학술논문

A Gamma-ray Pulsar Timing Array Constrains the Nanohertz Gravitational Wave Background
Document Type
Working Paper
Author
Ajello, M.Atwood, W. B.Baldini, L.Ballet, J.Barbiellini, G.Bastieri, D.Bellazzini, R.Berretta, A.Bhattacharyya, B.Bissaldi, E.Blandford, R. D.Bloom, E.Bonino, R.Bruel, P.Buehler, R.Burns, E.Buson, S.Cameron, R. A.Caraveo, P. A.Cavazzuti, E.Cibrario, N.Ciprini, S.Clark, C. J.Cognard, I.Coronado-Blázquez, J.Crnogorcevic, M.Cromartie, H.Crowter, K.Cutini, S.D'Ammando, F.Gaetano, S. D.Palma, F. d.Digel, S. W.Lalla, N. D.Dirirsa, F. Fan.Venere, L. D.Domínguez, A.Ferrara, E. C.Fiori, A.Franckowiak, A.Fukazawa, Y.Funk, S.Fusco, P.Gammaldi, V.Gargano, F.Gasparrini, D.Giglietto, N.Giordano, F.Giroletti, M.Green, D.Grenier, I. A.Guillemot, L.Guiriec, S.Gustafsson, M.Harding, A. K.Hays, E.Hewitt, J. W.Horan, D.Hou, X.Jóhannesson, G.Keith, M. J.Kerr, M.Kramer, M.Kuss, M.Larsson, S.Latronico, L.Li, J.Longo, F.Loparco, F.Lovellette, M. N.Lubrano, P.Maldera, S.Manfreda, A.Martí-Devesa, G.Mazziotta, M. N.Mereu, I.Michelson, P. F.Mirabal, N.Mitthumsiri, W.Mizuno, T.Monzani, M. E.Morselli, A.Negro, M.Nieder, L.Ojha, R.Omodei, N.Orienti, M.Orlando, E.Ormes, J. F.Paneque, D.Parthasarathy, A.Pei, Z.Persic, M.Pesce-Rollins, M.Pillera, R.Poon, H.Porter, T. A.Principe, G.Racusin, J. L.Rainò, S.Rando, R.Rani, B.Ransom, S. M.Ray, P. S.Razzano, M.Razzaque, S.Reimer, A.Reimer, O.Roy, J.Sánchez-Conde, M.Parkinson, P. M. Sa.Scargle, J.Scotton, L.Serini, D.Sgrò, C.Siskind, E. J.Smith, D. A.Spandre, G.Spiewak, R.Spinelli, P.Stairs, I.Suson, D. J.Swihart, S. J.Tabassum, S.Thayer, J. B.Theureau, G.Torres, D. F.Troja, E.Valverde, J.Wadiasingh, Z.Wood, K.Zaharijas, G.
Source
Subject
Astrophysics - High Energy Astrophysical Phenomena
Language
Abstract
After large galaxies merge, their central supermassive black holes are expected to form binary systems whose orbital motion generates a gravitational wave background (GWB) at nanohertz frequencies. Searches for this background utilize pulsar timing arrays, which perform long-term monitoring of millisecond pulsars (MSPs) at radio wavelengths. We use 12.5 years of Fermi Large Area Telescope data to form a gamma-ray pulsar timing array. Results from 35 bright gamma-ray pulsars place a 95\% credible limit on the GWB characteristic strain of $1.0\times10^{-14}$ at 1 yr$^{-1}$, which scales as the observing time span $t_{\mathrm{obs}}^{-13/6}$. This direct measurement provides an independent probe of the GWB while offering a check on radio noise models.
Comment: 3 figures in the main text. 3 figures and 8 tables are in the supplementary material