Telescopes Unite In Unprecedented Observations of Famous Black Hole
In April 2019, scientists released the first image of a black hole in the galaxy M87 using the Event Horizon Telescope (EHT). However, that remarkable achievement was just the beginning of the science story to be told. Data from 19 observatories are being released that promise to give unparalleled insight into this black hole and the system it powers, and to improve tests of Einstein’s General Theory of Relativity. Astronomers from the Academia Sinica, Institute of Astronomy and Astrophysics (ASIAA) contributed this global effort.
Zooming out the black hole in Messier 87 through the electromagnetic spectrum. Each step provides data across many factors of ten in scale, both of wavelengths of light and physical size.
Credit : The EHT Multi-wavelength Science Working Group, the collaborations of the EHT, EAVN, H.E.S.S., MAGIC and VERITAS; EVN; VLBA; GMVA; HST; Swift; Chandra; NuSTAR; Fermi; NASA, ESA and ESO.
The Astrophysical Journal Letter describing these results is available here (https://iopscience.iop.org/article/10.3847/2041-8213/abef71). This paper was led by 33 members of the EHT Multiwavelength Science Working Group, and includes as coauthors members of the following collaborations: the entire Event Horizon Telescope Collaboration; the Fermi Large Area Telescope Collaboration; the H.E.S.S collaboration; the MAGIC collaboration; the VERITAS collaboration and the EAVN collaboration. The coordinators of the EHT Multiwavelength Science Working Group are Sera Markoff, Kazuhiro Hada, and Daryl Haggard, who together with Juan Carlos Algaba and Mislav Baloković, also coordinated work on the paper.
Partner MWL facilities include: European VLBI Network (EVN); High Sensitivity Array (HSA); VLBI Exploration of Radio Astrometry (VERA); Korea VLBI Network (KVN); East Asian VLBI Network/KVN and VERA Array (EAVN/KaVA); Very Long Baseline Array (VLBA); Global Millimeter VLBI Array (GMVA); Very Large Telescope Interferometer GRAVITY Instrument (VLTI/GRAVITY); Neil Gehrels Swift Observatory (Swift); Hubble Space Telescope (HST); Chandra X-ray Observatory (Chandra); Nuclear Spectroscopic Telescope Array (NuSTAR); High Throughput X-ray Spectroscopy Mission and X-ray Multi-Mirror Mission (XMM-Newton); Fermi Large Area Space Telescope (Fermi-LAT); High Energy Stereoscopic System (H.E.S.S.); Major Atmospheric Gamma Imaging Cherenkov Telescopes (MAGIC); Very Energetic Radiation Imaging Telescope Array System (VERITAS).
The 2017 campaign involved a large number of observatories and telescopes. At radio wavelengths it involved: the European Very Long Baseline Interferometry (VLBI) Network (EVN) on May 9, 2017; the High Sensitivity Array (HSA), which includes the Very Large Array (VLA), the Effelsberg 100m antenna and the 10 stations of the National Radio Astronomy Observatory (NRAO) Very Long Baseline Array (VLBA) on May 15, 16 and 20; the VLBI Exploration of Radio Astronomy (VERA) over 17 different times in 2017; the Korean VLBI Network (KVN) over seven epochs between March and December; the East Asian VLBI Network (EAVN) and the KVN and VERA Array (KaVA) , over 14 epochs between March and May 2017; the VLBA on May 5, 2017; the Global Millimeter-VLBI-Array (GMVA) on March 30, 2017; the Atacama Large Millimeter/submillimeter Array (ALMA); the Submillimeter Array (SMA) as part of an ongoing monitoring program. At ultraviolet (UV) wavelengths it involved the Neil Gehrels Swift Observatory (Swift) with multiple observations between March 22 and April 20, 2017; and at optical wavelengths: Swift; and the Hubble Space Telescope on April 7, 12, and 17, 2017. (The Hubble data were retrieved from the Hubble archive because it was part of an independent observing program.) At X-ray wavelengths it involved the Chandra X-ray Observatory on April 11 and 14, 2017; the Nuclear Spectroscopic Telescope Array (NuSTAR) on April 11 and 14, 2017; and Swift. At gamma-ray wavelengths it involved Fermi from March 22 to April 20, 2017; the High Energy Stereoscopic System (H.E.S.S); the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescopes, and the Very Energetic Radiation Imaging Telescope Array System (VERITAS).
The EHT Multi-wavelength (MWL) Working Group is a collective of EHT Collaboration members and external partners working together to ensure broadband MWL coverage during EHT campaigns, to maximize science output. The EHT collaboration involves more than 300 researchers from Africa, Asia, Europe, North and South America. The international collaboration is working to capture the most detailed black hole images ever obtained by creating a virtual Earth-sized telescope. Supported by considerable international investment, the EHT links existing telescopes using novel systems — creating a fundamentally new instrument with the highest angular resolving power that has yet been achieved.
The individual EHT telescopes involved are: ALMA, APEX, the IRAM 30-meter Telescope, the James Clerk Maxwell Telescope (JCMT), the Large Millimeter Telescope (LMT), the Submillimeter Array (SMA), the Submillimeter Telescope (SMT), and the South Pole Telescope (SPT). The Greenland Telescope, the Kitt Peak Telescope, and NOEMA joined EHT after the 2017 observations.
Dr. Satoki Matsushita Email: firstname.lastname@example.org