The Event Horizon Telescope Image of the Quasar NRAO 530

Jorstad S.;Wielgus M.;Lico R.;Issaoun S.;Broderick A. E.;Pesce D. W.;Liu J.;Zhao G. -Y.;Krichbaum T. P.;Blackburn L.;Chan C. -K.;Janssen M.;Ramakrishnan V.;Akiyama K.;Alberdi A.;Algaba J. C.;Bouman K. L.;Cho I.;Fuentes A.;Gomez J. L.;Gurwell M.;Johnson M. D.;Kim J. -Y.;Lu R. -S.;Marti-Vidal I.;Moscibrodzka M.;Potzl F. M.;Traianou E.;van Bemmel I.;Alef W.;Anantua R.;Asada K.;Azulay R.;Bach U.;Baczko A. -K.;Ball D.;Balokovic M.;Barrett J.;Baubock M.;Benson B. A.;Bintley D.;Blundell R.;Bower G. C.;Boyce H.;Bremer M.;Brinkerink C. D.;Brissenden R.;Britzen S.;Broguiere D.;Bronzwaer T.;Bustamante S.;Byun D. -Y.;Carlstrom J. E.;Ceccobello C.;Chael A.;Chatterjee K.;Chatterjee S.;Chen M. -T.;Chen Y.;Cheng X.;Christian P.;Conroy N. S.;Conway J. E.;Cordes J. M.;Crawford T. M.;Crew G. B.;Cruz-Osorio A.;Cui Y.;Davelaar J.;De Laurentis M.;Deane R.;Dempsey J.;Desvignes G.;Dexter J.;Dhruv V.;Doeleman S. S.;Dougal S.;Dzib S. A.;Eatough R. P.;Emami R.;Falcke H.;Farah J.;Fish V. L.;Fomalont E.;Ford H. A.;Fraga-Encinas R.;Freeman W. T.;Friberg P.;Fromm C. M.;Galison P.;Gammie C. F.;Garcia R.;Gentaz O.;Georgiev B.;Goddi C.;Gold R.;Gomez-Ruiz A. I.;Gu M.;Hada K.;Haggard D.;Haworth K.;Hecht M. H.;Hesper R.;Heumann D.;Ho L. C.;Ho P.;Honma M.;Huang C. L.;Huang L.;Hughes D. H.;Ikeda S.;Impellizzeri C. M. V.;Inoue M.;James D. J.;Jannuzi B. T.;Jeter B.;Jiang W.;Jimenez-Rosales A.;Joshi A. V.;Jung T.;Karami M.;Karuppusamy R.;Kawashima T.;Keating G. K.;Kettenis M.;Kim D. -J.;Kim J.;Kim J.;Kino M.;Koay J. Y.;Kocherlakota P.;Kofuji Y.;Koyama S.;Kramer C.;Kramer M.;Kuo C. -Y.;La Bella N.;Lauer T. R.;Lee D.;Lee S. -S.;Leung P. K.;Levis A.;Li Z.;Lindahl G.;Lindqvist M.;Lisakov M.;Liu K.;Liuzzo E.;Lo W. -P.;Lobanov A. P.;Loinard L.;Lonsdale C. J.;MacDonald N. R.;Mao J.;Marchili N.;Markoff S.;Marrone D. P.;Marscher A. P.;Matsushita S.;Matthews L. D.;Medeiros L.;Menten K. M.;Michalik D.;Mizuno I.;Mizuno Y.;Moran J. M.;Moriyama K.;Muller C.;Mus A.;Musoke G.;Myserlis I.;Nadolski A.;Nagai H.;Nagar N. M.;Nakamura M.;Narayan R.;Narayanan G.;Natarajan I.;Nathanail A.;Fuentes S. N.;Neilsen J.;Neri R.;Ni C.;Noutsos A.;Nowak M. A.;Oh J.;Okino H.;Olivares H.;Ortiz-Leon G. N.;Oyama T.;Ozel F.;Palumbo D. C. M.;Paraschos G. F.;Park J.;Parsons H.;Patel N.;Pen U. -L.;Pietu V.;Plambeck R.;PopStefanija A.;Porth O.;Prather B.;Preciado-Lopez J. A.;Psaltis D.;Pu H. -Y.;Rao R.;Rawlings M. G.;Raymond A. W.;Rezzolla L.;Ricarte A.;Ripperda B.;Roelofs F.;Rogers A.;Ros E.;Romero-Canizales C.;Roshanineshat A.;Rottmann H.;Roy A. L.;Ruiz I.;Ruszczyk C.;Rygl K. L. J.;Sanchez S.;Sanchez-Arguelles D.;Sanchez-Portal M.;Sasada M.;Satapathy K.;Savolainen T.;Schloerb F. P.;Schonfeld J.;Schuster K. -F.;Shao L.;Shen Z.;Small D.;Sohn B. W.;SooHoo J.;Souccar K.;Sun H.;Tazaki F.;Tetarenko A. J.;Tiede P.;Tilanus R. P. J.;Titus M.;Torne P.;Trent T.;Trippe S.;Turk M.;van Langevelde H. J.;van Rossum D. R.;Vos J.;Wagner J.;Ward-Thompson D.;Wardle J.;Weintroub J.;Wex N.;Wharton R.;Wiik K.;Witzel G.;Wondrak M. F.;Wong G. N.;Wu Q.;Yamaguchi P.;Yoon D.;Young A.;Young K.;Younsi Z.;Yuan F.;Yuan Y. -F.;Zensus J. A.;Zhang S.;Zhao S. -S.

2023-01-01

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Abstract

We report on the observations of the quasar NRAO 530 with the Event Horizon Telescope (EHT) on 2017 April 5−7, when NRAO 530 was used as a calibrator for the EHT observations of Sagittarius A*. At z = 0.902, this is the most distant object imaged by the EHT so far. We reconstruct the first images of the source at 230 GHz, at an unprecedented angular resolution of ∼20 μas, both in total intensity and in linear polarization (LP). We do not detect source variability, allowing us to represent the whole data set with static images. The images reveal a bright feature located on the southern end of the jet, which we associate with the core. The feature is linearly polarized, with a fractional polarization of ∼5%-8%, and it has a substructure consisting of two components. Their observed brightness temperature suggests that the energy density of the jet is dominated by the magnetic field. The jet extends over 60 μas along a position angle ∼ −28°. It includes two features with orthogonal directions of polarization (electric vector position angle), parallel and perpendicular to the jet axis, consistent with a helical structure of the magnetic field in the jet. The outermost feature has a particularly high degree of LP, suggestive of a nearly uniform magnetic field. Future EHT observations will probe the variability of the jet structure on microarcsecond scales, while simultaneous multiwavelength monitoring will provide insight into the high-energy emission origin.