d96a52f8ef77f0c6bf832b8078/citekhatri}, description = {The NANOGrav 12.5-year Data Set: Search For An Isotropic Stochastic Gravitational-Wave Background}, interhash = {880c40b30107456d16a04c1e9b8e966e}, intrahash = {3e8fe3d96a52f8ef77f0c6bf832b8078}, keywords = {tifr}, note = {cite arxiv:2009.04496Comment: 24 pages, 13 figures, 5 tables, 3 appendices. Submitted to The Astrophysical Journal Letters}, timestamp = {2020-09-11T08:02:09.000+0200}, title = {The NANOGrav 12.5-year Data Set: Search For An Isotropic Stochastic Gravitational-Wave Background}, url = {http://arxiv.org/abs/2009.04496}, year = 2020 }