DOCSLIB.ORG

Ejected Superluminal Features Associated with the VHE Flare in AGN Jets: Sites Constrained by Smbhs

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Ejected Superluminal Features Associated with the VHE Flare in AGN Jets: Sites Constrained by Smbhs Ejected Superluminal Features Associated with the VHE Flare in AGN Jets: Sites Constrained by SMBHs Image credit: W. B. Sparks (STScI) Masanori Nakamura (ASIAA) Collaborators: K. Asada (ASIAA), J. A. Biretta (STScI), D. A. Garofalo (CSUN), C. A. Norman (JHU), D. L. Meier (JPL), W. B. Sparks (STScI) TIARA WS on Transient Universe, Dec. 2011, NTHU Outline ✤ Evidence for magnetic acceleration & collimation M87 of the active galactic nuclei (AGN) jet in M87 ✤ Quad MHD shock model for sub/super-luminal ejections ✤ Stationary feature in AGN jets constrained by the SMBH ✤ ASIAA “Greenland Telescope Project”: sub-mm VLBI for exploring the SMBH shadow & origin of AGN jets Outline ✤ Evidence for magnetic acceleration & collimation of the active galactic nuclei (AGN) jet in M87 ✤ Quad MHD shock model for sub/super-luminal ejections ✤ Stationary feature in AGN jets constrained by the SMBH ✤ ASIAA “Greenland Telescope Project”: sub-mm VLBI for exploring the SMBH shadow & origin of AGN jets Observational Overview Observations • Good Resolution • Nearby: D 16 Mpc (1 mas = 0.08 pc) ∼ • FR I: Misaligned BL Lac (θ 14 ◦ ; Wang & Zhou 2009) view ∼ • SMBH mass: (6 . 6 0 . 4) 10 9 M (Gebhardt et al. 2011) ± × ⊙ • VLBA resolution: 20 RS at 43 GHz • Sub-mm VLBI resolution: 3 RS at 345 GHz (w/ GL) VLBA Movie at 43GHz (C. Walker, NRAO) • Well studied at wavelengths from radio to X-ray • Proper motions (sub/super-luminal feature) • Polarization (20-60%; ordered B-fields) • Substructure (limb-brightened, knots, wiggles, ...), indicating a role of B-fields • In situ particle acceleration (Fermi-I diffusive shock process ) HST Movie (J. Biretta, STScI) Observations (cont.) X-ray: XMM-Newton M87 M87 Forman et al. (2005) Radio: VLA M87 Image credit: X-ray (NASA/CXC/KIPAC/N. Werner, E. Million et al); Radio (NRAO/ AUI/NSF/F. Owen) • Transferring the enormous energy in the nucleus Owen et al. (2000) on the circumgalactic environment (from 10-3 to 105 parsec) Superluminal Motions Biretta et al. (1995, 1999) • Fastest apparent speeds 6c indicates a jet orientation within 19° of the line of sight ∼ and requires γ 6 ≥ • A monotonic decay of the speed of knots suggests the deceleration of shock fronts Recent Flare-up at HST-1 CORE HST-1 A New Components After Flaring TeV GeV Cheung et al. (2007) Abramowski et al., ApJ, in press • A flaring from radio through optical to X-ray (factor 50) bands (Harris et al. 2006), ∼ indicating a site for TeV γ-ray emissions (Harris et al. 2009) • HST-1c evidently splits into two roughly equally bright features: superluminal (c1; 4.3c) and a trailing sub-luminal (c2; 0.47c) features during 2005 - 2006 Q. HST-1 as an origin of superluminal knots (Cheung et al. 2007)? (eg. Biretta et al. 1999) Short Tips for MHD Jets Extraction of Matter and Energy in the Vicinity of the SMBH Sturrock & Barns (1972) Punsly et al. (2009) ➡ Initiation by Piddington (1970); Sturrock & Barnes (1972) ,inspired by some early work for solar winds (Weber & Davis 1967; Ozernoi & Usov 1973) • Magnetized accretion disk: Lovelace (1976); Blandford (1976); Blandford & Payne (1983) • SMBH Magnetosphere: Blandford & Znajek (1977); Hirotani et al. (1992); Meier (2001) • Hybrid model: Meier (1999); Garofalo (2009) Global Picture of MHD Outflows Two constants along a poloidal stream line: Magnetic tension rBφBp (hoop-stress) drives l = rVφ − 4πρVp both collimation & 1 1 Γ p 1 acceleration e = V 2 + (V Ωr)2 + +Φ Ω2r2 2 p 2 φ Γ 1 ρ 2 Bp + Bφ Vp − − Vp = Vf − (Not a critical point) z-component of the momentum eq.: ρ(V )V = ·∇ z ∂p ρ∂Φ 1 ∂B2 1 Magnetic pressure + (B )B driven −∂z − ∂z − 8π ∂z 4π ·∇ z The Alfvén Mach number m1/2, the fast magnetosonic number n1/2, the 1/2 poloidal velocity U f, the toroidal velocity g, and the magnetic pitch Bφ/ Bz along a single streamline Vp = VA Magneto-centrifugal driven Blandford & Payne (1982)’s solution & Payne (1982)’s Blandford Pelletier & Pudritz (1992)’s solution Pelletier & Pudritz (1992)’s Vp = Vs Gas pressure driven Vφ Contopoulos (1995) Blandford & Payne (1982) START the Exhaust Inspection of the Jet Engine Image Credit: W. Steffen Puzzle Remains Unsolved for 2 Decades Distance from the nucleus: z (arcsec) Junor et al. (1999) 10-3 10-2 10-1 1 101 log r (arcsec) -1 0 1 8 N2 L HST-1 D E F AB C Reid et al. (1989) Junor & Biretta (1995) Biretta et al. (1995) 6 Biretta et al. (1999) Cheung et al. (2007) ) c Kovalev et al. (2007) / V 4 Apparent speed ( 2 0 10-2 10-1 1 101 102 103 Distance from the nucleus: z (pc) • Superluminal motions begin at HST-1, lying about 1” ( 80 pc) from the nucleus ∼ • Many VLBI observations show sub-luminal motions upstream of HST-1 • Visible pc-scale features may reside in slower layers near the surface (Biretta et al. 1999) or possibly standing shocks and/or instability patterns (Kovalev et al. 2007)? ➡ Q. No “systematic” acceleration towards HST-1 exists although collimation occurs asymptotically? Or proper motions do not correspond to the real flow speed at all? Superluminal Motions Upstream of HST-1 Three years monitoring of the M87 jet using European VLBI Network (EVN) at 1.6GHz Asada, MN, et al. A Missing Link Found! Distance from the nucleus: z (arcsec) Junor et al. (1999) 10-3 10-2 10-1 1 101 log r (arcsec) -1 0 1 8 N2 L HST-1 D E F AB C Reid et al. (1989) Junor & Biretta (1995) Biretta et al. (1995) 6 Biretta et al. (1999) Cheung et al. (2007) ) c Kovalev et al. (2007) / V Asada et al. (2011) 4 Apparent speed ( 2 0 10-2 10-1 1 101 102 103 Distance from the nucleus: z (pc) Asada, MN, et al. ✓ Yes, We found final pieces of the puzzle, but γ～1/θ as expected? • The (bulk) acceleration (γ) and collimation (θ) are correlated in a parabolic streamline α (z r , 1 < α 2 ) (Zakamska et al. 2008; Komissarov et al. 2009; Tchekhovskoy et al. 2009):γθ 1 ∝ (α 1)/α • Acceleration/collimation occurs logarithmically (Komissarov 2009):γ z − ∝ ➡ We need to determine the jet structure (α)! The Structure of the M87 Jet (a) MERLIN image at 1.6 GHz VLBA at 43 GHz VLBA at 15 GHz EVN at 1.6 GHz MERLIN at 1.6 GHz Parabolic streamline Bondi radius (confined by the ISM): 1.73 0.05 z r ± s ∝ Conical streamline (unconfined, freely expanding): (b) EVN image at 1.6 GHz 0.96 0.1 z r ± ∝ jet radius r [r ] radius r jet Over-collimation ISCO (c) VLBA image at 15 GHz distance from the core z [rs ] ✓ The jet maintains the parabolic stream with α=1.73 over 105 Rs ✓ A transition of streamlines presumably occurs at an ISM transition beyond the gravitational influence of the SMBH ✓ Propose a way to identify the jet ejection radius by tracing back of the ridge line Asada & MN (arXiv:1110.1793) Sub-to Superlumial Transition Deprojected distance from the nucleus: z (pc) 10-3 10-2 10-1 1 101 102 103 104 N2 L HST-1 D E F ABC Reid et al. (1989), VLBI 1.6 GHz 1 2 10 Biretta et al. (1995), VLA 15 GHz 10 cf. Ejection point (BP82) Biretta et al. (1999), HST Kellermann et al. (2004), VLBA 15 GHz ) Cheung et al. (2007), VLBA 1.6 GHz c / Expected slope on Kovalev et al. (2007), VLBA 15 GHz 1 1 10 α 0.43 0.01 app. the stream line: z∝r θ z− ± (deg.) V Asada et al. (2011), EVN 1.6 GHz e ( ∝ app. ` 10-1 1 Owen et al. (1980, 1989), VLA 15 GHz Junor & Biretta (unpublished), VLBA 609 MHz Reid et al. (1989), VLBI 1.6 GHz Jet opening angle: Junor et al. (unpublished), VSOP + VLBA 5 GHz Apparent speed: Junor & Biretta (1995), VLBI 22 GHz -2 -1 10 10 Junor et al. (1999), VLBI 43 GHz Asada et al. (2010), EVN 1.6 GHz Asada et al. (2010), VLBA 15 GHz Ly et al. (2007), VLBA 43 GHz 10-3 10-2 10-2 10-1 1 101 102 103 104 105 10-3 10-2 10-1 1 101 102 103 104 105 Deprojected distance from the nucleus: z (mas) Deprojected distance from the nucleus: z (mas) Asada, MN, et al. Q. Do they exhibit an asymptotic acceleration from non-relativistic (0.01c) 2-5 to relativistic speed (0.99c) over an extremely large scale 10 Rs ? Magnetic Acceleration & Collimation (MAC) Zone 102 Reid et al. (1989), VLBI 1.6 GHz 1 Biretta et al. (1999), HST γ 101 Kellermann et al. (2004), VLBA 15 GHz ≡ 1 (V/c)2 a Cheung et al. (2007), VLBA 1.6 GHz − Kovalev et al. (2007), VLBA 15GHz Asada et al. (2011), EVN 1.6 GHz 1 101 Walker et al. (2008), VLBA 43 GHz -1 Acciari et al. (2009), VLBA 43 GHz a (α 1)/α z − ∝ 10-1 Lorentz factor: 1 1 10-2 2/α z 10-1 -3 ∝ ) 10 Reid et al. (1989), VLBI 1.6 GHz c / Specific Kinetic Energy: Biretta et al. (1999), HST 2GM V BH ( -2 Kellermann et al. (2004), VLBA 15 GHz Vesc = 10 ` z 10-4 Cheung et al. (2007), VLBA 1.6 GHz Kovalev et al. (2007), VLBA 15GHz Walker et al. (2008), VLBA 43 GHz 10-3 Speed: Acciari et al. (2009), VLBA 43 GHz -5 10 Asada et al. (2011), EVN 1.6 GHz 10-4 1 101 102 103 104 1 101 102 103 104 Deprojected distance from the nucleus: z (mas) MN, Asada, et al.
Load more

Recommended publications
  • Curriculum Vitae
    CURRICULUM VITAE Ming-Tang Chen, Ph.D., Physics Research Fellow Deputy Director of ASIAA Hawaii Operations Academia Sinica, Institute of Astronomy and Astrophysics (Taiwan) PO Box 23-141, Taipei, Taiwan, ROC (USA) 645 N. A’ohoku Place, Hilo, HI 96720, USA Telephone (TW): +886-2-2366-5348 Telephone (US): +1-808-938-4708 Email: [email protected] CURRICULUM VITAE ................................................................................................... 1 Brief Biography: .............................................................................................................. 2 Person Data: ..................................................................................................................... 2 Education: ........................................................................................................................ 2 Knowledge & Skills: ....................................................................................................... 2 Professional TitleS: .......................................................................................................... 2 Committee Service: ......................................................................................................... 3 Grant Executed: ............................................................................................................... 4 International Invited Talks: ............................................................................................. 5 Current and Past Research Topics: .................................................................................
    [Show full text]
  • Seeing Black Holes: from the Computer to the Telescope
    universe Review Seeing Black Holes: From the Computer to the Telescope Jean-Pierre Luminet 1,2,3 1 Aix Marseille University, CNRS, LAM, 13013 Marseille, France; [email protected] or [email protected] 2 Aix Marseille University, CNRS, CPT, 13009 Marseille, France 3 Observatoire de Paris, CNRS, LUTH, 92195 Meudon, France Received: 7 July 2018; Accepted: 6 August 2018; Published: 9 August 2018 Abstract: Astronomical observations are about to deliver the very first telescopic image of the massive black hole lurking at the Galactic Center. The mass of data collected in one night by the Event Horizon Telescope network, exceeding everything that has ever been done in any scientific field, should provide a recomposed image in 2018. All this, forty years after the first numerical simulations performed by the present author. Keywords: black hole; numerical simulation; observation; general relativity 1. Introduction According to the laws of general relativity (for recent overviews at the turn of its centennial, see, e.g., [1,2]), black holes are, by definition, invisible. Contrary to uncollapsed stars, their surface is neither a solid nor a gas; it is an intangible frontier known as the event horizon. Beyond this horizon, gravity is so strong that nothing escapes, not even light. Seen projected onto the background of the sky, the event horizon would probably resemble a perfectly black disk if the black hole is static (Schwarzschild black hole) or a slightly flattened disk if it is rotating (Kerr black hole). A black hole however, be it small and of stellar mass or giant and supermassive, is rarely “bare”; in typical astrophysical conditions it is usually surrounded by gaseous matter.
    [Show full text]
  • Sub-Mm VLBI from the Arctic — Imaging Black Holes
    Astrophysics from Antarctica Proceedings IAU Symposium No. 288, 2012 c International Astronomical Union 2013 M. G. Burton, X. Cui & N. F. H. Tothill, eds. doi:10.1017/S1743921312016870 Sub-mm VLBI from the Arctic — Imaging Black Holes Makoto Inoue1 and the Greenland Telescope team1,2,3,4 1 Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei, 10617 Taiwan, R.O.C. email: [email protected] 2 Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138, USA 3 MIT Haystack Observatory, Off Route 40, Westford, MA 01886-1299, USA 4 National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-4608, USA Abstract. We are deploying a new station for sub-millimeter Very Long Baseline Interferom- etry (VLBI) to obtain shadow images of Supermassive Black Hole (SMBH). Sub-mm VLBI is thought to be the only way so far to get the direct image of SMBH by its shadow, thanks to the superb angular resolution and high transparency against dense plasma around SMBH. At the Summit Station on Greenland, we have started monitoring the opacity at sub-mm region. The Summit Station subtends long baselines with the Atacama Large Milimeter/submillimeter Array (ALMA) in Chile and Submillimeter Array (SMA) in Hawaii. In parallel, we started retrofitting the ALMA North America prototype telescope (renamed as Greenland Telescope: GLT) for the cold environment. Keywords. Supermassive Black Hole (SMBH), Sub-millimeter telescope, Very Long Baseline Interferometry (VLBI) 1. Introduction An experiment in the sub-millimeter (submm) Very Long Baseline Interferometry (VLBI) has shown the capability for direct imaging of Sumermassive Black Hole (SMBH) (Doelaman et al.
    [Show full text]
  • First Results from the Event Horizon Telescope
    First results from the Event Horizon Telescope Dom Pesce On behalf of the Event Horizon Telescope collaboration March 10, 2020 EDSU conference The goal (ca. 2017) The goal is to take a picture of a black hole The goal (ca. 2017) Subrahmanyan Chandrasekhar The goal is to take a picture of a black hole • General relativity makes a prediction for the apparent shape of a black hole “It is conceptually interesting, if not astrophysically very important, to calculate the precise apparent shape of the black hole… Unfortunately, there seems to be no hope of observing this effect.” - James Bardeen, 1973 James Bardeen Photon ring and black hole shadow The warped spacetime around a black hole causes photon trajectories to bend event horizon b photon orbit Photon ring and black hole shadow The warped spacetime around a black hole causes photon trajectories to bend The closer these trajectories get to a critical impact parameter, the more tightly wound they become Photon ring and black hole shadow The warped spacetime around a black hole causes photon trajectories to bend The closer these trajectories get to a critical impact parameter, the more tightly wound they become Photon ring and black hole shadow The warped spacetime around a black hole causes photon trajectories to bend The closer these trajectories get to a critical impact parameter, the more tightly wound they become The trajectories interior to this critical impact parameter intersect the horizon, and these collectively form the black hole “shadow” (Falcke, Melia, & Agol 2000) while the bright surrounding region constitutes the “photon ring” Adapted from: Asada et al.
    [Show full text]
  • Greenland Telescope Project --- Direct Confirmation of Black Hole with Sub-Millimeter VLBI
    Greenland Telescope Project --- Direct Confirmation of Black Hole with Sub-millimeter VLBI --- Inoue, M.§; Algaba-Marcos, J.C.; Asada, K.; Chang, C.-C.; Chen, M.-T.; Han, J.; Hirashita, H.; Ho, P.T.P.; Hsieh, S.-N.; Huang, T.; Jiang, H.; Koch, P.M.; Kubo, D.Y.; Kuo, C.-Y.; Liu, B.; Martin-Cocher, P.; Matsushita, S.; Meyer-Zhao, Z.; Nakamura, M.; Nishioka, H.; Nystrom, G.; Pradel, N.; Pu, H.-Y.; Raffin, P.A.; Shen, H.-Y.; Snow, W.; Srinivasan, R.; and Wei, T.-S. Academia Sinica Institute of Astronomy and Astrophysics 11F of Astronomy-Mathematics Building, AS/NTU, No.1, Sec. 4, Roosevelt Rd, Taipei 10617, Taiwan, R.O.C. Blundell, R.; Burgos, R.; Grimes, P.; Keto, E.; Paine, S.; Patel, N.; and Sridharan, T.K. Harvard-Smithsonian Center for Astrophysics 60 Garden Street, Cambridge, MA 02138, USA Doeleman, S.S.; and Fish, V. MIT Haystack Observatory Off Route 40, Westford, MA 01886-1299, USA and Brisken, W.; and Napier, P. National Radio Astronomy Observatory Array Operation Center, P.O. Box O, 1003 Lopezville Road, Socorro, NM 87801-0387, USA § Email address: [email protected] 1 Abstract A 12-m diameter radio telescope will be deployed to the Summit Station in Greenland to provide direct confirmation of a Super Massive Black Hole (SMBH) by observing its shadow image in the active galaxy M87. The telescope (Greenland Telescope: GLT) is to become one of the Very Long Baseline Interferometry (VLBI) stations at sub-millimeter (submm) regime, providing the longest baseline > 9,000 km to achieve an exceptional angular resolution of 20 µas at 350 GHz, which will enable us to resolve the shadow size of ~40 µas.
    [Show full text]
  • Event Horizon Telescope: the Black Hole Seen Round the World
    EVENT HORIZON TELESCOPE: THE BLACK HOLE SEEN ROUND THE WORLD HEARING BEFORE THE COMMITTEE ON SCIENCE, SPACE, AND TECHNOLOGY HOUSE OF REPRESENTATIVES ONE HUNDRED SIXTEENTH CONGRESS FIRST SESSION MAY 16, 2019 Serial No. 116–19 Printed for the use of the Committee on Science, Space, and Technology ( Available via the World Wide Web: http://science.house.gov U.S. GOVERNMENT PUBLISHING OFFICE 36–301PDF WASHINGTON : 2019 COMMITTEE ON SCIENCE, SPACE, AND TECHNOLOGY HON. EDDIE BERNICE JOHNSON, Texas, Chairwoman ZOE LOFGREN, California FRANK D. LUCAS, Oklahoma, DANIEL LIPINSKI, Illinois Ranking Member SUZANNE BONAMICI, Oregon MO BROOKS, Alabama AMI BERA, California, BILL POSEY, Florida Vice Chair RANDY WEBER, Texas CONOR LAMB, Pennsylvania BRIAN BABIN, Texas LIZZIE FLETCHER, Texas ANDY BIGGS, Arizona HALEY STEVENS, Michigan ROGER MARSHALL, Kansas KENDRA HORN, Oklahoma RALPH NORMAN, South Carolina MIKIE SHERRILL, New Jersey MICHAEL CLOUD, Texas BRAD SHERMAN, California TROY BALDERSON, Ohio STEVE COHEN, Tennessee PETE OLSON, Texas JERRY MCNERNEY, California ANTHONY GONZALEZ, Ohio ED PERLMUTTER, Colorado MICHAEL WALTZ, Florida PAUL TONKO, New York JIM BAIRD, Indiana BILL FOSTER, Illinois JAIME HERRERA BEUTLER, Washington DON BEYER, Virginia JENNIFFER GONZA´ LEZ-COLO´ N, Puerto CHARLIE CRIST, Florida Rico SEAN CASTEN, Illinois VACANCY KATIE HILL, California BEN MCADAMS, Utah JENNIFER WEXTON, Virginia (II) CONTENTS May 16, 2019 Page Hearing Charter .....................................................................................................
    [Show full text]
  • Greenland Telescope (GLT) Frontend/Backend Commissioning
    Greenland Telescope (GLT): Imaging the Black Hole Shadow Satoki Matsushita (ASIAA; Academia Sinica Institute of Astronomy and Astrophysics, Taiwan) & the GLT Project Team (ASIAA & SAO) Primary Science Target: Direct Imaging of the Shadow of Black Holes Sizes of Black Holes Shadow Size Mass Distance (masec) (106 Mo) (Mpc) Sgr A* 50 4.1 +- 0.6 0.008 M87 39 6600 +- 400 17.0 M31 18 180 +- 80 0.80 M60 12 2100 +- 600 16.5 NGC 5128 (Cen A) 7 310 +- 30 4.5 Gebhardt et al. (2011) Note: Here we assume Rshadow ~ 5 x Rsch Spatial Resolution • Spatial resolution goes high with shorter wavelength (or higher frequency) and bigger telescope (or longer baseline): • Resolution ~ l/D l: Wavelength D: Diameter of telescope (or baseline length) • Spatial resolutions of the optical/infrared telescopes: • Hubble Space Telescope (HST): 0.04” (40 milliarcsec) • James Webb Space Telescope (JWST): 0.03” (30 milliarcsec) • VLT Interferometer (VLTI): 0.002” (2 milliarcsec) a Too large to image black holes, whose sizes are marcsec scale. ⇒ Submillimeter Interferometry !!! Feasibility of Submillimeter VLBI Doeleman et al. (2008) Doeleman et al. (2012) Sgr A* Vir A* (M 87) Size ≈ 40 µas (≈ 4 rsch) Size ≈ 40 µas (≈ 5 rsch) Why Greenland? Submillimeter Telescopes in the World • Atacama Large Millimeter Array (ALMA), Chile • ALMA Pathfinder Experiment (APEX), Chile • James Clerk Maxwell Telescope (JCMT), Hawaii • Large Millimeter Telescope (LMT), Mexico • IRAM 30-meter Telescope, Spain • South Pole Telescope (SPT), South Pole • Submillimeter Array (SMA), Hawaii • Submillimeter Telescope (SMT), Arizona M. Johnson/SAO Telescope Site Selection • Site selection criteria: • Precipitable water vapor (PWV) is low.
    [Show full text]
  • Electronics Instrumentation for the Greenland Telescope
    Electronics Instrumentation for the Greenland Telescope Derek Kubo1a, Chih-Chiang Hana, Hiroaki Nishiokaa, Ryan Chilsona, Ranjani Srinivasana, Sheng- Feng Yena, Kuo-Chieh Fua, Homin Jianga, Kuan-Yu Liua, Ta-Shun Weia, Chih-Wei Huanga, Chen- Yu Yua, Peter Oshiroa, Shu-Hao Changa, Chung-Cheng Chena, Philippe Raffina, Yau-De Huanga, Pierre Martin-Cochera, Ming-Tang Chena, Makoto Inouea, Satoki Matsushitaa, Keiichi Asadaa, Shoko Koyamaa, Patrick Kocha, Paul T. P. Hoa, Yang-Tai Shawa, Timothy J. Nortonb, Nimesh A. Patelb, Shepherd S. Doelemanb, Daniel Bintleyc, Craig Waltherc, Per Fribergc, Jessica Dempseyc, Hideo Ogawad, Kimihiro Kimurad, Yutaka Hasegawad, Ching-Tang Liue, Kou-Chang Hane, Song- Chu Change, Li-Ming Lue aAcademia Sinica, Institute of Astronomy & Astrophysics, No 1, Sec 4, Roosevelt Rd, Taipei 10617, Taiwan, ROC; bHarvard-Smithsonian Center for Astrophysics, 60 Garden St, Cambridge, MA 02138, USA; cEast Asian Observatory, 660 N Aohoku Pl, Hilo, HI 96720, USA; dOsaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan; eNational Chung-Shan Institute of Science and Technology, No 300-5, Ln 277, Xian St, Xitun Dist, Taichung City, 40722, Taiwan, ROC. ABSTRACT The Greenland Telescope project has recently participated in an experiment to image the supermassive black hole shadow at the center of M87 using Very Long Baseline Interferometry technique in April of 2018. The antenna consists of the 12-m ALMA North American prototype antenna that was modified to support two auxiliary side containers and to withstand an extremely cold environment. The telescope is currently at Thule Air Base in Greenland with the long-term goal to move the telescope over the Greenland ice sheet to Summit Station.
    [Show full text]
  • Greenland Telescope (GLT) Project
    EPJ W e b o f Con ferenc es 61 , 01008 (2013) / / DOI: 10.1051 epjconf 20136101008 C Owned by the authors, published by EDP Sciences, 2013 Greenland Telescope (GLT) Project ”A Direct Confirmation of Black Hole with Submillimeter VLBI” M. Nakamura1, J. C. Algaba1, K. Asada1, B. Chen1, M.-T. Chen1, J. Han1, P. H. P. Ho1, S.-N. Hsieh1, T. Huang1, M. Inoue1, P. Koch1, C.-Y. Kuo1, P. Martin-Cocher1, S. Matsushita1, Z. Meyer-Zhao1, H. Nishioka1, G. Nystrom2, N. Pradel1, H.-Y. Pu1, P. Raffin1, H.-Y. Shen1, C.-Y. Tseng1, and the Greenland Telescope Project Team1,2,3,4 1Institute of Astronomy and Astrophysics, Academia Sinica, 11F of Astronomy-Mathematics Building, AS/NTU No 1, Sec 4, Roosevelt Rd., Taipei 10617, Taiwan 2Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA 3MIT Haystack Observatory, Off Route 40, Westford, MA 01886-1299, USA 4NRAO, 520 Edgemont Road, Charlottesville, VA 22903-2475, USA Abstract. The GLT project is deploying a new submillimeter (submm) VLBI station in Greenland. Our primary scientific goal is to image a shadow of the supermassive black hole (SMBH) of six billion solar masses in M87 at the center of the Virgo cluster of galaxies. The expected SMBH shadow size of 40-50 µas requires superbly high angular resolution, suggesting that the submm VLBI would be the only way to obtain the shadow image. The Summit station in Greenland enables us to establish baselines longer than 9,000 km with ALMA in Chile and SMA in Hawaii as well as providing a unique u–v coverage for imaging M87.
    [Show full text]
  • Danish Press Conference on First Result from the Event Horizon Telescope
    Danish Press Conference on First Result from the Event Horizon Telescope Left panel : A simulated image showing turbulent plasma glowing as it is swallowed up by a supermassive black hole (credit: University of Arizona). Right panel: The Greenland Telescope, currently located at the Thule Air Base in northern Greenland. April 1, 2019 The Event Horizon Telescope (EHT) project and DTU Space, National Space Institute will hold a press conference to present a groundbreaking result from the EHT. ● What: Press conference announcing a groundbreaking result from the EHT. The Greenland Telescope is due to join the worldwide network of telescopes that make up the EHT thereby boosting its discovery capabilities, and presenting an opportunity for Danish astronomers to be part of future ground­breaking discoveries with the EHT. ● Who: Introductory remarks by Thomas R. Greve (DAWN/DTU­Space). A panel of expert astrophysicists from Denmark and Taiwan will answer questions: ○ VIP guest: Paul Ho, East Asian Observatories Director, PI of the Greenland Telescope, and co­investigator of the EHT result. ○ Thomas R. Greve, DAWN, DTU Space, Technical University of Denmark ○ Marianne Vestergaard, DARK, The Niels Bohr Institute, University of Copenhagen ○ Jes K. Jørgensen, StarPlan, The Niels Bohr Institute, University of Copenhagen ○ Ivalu B. Christensen, Lund University and Astrophysicist from Greenland ● When: Wednesday, April 10, 2019, 15:00 CEST. ● Where: The press conference will be held at DTU Space, Elektrovej 328, 2800 Lyngby, Denmark. The conference will be streamed online on: ■ www.greenlandtelescope.dk/outreach/ ■ https://www.facebook.com/GLTdenmark/ . ■ http://www.facebook.com/darkcosmologycentre/ ● RSVP: Me dia representatives can register to attend the event in person by contacting [email protected].
    [Show full text]
  • The Greenland Telescope
    The Greenland Telescope Thomas R. Greve What is the GLT? - A brief history US proto-type antenna for ALMA Designed and build by VERTEX (2000-2004) Atacama Large Millimeter/submillimeter Array (ALMA) What is the GLT? - A brief history US proto-type antenna for ALMA Designed and build by VERTEX (2000-2004) Awarded to Academia Sinica (TW) and Smithsonian Astrophysical Observatorty (US) by National Science Foundation in 2011 (value 10M$) Atacama Large Millimeter/submillimeter Array (ALMA) What is the GLT? - Currents partners & budget • NSF: ~22M$ (local infrastructure) • SAO: ~10M$ (support buildings) • ASIAA: ~14M$ (telescope facility) What is the GLT? - Specifications • 12m radio telescope, optimised for observations at sub-mm wavelengths • Cassegrain system with 15 arcminute field of view • Currently located at Thule Airbase →Greenland Summit (~2022). • Summit: N72.5 W38.5, altitude 3200m. Excellent atmospheric conditions for sub-mm observations What is the GLT? - Specifications • 12m radio telescope, optimised for observations at sub-mm wavelengths • Cassegrain system with 15 arcminute field of view • Currently located at Thule Airbase →Greenland Summit (~2022). TARGET: SUMMIT STATION• Summit: GREENLAND N72.5 W38.5, altitude 3200m. Excellent atmospheric conditions for !N!72.5,!W!38.5,!al-tude:!3200!m! sub-mm observations What is the GLT? - Observations and current instrumentation • 2016: Arrival in Thule • 2017: First light • 2018: first 230GHz fringes between GLT and ALMA • 2018: 350GHz VLBI testing • Participating in EHT observations since
    [Show full text]
  • Astro2020 APC White Paper Studying Black Holes on Horizon Scales with VLBI Ground Arrays
    Astro2020 APC White Paper Studying Black Holes on Horizon Scales with VLBI Ground Arrays Lindy Blackburn1;2;∗ Sheperd Doeleman1;2;∗, Jason Dexter12, José L. Gómez16, Michael D. Johnson1;2, Daniel C. Palumbo1;2, Jonathan Weintroub1;2, Joseph R. Farah1;2;21, Vincent Fish4, Laurent Loinard18;19, Colin Lonsdale4, Gopal Narayanan28, Nimesh A. Patel2, Dominic W. Pesce1;2, Alexander Raymond1;2, Remo Tilanus17;22;23, Maciek Wielgus1;2, Kazunori Akiyama1;3;4;5, Geoffrey Bower6, Avery Broderick7;8;9, Roger Deane10;11, Christian Michael Fromm13, Charles Gammie14;15, Roman Gold13, Michael Janssen17, Tomohisa Kawashima4, Thomas Krichbaum29, Daniel P. Marrone20, Lynn D. Matthews4, Yosuke Mizuno13, Luciano Rezzolla13, Freek Roelofs17, Eduardo Ros29, Tuomas K. Savolainen29;30;31, Feng Yuan24;25;26, Guangyao Zhao27 1 Black Hole Initiative at Harvard University, 20 Garden Street, Cam- and Particle Physics (IMAPP), Radboud University, P.O. Box 9010, bridge, MA 02138, USA 6500 GL Nijmegen, The Netherlands 2 Center for Astrophysics j Harvard & Smithsonian, 60 Garden Street, 18 Instituto de Radioastronomía y Astrofísica, Universidad Nacional Cambridge, MA 02138, USA Autónoma de México, Morelia 58089, México 3 National Radio Astronomy Observatory, 520 Edgemont Road, Char- 19 Instituto de Astronomía, Universidad Nacional Autónoma de México, lottesville, VA 22903, USA CdMx 04510, México 4 Massachusetts Institute of Technology, Haystack Observatory, 99 Mill- 20 Steward Observatory and Department of Astronomy, University of stone Road, Westford, MA 01886, USA Arizona, 933 N. Cherry Ave., Tucson, AZ 85721, USA 5 National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, 21 University of Massachusetts Boston, 100 William T, Morrissey Blvd, Tokyo 181-8588, Japan Boston, MA 02125, USA 6 Institute of Astronomy and Astrophysics, Academia Sinica, 645 N.
    [Show full text]