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1. Observing the Sun with the Atacama Large Millimeter-submillimeter Array (ALMA): Fast-Scan Single-Dish Mapping

Author

White, S. M., Iwai, K., Phillips, N. M., Hills, R. E., Hirota, A., Yagoubov, P., Siringo, G., Shimojo, M., Bastian, T. S., Hales, A. S., Sawada, T., Asayama, S., Sugimoto, M., Marson, R. G., Kawasaki, W., Muller, E., Nakazato, T., Sugimoto, K., Brajsa, R., Skokic, I., Barta, M., Kim, S., Remijan, A., de Gregorio, I., Corder, S. A., Hudson, H. S., Loukitcheva, M., Chen, B., De Pontieu, B., Fleishmann, G. D., Gary, D. E., Kobelski, A., Wedemeyer, S., and Yan, Y.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The Atacama Large Millimeter-submillimeter Array (ALMA) radio telescope has commenced science observations of the Sun starting in late 2016. Since the Sun is much larger than the field of view of individual ALMA dishes, the ALMA interferometer is unable to measure the background level of solar emission when observing the solar disk. The absolute temperature scale is a critical measurement for much of ALMA solar science, including the understanding of energy transfer through the solar atmosphere, the properties of prominences, and the study of shock heating in the chromosphere. In order to provide an absolute temperature scale, ALMA solar observing will take advantage of the remarkable fast-scanning capabilities of the ALMA 12m dishes to make single-dish maps of the full Sun. This article reports on the results of an extensive commissioning effort to optimize the mapping procedure, and it describes the nature of the resulting data. Amplitude calibration is discussed in detail: a path that utilizes the two loads in the ALMA calibration system as well as sky measurements is described and applied to commissioning data. Inspection of a large number of single-dish datasets shows significant variation in the resulting temperatures, and based on the temperature distributions we derive quiet-Sun values at disk center of 7300 K at lambda=3 mm and 5900 K at lambda=1.3 mm. These values have statistical uncertainties of order 100 K, but systematic uncertainties in the temperature scale that may be significantly larger. Example images are presented from two periods with very different levels of solar activity. At a resolution of order 25 arcsec, the 1.3 mm wavelength images show temperatures on the disk that vary over about a 2000 K range., Comment: Solar Physics, accepted: 24 pages, 13 figures

Published
2017
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2. An Overview of the 2014 ALMA Long Baseline Campaign

Author

Partnership, ALMA, Fomalont, E. B., Vlahakis, C., Corder, S., Remijan, A., Barkats, D., Lucas, R., Hunter, T. R., Brogan, C. L., Asaki, Y., Matsushita, S., Dent, W. R. F., Hills, R. E., Phillips, N., Richards, A. M. S., Cox, P., Amestica, R., Broguiere, D., Cotton, W., Hales, A. S., Hiriart, R., Hirota, A., Hodge, J. A., Impellizzeri, C. M. V., Kern, J., Kneissl, R., Liuzzo, E., Marcelino, N., Marson, R., Mignano, A., Nakanishi, K., Nikolic, B., Perez, J. E., Pérez, L. M., Toledo, I., Aladro, R., Butler, B., Cortes, J., Cortes, P., Dhawan, V., Di Francesco, J., Espada, D., Galarza, F., Garcia-Appadoo, D., Guzman-Ramirez, L., Humphreys, E. M., Jung, T., Kameno, S., Laing, R. A., Leon, S., Mangum, J., Marconi, G., Nagai, H., Nyman, L. -A., Radiszcz, M., Rodón, J. A., Sawada, T., Takahashi, S., Tilanus, R. P. J., van Kempen, T., Vilaro, B. Vila, Watson, L. C., Wiklind, T., Gueth, F., Tatematsu, K., Wootten, A., Castro-Carrizo, A., Chapillon, E., Dumas, G., de Gregorio-Monsalvo, I., Francke, H., Gallardo, J., Garcia, J., Gonzalez, S., Hibbard, J. E., Hill, T., Kaminski, T., Karim, A., Krips, M., Kurono, Y., Lopez, C., Martin, S., Maud, L., Morales, F., Pietu, V., Plarre, K., Schieven, G., Testi, L., Videla, L., Villard, E., Whyborn, N., Zwaan, M. A., Alves, F., Andreani, P., Avison, A., Barta, M., Bedosti, F., Bendo, G. J., Bertoldi, F., Bethermin, M., Biggs, A., Boissier, J., Brand, J., Burkutean, S., Casasola, V., Conway, J., Cortese, L., Dabrowski, B., Davis, T. A., Trigo, M. Diaz, Fontani, F., Franco-Hernandez, R., Fuller, G., Madrid, R. Galvan, Giannetti, A., Ginsburg, A., Graves, S. F., Hatziminaoglou, E., Hogerheijde, M., Jachym, P., Serra, I. Jimenez, Karlicky, M., Klaasen, P., Kraus, M., Kunneriath, D., Lagos, C., Longmore, S., Leurini, S., Maercker, M., Magnelli, B., Vidal, I. Marti, Massardi, M., Maury, A., Muehle, S., Muller, S., Muxlow, T., O'Gorman, E., Paladino, R., Petry, D., Pineda, J., Randall, S., Richer, J. S., Rossetti, A., Rushton, A., Rygl, K., Monge, A. Sanchez, Schaaf, R., Schilke, P., Stanke, T., Schmalzl, M., Stoehr, F., Urban, S., van Kampen, E., Vlemmings, W., Wang, K., Wild, W., Yang, Y., Iguchi, S., Hasegawa, T., Saito, M., Inatani, J., Mizuno, N., Asayama, S., Kosugi, G., Morita, K. -I., Chiba, K., Kawashima, S., Okumura, S. K., Ohashi, N., Ogasawara, R., Sakamoto, S., Noguchi, T., Huang, Y. -D., Liu, S. -Y., Kemper, F., Koch, P. M., Chen, M. -T., Chikada, Y., Hiramatsu, M., Iono, D., Shimojo, M., Komugi, S., Kim, J., Lyo, A. -R., Muller, E., Herrera, C., Miura, R. E., Ueda, J., Chibueze, J., Su, Y. -N., Trejo-Cruz, A., Wang, K. -S., Kiuchi, H., Ukita, N., Sugimoto, M., Kawabe, R., Hayashi, M., Miyama, S., Ho, P. T. P., Kaifu, N., Ishiguro, M., Beasley, A. J., Bhatnagar, S., Braatz III, J. A., Brisbin, D. G., Brunetti, N., Carilli, C., Crossley, J. H., D'Addario, L., Meyer, J. L. Donovan, Emerson, D. T., Evans, A. S., Fisher, P., Golap, K., Griffith, D. M., Hale, A. E., Halstead, D., Hardy, E. J., Hatz, M. C., Holdaway, M., Indebetouw, R., Jewell, P. R., Kepley, A. A., Kim, D. -C., Lacy, M. D., Leroy, A. K., Liszt, H. S., Lonsdale, C. J., Matthews, B., McKinnon, M., Mason, B. S., Moellenbrock, G., Moullet, A., Myers, S. T., Ott, J., Peck, A. B., Pisano, J., Radford, S. J. E., Randolph, W. T., Venkata, U. Rao, Rawlings, M. G., Rosen, R., Schnee, S. L., Scott, K. S., Sharp, N. K., Sheth, K., Simon, R. S., Tsutsumi, T., and Wood, S. J.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

A major goal of the Atacama Large Millimeter/submillimeter Array (ALMA) is to make accurate images with resolutions of tens of milliarcseconds, which at submillimeter (submm) wavelengths requires baselines up to ~15 km. To develop and test this capability, a Long Baseline Campaign (LBC) was carried out from September to late November 2014, culminating in end-to-end observations, calibrations, and imaging of selected Science Verification (SV) targets. This paper presents an overview of the campaign and its main results, including an investigation of the short-term coherence properties and systematic phase errors over the long baselines at the ALMA site, a summary of the SV targets and observations, and recommendations for science observing strategies at long baselines. Deep ALMA images of the quasar 3C138 at 97 and 241 GHz are also compared to VLA 43 GHz results, demonstrating an agreement at a level of a few percent. As a result of the extensive program of LBC testing, the highly successful SV imaging at long baselines achieved angular resolutions as fine as 19 mas at ~350 GHz. Observing with ALMA on baselines of up to 15 km is now possible, and opens up new parameter space for submm astronomy., Comment: 11 pages, 7 figures, 2 tables; accepted for publication in the Astrophysical Journal Letters; this version with small changes to affiliations

Published
2015
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3. Multi-wavelength observations of the red giant R Doradus with the MAPPIT interferometer

Author

Jacob, A. P., Bedding, T. R., Robertson, J. G., Barton, J. R., Haniff, C. A., Marson, R. G., and Scholz, M.

Subjects
Astrophysics
Abstract

We present visibility measurements of the nearby Mira-like star R Doradus taken over a wide range of wavelengths (650-990 nm). The observations were made using MAPPIT (Masked APerture-Plane Interference Telescope), an interferometer operating at the 3.9-m Anglo-Australian Telescope. We used a slit to mask the telescope aperture and prism to disperse the interference pattern in wavelength. We observed in R Dor strong decreases in visibility within the TiO absorption bands. The results are in general agreement with theory but differ in detail, suggesting that further work is needed to refine the theoretical models., Comment: 2 pages. Poster at IAU Symposium 205: Galaxies and their Constituents at the Highest Angular Resolutions, Manchester UK, August 2000. Proceedings to be published by ASP, edited by R. Schilizzi, S. Vogel, F. Paresce, M. Elvis

Published
2000

4. Multi-wavelength visibility measurements of the red giant R Doradus

Author

Jacob, A. P., Bedding, T. R., Robertson, J. G., Barton, J. R., Haniff, C. A., Marson, R. G., and Scholz, M.

Subjects
Astrophysics
Abstract

We present visibility measurements of the nearby Mira-like star R Doradus taken over a wide range of wavelengths (650--990 nm). The observations were made using MAPPIT (Masked APerture-Plane Interference Telescope), an interferometer operating at the 3.9-m Anglo-Australian Telescope. We used a slit to mask the telescope aperture and prism to disperse the interference pattern in wavelength. We observed in R Dor strong decreases in visibility within the TiO absorption bands. The results are in general agreement with theory but differ in detail, suggesting that further work is needed to refine the theoretical models., Comment: 8 pages; SPIE Conf. 4006 "Interferometry in Optical Astronomy"

Published
2000
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5. Interferometry and spectroscopy of Beta Cen: a Beta Cephei star in a binary system

Author

Robertson, J. G., Bedding, T. R., Aerts, C., Waelkens, C., Marson, R. G., and Barton, J. R.

Subjects
Astrophysics
Abstract

Beta Cen is a bright Beta Cephei variable and has long been suspected to be a binary. Here we report interferometric observations with the 3.9-m Anglo-Australian Telescope at a single epoch which show the star to be a binary with components separated by 15 milliarcsec and having approximately equal luminosities at 486 nm. We also present high-resolution spectra taken over five nights with the ESO CAT which show Beta Cen to be a double-lined spectroscopic binary. We identify two pulsation frequencies in the primary. Further spectroscopic and interferometric studies of this double star should allow determination of its orbital parameters and component masses., Comment: 8 pages, 12 postscript figure files, grouped into 8 figures. Accepted for Monthly Notices of RAS. Topmargin revised for US Letter or A4 paper

Published
1998
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6. The angular diameter of R Doradus: a nearby Mira-like star

Author

Bedding, T. R., Zijlstra, A. A., von der Luhe, O., Robertson, J. G., Marson, R. G., Barton, J. R., and Carter, B. S.

Subjects
Astrophysics
Abstract

We find the angular diameter of R Doradus to be 57 +/- 5 mas, exceeding that of Betelgeuse and implying that R Dor is larger in apparent size than every star except the Sun. R Dor is shown to be closely related to the Mira variables. We estimate an effective temperature of 2740 +/- 190 K, a distance of 61 +/- 7 pc, a luminosity of 6500 +/- 1400 Lsol and a radius of 370 +/- 50 Rsol. The characteristics of R Dor are consistent with it being near the edge of a Mira instability strip. We detect non-zero closure phases from R Dor, indicating an asymmetric brightness distribution. We also observed W Hya, a small-amplitude Mira, for which we find an angular diameter of 44 +/- 4 mas., Comment: MNRAS (accepted); 7 pages, LaTeX with necessary style file and PostScript figures

Published
1997
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7. An Optical Interferometer with Wavelength Dispersion

Author

Bedding, T. R., Robertson, J. G., and Marson, R. G.

Subjects
Astrophysics
Abstract

MAPPIT is an optical interferometer installed at the coude focus of the 3.9-m Anglo-Australian Telescope. The instrument combines non-redundant masking with wavelength dispersion and is able to record fringes simultaneously over a wide bandwidth. For typical observations centred near 600 nm, the bandwidth is 55 nm and the spectral resolution is 3 nm. This paper describes the instrument and the data processing methods and presents some results. We find the star sigma Sgr to be a close binary; the system is only partially resolved, with a separation of (11.5 +/- 2) milliarcsec (assuming the components to have equal magnitudes). We also give angular diameter measurements of two red giant stars, alpha Sco and beta Gru. The observations of beta Gru (spectral type M5 III) resolve the star for the first time and give an equivalent uniform-disk diameter of (27 +/- 3) milliarcsec., Comment: Accepted for publication in Astronomy and Astrophysics. (9 pages, uuencoded and compressed PostScript; hardcopy on request from tbedding@eso.org). ESO-BRM0494

Published
1994

8. Off-Target drug effects resulting in altered gene expression events with epigenetic and ⿿Quasi-Epigenetic⿿ origins

Author

Anderson, Stephen J., Feye, Kristina M., Schmidt-McCormack, Garrett R., Malovic, Emir, Mlynarczyk, Gregory S.A., Izbicki, Patricia, Arnold, Larissa F., Jefferson, Matthew A., de la Rosa, Bierlein M., Wehrman, Rita F., Luna, K.C., Hu, Hilary Z., Kondru, Naveen C., Kleinhenz, Michael D., Smith, Joe S., Manne, Sireesha, Putra, Marson R., Choudhary, Shivani, Massey, Nyzil, Luo, Diou, Berg, Carrie A., Acharya, Sreemoyee, Sharma, Shaunik, Kanuri, Sri Harsha, Lange, Jennifer K., and Carlson, Steve A.

Published
2016
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10. Off-Target drug effects resulting in altered gene expression events with epigenetic and “Quasi-Epigenetic” origins

Author

Anderson, Stephen J., Feye, Kristina M., Schmidt-McCormack, Garrett R., Malovic, Emir, Mlynarczyk, Gregory S.A., Izbicki, Patricia, Arnold, Larissa F., Jefferson, Matthew A., de la Rosa, Bierlein M., Wehrman, Rita F., Luna, K. C., Hu, Hilary Z., Kondru, Naveen C., Kleinhenz, Michael D., Smith, Joe S., Manne, Sireesha, Putra, Marson R., Choudhary, Shivani, Massey, Nyzil, Luo, Diou, Berg, Carrie A., Acharya, Sreemoyee, Sharma, Shaunik, Kanuri, Sri Harsha, Lange, Jennifer K., and Carlson, Steve A.

Published
2016
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12. Nickel nano-wires filled alumina templates for microwave electronics

Author

Kuanr, Bijoy K., Veerakumar, V., Marson, R., Mishra, S.R., Kuanr, Alka V., Camley, R.E., and Celinski, Z.

Subjects
Nickel -- Magnetic properties, Magnetization -- Magnetic properties, Aluminum oxide -- Magnetic properties, Ferromagnetism -- Magnetic properties, Waveguides -- Magnetic properties, Business, Electronics, Electronics and electrical industries
Published
2009

13. Project numbat - a mine emergency survey vehicle

Author

International Conference on Mining Machinery (2nd : 1988 : Brisbane, Qld.), Leach, JHJ, Mallett, CW, Hainsworth, D, Curwen, K, Vallis, NJ, Seevinck, R, Jacka, C, Marson, R, Rogers, G, Sweetnam, T, and Williams, D

Published
1988

14. Observing the Sun with the Atacama Large Millimeter/submillimeter Array (ALMA): Fast-Scan Single-Dish Mapping

Author

White, S. M., primary, Iwai, K., additional, Phillips, N. M., additional, Hills, R. E., additional, Hirota, A., additional, Yagoubov, P., additional, Siringo, G., additional, Shimojo, M., additional, Bastian, T. S., additional, Hales, A. S., additional, Sawada, T., additional, Asayama, S., additional, Sugimoto, M., additional, Marson, R. G., additional, Kawasaki, W., additional, Muller, E., additional, Nakazato, T., additional, Sugimoto, K., additional, Brajša, R., additional, Skokić, I., additional, Bárta, M., additional, Kim, S., additional, Remijan, A. J., additional, de Gregorio, I., additional, Corder, S. A., additional, Hudson, H. S., additional, Loukitcheva, M., additional, Chen, B., additional, De Pontieu, B., additional, Fleishmann, G. D., additional, Gary, D. E., additional, Kobelski, A., additional, Wedemeyer, S., additional, and Yan, Y., additional

Published
2017
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15. Sezione 5 La Qualità delle Cure . Capitolo 20. Appropriatezza nelle cure palliative. Capitolo 21. Standard qualitativi e prove di efficacia nelle cure palliative. Capitolo 22. Approccio critico alle evidenze scientifiche. Capitolo 23. Uso delle prove di efficacia per supportare le decisioni cliniche

Author

Prandi, Cesarina, Catania, Gianluca, D'Angelo, D., De Marinis, M. G., Franceschini, C., Grubich, S., Intravaia, G., Lazzarin, P., Malinverni, E., Marsaglia, C., Marson, R., Marzi, A., Mastroianni L. Orsi, C. M. a. s. t. r. o. i. a. n. n. i. L. Orsi, Pedroni, C., Penco, I., and Russo, A. M.

Published
2015

16. The 2014 ALMA Long Baseline Campaign: An Overview

Author

ALMA Partnership: Fomalont, E. B., Vlahakis, C., Corder, S., Remijan, A., Barkats, D., Lucas, R., Hunter, T. R., Brogan, C. L., Asaki, Yoshiharu, Matsushita, S., Dent, W. R. F., Hills, R. E., Phillips, N., Richards, A. M. S., Cox, P., Amestica, R., Broguiere, D., Cotton, W., Hales, A. S., Hiriart, R., Hirota, A., Hodge, J. A., Impellizzeri, C. M. V., Kern, J., Kneissl, R., Liuzzo, E., Marcelino, N., Marson, R., Mignano, A., Nakanishi, K., 朝木, 義晴, 松下, 聡樹, ALMA Partnership: Fomalont, E. B., Vlahakis, C., Corder, S., Remijan, A., Barkats, D., Lucas, R., Hunter, T. R., Brogan, C. L., Asaki, Yoshiharu, Matsushita, S., Dent, W. R. F., Hills, R. E., Phillips, N., Richards, A. M. S., Cox, P., Amestica, R., Broguiere, D., Cotton, W., Hales, A. S., Hiriart, R., Hirota, A., Hodge, J. A., Impellizzeri, C. M. V., Kern, J., Kneissl, R., Liuzzo, E., Marcelino, N., Marson, R., Mignano, A., Nakanishi, K., 朝木, 義晴, and 松下, 聡樹

Abstract

著者人数: 248名, Accepted: 2015-04-10

Published
2016

18. THE 2014 ALMA LONG BASELINE CAMPAIGN: AN OVERVIEW

Author

Fomalont, E. B., Vlahakis, C., Corder, S., Remijan, A., Barkats, D., Lucas, R., Hunter, T. R., Brogan, C. L., Asaki, Y., Matsushita, S., Dent, W. R. F., Hills, R. E., Phillips, N., Richards, A. M. S., Cox, P., Amestica, R., Broguiere, D., Cotton, W., Hales, A. S., Hiriart, R., Hirota, A., Hodge, J. A., Impellizzeri, C. M. V., Kern, J., Kneissl, R., Liuzzo, E., Marcelino, N., Marson, R., Mignano, A., Nakanishi, K., Nikolic, B., Perez, J. E., Perez, L. M., Toledo, I., Aladro, R., Butler, B., Cortes, J., Cortes, P., Dhawan, V., Di Francesco, J., Espada, D., Galarza, F., Garcia-Appadoo, D., Guzman-Ramirez, L., Humphreys, E. M., Jung, T., Kameno, S., Laing, R. A., Leon, S., Mangum, J., Marconi, G., Nagai, H., Nyman, L. -A., Radiszcz, M., Rodon, J. A., Sawada, T., Takahashi, S., Tilanus, R. P. J., van Kempen, T., Vila Vilaro, B., Watson, L. C., Wiklind, T., Gueth, F., Tatematsu, K., Wootten, A., Castro-Carrizo, A., Chapillon, E., Dumas, G., de Gregorio-Monsalvo, I., Francke, H., Gallardo, J., Garcia, J., Gonzalez, S., Hibbard, J. E., Hill, T., Kaminski, T., Karim, A., Krips, M., Kurono, Y., Lopez, C., Martin, S., Maud, L., Morales, F., Pietu, V., Plarre, K., Schieven, G., Testi, L., Videla, L., Villard, E., Whyborn, N., Zwaan, M. A., Alves, F., Andreani, P., Avison, A., Barta, M., Bedosti, F., Bendo, G. J., Bertoldi, F., Bethermin, M., Biggs, A., Boissier, J., Brand, J., Burkutean, S., Casasola, V., Conway, J., Cortese, L., Dabrowski, B., Davis, T. A., Trigo, M. Diaz, Fontani, F., Franco-Hernandez, R., Fuller, G., Galvan Madrid, R., Giannetti, A., Ginsburg, A., Graves, S. F., Hatziminaoglou, E., Hogerheijde, M., Jachym, P., Serra, I. Jimenez, Karlicky, M., Klaasen, P., Kraus, M., Kunneriath, D., Lagos, C., Longmore, S., Leurini, S., Maercker, M., Magnelli, B., Vidal, I. Marti, Massardi, M., Maury, A., Muehle, S., Muller, S., Muxlow, T., O'Gorman, E., Paladino, R., Petry, D., Pineda, J., Randall, S., Richer, J. S., Rossetti, A., Rushton, A., Rygl, K., Monge, A. Sanchez, Schaaf, R., Schilke, P., Stanke, T., Schmalzl, M., Stoehr, F., Urban, S., van Kampen, E., Vlemmings, W., Wang, K., Wild, W., Yang, Y., Iguchi, S., Hasegawa, T., Saito, M., Inatani, J., Mizuno, N., Asayama, S., Kosugi, G., Morita, K. -I., Chiba, K., Kawashima, S., Okumura, S. K., Ohashi, N., Ogasawara, R., Sakamoto, S., Noguchi, T., Huang, Y. -D., Liu, S. -Y., Kemper, F., Koch, P. M., Chen, M. -T., Chikada, Y., Hiramatsu, M., Iono, D., Shimojo, M., Komugi, S., Kim, J., Lyo, A. -R., Muller, E., Herrera, C., Miura, R. E., Ueda, J., Chibueze, J., Su, Y. -N., Trejo-Cruz, A., Wang, K. -S., Kiuchi, H., Ukita, N., Sugimoto, M., Kawabe, R., Hayashi, M., Miyama, S., Ho, P. T. P., Kaifu, N., Ishiguro, M., Beasley, A. J., Bhatnagar, S., Braatz, J. A., III, Brisbin, D. G., Brunetti, N., Carilli, C., Crossley, J. H., D'Addario, L., Meyer, J. L. Donovan, Emerson, D. T., Evans, A. S., Fisher, P., Golap, K., Griffith, D. M., Hale, A. E., Halstead, D., Hardy, E. J., Hatz, M. C., Holdaway, M., Indebetouw, R., Jewell, P. R., Kepley, A. A., Kim, D. -C., Lacy, M. D., Leroy, A. K., Liszt, H. S., Lonsdale, C. J., Matthews, B., McKinnon, M., Mason, B. S., Moellenbrock, G., Moullet, A., Myers, S. T., Ott, J., Peck, A. B., Pisano, J., Radford, S. J. E., Randolph, W. T., Venkata, U. Rao, Rawlings, M. G., Rosen, R., Schnee, S. L., Scott, K. S., Sharp, N. K., Sheth, K., Simon, R. S., Tsutsumi, T., Wood, S. J., Fomalont, E. B., Vlahakis, C., Corder, S., Remijan, A., Barkats, D., Lucas, R., Hunter, T. R., Brogan, C. L., Asaki, Y., Matsushita, S., Dent, W. R. F., Hills, R. E., Phillips, N., Richards, A. M. S., Cox, P., Amestica, R., Broguiere, D., Cotton, W., Hales, A. S., Hiriart, R., Hirota, A., Hodge, J. A., Impellizzeri, C. M. V., Kern, J., Kneissl, R., Liuzzo, E., Marcelino, N., Marson, R., Mignano, A., Nakanishi, K., Nikolic, B., Perez, J. E., Perez, L. M., Toledo, I., Aladro, R., Butler, B., Cortes, J., Cortes, P., Dhawan, V., Di Francesco, J., Espada, D., Galarza, F., Garcia-Appadoo, D., Guzman-Ramirez, L., Humphreys, E. M., Jung, T., Kameno, S., Laing, R. A., Leon, S., Mangum, J., Marconi, G., Nagai, H., Nyman, L. -A., Radiszcz, M., Rodon, J. A., Sawada, T., Takahashi, S., Tilanus, R. P. J., van Kempen, T., Vila Vilaro, B., Watson, L. C., Wiklind, T., Gueth, F., Tatematsu, K., Wootten, A., Castro-Carrizo, A., Chapillon, E., Dumas, G., de Gregorio-Monsalvo, I., Francke, H., Gallardo, J., Garcia, J., Gonzalez, S., Hibbard, J. E., Hill, T., Kaminski, T., Karim, A., Krips, M., Kurono, Y., Lopez, C., Martin, S., Maud, L., Morales, F., Pietu, V., Plarre, K., Schieven, G., Testi, L., Videla, L., Villard, E., Whyborn, N., Zwaan, M. A., Alves, F., Andreani, P., Avison, A., Barta, M., Bedosti, F., Bendo, G. J., Bertoldi, F., Bethermin, M., Biggs, A., Boissier, J., Brand, J., Burkutean, S., Casasola, V., Conway, J., Cortese, L., Dabrowski, B., Davis, T. A., Trigo, M. Diaz, Fontani, F., Franco-Hernandez, R., Fuller, G., Galvan Madrid, R., Giannetti, A., Ginsburg, A., Graves, S. F., Hatziminaoglou, E., Hogerheijde, M., Jachym, P., Serra, I. Jimenez, Karlicky, M., Klaasen, P., Kraus, M., Kunneriath, D., Lagos, C., Longmore, S., Leurini, S., Maercker, M., Magnelli, B., Vidal, I. Marti, Massardi, M., Maury, A., Muehle, S., Muller, S., Muxlow, T., O'Gorman, E., Paladino, R., Petry, D., Pineda, J., Randall, S., Richer, J. S., Rossetti, A., Rushton, A., Rygl, K., Monge, A. Sanchez, Schaaf, R., Schilke, P., Stanke, T., Schmalzl, M., Stoehr, F., Urban, S., van Kampen, E., Vlemmings, W., Wang, K., Wild, W., Yang, Y., Iguchi, S., Hasegawa, T., Saito, M., Inatani, J., Mizuno, N., Asayama, S., Kosugi, G., Morita, K. -I., Chiba, K., Kawashima, S., Okumura, S. K., Ohashi, N., Ogasawara, R., Sakamoto, S., Noguchi, T., Huang, Y. -D., Liu, S. -Y., Kemper, F., Koch, P. M., Chen, M. -T., Chikada, Y., Hiramatsu, M., Iono, D., Shimojo, M., Komugi, S., Kim, J., Lyo, A. -R., Muller, E., Herrera, C., Miura, R. E., Ueda, J., Chibueze, J., Su, Y. -N., Trejo-Cruz, A., Wang, K. -S., Kiuchi, H., Ukita, N., Sugimoto, M., Kawabe, R., Hayashi, M., Miyama, S., Ho, P. T. P., Kaifu, N., Ishiguro, M., Beasley, A. J., Bhatnagar, S., Braatz, J. A., III, Brisbin, D. G., Brunetti, N., Carilli, C., Crossley, J. H., D'Addario, L., Meyer, J. L. Donovan, Emerson, D. T., Evans, A. S., Fisher, P., Golap, K., Griffith, D. M., Hale, A. E., Halstead, D., Hardy, E. J., Hatz, M. C., Holdaway, M., Indebetouw, R., Jewell, P. R., Kepley, A. A., Kim, D. -C., Lacy, M. D., Leroy, A. K., Liszt, H. S., Lonsdale, C. J., Matthews, B., McKinnon, M., Mason, B. S., Moellenbrock, G., Moullet, A., Myers, S. T., Ott, J., Peck, A. B., Pisano, J., Radford, S. J. E., Randolph, W. T., Venkata, U. Rao, Rawlings, M. G., Rosen, R., Schnee, S. L., Scott, K. S., Sharp, N. K., Sheth, K., Simon, R. S., Tsutsumi, T., and Wood, S. J.

Abstract

A major goal of the Atacama Large Millimeter/submillimeter Array (ALMA) is to make accurate images with resolutions of tens of milliarcseconds, which at submillimeter (submm) wavelengths requires baselines up to similar to 15 km. To develop and test this capability, a Long Baseline Campaign (LBC) was carried out from 2014 September to late November, culminating in end-to-end observations, calibrations, and imaging of selected Science Verification (SV) targets. This paper presents an overview of the campaign and its main results, including an investigation of the short-term coherence properties and systematic phase errors over the long baselines at the ALMA site, a summary of the SV targets and observations, and recommendations for science observing strategies at long baselines. Deep ALMA images of the quasar 3C 138 at 97 and 241 GHz are also compared to VLA 43 GHz results, demonstrating an agreement at a level of a few percent. As a result of the extensive program of LBC testing, the highly successful SV imaging at long baselines achieved angular resolutions as fine as 19 mas at similar to 350 GHz. Observing with ALMA on baselines of up to 15 km is now possible, and opens up new parameter space for submm astronomy.

Published
2015

19. THE 2014 ALMA LONG BASELINE CAMPAIGN: AN OVERVIEW

Author

Partnership, ALMA, primary, Fomalont, E. B., additional, Vlahakis, C., additional, Corder, S., additional, Remijan, A., additional, Barkats, D., additional, Lucas, R., additional, Hunter, T. R., additional, Brogan, C. L., additional, Asaki, Y., additional, Matsushita, S., additional, Dent, W. R. F., additional, Hills, R. E., additional, Phillips, N., additional, Richards, A. M. S., additional, Cox, P., additional, Amestica, R., additional, Broguiere, D., additional, Cotton, W., additional, Hales, A. S., additional, Hiriart, R., additional, Hirota, A., additional, Hodge, J. A., additional, Impellizzeri, C. M. V., additional, Kern, J., additional, Kneissl, R., additional, Liuzzo, E., additional, Marcelino, N., additional, Marson, R., additional, Mignano, A., additional, Nakanishi, K., additional, Nikolic, B., additional, Perez, J. E., additional, Pérez, L. M., additional, Toledo, I., additional, Aladro, R., additional, Butler, B., additional, Cortes, J., additional, Cortes, P., additional, Dhawan, V., additional, Francesco, J. Di, additional, Espada, D., additional, Galarza, F., additional, Garcia-Appadoo, D., additional, Guzman-Ramirez, L., additional, Humphreys, E. M., additional, Jung, T., additional, Kameno, S., additional, Laing, R. A., additional, Leon, S., additional, Mangum, J., additional, Marconi, G., additional, Nagai, H., additional, Nyman, L.-A., additional, Radiszcz, M., additional, Rodón, J. A., additional, Sawada, T., additional, Takahashi, S., additional, Tilanus, R. P. J., additional, Kempen, T. van, additional, Vilaro, B. Vila, additional, Watson, L. C., additional, Wiklind, T., additional, Gueth, F., additional, Tatematsu, K., additional, Wootten, A., additional, Castro-Carrizo, A., additional, Chapillon, E., additional, Dumas, G., additional, de Gregorio-Monsalvo, I., additional, Francke, H., additional, Gallardo, J., additional, Garcia, J., additional, Gonzalez, S., additional, Hibbard, J. E., additional, Hill, T., additional, Kaminski, T., additional, Karim, A., additional, Krips, M., additional, Kurono, Y., additional, Lopez, C., additional, Martin, S., additional, Maud, L., additional, Morales, F., additional, Pietu, V., additional, Plarre, K., additional, Schieven, G., additional, Testi, L., additional, Videla, L., additional, Villard, E., additional, Whyborn, N., additional, Zwaan, M. A., additional, Alves, F., additional, Andreani, P., additional, Avison, A., additional, Barta, M., additional, Bedosti, F., additional, Bendo, G. J., additional, Bertoldi, F., additional, Bethermin, M., additional, Biggs, A., additional, Boissier, J., additional, Brand, J., additional, Burkutean, S., additional, Casasola, V., additional, Conway, J., additional, Cortese, L., additional, Dabrowski, B., additional, Davis, T. A., additional, Trigo, M. Diaz, additional, Fontani, F., additional, Franco-Hernandez, R., additional, Fuller, G., additional, Madrid, R. Galvan, additional, Giannetti, A., additional, Ginsburg, A., additional, Graves, S. F., additional, Hatziminaoglou, E., additional, Hogerheijde, M., additional, Jachym, P., additional, Serra, I. Jimenez, additional, Karlicky, M., additional, Klaasen, P., additional, Kraus, M., additional, Kunneriath, D., additional, Lagos, C., additional, Longmore, S., additional, Leurini, S., additional, Maercker, M., additional, Magnelli, B., additional, Vidal, I. Marti, additional, Massardi, M., additional, Maury, A., additional, Muehle, S., additional, Muller, S., additional, Muxlow, T., additional, O’Gorman, E., additional, Paladino, R., additional, Petry, D., additional, Pineda, J., additional, Randall, S., additional, Richer, J. S., additional, Rossetti, A., additional, Rushton, A., additional, Rygl, K., additional, Monge, A. Sanchez, additional, Schaaf, R., additional, Schilke, P., additional, Stanke, T., additional, Schmalzl, M., additional, Stoehr, F., additional, Urban, S., additional, Kampen, E. van, additional, Vlemmings, W., additional, Wang, K., additional, Wild, W., additional, Yang, Y., additional, Iguchi, S., additional, Hasegawa, T., additional, Saito, M., additional, Inatani, J., additional, Mizuno, N., additional, Asayama, S., additional, Kosugi, G., additional, Morita, K.-I., additional, Chiba, K., additional, Kawashima, S., additional, Okumura, S. K., additional, Ohashi, N., additional, Ogasawara, R., additional, Sakamoto, S., additional, Noguchi, T., additional, Huang, Y.-D., additional, Liu, S.-Y., additional, Kemper, F., additional, Koch, P. M., additional, Chen, M.-T., additional, Chikada, Y., additional, Hiramatsu, M., additional, Iono, D., additional, Shimojo, M., additional, Komugi, S., additional, Kim, J., additional, Lyo, A.-R., additional, Muller, E., additional, Herrera, C., additional, Miura, R. E., additional, Ueda, J., additional, Chibueze, J., additional, Su, Y.-N., additional, Trejo-Cruz, A., additional, Wang, K.-S., additional, Kiuchi, H., additional, Ukita, N., additional, Sugimoto, M., additional, Kawabe, R., additional, Hayashi, M., additional, Miyama, S., additional, Ho, P. T. P., additional, Kaifu, N., additional, Ishiguro, M., additional, Beasley, A. J., additional, Bhatnagar, S., additional, III, J. A. Braatz, additional, Brisbin, D. G., additional, Brunetti, N., additional, Carilli, C., additional, Crossley, J. H., additional, D’Addario, L., additional, Meyer, J. L. Donovan, additional, Emerson, D. T., additional, Evans, A. S., additional, Fisher, P., additional, Golap, K., additional, Griffith, D. M., additional, Hale, A. E., additional, Halstead, D., additional, Hardy, E. J., additional, Hatz, M. C., additional, Holdaway, M., additional, Indebetouw, R., additional, Jewell, P. R., additional, Kepley, A. A., additional, Kim, D.-C., additional, Lacy, M. D., additional, Leroy, A. K., additional, Liszt, H. S., additional, Lonsdale, C. J., additional, Matthews, B., additional, McKinnon, M., additional, Mason, B. S., additional, Moellenbrock, G., additional, Moullet, A., additional, Myers, S. T., additional, Ott, J., additional, Peck, A. B., additional, Pisano, J., additional, Radford, S. J. E., additional, Randolph, W. T., additional, Venkata, U. Rao, additional, Rawlings, M. G., additional, Rosen, R., additional, Schnee, S. L., additional, Scott, K. S., additional, Sharp, N. K., additional, Sheth, K., additional, Simon, R. S., additional, Tsutsumi, T., additional, and Wood, S. J., additional

Published
2015
Full Text
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35. Working with OTAs.

Author

Marson, R.

Subjects
*ELECTRONIC equipment design
Abstract

There are many types of operational amplifiers in use today. Examines Operational Transconductance Amplifier, or OTA, and how to use it in your designs and projects.

Published
1988

41. THE PAPER ELECTROPHORESIS OF THE IRON (II)-IRON (III) SYSTEM

Author

NAVAL RADIOLOGICAL DEFENSE LAB SAN FRANCISCO CALIF, Lingren,W. E., Reeck,G., Marson,R., NAVAL RADIOLOGICAL DEFENSE LAB SAN FRANCISCO CALIF, Lingren,W. E., Reeck,G., and Marson,R.

Abstract

The iron(II) - iron(III) equilibrium mixture in a sulfuric acid solution of pH 2.6 is separable by paper electrophoresis. An attempt was made to determine whether the electrophoretic system affected this equilibrium. Maximum differences of about 10% from the iron(II) - iron(III) true equilibrium ratio were observed after the separation by paper electrophoresis. (Author), Prepared in cooperation with Atomic Energy Commision, Contract AT(49-5)-2084(2)

Published
1966

50. First M87 Event Horizon Telescope Results. I. the Shadow of the Supermassive Black Hole

Author

Olivier Gentaz, David J. James, Hector Olivares, John E. Barrett, Alan P. Marscher, C. M. Violette Impellizzeri, Peter Oshiro, Peter Galison, Tyler Trent, Sang-Sung Lee, Arturo I. Gómez-Ruiz, Satoki Matsushita, Carsten Kramer, Scott Paine, Dimitrios Psaltis, Mareki Honma, Kazi L.J. Rygl, Shuo Zhang, Jan Wagner, Daniel P. Marrone, Ryan Chilson, Jorge A. Preciado-López, Christopher Beaudoin, Sara Issaoun, André Young, A. A. Stark, Jordy Davelaar, Hiroshi Nagai, Zhiqiang Shen, Pablo Torne, Chris Eckert, John Wardle, Ranjani Srinivasan, David M. Gale, David Ball, Alan L. Roy, Lupin C.C. Lin, Thomas Bronzwaer, Kazunori Akiyama, W. B. Everett, Li Ming Lu, Ta Shun Wei, Sheperd S. Doeleman, Shu Hao Chang, Roberto Garcia, Richard L. Plambeck, Maciek Wielgus, Iniyan Natarajan, Raquel Fraga-Encinas, Hiroaki Nishioka, Mark G. Rawlings, Tirupati K. Sridharan, Geoffrey B. Crew, Vernon Fath, Michael H. Hecht, Frederic Gueth, Jun Yi Koay, David Sánchez-Arguelles, Chih Chiang Han, Michael Kramer, Mariafelicia De Laurentis, Kuo Liu, Oliver Porth, Jae-Young Kim, Ilje Cho, Shan Shan Zhao, Hotaka Shiokawa, Martin P. McColl, Song Chu Chang, Lei Huang, William Stahm, Makoto Inoue, Svetlana G. Jorstad, Andrew Chael, Chih Cheng Chang, Thomas P. Krichbaum, Dominic W. Pesce, Chung Chen Chen, Laura Vertatschitsch, Jonathan Weintroub, Alejandro F. Sáez-Madain, Sera Markoff, Shuichiro Tsuda, Ryan Berthold, Chao-Te Li, M. C. H. Wright, Daniel R. van Rossum, J. Peñalver, Neal R. Erickson, Remo P. J. Tilanus, John E. Carlstrom, Roger Deane, Minfeng Gu, Michael Titus, Laurent Loinard, Lia Medeiros, C. Y. Kuo, Iain Coulson, Michael Janssen, Ben Prather, Katherine L. Bouman, Lucy M. Ziurys, Norbert Wex, Freek Roelofs, Feng Gao, Yau De Huang, Dan Bintley, N. W. Halverson, Benjamin R. Ryan, Nimesh A. Patel, Aaron Faber, Mansour Karami, Robert Freund, Ming-Tang Chen, K. T. Story, Gertie Geertsema, Daryl Haggard, Paul Shaw, Ronald Grosslein, S. A. Dzib, Joseph Crowley, Kuo Chang Han, Shoko Koyama, José L. Gómez, Chet Ruszczyk, David R. Smith, Michael Bremer, Daniel Michalik, James Hoge, Karl M. Menten, Juan-Carlos Algaba, Aristeidis Noutsos, William Snow, Thomas W. Folkers, Masanori Nakamura, Homin Jiang, James M. Cordes, Uwe Bach, Christopher Risacher, Rurik A. Primiani, Pierre Christian, David H. Hughes, Wen Ping Lo, Geoffrey C. Bower, James M. Moran, Ciriaco Goddi, Yi Chen, Christopher Greer, Roger J. Cappallo, Ilse van Bemmel, Andreas Eckart, Ziyan Zhu, Chi H. Nguyen, Rubén Herrero-Illana, Robert Wharton, Antonio Hernández-Gómez, Bart Ripperda, Dominique Broguiere, Pim Schellart, Mark Derome, Chih-Wei Locutus Huang, Chen Yu Yu, Kuan Yu Liu, Lijing Shao, Christiaan D. Brinkerink, Michael D. Johnson, Mark Kettenis, Michael Lindqvist, Frederick K. Baganoff, John Conway, Remi Sassella, Nathan Whitehorn, Eduardo Ros, David P. Woody, Jessica Dempsey, Gopal Narayanan, Elisabetta Liuzzo, Akihiko Hirota, D. A. Graham, Hiroki Okino, Vincent Piétu, Alexander W. Raymond, Gregory Desvignes, Anne Kathrin Baczko, Arash Roshanineshat, Kevin M. Silva, Timothy Norton, Heino Falcke, Aleksandar Popstefanija, Ken H. Young, Per Friberg, Paul Yamaguchi, Derek Kubo, E. Castillo-Domínguez, Jason W. Henning, R. Laing, Kimihiro Kimura, Rodrigo Córdova Rosado, Roman Gold, Helge Rottmann, Silke Britzen, J. Anton Zensus, Roger Brissenden, Ru-Sen Lu, Ye-Fei Yuan, F. Peter Schloerb, Stephen R. McWhirter, Joseph R. Farah, Ue-Li Pen, Yosuke Mizuno, Charles F. Gammie, Mel Rose, Harriet Parsons, Venkatessh Ramakrishnan, Philippe Raffin, Ignacio Ruiz, Mahito Sasada, Kamal Souccar, Joseph Neilsen, J. G. A. Wouterloot, Jirong Mao, Colin J. Lonsdale, Feng Yuan, Jadyn Anczarski, Lindy Blackburn, N. Phillips, Don Sousa, Ramesh Narayan, Alan R. Whitney, Paul T. P. Ho, Kyle D. Massingill, Patrick M. Koch, Taehyun Jung, Erik M. Leitch, Junhan Kim, Nicolas Pradel, Kevin A. Dudevoir, Britton Jeter, Jason SooHoo, Tomohisa Kawashima, T. M. Crawford, Mark Gurwell, A. Montaña, R. P. Eatough, Sascha Trippe, Ivan Marti-Vidal, Dirk Muders, Craig Walther, Atish Kamble, Qingwen Wu, Chunchong Ni, George Nystrom, Yusuke Kono, Ryan Keisler, Huib Jan van Langevelde, Stefan Heyminck, Kenji Toma, Do-Young Byun, Sjoerd T. Timmer, Antxon Alberdi, Hung Yi Pu, Hugo Messias, Feryal Özel, Kotaro Moriyama, John David, M. Poirier, Mislav Baloković, Fumie Tazaki, Keiichi Asada, S. Sánchez, Wu Jiang, Tomoaki Oyama, Shami Chatterjee, Des Small, Richard Lacasse, Ray Blundell, Motoki Kino, Michael A. Nowak, Jason Dexter, Walter Alef, Jinchi Hao, Zhiyuan Li, Garrett K. Keating, Christian M. Fromm, Cornelia Müller, Ching Tang Liu, Alexandra S. Rahlin, William Montgomerie, Andrei P. Lobanov, Bradford Benson, George N. Wong, Kazuhiro Hada, Sven Dornbusch, George Reiland, Boris Georgiev, Luciano Rezzolla, Jongsoo Kim, W. Boland, Ramprasad Rao, Guang-Yao Zhao, Buell T. Jannuzi, Sandra Bustamente, Daniel C. M. Palumbo, Tod R. Lauer, Karl Friedrich Schuster, Ronald Hesper, Zheng Meyer-Zhao, John Kuroda, Ramesh Karuppusamy, Pierre Martin-Cocher, Chi-kwan Chan, Timothy C. Chuter, Izumi Mizuno, Vincent L. Fish, Yutaka Hasegawa, Roberto Neri, Matthew R. Dexter, Paul Tiede, Rodrigo Amestica, S. Navarro, William T. Freeman, Callie Matulonis, Luis C. Ho, Hideo Ogawa, Shiro Ikeda, Ralph G. Marson, A. Nadolski, J. Blanchard, Ed Fomalont, Monika Moscibrodzka, Nicholas R. MacDonald, Gisela N. Ortiz-León, Bong Won Sohn, David C. Forbes, Lynn D. Matthews, Avery E. Broderick, Ziri Younsi, Tuomas Savolainen, Neil M. Nagar, Alexander Allardi, M. Mora-Klein, Yuzhu Cui, Yan-Rong Li, Koushik Chatterjee, Rebecca Azulay, M. Zeballos, Alan E. E. Rogers, Event Horizon Telescope Collaboration, T., Akiyama, K., Alberdi, A., Alef, W., Asada, K., Azulay, R., Baczko, A. -K., Ball, D., Balokovic, M., Barrett, J., Bintley, D., Blackburn, L., Boland, W., Bouman, K. L., Bower, G. C., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Byun, D. -Y., Carlstrom, J. E., Chael, A., Chan, C. -K., Chatterjee, S., Chatterjee, K., Chen, M. -T., Chen, Y., Cho, I., Christian, P., Conway, J. E., Cordes, J. M., Crew, G. B., Cui, Y., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Doeleman, S. S., Eatough, R. P., Falcke, H., Fish, V. L., Fomalont, E., Fraga-Encinas, R., Freeman, W. T., Friberg, P., Fromm, C. M., Gomez, J. L., Galison, P., Gammie, C. F., Garcia, R., Gentaz, O., Georgiev, B., Goddi, C., Gold, R., Gu, M., Gurwell, M., Hada, K., Hecht, M. H., Hesper, R., Ho, L. C., Ho, P., Honma, M., Huang, C. -W. L., Huang, L., Hughes, D. H., Ikeda, S., Inoue, M., Issaoun, S., James, D. J., Jannuzi, B. T., Janssen, M., Jeter, B., Jiang, W., Johnson, M. D., Jorstad, S., Jung, T., Karami, M., Karuppusamy, R., Kawashima, T., Keating, G. K., Kettenis, M., Kim, J. -Y., Kim, J., Kino, M., Koay, J. Y., Koch, P. M., Koyama, S., Kramer, M., Kramer, C., Krichbaum, T. P., Kuo, C. -Y., Lauer, T. R., Lee, S. -S., Li, Y. -R., Li, Z., Lindqvist, M., Liu, K., Liuzzo, E., Lo, W. -P., Lobanov, A. P., Loinard, L., Lonsdale, C., Lu, R. -S., Macdonald, N. R., Mao, J., Markoff, S., Marrone, D. P., Marscher, A. P., Marti-Vidal, I., Matsushita, S., Matthews, L. D., Medeiros, L., Menten, K. M., Mizuno, Y., Mizuno, I., Moran, J. M., Moriyama, K., Moscibrodzka, M., Muller, C., Nagai, H., Nagar, N. M., Nakamura, M., Narayan, R., Narayanan, G., Natarajan, I., Neri, R., Ni, C., Noutsos, A., Okino, H., Olivares, H., Ortiz-Leon, G. N., Oyama, T., Ozel, F., Palumbo, D. C. M., Patel, N., Pen, U. -L., Pesce, D. W., Pietu, V., Plambeck, R., Popstefanija, A., Porth, O., Prather, B., Preciado-Lopez, J. A., Psaltis, D., Pu, H. -Y., Ramakrishnan, V., Rao, R., Rawlings, M. G., Raymond, A. W., Rezzolla, L., Ripperda, B., Roelofs, F., Rogers, A., Ros, E., Rose, M., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruszczyk, C., Ryan, B. R., Rygl, K. L. J., Sanchez, S., Sanchez-Arguelles, D., Sasada, M., Savolainen, T., Schloerb, F. P., Schuster, K. -F., Shao, L., Shen, Z., Small, D., Sohn, B. W., Soohoo, J., Tazaki, F., Tiede, P., Tilanus, R. P. J., Titus, M., Toma, K., Torne, P., Trent, T., Trippe, S., Tsuda, S., Bemmel, I. V., Van Langevelde, H. J., Van Rossum, D. R., Wagner, J., Wardle, J., Weintroub, J., Wex, N., Wharton, R., Wielgus, M., Wong, G. N., Wu, Q., Young, K., Young, A., Younsi, Z., Yuan, F., Yuan, Y. -F., Zensus, J. A., Zhao, G., Zhao, S. -S., Zhu, Z., Algaba, J. -C., Allardi, A., Amestica, R., Anczarski, J., Bach, U., Baganoff, F. K., Beaudoin, C., Benson, B. A., Berthold, R., Blanchard, J. M., Blundell, R., Bustamente, S., Cappallo, R., Castillo-Dominguez, E., Chang, C. -C., Chang, S. -H., Chang, S. -C., Chen, C. -C., Chilson, R., Chuter, T. C., Rosado, R. C., Coulson, I. M., Crawford, T. M., Crowley, J., David, J., Derome, M., Dexter, M., Dornbusch, S., Dudevoir, K. A., Dzib, S. A., Eckart, A., Eckert, C., Erickson, N. R., Everett, W. B., Faber, A., Farah, J. R., Fath, V., Folkers, T. W., Forbes, D. C., Freund, R., Gomez-Ruiz, A. I., Gale, D. M., Gao, F., Geertsema, G., Graham, D. A., Greer, C. H., Grosslein, R., Gueth, F., Haggard, D., Halverson, N. W., Han, C. -C., Han, K. -C., Hao, J., Hasegawa, Y., Henning, J. W., Hernandez-Gomez, A., Herrero-Illana, R., Heyminck, S., Hirota, A., Hoge, J., Huang, Y. -D., Impellizzeri, C. M. V., Jiang, H., Kamble, A., Keisler, R., Kimura, K., Kono, Y., Kubo, D., Kuroda, J., Lacasse, R., Laing, R. A., Leitch, E. M., Li, C. -T., Lin, L. C. -C., Liu, C. -T., Liu, K. -Y., Lu, L. -M., Marson, R. G., Martin-Cocher, P. L., Massingill, K. D., Matulonis, C., Mccoll, M. P., Mcwhirter, S. R., Messias, H., Meyer-Zhao, Z., Michalik, D., Montana, A., Montgomerie, W., Mora-Klein, M., Muders, D., Nadolski, A., Navarro, S., Neilsen, J., Nguyen, C. H., Nishioka, H., Norton, T., Nowak, M. A., Nystrom, G., Ogawa, H., Oshiro, P., Parsons, H., Paine, S. N., Penalver, J., Phillips, N. M., Poirier, M., Pradel, N., Primiani, R. A., Raffin, P. A., Rahlin, A. S., Reiland, G., Risacher, C., Ruiz, I., Saez-Madain, A. F., Sassella, R., Schellart, P., Shaw, P., Silva, K. M., Shiokawa, H., Smith, D. R., Snow, W., Souccar, K., Sousa, D., Sridharan, T. K., Srinivasan, R., Stahm, W., Stark, A. A., Story, K., Timmer, S. T., Vertatschitsch, L., Walther, C., Wei, T. -S., Whitehorn, N., Whitney, A. R., Woody, D. P., Wouterloot, J. G. A., Wright, M., Yamaguchi, P., Yu, C. -Y., Zeballos, M., Zhang, S., Ziurys, L., Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), Instituto de RadioAstronomía Milimétrica (IRAM), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Event Horizon Telescope, Academy of Finland, European Commission, Alexander von Humboldt Foundation, John Templeton Foundation, China Scholarship Council, Comisión Nacional de Investigación Científica y Tecnológica (Chile), Consejo Nacional de Ciencia y Tecnología (México), European Research Council, Generalitat Valenciana, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Gordon and Betty Moore Foundation, Istituto Nazionale di Fisica Nucleare, Japanese Government, Japan Society for the Promotion of Science, Chinese Academy of Sciences, Max Planck Society, Ministry of Science and Technology (Taiwan), National Aeronautics and Space Administration (US), National Science Foundation (US), National Natural Science Foundation of China, Natural Sciences and Engineering Research Council of Canada, National Research Foundation of Korea, Netherlands Organization for Scientific Research, National Research Foundation (South Africa), Russian Science Foundation, Ministero dell'Istruzione, dell'Università e della Ricerca, Alberdi, Antxón, Gómez Fernández, J. L., Alberdi, Antxón [0000-0002-9371-1033], Gómez Fernández, J. L. [0000-0003-4190-7613], Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Anne Lähteenmäki Group, Department of Electronics and Nanoengineering, Aalto-yliopisto, Aalto University, Astronomy, High Energy Astrophys. & Astropart. Phys (API, FNWI), and Gravitation and Astroparticle Physics Amsterdam

Subjects
010504 meteorology & atmospheric sciences, individual (M87) [galaxies], Event horizon, Astronomy, black hole physics, jets [galaxies], galaxies: individual, Astrophysics, high-resolution, 7. Clean energy, 01 natural sciences, Photon sphere, General Relativity and Quantum Cosmology, accretion, sagittarius-a-asterisk, 010303 astronomy & astrophysics, galactic-center, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, radio-sources, accretion disks, Galactic Center, grmhd simulations, 3. Good health, energy-distributions, active [galaxies], Anatomy, Astrophysics - High Energy Astrophysical Phenomena, Active galactic nucleus, Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), Astrophysics::Cosmology and Extragalactic Astrophysics, galaxies: individual: M87, galaxies: individual (M87), Cell and Developmental Biology, 0103 physical sciences, (M87), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Event Horizon Telescope, Supermassive black hole, ghz vlbi observations, faraday-rotation, Astronomy and Astrophysics, galaxies: jets, Astrophysics - Astrophysics of Galaxies, Black hole, Rotating black hole, Space and Planetary Science, gravitation, Astrophysics of Galaxies (astro-ph.GA), advection-dominated accretion, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], ionized-gas
Abstract

When surrounded by a transparent emission region, black holes are expected to reveal a dark shadow caused by gravitational light bending and photon capture at the event horizon. To image and study this phenomenon, we have assembled the Event Horizon Telescope, a global very long baseline interferometry array observing at a wavelength of 1.3 mm. This allows us to reconstruct event-horizon-scale images of the supermassive black hole candidate in the center of the giant elliptical galaxy M87. We have resolved the central compact radio source as an asymmetric bright emission ring with a diameter of 42 ± 3 μas, which is circular and encompasses a central depression in brightness with a flux ratio 10:1. The emission ring is recovered using different calibration and imaging schemes, with its diameter and width remaining stable over four different observations carried out in different days. Overall, the observed image is consistent with expectations for the shadow of a Kerr black hole as predicted by general relativity. The asymmetry in brightness in the ring can be explained in terms of relativistic beaming of the emission from a plasma rotating close to the speed of light around a black hole. We compare our images to an extensive library of ray-traced general-relativistic magnetohydrodynamic simulations of black holes and derive a central mass of M = (6.5 ± 0.7) × 109 Me. Our radiowave observations thus provide powerful evidence for the presence of supermassive black holes in centers of galaxies and as the central engines of active galactic nuclei. They also present a new tool to explore gravity in its most extreme limit and on a mass scale that was so far not accessible.© 2019. The American Astronomical Society, The authors of this Letter thank the following organizations and programs: the Academy of Finland (projects 274477, 284495, 312496); the Advanced European Network of E-infrastructures for Astronomy with the SKA (AENEAS) project, supported by the European Commission Framework Programme Horizon 2020 Research and Innovation action under grant agreement 731016; the Alexander von Humboldt Stiftung; the Black Hole Initiative at Harvard University, through a grant (60477) from the John Templeton Foundation; the China Scholarship Council; Comisión Nacional de Investigación Científica y Tecnológica (CONICYT, Chile, via PIA ACT172033, Fondecyt 1171506, BASAL AFB170002, ALMA-conicyt 31140007); Consejo Nacional de Ciencia y Tecnología (CONACYT, Mexico, projects 104497, 275201, 279006, 281692); the Delaney Family via the Delaney Family John A. Wheeler Chair at Perimeter Institute; Dirección General de Asuntos del Personal Académico-Universidad Nacional 9 The Astrophysical Journal Letters, 875:L1 (17pp), 2019 April 10 The EHT Collaboration et al. Autónoma de México (DGAPA-UNAM, project IN112417); the European Research Council (ERC) Synergy Grant “BlackHoleCam: Imaging the Event Horizon of Black Holes” (grant 610058); the Generalitat Valenciana postdoctoral grant APOSTD/2018/177; the Gordon and Betty Moore Foundation (grants GBMF-3561, GBMF-5278); the Istituto Nazionale di Fisica Nucleare (INFN) sezione di Napoli, iniziative specifiche TEONGRAV; the International Max Planck Research School for Astronomy and Astrophysics at the Universities of Bonn and Cologne; the Jansky Fellowship program of the National Radio Astronomy Observatory (NRAO); the Japanese Government (Monbukagakusho: MEXT) Scholarship; the Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for JSPS Research Fellowship (JP17J08829); JSPS Overseas Research Fellowships; the Key Research Program of Frontier Sciences, Chinese, Academy of Sciences (CAS, grants QYZDJ-SSW-SLH057, QYZDJ-SSW-SYS008); the Leverhulme Trust Early Career Research Fellowship; the Max-Planck-Gesellschaft (MPG); the Max Planck Partner Group of the MPG and the CAS; the MEXT/JSPS KAKENHI (grants 18KK0090, JP18K13594, JP18K03656, JP18H03721, 18K03709, 18H01245, 25120007); the MIT International Science and Technology Initiatives (MISTI) Funds; the Ministry of Science and Technology (MOST) of Taiwan (105-2112-M-001-025-MY3, 106-2112-M001-011, 106-2119-M-001-027, 107-2119-M-001-017, 107- 2119-M-001-020, and 107-2119-M-110-005); the National Aeronautics and Space Administration (NASA, Fermi Guest Investigator grant 80NSSC17K0649); the National Institute of Natural Sciences (NINS) of Japan; the National Key Research and Development Program of China (grant 2016YFA0400704, 2016YFA0400702); the National Science Foundation (NSF, grants AST-0096454, AST-0352953, AST-0521233, AST0705062, AST-0905844, AST-0922984, AST-1126433, AST1140030, DGE-1144085, AST-1207704, AST-1207730, AST1207752, MRI-1228509, OPP-1248097, AST-1310896, AST1312651, AST-1337663, AST-1440254, AST-1555365, AST1715061, AST-1615796, AST-1614868, AST-1716327, OISE1743747, AST-1816420); the Natural Science Foundation of China (grants 11573051, 11633006, 11650110427, 10625314, 11721303, 11725312, 11873028, 11873073, U1531245, 11473010); the Natural Sciences and Engineering Research Council of Canada (NSERC, including a Discovery Grant and the NSERC Alexander Graham Bell Canada Graduate Scholarships-Doctoral Program); the National Youth Thousand Talents Program of China; the National Research Foundation of Korea (grant 2015-R1D1A1A01056807, the Global PhD Fellowship Grant: NRF-2015H1A2A1033752, and the Korea Research Fellowship Program: NRF-2015H1D3A1066561); the Netherlands Organization for Scientific Research (NWO) VICI award (grant 639.043.513) and Spinoza Prize (SPI 78-409); the New Scientific Frontiers with Precision, Radio Interferometry Fellowship awarded by the South African Radio Astronomy Observatory (SARAO), which is a facility of the National Research Foundation (NRF), an agency of the Department of Science and Technology (DST) of South Africa; the Onsala Space Observatory (OSO) national infrastructure, for the provisioning of its facilities/observational support (OSO receives funding through the Swedish Research Council under grant 2017-00648); the Perimeter Institute for Theoretical Physics (research at Perimeter Institute is supported by the Government of Canada through the Department of Innovation, Science and Economic Development Canada and by the Province of Ontario through the Ministry of Economic Development, Job Creation and Trade); the Russian Science Foundation (grant 17-12-01029); the Spanish Ministerio de Economía y Competitividad (grants AYA2015-63939-C2-1-P, AYA2016-80889-P); the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award for the Instituto de Astrofísica de Andalucía (SEV-2017-0709); the Toray Science Foundation; the US Department of Energy (USDOE) through the Los Alamos National Laboratory (operated by Triad National Security, LLC, for the National Nuclear Security Administration of the USDOE (Contract 89233218CNA000001)); the Italian Ministero dell’Istruzione Università e Ricerca through the grant Progetti Premiali 2012-iALMA (CUP C52I13000140001); the European Unionʼs Horizon 2020 research and innovation programme under grant agreement No 730562 RadioNet; ALMA North America Development Fund; Chandra TM6-17006X

Published
2019
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