230 GHz VLBI OBSERVATIONS OF M87: EVENT-HORIZON-SCALE STRUCTURE DURING AN ENHANCED VERY-HIGH-ENERGY γ-RAY STATE IN 2012

Kazunori Akiyama; Ru Sen Lu; Vincent L. Fish; Sheperd S. Doeleman; Avery E. Broderick; Jason Dexter; Kazuhiro Hada; Motoki Kino; Hiroshi Nagai; Mareki Honma; Michael D. Johnson; Juan C. Algaba; Keiichi Asada; Christiaan Brinkerink; Ray Blundell; Geoffrey C. Bower; Roger Cappallo; Geoffrey B. Crew; Matt Dexter; Sergio A. Dzib; Robert Freund; Per Friberg; Mark Gurwell; Paul T.P. Ho; Makoto Inoue; Thomas P. Krichbaum; Laurent Loinard; David MacMahon; Daniel P. Marrone; James M. Moran; Masanori Nakamura; Neil M. Nagar; Gisela Ortiz-Leon; Richard Plambeck; Nicolas Pradel; Rurik A. Primiani; Alan E.E. Rogers; Alan L. Roy; Jason SooHoo; Jonathan León Tavares; Remo P.J. Tilanus; Michael Titus; Jan Wagner; Jonathan Weintroub; Paul Yamaguchi; Ken H. Young; Anton Zensus; Lucy M. Ziurys

doi:10.1088/0004-637X/807/2/150

230 GHz VLBI OBSERVATIONS OF M87: EVENT-HORIZON-SCALE STRUCTURE DURING AN ENHANCED VERY-HIGH-ENERGY γ-RAY STATE IN 2012

Kazunori Akiyama, Ru Sen Lu, Vincent L. Fish, Sheperd S. Doeleman, Avery E. Broderick, Jason Dexter, Kazuhiro Hada, Motoki Kino, Hiroshi Nagai, Mareki Honma, Michael D. Johnson, Juan C. Algaba, Keiichi Asada, Christiaan Brinkerink, Ray Blundell, Geoffrey C. Bower, Roger Cappallo, Geoffrey B. Crew, Matt Dexter, Sergio A. DzibRobert Freund, Per Friberg, Mark Gurwell, Paul T.P. Ho, Makoto Inoue, Thomas P. Krichbaum, Laurent Loinard, David MacMahon, Daniel P. Marrone, James M. Moran, Masanori Nakamura, Neil M. Nagar, Gisela Ortiz-Leon, Richard Plambeck, Nicolas Pradel, Rurik A. Primiani, Alan E.E. Rogers, Alan L. Roy, Jason SooHoo, Jonathan León Tavares, Remo P.J. Tilanus, Michael Titus, Jan Wagner, Jonathan Weintroub, Paul Yamaguchi, Ken H. Young, Anton Zensus, Lucy M. Ziurys

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103 Scopus citations

Abstract

We report on 230 GHz (1.3 mm) very long baseline interferometry (VLBI) observations of M87 with the Event Horizon Telescope using antennas on Mauna Kea in Hawaii, Mt. Graham in Arizona, and Cedar Flat in California. For the first time, we have acquired 230 GHz VLBI interferometric phase information on M87 through measurement of the closure phase on the triangle of long baselines. Most of the measured closure phases are consistent with 0° as expected by physically motivated models for 230 GHz structure such as jet models and accretion disk models. The brightness temperature of the event-horizon-scale structure is ∼1 × 10¹⁰ K derived from the compact flux density of ∼1 Jy and the angular size of ∼40 μas ∼ 5.5 R_s, which is broadly consistent with the peak brightness of the radio cores at 1-86 GHz located within ∼10² R_s. Our observations occurred in the middle of an enhancement in very-high-energy (VHE) γ-ray flux, presumably originating in the vicinity of the central black hole. Our measurements, combined with results of multi-wavelength observations, favor a scenario in which the VHE region has an extended size of ∼20-60 R_s.

Original language	English (US)
Article number	150
Journal	Astrophysical Journal
Volume	807
Issue number	2
DOIs	https://doi.org/10.1088/0004-637X/807/2/150
State	Published - Jul 10 2015

Keywords

galaxies: active
galaxies: individual (M87)
galaxies: jets
radio continuum: galaxies
techniques: high angular resolution
techniques: interferometric

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

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10.1088/0004-637X/807/2/150

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Akiyama, K., Lu, R. S., Fish, V. L., Doeleman, S. S., Broderick, A. E., Dexter, J., Hada, K., Kino, M., Nagai, H., Honma, M., Johnson, M. D., Algaba, J. C., Asada, K., Brinkerink, C., Blundell, R., Bower, G. C., Cappallo, R., Crew, G. B., Dexter, M., ... Ziurys, L. M. (2015). 230 GHz VLBI OBSERVATIONS OF M87: EVENT-HORIZON-SCALE STRUCTURE DURING AN ENHANCED VERY-HIGH-ENERGY γ-RAY STATE IN 2012. Astrophysical Journal, 807(2), Article 150. https://doi.org/10.1088/0004-637X/807/2/150

Akiyama, K, Lu, RS, Fish, VL, Doeleman, SS, Broderick, AE, Dexter, J, Hada, K, Kino, M, Nagai, H, Honma, M, Johnson, MD, Algaba, JC, Asada, K, Brinkerink, C, Blundell, R, Bower, GC, Cappallo, R, Crew, GB, Dexter, M, Dzib, SA, Freund, R, Friberg, P, Gurwell, M, Ho, PTP, Inoue, M, Krichbaum, TP, Loinard, L, MacMahon, D, Marrone, DP, Moran, JM, Nakamura, M, Nagar, NM, Ortiz-Leon, G, Plambeck, R, Pradel, N, Primiani, RA, Rogers, AEE, Roy, AL, SooHoo, J, Tavares, JL, Tilanus, RPJ, Titus, M, Wagner, J, Weintroub, J, Yamaguchi, P, Young, KH, Zensus, A & Ziurys, LM 2015, '230 GHz VLBI OBSERVATIONS OF M87: EVENT-HORIZON-SCALE STRUCTURE DURING AN ENHANCED VERY-HIGH-ENERGY γ-RAY STATE IN 2012', Astrophysical Journal, vol. 807, no. 2, 150. https://doi.org/10.1088/0004-637X/807/2/150

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title = "230 GHz VLBI OBSERVATIONS OF M87: EVENT-HORIZON-SCALE STRUCTURE DURING AN ENHANCED VERY-HIGH-ENERGY γ-RAY STATE IN 2012",

abstract = "We report on 230 GHz (1.3 mm) very long baseline interferometry (VLBI) observations of M87 with the Event Horizon Telescope using antennas on Mauna Kea in Hawaii, Mt. Graham in Arizona, and Cedar Flat in California. For the first time, we have acquired 230 GHz VLBI interferometric phase information on M87 through measurement of the closure phase on the triangle of long baselines. Most of the measured closure phases are consistent with 0° as expected by physically motivated models for 230 GHz structure such as jet models and accretion disk models. The brightness temperature of the event-horizon-scale structure is ∼1 × 1010 K derived from the compact flux density of ∼1 Jy and the angular size of ∼40 μas ∼ 5.5 Rs, which is broadly consistent with the peak brightness of the radio cores at 1-86 GHz located within ∼102 Rs. Our observations occurred in the middle of an enhancement in very-high-energy (VHE) γ-ray flux, presumably originating in the vicinity of the central black hole. Our measurements, combined with results of multi-wavelength observations, favor a scenario in which the VHE region has an extended size of ∼20-60 Rs.",

keywords = "galaxies: active, galaxies: individual (M87), galaxies: jets, radio continuum: galaxies, techniques: high angular resolution, techniques: interferometric",

author = "Kazunori Akiyama and Lu, {Ru Sen} and Fish, {Vincent L.} and Doeleman, {Sheperd S.} and Broderick, {Avery E.} and Jason Dexter and Kazuhiro Hada and Motoki Kino and Hiroshi Nagai and Mareki Honma and Johnson, {Michael D.} and Algaba, {Juan C.} and Keiichi Asada and Christiaan Brinkerink and Ray Blundell and Bower, {Geoffrey C.} and Roger Cappallo and Crew, {Geoffrey B.} and Matt Dexter and Dzib, {Sergio A.} and Robert Freund and Per Friberg and Mark Gurwell and Ho, {Paul T.P.} and Makoto Inoue and Krichbaum, {Thomas P.} and Laurent Loinard and David MacMahon and Marrone, {Daniel P.} and Moran, {James M.} and Masanori Nakamura and Nagar, {Neil M.} and Gisela Ortiz-Leon and Richard Plambeck and Nicolas Pradel and Primiani, {Rurik A.} and Rogers, {Alan E.E.} and Roy, {Alan L.} and Jason SooHoo and Tavares, {Jonathan Le{\'o}n} and Tilanus, {Remo P.J.} and Michael Titus and Jan Wagner and Jonathan Weintroub and Paul Yamaguchi and Young, {Ken H.} and Anton Zensus and Ziurys, {Lucy M.}",

year = "2015",

month = jul,

day = "10",

doi = "10.1088/0004-637X/807/2/150",

language = "English (US)",

volume = "807",

journal = "Astrophysical Journal",

issn = "0004-637X",

publisher = "American Astronomical Society",

number = "2",

}

TY - JOUR

T1 - 230 GHz VLBI OBSERVATIONS OF M87

T2 - EVENT-HORIZON-SCALE STRUCTURE DURING AN ENHANCED VERY-HIGH-ENERGY γ-RAY STATE IN 2012

AU - Akiyama, Kazunori

AU - Lu, Ru Sen

AU - Fish, Vincent L.

AU - Doeleman, Sheperd S.

AU - Broderick, Avery E.

AU - Dexter, Jason

AU - Hada, Kazuhiro

AU - Kino, Motoki

AU - Nagai, Hiroshi

AU - Honma, Mareki

AU - Johnson, Michael D.

AU - Algaba, Juan C.

AU - Asada, Keiichi

AU - Brinkerink, Christiaan

AU - Blundell, Ray

AU - Bower, Geoffrey C.

AU - Cappallo, Roger

AU - Crew, Geoffrey B.

AU - Dexter, Matt

AU - Dzib, Sergio A.

AU - Freund, Robert

AU - Friberg, Per

AU - Gurwell, Mark

AU - Ho, Paul T.P.

AU - Inoue, Makoto

AU - Krichbaum, Thomas P.

AU - Loinard, Laurent

AU - MacMahon, David

AU - Marrone, Daniel P.

AU - Moran, James M.

AU - Nakamura, Masanori

AU - Nagar, Neil M.

AU - Ortiz-Leon, Gisela

AU - Plambeck, Richard

AU - Pradel, Nicolas

AU - Primiani, Rurik A.

AU - Rogers, Alan E.E.

AU - Roy, Alan L.

AU - SooHoo, Jason

AU - Tavares, Jonathan León

AU - Tilanus, Remo P.J.

AU - Titus, Michael

AU - Wagner, Jan

AU - Weintroub, Jonathan

AU - Yamaguchi, Paul

AU - Young, Ken H.

AU - Zensus, Anton

AU - Ziurys, Lucy M.

PY - 2015/7/10

Y1 - 2015/7/10

N2 - We report on 230 GHz (1.3 mm) very long baseline interferometry (VLBI) observations of M87 with the Event Horizon Telescope using antennas on Mauna Kea in Hawaii, Mt. Graham in Arizona, and Cedar Flat in California. For the first time, we have acquired 230 GHz VLBI interferometric phase information on M87 through measurement of the closure phase on the triangle of long baselines. Most of the measured closure phases are consistent with 0° as expected by physically motivated models for 230 GHz structure such as jet models and accretion disk models. The brightness temperature of the event-horizon-scale structure is ∼1 × 1010 K derived from the compact flux density of ∼1 Jy and the angular size of ∼40 μas ∼ 5.5 Rs, which is broadly consistent with the peak brightness of the radio cores at 1-86 GHz located within ∼102 Rs. Our observations occurred in the middle of an enhancement in very-high-energy (VHE) γ-ray flux, presumably originating in the vicinity of the central black hole. Our measurements, combined with results of multi-wavelength observations, favor a scenario in which the VHE region has an extended size of ∼20-60 Rs.

AB - We report on 230 GHz (1.3 mm) very long baseline interferometry (VLBI) observations of M87 with the Event Horizon Telescope using antennas on Mauna Kea in Hawaii, Mt. Graham in Arizona, and Cedar Flat in California. For the first time, we have acquired 230 GHz VLBI interferometric phase information on M87 through measurement of the closure phase on the triangle of long baselines. Most of the measured closure phases are consistent with 0° as expected by physically motivated models for 230 GHz structure such as jet models and accretion disk models. The brightness temperature of the event-horizon-scale structure is ∼1 × 1010 K derived from the compact flux density of ∼1 Jy and the angular size of ∼40 μas ∼ 5.5 Rs, which is broadly consistent with the peak brightness of the radio cores at 1-86 GHz located within ∼102 Rs. Our observations occurred in the middle of an enhancement in very-high-energy (VHE) γ-ray flux, presumably originating in the vicinity of the central black hole. Our measurements, combined with results of multi-wavelength observations, favor a scenario in which the VHE region has an extended size of ∼20-60 Rs.

KW - galaxies: active

KW - galaxies: individual (M87)

KW - galaxies: jets

KW - radio continuum: galaxies

KW - techniques: high angular resolution

KW - techniques: interferometric

UR - http://www.scopus.com/inward/record.url?scp=84937033429&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84937033429&partnerID=8YFLogxK

U2 - 10.1088/0004-637X/807/2/150

DO - 10.1088/0004-637X/807/2/150

M3 - Article

AN - SCOPUS:84937033429

SN - 0004-637X

VL - 807

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 2

M1 - 150

ER -

230 GHz VLBI OBSERVATIONS OF M87: EVENT-HORIZON-SCALE STRUCTURE DURING AN ENHANCED VERY-HIGH-ENERGY γ-RAY STATE IN 2012

Abstract

Keywords

ASJC Scopus subject areas

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