First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole
© 2019. The American Astronomical Society.. We present the first Event Horizon Telescope (EHT) images of M87, using observations from April 2017 at 1.3 mm wavelength. These images show a prominent ring with a diameter of ∼40 μas, consistent with the size and shape of the lensed photon orbit encircli...
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | English |
| Published: |
American Astronomical Society
2021
|
| Online Access: | https://hdl.handle.net/1721.1/134644 |
| _version_ | 1826188577517600768 |
|---|---|
| author | The Event Horizon Telescope Collaboration |
| author2 | Haystack Observatory |
| author_facet | Haystack Observatory The Event Horizon Telescope Collaboration |
| author_sort | The Event Horizon Telescope Collaboration |
| collection | MIT |
| description | © 2019. The American Astronomical Society.. We present the first Event Horizon Telescope (EHT) images of M87, using observations from April 2017 at 1.3 mm wavelength. These images show a prominent ring with a diameter of ∼40 μas, consistent with the size and shape of the lensed photon orbit encircling the "shadow" of a supermassive black hole. The ring is persistent across four observing nights and shows enhanced brightness in the south. To assess the reliability of these results, we implemented a two-stage imaging procedure. In the first stage, four teams, each blind to the others' work, produced images of M87 using both an established method (CLEAN) and a newer technique (regularized maximum likelihood). This stage allowed us to avoid shared human bias and to assess common features among independent reconstructions. In the second stage, we reconstructed synthetic data from a large survey of imaging parameters and then compared the results with the corresponding ground truth images. This stage allowed us to select parameters objectively to use when reconstructing images of M87. Across all tests in both stages, the ring diameter and asymmetry remained stable, insensitive to the choice of imaging technique. We describe the EHT imaging procedures, the primary image features in M87, and the dependence of these features on imaging assumptions. |
| first_indexed | 2024-09-23T08:01:32Z |
| format | Article |
| id | mit-1721.1/134644 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T08:01:32Z |
| publishDate | 2021 |
| publisher | American Astronomical Society |
| record_format | dspace |
| spelling | mit-1721.1/1346442023-01-06T20:34:27Z First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole The Event Horizon Telescope Collaboration Haystack Observatory Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science © 2019. The American Astronomical Society.. We present the first Event Horizon Telescope (EHT) images of M87, using observations from April 2017 at 1.3 mm wavelength. These images show a prominent ring with a diameter of ∼40 μas, consistent with the size and shape of the lensed photon orbit encircling the "shadow" of a supermassive black hole. The ring is persistent across four observing nights and shows enhanced brightness in the south. To assess the reliability of these results, we implemented a two-stage imaging procedure. In the first stage, four teams, each blind to the others' work, produced images of M87 using both an established method (CLEAN) and a newer technique (regularized maximum likelihood). This stage allowed us to avoid shared human bias and to assess common features among independent reconstructions. In the second stage, we reconstructed synthetic data from a large survey of imaging parameters and then compared the results with the corresponding ground truth images. This stage allowed us to select parameters objectively to use when reconstructing images of M87. Across all tests in both stages, the ring diameter and asymmetry remained stable, insensitive to the choice of imaging technique. We describe the EHT imaging procedures, the primary image features in M87, and the dependence of these features on imaging assumptions. 2021-10-27T20:05:57Z 2021-10-27T20:05:57Z 2019 2019-05-23T15:06:51Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/134644 en 10.3847/2041-8213/ab0e85 Astrophysical Journal Letters Creative Commons Attribution 3.0 unported license https://creativecommons.org/licenses/by/3.0/ application/pdf American Astronomical Society IOP Publishing |
| spellingShingle | The Event Horizon Telescope Collaboration First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole |
| title | First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole |
| title_full | First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole |
| title_fullStr | First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole |
| title_full_unstemmed | First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole |
| title_short | First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole |
| title_sort | first m87 event horizon telescope results iv imaging the central supermassive black hole |
| url | https://hdl.handle.net/1721.1/134644 |
| work_keys_str_mv | AT theeventhorizontelescopecollaboration firstm87eventhorizontelescoperesultsivimagingthecentralsupermassiveblackhole |