Millimeter Light Curves of Sagittarius A* Observed during the 2017 Event Horizon Telescope Campaign
Journal article, 2022
The Event Horizon Telescope (EHT) observed the compact radio source, Sagittarius A* (Sgr A*), in the Galactic Center on 2017 April 5-11 in the 1.3 mm wavelength band. At the same time, interferometric array data from the Atacama Large Millimeter/submillimeter Array and the Submillimeter Array were collected, providing Sgr A* light curves simultaneous with the EHT observations. These data sets, complementing the EHT very long baseline interferometry, are characterized by a cadence and signal-to-noise ratio previously unattainable for Sgr A* at millimeter wavelengths, and they allow for the investigation of source variability on timescales as short as a minute. While most of the light curves correspond to a low variability state of Sgr A*, the April 11 observations follow an X-ray flare and exhibit strongly enhanced variability. All of the light curves are consistent with a red-noise process, with a power spectral density (PSD) slope measured to be between -2 and -3 on timescales between 1 minute and several hours. Our results indicate a steepening of the PSD slope for timescales shorter than 0.3 hr. The spectral energy distribution is flat at 220 GHz, and there are no time lags between the 213 and 229 GHz frequency bands, suggesting low optical depth for the event horizon scale source. We characterize Sgr A*'s variability, highlighting the different behavior observed just after the X-ray flare, and use Gaussian process modeling to extract a decorrelation timescale and a PSD slope. We also investigate the systematic calibration uncertainties by analyzing data from independent data reduction pipelines.
Author
Maciek Wielgus
Max Planck Society
Nicola Marchili
Max Planck Society
Istituto nazionale di astrofisica (INAF)
Ivan Marti-Vidal
Universitat de Valencia
Garrett K. Keating
Harvard-Smithsonian Center for Astrophysics
Venkatessh Ramakrishnan
University of Turku
Aalto University
University of Concepcion
Paul Tiede
Harvard University
Harvard-Smithsonian Center for Astrophysics
Ed Fomalont
National Radio Astronomy Observatory
Sara Issaoun
Harvard-Smithsonian Center for Astrophysics
Joseph Neilsen
Villanova University
Michael A. Nowak
Washington University in St. Louis
Lindy Blackburn
Harvard-Smithsonian Center for Astrophysics
Harvard University
Charles F. Gammie
University of Illinois
Ciriaco Goddi
University of Cagliari
INAF Osservatorio Astronomico di Cagliari
Daryl Haggard
McGill University
Daeyoung Lee
University of Illinois
Monika Moscibrodzka
Radboud University
Alexandra J. Tetarenko
Texas Tech University at Lubbock
Geoffrey C. Bower
University of Hawaii
Academia Sinica
Chi-kwan Chan
University of Arizona
Koushik Chatterjee
Harvard-Smithsonian Center for Astrophysics
Harvard University
Paul M. Chesler
Harvard University
Jason Dexter
University of Colorado at Boulder
Sheperd S. Doeleman
Harvard-Smithsonian Center for Astrophysics
Harvard University
Boris Georgiev
University of Waterloo
Perimeter Institute for Theoretical Physics
Mark Gurwell
Harvard-Smithsonian Center for Astrophysics
Michael D. Johnson
Harvard University
Harvard-Smithsonian Center for Astrophysics
Daniel P. Marrone
University of Arizona
Alejandro Mus
Universitat de Valencia
Dimitrios Psaltis
University of Arizona
Bart Ripperda
Princeton University
Flatiron Institute
Gunther Witzel
Max Planck Society
Kazunori Akiyama
Massachusetts Institute of Technology (MIT)
National Astronomical Observatory of Japan
Harvard University
Antxon Alberdi
Spanish National Research Council (CSIC)
Walter Alef
Max Planck Society
Juan Carlos Algaba
University of Malaya
Richard Anantua
Harvard-Smithsonian Center for Astrophysics
University of Texas at San Antonio
Harvard University
Keiichi Asada
Academia Sinica
Rebecca Azulay
Universitat de Valencia
Max Planck Society
Uwe Bach
Max Planck Society
Anne-Kathrin Baczko
Max Planck Society
David Ball
University of Arizona
Mislav Balokovic
Yale University
John Barrett
Massachusetts Institute of Technology (MIT)
Michi Baubock
University of Illinois
Bradford A. Benson
Fermi National Accelerator Laboratory
University of Chicago
Dan Bintley
James Clerk Maxwell Telescope
East Asian Observatory
Raymond Blundell
Harvard-Smithsonian Center for Astrophysics
Wilfred Boland
Nederlandse Onderzoekschool voor Astronomie (NOVA)
Katherine L. Bouman
California Institute of Technology (Caltech)
Hope Boyce
McGill University
Michael Bremer
Institut de Radioastronomie Millimétrique (IRAM)
Christiaan D. Brinkerink
Radboud University
Roger Brissenden
Harvard-Smithsonian Center for Astrophysics
Harvard University
Silke Britzen
Max Planck Society
Avery E. Broderick
Perimeter Institute for Theoretical Physics
University of Waterloo
Dominique Broguiere
Institut de Radioastronomie Millimétrique (IRAM)
Thomas Bronzwaer
Radboud University
Sandra Bustamante
University of Massachusetts
Do-Young Byun
University of Science and Technology (UST)
Korea Astronomy and Space Science Institute
John E. Carlstrom
University of Chicago
Chiara Ceccobello
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Andrew Chael
Princeton University
Shami Chatterjee
Cornell University
Ming-Tang Chen
Academia Sinica
Yongjun Chen
Chinese Academy of Sciences
Ilje Cho
Spanish National Research Council (CSIC)
Pierre Christian
Fairfield University
Nicholas S. Conroy
Harvard-Smithsonian Center for Astrophysics
University of Illinois
John Conway
Chalmers, Space, Earth and Environment, Onsala Space Observatory
James M. Cordes
Cornell University
Thomas M. Crawford
University of Chicago
Geoffrey B. Crew
Massachusetts Institute of Technology (MIT)
Alejandro Cruz-Osorio
Goethe University Frankfurt
Yuzhu Cui
Shanghai Jiao Tong University
National Astronomical Observatory of Japan
The Graduate University for Advanced Studies (SOKENDAI)
Jordy Davelaar
Radboud University
Flatiron Institute
Columbia University
Mariafelicia De Laurentis
National Institute for Nuclear Physics
Goethe University Frankfurt
University of Naples Federico II
Roger Deane
University of Witwatersrand
University of Pretoria
Rhodes University
Jessica Dempsey
Netherlands Institute for Radio Astronomy (ASTRON)
James Clerk Maxwell Telescope
East Asian Observatory
Gregory Desvignes
Paris Descartes University
Max Planck Society
Vedant Dhruv
University of Illinois
Sergio A. Dzib
Institut de Radioastronomie Millimétrique (IRAM)
Max Planck Society
Ralph P. Eatough
Max Planck Society
Chinese Academy of Sciences
Razieh Emami
Harvard-Smithsonian Center for Astrophysics
Heino Falcke
Radboud University
Joseph Farah
Las Cumbres Observatory Global Telescope Network
University of California at Santa Barbara
Vincent L. Fish
Massachusetts Institute of Technology (MIT)
H. Alyson Ford
University of Arizona
Raquel Fraga-Encinas
Radboud University
William T. Freeman
Massachusetts Institute of Technology (MIT)
Google Inc.
Per Friberg
East Asian Observatory
James Clerk Maxwell Telescope
Christian M. Fromm
University of Würzburg
Goethe University Frankfurt
Max Planck Society
Antonio Fuentes
Spanish National Research Council (CSIC)
Peter Galison
Harvard University
Roberto Garcia
Institut de Radioastronomie Millimétrique (IRAM)
Olivier Gentaz
Institut de Radioastronomie Millimétrique (IRAM)
Roman Gold
University of Southern Denmark
Goethe University Frankfurt
Gomez-Ruiz
National Institute of Astrophysics, Optics and Electronics
National Council for Science and Technology Mexico
Jose L. Gomez
Institute of Astrophysics of Andalusia (IAA)
Minfeng Gu
Chinese Academy of Sciences
Kazuhiro Hada
The Graduate University for Advanced Studies (SOKENDAI)
National Astronomical Observatory of Japan
Kari Haworth
Harvard-Smithsonian Center for Astrophysics
Michael H. Hecht
Massachusetts Institute of Technology (MIT)
Ronald Hesper
University of Groningen
Luis C. Ho
Beijing University of Technology
Paul Ho
James Clerk Maxwell Telescope
Academia Sinica
Mareki Honma
The Graduate University for Advanced Studies (SOKENDAI)
National Astronomical Observatory of Japan
University of Tokyo
Chih-Wei L. Huang
Academia Sinica
Lei Huang
Chinese Academy of Sciences
David H. Hughes
National Institute of Astrophysics, Optics and Electronics
Shiro Ikeda
The Institute of Statistical Mathematics
National Astronomical Observatory of Japan
The Graduate University for Advanced Studies (SOKENDAI)
University of Tokyo
C. M. Violette Impellizzeri
National Radio Astronomy Observatory
Leiden University
Makoto Inoue
Academia Sinica
David J. James
ASTRAVEO
Buell T. Jannuzi
University of Arizona
Michael Janssen
Max Planck Society
Britton Jeter
Academia Sinica
Wu Jiang
Chinese Academy of Sciences
Alejandra Jimenez-Rosales
Radboud University
Svetlana Jorstad
Boston University
Joshi
University of Illinois
Taehyun Jung
Korea Astronomy and Space Science Institute
University of Science and Technology (UST)
Mansour Karami
University of Waterloo
Perimeter Institute for Theoretical Physics
Ramesh Karuppusamy
Max Planck Society
Tomohisa Kawashima
University of Tokyo
Mark Kettenis
Joint Institute for VLBI in Europe (JIVE)
Dong-Jin Kim
Max Planck Society
Jae-Young Kim
Kyungpook National University
Korea Astronomy and Space Science Institute
Max Planck Society
Jongsoo Kim
Korea Astronomy and Space Science Institute
Junhan Kim
University of Arizona
California Institute of Technology (Caltech)
Motoki Kino
Kogakuin University of Technology and Engineering
National Astronomical Observatory of Japan
Jun Yi Koay
Academia Sinica
Prashant Kocherlakota
Goethe University Frankfurt
Yutaro Kofuji
National Astronomical Observatory of Japan
University of Tokyo
Patrick M. Koch
Academia Sinica
Shoko Koyama
Academia Sinica
Niigata University
Carsten Kramer
Institut de Radioastronomie Millimétrique (IRAM)
Michael Kramer
Max Planck Society
Thomas P. Krichbaum
Max Planck Society
Cheng-Yu Kuo
National Sun Yat-Sen University
Academia Sinica
Noemi La Bella
Radboud University
Tod R. Lauer
National Optical Astronomy Observatory
Sang-Sung Lee
Korea Astronomy and Space Science Institute
Po Kin Leung
Chinese University of Hong Kong
Aviad Levis
California Institute of Technology (Caltech)
Zhiyuan Li
Nanjing University
Rocco Lico
Spanish National Research Council (CSIC)
Max Planck Society
Istituto nazionale di astrofisica (INAF)
Greg Lindahl
Harvard-Smithsonian Center for Astrophysics
Michael Lindqvist
Chalmers, Space, Earth and Environment, Onsala Space Observatory
Mikhail Lisakov
Max Planck Society
Jun Liu
Max Planck Society
Kuo Liu
Max Planck Society
Elisabetta Liuzzo
Istituto nazionale di astrofisica (INAF)
Wen-Ping Lo
National Taiwan University
Academia Sinica
Andrei P. Lobanov
Max Planck Society
Laurent Loinard
Universidad Nacional Autonoma de Mexico
Colin Lonsdale
Massachusetts Institute of Technology (MIT)
Ru-Sen Lu
Chinese Academy of Sciences
East Asian Observatory
Max Planck Society
James Clerk Maxwell Telescope
Jirong Mao
Chinese Academy of Sciences
East Asian Observatory
James Clerk Maxwell Telescope
Sera Markoff
University of Amsterdam
Alan P. Marscher
Boston University
Satoki Matsushita
Academia Sinica
Lynn D. Matthews
Massachusetts Institute of Technology (MIT)
Lia Medeiros
Institute for Advanced Study
University of Arizona
Karl M. Menten
Max Planck Society
Daniel Michalik
University of Chicago
European Space Research and Technology Centre (ESA ESTEC)
Izumi Mizuno
James Clerk Maxwell Telescope
East Asian Observatory
Yosuke Mizuno
Goethe University Frankfurt
Shanghai Jiao Tong University
James M. Moran
Harvard-Smithsonian Center for Astrophysics
Harvard University
Kotaro Moriyama
National Astronomical Observatory of Japan
Goethe University Frankfurt
Massachusetts Institute of Technology (MIT)
Cornelia Mueller
Radboud University
Max Planck Society
Gibwa Musoke
Radboud University
Chinese Academy of Sciences
Ioannis Myserlis
Institut de Radioastronomie Millimétrique (IRAM)
Andrew Nadolski
University of Illinois
Hiroshi Nagai
National Astronomical Observatory of Japan
The Graduate University for Advanced Studies (SOKENDAI)
Neil M. Nagar
University of Concepcion
Masanori Nakamura
National Institute of Technology, Hachinohe College
Academia Sinica
Ramesh Narayan
Harvard University
Harvard-Smithsonian Center for Astrophysics
Gopal Narayanan
University of Massachusetts
Iniyan Natarajan
South African Radio Astronomy Observatory (SARAO)
University of Witwatersrand
Antonios Nathanail
National and Kapodistrian University of Athens
Goethe University Frankfurt
Santiago Navarro Fuentes
Institut de Radioastronomie Millimétrique (IRAM)
Roberto Neri
Institut de Radioastronomie Millimétrique (IRAM)
Chunchong Ni
University of Waterloo
Perimeter Institute for Theoretical Physics
Aristeidis Noutsos
Max Planck Society
Junghwan Oh
Sejong University
Hiroki Okino
National Astronomical Observatory of Japan
University of Tokyo
Hector Olivares
Radboud University
Gisela N. Ortiz-Leon
Universidad Nacional Autonoma de Mexico
Tomoaki Oyama
National Astronomical Observatory of Japan
Feryal Ozel
University of Arizona
Daniel C. M. Palumbo
Harvard University
Harvard-Smithsonian Center for Astrophysics
Georgios Filippos Paraschos
Max Planck Society
Jongho Park
Academia Sinica
Harriet Parsons
James Clerk Maxwell Telescope
East Asian Observatory
Nimesh Patel
Harvard-Smithsonian Center for Astrophysics
Ue-Li Pen
Canadian Institute for Advanced Research
University of Toronto
Academia Sinica
Perimeter Institute for Theoretical Physics
Dominic W. Pesce
Harvard-Smithsonian Center for Astrophysics
Harvard University
Vincent Pietu
Institut de Radioastronomie Millimétrique (IRAM)
Richard Plambeck
University of California at Berkeley
Aleksandar PopStefanija
University of Massachusetts
Oliver Porth
Goethe University Frankfurt
Chinese Academy of Sciences
Felix M. Potzl
University College Cork
Max Planck Society
Ben Prather
University of Illinois
Jorge A. Preciado-Lopez
Perimeter Institute for Theoretical Physics
Hung-Yi Pu
Academia Sinica
National Taiwan Normal University
Ramprasad Rao
Academia Sinica
Mark G. Rawlings
NSF's National Optical-Infrared Astronomy Research Laboratory (NOIRLab)
James Clerk Maxwell Telescope
East Asian Observatory
Alexander W. Raymond
Harvard-Smithsonian Center for Astrophysics
Harvard University
Luciano Rezzolla
Trinity College Dublin
Frankfurt Institute for Advanced Studies
Goethe University Frankfurt
Angelo Ricarte
Harvard University
Harvard-Smithsonian Center for Astrophysics
Freek Roelofs
Radboud University
Harvard University
Harvard-Smithsonian Center for Astrophysics
Alan Rogers
Massachusetts Institute of Technology (MIT)
Eduardo Ros
Max Planck Society
Cristina Romero-Canizales
Academia Sinica
Arash Roshanineshat
University of Arizona
Helge Rottmann
Max Planck Society
Alan L. Roy
Max Planck Society
Ignacio Ruiz
Institut de Radioastronomie Millimétrique (IRAM)
Chet Ruszczyk
Massachusetts Institute of Technology (MIT)
Kazi L. J. Rygl
Istituto nazionale di astrofisica (INAF)
Salvador Sanchez
Institut de Radioastronomie Millimétrique (IRAM)
David Sanchez-Arguelles
National Council for Science and Technology Mexico
National Institute of Astrophysics, Optics and Electronics
Miguel Sanchez-Portal
Institut de Radioastronomie Millimétrique (IRAM)
Mahito Sasada
National Astronomical Observatory of Japan
Hiroshima University
Kaushik Satapathy
University of Arizona
Tuomas Savolainen
Max Planck Society
Aalto University
F. Peter Schloerb
University of Massachusetts
Karl-Friedrich Schuster
Institut de Radioastronomie Millimétrique (IRAM)
Lijing Shao
Max Planck Society
Beijing University of Technology
Zhiqiang Shen
Chinese Academy of Sciences
James Clerk Maxwell Telescope
East Asian Observatory
Des Small
Joint Institute for VLBI in Europe (JIVE)
Bong Won Sohn
James Clerk Maxwell Telescope
Korea Astronomy and Space Science Institute
University of Science and Technology (UST)
East Asian Observatory
Yonsei University
Jason SooHoo
Massachusetts Institute of Technology (MIT)
Kamal Souccar
University of Massachusetts
He Sun
California Institute of Technology (Caltech)
Fumie Tazaki
National Astronomical Observatory of Japan
Remo P. J. Tilanus
University of Arizona
Netherlands Organisation for Scientific Research (NWO)
Leiden University
Radboud University
Michael Titus
Massachusetts Institute of Technology (MIT)
Pablo Torne
Shanghai Jiao Tong University
Max Planck Society
Efthalia Traianou
Max Planck Society
Institute of Astrophysics of Andalusia (IAA)
Tyler Trent
University of Arizona
Sascha Trippe
James Clerk Maxwell Telescope
East Asian Observatory
Seoul National University
Ilse van Bemmel
Joint Institute for VLBI in Europe (JIVE)
Huib Jan van Langevelde
Joint Institute for VLBI in Europe (JIVE)
University of New Mexico
Leiden University
Daniel R. van Rossum
Radboud University
Jesse Vos
Radboud University
Jan Wagner
Max Planck Society
Derek Ward-Thompson
University of Central Lancashire
John Wardle
Brandeis University
Jonathan Weintroub
Harvard University
Harvard-Smithsonian Center for Astrophysics
Norbert Wex
Max Planck Society
Robert Wharton
Max Planck Society
Kaj Wiik
University of Turku
Michael F. Wondrak
Radboud University
George N. Wong
University College London (UCL)
University of Amsterdam
Qingwen Wu
East Asian Observatory
Huazhong University of Science and Technology
James Clerk Maxwell Telescope
Paul Yamaguchi
Harvard-Smithsonian Center for Astrophysics
Doosoo Yoon
Chinese Academy of Sciences
Andre Young
Radboud University
Ken Young
Harvard-Smithsonian Center for Astrophysics
Ziri Younsi
Princeton University
Goethe University Frankfurt
Feng Yuan
Chinese Academy of Sciences
East Asian Observatory
James Clerk Maxwell Telescope
Ye-Fei Yuan
James Clerk Maxwell Telescope
East Asian Observatory
University of Science and Technology of China
J. Anton Zensus
Max Planck Society
Shuo Zhang
Bard College
Guang-Yao Zhao
Spanish National Research Council (CSIC)
Shan-Shan Zhao
Chinese Academy of Sciences
Astrophysical Journal Letters
2041-8205 (ISSN) 2041-8213 (eISSN)
Vol. 930 2 L19Subject Categories
Astronomy, Astrophysics and Cosmology
Atom and Molecular Physics and Optics
Other Physics Topics
DOI
10.3847/2041-8213/ac6428