A Search for Pulsars around Sgr A* in the First Event Horizon Telescope Data Set
Torne, Pablo;Liu, Kuo;Eatough, Ralph P.;Wongphechauxsorn, Jompoj;Cordes, James M.;Desvignes, Gregory;De Laurentis, Mariafelicia;Kramer, Michael;Ransom, Scott M.;Chatterjee, Shami;Wharton, Robert;Karuppusamy, Ramesh;Blackburn, Lindy;Janssen, Michael;Chan, Chi-kwan;Crew Geoffrey;Matthews, Lynn D.;Goddi, Ciriaco;Rottmann, Helge;Wagner, Jan;Sánchez, Salvador;Ruiz, Ignacio;Abbate, Federico;Bower, Geoffrey C.;Salamanca, Juan J.;Gómez-Ruiz, Arturo I.;Herrera-Aguilar, Alfredo;Jiang 江, Wu 悟;Lu 路, Ru-Sen 如森;Pen, Ue-Li;Raymond, Alexander W.;Shao, Lijing;Shen 沈, Zhiqiang 志强;Paubert, Gabriel;Sanchez-Portal, Miguel;Kramer, Carsten;Castillo, Manuel;Navarro, Santiago;John, David;Schuster, Karl-Friedrich;Johnson, Michael D.;Rygl, Kazi L. J.;Akiyama, Kazunori;Alberdi, Antxon;Alef, Walter;Algaba, Juan Carlos;Anantua, Richard;Asada, Keiichi;Azulay, Rebecca;Bach, Uwe;Baczko, Anne-Kathrin;Ball, David;Baloković, Mislav;Barrett, John;Bauböck, Michi;Benson, Bradford A.;Bintley, Dan;Blundell, Raymond;Bouman, Katherine L.;Boyce, Hope;Bremer, Michael;Brinkerink, Christiaan D.;Brissenden, Roger;Britzen, Silke;Broderick, Avery E.;Broguiere, Dominique;Bronzwaer, Thomas;Bustamante, Sandra;Byun, Do-Young;Carlstrom, John E.;Ceccobello, Chiara;Chael, Andrew;Chang, Dominic O.;Chatterjee, Koushik;Chen, Ming-Tang;Chen 陈, Yongjun 永军;Cheng, Xiaopeng;Cho, Ilje;Christian, Pierre;Conroy, Nicholas S.;Conway, John E.;Crawford, Thomas M.;Cruz-Osorio, Alejandro;Cui 崔, Yuzhu 玉竹;Dahale, Rohan;Davelaar, Jordy;Deane, Roger;Dempsey, Jessica;Dexter, Jason;Dhruv, Vedant;Doeleman, Sheperd S.;Dougal, Sean;Dzib, Sergio A.;Emami, Razieh;Falcke, Heino;Farah, Joseph;Fish, Vincent L.;Fomalont, Ed;Ford, H. Alyson;Foschi, Marianna;Fraga-Encinas, Raquel;Freeman, William T.;Friberg, Per;Fromm, Christian M.;Fuentes, Antonio;Galison, Peter;Gammie, Charles F.;García, Roberto;Gentaz, Olivier;Georgiev, Boris;Gold, Roman;Gómez, José L.;Gu 顾, Minfeng 敏峰;Gurwell, Mark;Hada, Kazuhiro;Haggard, Daryl;Haworth, Kari;Hecht, Michael H.;Hesper, Ronald;Heumann, Dirk;Ho 何, Luis C. 子山;Ho, Paul;Honma, Mareki;Huang, Chih-Wei L.;Huang 黄, Lei 磊;Hughes, David H.;Ikeda, Shiro;Impellizzeri, C. M. Violette;Inoue, Makoto;Issaoun, Sara;James, David J.;Jannuzi, Buell T.;Jeter, Britton;Jiménez-Rosales, Alejandra;Jorstad, Svetlana;Joshi, Abhishek V.;Jung, Taehyun;Karami, Mansour;Kawashima, Tomohisa;Keating, Garrett K.;Kettenis, Mark;Kim, Dong-Jin;Kim, Jae-Young;Kim, Jongsoo;Kim, Junhan;Kino, Motoki;Koay, Jun Yi;Kocherlakota, Prashant;Kofuji, Yutaro;Koyama, Shoko;Krichbaum, Thomas P.;Kuo, Cheng-Yu;La Bella, Noemi;Lauer, Tod R.;Lee, Daeyoung;Lee, Sang-Sung;Leung, Po Kin;Levis, Aviad;Li 李, Zhiyuan 志远;Lico, Rocco;Lindahl, Greg;Lindqvist, Michael;Lisakov, Mikhail;Liu 刘, Jun 俊;Liuzzo, Elisabetta;Lo, Wen-Ping;Lobanov, Andrei P.;Loinard, Laurent;Lonsdale, Colin J.;MacDonald, Nicholas R.;Mao 毛, Jirong 基荣;Marchili, Nicola;Markoff, Sera;Marrone, Daniel P.;Marscher, Alan P.;Martí-Vidal, Iván;Matsushita, Satoki;Medeiros, Lia;Menten, Karl M.;Michalik, Daniel;Mizuno, Izumi;Mizuno, Yosuke;Moran, James M.;Moriyama, Kotaro;Moscibrodzka, Monika;Müller, Cornelia;Müller, Hendrik;Mus, Alejandro;Musoke, Gibwa;Myserlis, Ioannis;Nadolski, Andrew;Nagai, Hiroshi;Nagar, Neil M.;Nakamura, Masanori;Narayan, Ramesh;Narayanan, Gopal;Natarajan, Iniyan;Nathanail, Antonios;Neilsen, Joey;Neri, Roberto;Ni, Chunchong;Noutsos, Aristeidis;Nowak, Michael A.;Oh, Junghwan;Okino, Hiroki;Olivares, Héctor;Ortiz-León, Gisela N.;Oyama, Tomoaki;Özel, Feryal;Palumbo, Daniel C. M.;Paraschos, Georgios Filippos;Park, Jongho;Parsons, Harriet;Patel, Nimesh;Pesce, Dominic W.;Piétu, Vincent;Plambeck, Richard;PopStefanija, Aleksandar;Porth, Oliver;Pötzl, Felix M.;Prather, Ben;Preciado-López, Jorge A.;Psaltis, Dimitrios;Pu, Hung-Yi;Ramakrishnan, Venkatessh;Rao, Ramprasad;Rawlings, Mark G.;Rezzolla, Luciano;Ricarte, Angelo;Ripperda, Bart;Roelofs, Freek;Rogers, Alan;Ros, Eduardo;Romero-Cañizales, Cristina;Roshanineshat, Arash;Roy, Alan L.;Ruszczyk, Chet;Sánchez-Argüelles, David;Sasada, Mahito;Satapathy, Kaushik;Savolainen, Tuomas;Schloerb, F. Peter;Schonfeld, Jonathan;Small, Des;Sohn, Bong Won;SooHoo, Jason;Souccar, Kamal;Sun 孙, He 赫;Tetarenko, Alexandra J.;Tiede, Paul;Tilanus, Remo P. J.;Titus, Michael;Toscano, Teresa;Traianou, Efthalia;Trent, Tyler;Trippe, Sascha;Turk, Matthew;van Bemmel, Ilse;van Langevelde, Huib Jan;van Rossum, Daniel R.;Vos, Jesse;Ward-Thompson, Derek;Wardle, John;Weintroub, Jonathan;Wex, Norbert;Wielgus, Maciek;Wiik, Kaj;Witzel, Gunther;Wondrak, Michael F.;Wong, George N.;Wu 吴, Qingwen 庆文;Yadlapalli, Nitika;Yamaguchi, Paul;Yfantis, Aristomenis;Yoon, Doosoo;Young, André;Young, Ken;Younsi, Ziri;Yu 于, Wei 威;Yuan 袁, Feng 峰;Yuan 袁, Ye-Fei 业飞;Zensus, J. Anton;Zhang, Shuo;Zhao, Guang-Yao;Zhao 赵, Shan-Shan 杉杉
2023-01-01
Abstract
In 2017 the Event Horizon Telescope (EHT) observed the supermassive black hole at the center of the Milky Way, Sagittarius A* (Sgr A*), at a frequency of 228.1 GHz (lambda = 1.3 mm). The fundamental physics tests that even a single pulsar orbiting Sgr A* would enable motivate searching for pulsars in EHT data sets. The high observing frequency means that pulsars-which typically exhibit steep emission spectra-are expected to be very faint. However, it also negates pulse scattering, an effect that could hinder pulsar detections in the Galactic center. Additionally, magnetars or a secondary inverse Compton emission could be stronger at millimeter wavelengths than at lower frequencies. We present a search for pulsars close to Sgr A* using the data from the three most sensitive stations in the EHT 2017 campaign: the Atacama Large Millimeter/submillimeter Array, the Large Millimeter Telescope, and the IRAM 30 m Telescope. We apply three detection methods based on Fourier-domain analysis, the fast folding algorithm, and single-pulse searches targeting both pulsars and burst-like transient emission. We use the simultaneity of the observations to confirm potential candidates. No new pulsars or significant bursts were found. Being the first pulsar search ever carried out at such high radio frequencies, we detail our analysis methods and give a detailed estimation of the sensitivity of the search. We conclude that the EHT 2017 observations are only sensitive to a small fraction (less than or similar to 2.2%) of the pulsars that may exist close to Sgr A*, motivating further searches for fainter pulsars in the region.