apjlThe Astrophysical Journal LettersAPJLAstrophys. J. Lett.2041-82052041-8213The American Astronomical Societyapjlac667410.3847/2041-8213/ac6674ac6674AAS38469330High-Energy Phenomena and Fundamental PhysicsFirst Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky WayThe EHT Collaboration et al.0000-0002-9475-4254AkiyamaKazunori1230000-0002-9371-1033AlberdiAntxon4AlefWalter50000-0001-6993-1696AlgabaJuan Carlos60000-0003-3457-7660AnantuaRichard3780000-0001-6988-8763AsadaKeiichi90000-0002-2200-5393AzulayRebecca510110000-0002-7722-8412BachUwe50000-0003-3090-3975BaczkoAnne-Kathrin5BallDavid120000-0003-0476-6647BalokovićMislav130000-0002-9290-0764BarrettJohn10000-0002-5518-2812BauböckMichi140000-0002-5108-6823BensonBradford A.1516BintleyDan17180000-0002-9030-642XBlackburnLindy370000-0002-5929-5857BlundellRaymond70000-0003-0077-4367BoumanKatherine L.190000-0003-4056-9982BowerGeoffrey C.20210000-0002-6530-5783BoyceHope2223BremerMichael240000-0002-2322-0749BrinkerinkChristiaan D.250000-0002-2556-0894BrissendenRoger370000-0001-9240-6734BritzenSilke50000-0002-3351-760XBroderickAvery E.2627280000-0001-9151-6683BroguiereDominique240000-0003-1151-3971BronzwaerThomas250000-0001-6169-1894BustamanteSandra290000-0003-1157-4109ByunDo-Young30310000-0002-2044-7665CarlstromJohn E.163233340000-0002-4767-9925CeccobelloChiara350000-0003-2966-6220ChaelAndrew36370000-0001-6337-6126ChanChi-kwan1238390000-0002-2825-3590ChatterjeeKoushik370000-0002-2878-1502ChatterjeeShami400000-0001-6573-3318ChenMing-Tang200000-0001-5650-6770ChenYongjun永军41420000-0003-4407-9868ChengXiaopeng300000-0001-6083-7521ChoIlje40000-0001-6820-9941ChristianPierre430000-0003-2886-2377ConroyNicholas S.7440000-0003-2448-9181ConwayJohn E.350000-0002-4049-1882CordesJames M.400000-0001-9000-5013CrawfordThomas M.16320000-0002-2079-3189CrewGeoffrey B.10000-0002-3945-6342Cruz-OsorioAlejandro450000-0001-6311-4345CuiYuzhu玉竹4647480000-0002-2685-2434DavelaarJordy2549500000-0002-9945-682XLaurentisMariafelicia De4551520000-0003-1027-5043DeaneRoger5354550000-0003-1269-9667DempseyJessica1718560000-0003-3922-4055DesvignesGregory5570000-0003-3903-0373DexterJason580000-0001-6765-877XDhruvVedant140000-0002-9031-0904DoelemanSheperd S.370000-0002-3769-1314DougalSean120000-0001-6010-6200DzibSergio A.5240000-0001-6196-4135EatoughRalph P.5590000-0002-2791-5011EmamiRazieh70000-0002-2526-6724FalckeHeino250000-0003-4914-5625FarahJoseph60610000-0002-7128-9345FishVincent L.10000-0002-9036-2747FomalontEd620000-0002-9797-0972FordH. 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We present the first Event Horizon Telescope (EHT) observations of Sagittarius A* (Sgr A*), the Galactic center source associated with a supermassive black hole. These observations were conducted in 2017 using a global interferometric array of eight telescopes operating at a wavelength of λ = 1.3 mm. The EHT data resolve a compact emission region with intrahour variability. A variety of imaging and modeling analyses all support an image that is dominated by a bright, thick ring with a diameter of 51.8 ± 2.3 μas (68% credible interval). The ring has modest azimuthal brightness asymmetry and a comparatively dim interior. Using a large suite of numerical simulations, we demonstrate that the EHT images of Sgr A* are consistent with the expected appearance of a Kerr black hole with mass ∼4 × 106 M , which is inferred to exist at this location based on previous infrared observations of individual stellar orbits, as well as maser proper-motion studies. Our model comparisons disfavor scenarios where the black hole is viewed at high inclination (i > 50°), as well as nonspinning black holes and those with retrograde accretion disks. Our results provide direct evidence for the presence of a supermassive black hole at the center of the Milky Way, and for the first time we connect the predictions from dynamical measurements of stellar orbits on scales of 103–105 gravitational radii to event-horizon-scale images and variability. Furthermore, a comparison with the EHT results for the supermassive black hole M87* shows consistency with the predictions of general relativity spanning over three orders of magnitude in central mass.

unified-astronomy-thesaurushttp://astrothesaurus.org/uat/162Black holes162http://astrothesaurus.org/uat/886Kerr black holes886http://astrothesaurus.org/uat/1406Rotating black holes1406http://astrothesaurus.org/uat/726Heterodyne interferometry726http://astrothesaurus.org/uat/565Galactic center565ccc2041-8205/22/L12+21$33.00crossmarkyes