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1. Revealing the intermediate-mass black hole at the heart of the dwarf galaxy NGC 404 with sub-parsec resolution ALMA observations

Author

Davis, TA, Davis, TA, Nguyen, DD, Seth, AC, Greene, JE, Nyland, K, Barth, AJ, Bureau, M, Cappellari, M, Den Brok, M, Iguchi, S, Lelli, F, Liu, L, Neumayer, N, North, EV, Onishi, K, Sarzi, M, Smith, MD, Williams, TG, Davis, TA, Davis, TA, Nguyen, DD, Seth, AC, Greene, JE, Nyland, K, Barth, AJ, Bureau, M, Cappellari, M, Den Brok, M, Iguchi, S, Lelli, F, Liu, L, Neumayer, N, North, EV, Onishi, K, Sarzi, M, Smith, MD, and Williams, TG

Abstract

We estimate the mass of the intermediate-mass black hole at the heart of the dwarf elliptical galaxy NGC 404 using Atacama Large Millimetre/submillimetre Array (ALMA) observations of the molecular interstellar medium at an unprecedented linear resolution of ≈0.5 pc, in combination with existing stellar kinematic information. These ALMA observations reveal a central disc/torus of molecular gas clearly rotating around the black hole. This disc is surrounded by a morphologically and kinematically complex flocculent distribution of molecular clouds, that we resolve in detail. Continuum emission is detected from the central parts of NGC 404, likely arising from the Rayleigh-Jeans tail of emission from dust around the nucleus, and potentially from dusty massive star-forming clumps at discrete locations in the disc. Several dynamical measurements of the black hole mass in this system have been made in the past, but they do not agree. We show here that both the observed molecular gas and stellar kinematics independently require a 5 × 105M black hole once we include the contribution of the molecular gas to the potential. Our best estimate comes from the high-resolution molecular gas kinematics, suggesting the black hole mass of this system is 5.5+-3.8 × 105M (at the 99 per cent confidence level), in good agreement with our revised stellar kinematic measurement and broadly consistent with extrapolations from the black hole mass-velocity dispersion and black hole mass-bulge mass relations. This highlights the need to accurately determine the mass and distribution of each dynamically important component around intermediate-mass black holes when attempting to estimate their masses.

Published
2020

2. Revealing the intermediate-mass black hole at the heart of the dwarf galaxy NGC 404 with sub-parsec resolution ALMA observations

Author

Davis, TA, Davis, TA, Nguyen, DD, Seth, AC, Greene, JE, Nyland, K, Barth, AJ, Bureau, M, Cappellari, M, Den Brok, M, Iguchi, S, Lelli, F, Liu, L, Neumayer, N, North, EV, Onishi, K, Sarzi, M, Smith, MD, Williams, TG, Davis, TA, Davis, TA, Nguyen, DD, Seth, AC, Greene, JE, Nyland, K, Barth, AJ, Bureau, M, Cappellari, M, Den Brok, M, Iguchi, S, Lelli, F, Liu, L, Neumayer, N, North, EV, Onishi, K, Sarzi, M, Smith, MD, and Williams, TG

Abstract

We estimate the mass of the intermediate-mass black hole at the heart of the dwarf elliptical galaxy NGC 404 using Atacama Large Millimetre/submillimetre Array (ALMA) observations of the molecular interstellar medium at an unprecedented linear resolution of ≈0.5 pc, in combination with existing stellar kinematic information. These ALMA observations reveal a central disc/torus of molecular gas clearly rotating around the black hole. This disc is surrounded by a morphologically and kinematically complex flocculent distribution of molecular clouds, that we resolve in detail. Continuum emission is detected from the central parts of NGC 404, likely arising from the Rayleigh-Jeans tail of emission from dust around the nucleus, and potentially from dusty massive star-forming clumps at discrete locations in the disc. Several dynamical measurements of the black hole mass in this system have been made in the past, but they do not agree. We show here that both the observed molecular gas and stellar kinematics independently require a 5 × 105M black hole once we include the contribution of the molecular gas to the potential. Our best estimate comes from the high-resolution molecular gas kinematics, suggesting the black hole mass of this system is 5.5+-3.8 × 105M (at the 99 per cent confidence level), in good agreement with our revised stellar kinematic measurement and broadly consistent with extrapolations from the black hole mass-velocity dispersion and black hole mass-bulge mass relations. This highlights the need to accurately determine the mass and distribution of each dynamically important component around intermediate-mass black holes when attempting to estimate their masses.

Published
2020

3. WISDOM Project - I: Black Hole Mass Measurement Using Molecular Gas Kinematics in NGC 3665

Author

Onishi, K., Iguchi, S., Davis, T. A., Bureau, M., Cappellari, M., Sarzi, M., Blitz, L., Onishi, K., Iguchi, S., Davis, T. A., Bureau, M., Cappellari, M., Sarzi, M., and Blitz, L.

Abstract

As a part of the mm-Wave Interferometric Survey of Dark Object Masses (WISDOM) project, we present an estimate of the mass of the supermassive black hole (SMBH) in the nearby fast-rotator early-type galaxy NGC 3665. We obtained Combined Array for Research in Millimeter Astronomy (CARMA) B and C array observations of the $^{12}$CO$(J=2-1)$ emission line with a combined angular resolution of $0".59$. We analysed and modelled the three-dimensional molecular gas kinematics, obtaining a best-fit SMBH mass $M_{\rm BH}=5.75^{+1.49}_{-1.18} \times 10^{8}$ $M_{\odot}$, a mass-to-light ratio at $H$-band $(M/L)_{H}=1.45\pm0.04$ $(M/L)_{\odot, H}$, and other parameters describing the geometry of the molecular gas disc (statistical errors, all at $3\sigma$ confidence). We estimate the systematic uncertainties on the stellar $M/L$ to be $\approx0.2$ $(M/L)_{\odot, H}$, and on the SMBH mass to be $\approx0.4\times10^{8}$ $M_{\odot}$. The measured SMBH mass is consistent with that estimated from the latest correlations with galaxy properties. Following our older works, we also analysed and modelled the kinematics using only the major-axis position-velocity diagram, and conclude that the two methods are consistent., Comment: Accepted to MNRAS

Published
2017
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4. WISDOM Project - I: Black Hole Mass Measurement Using Molecular Gas Kinematics in NGC 3665

Author

Onishi, K., Iguchi, S., Davis, T. A., Bureau, M., Cappellari, M., Sarzi, M., Blitz, L., Onishi, K., Iguchi, S., Davis, T. A., Bureau, M., Cappellari, M., Sarzi, M., and Blitz, L.

Abstract

As a part of the mm-Wave Interferometric Survey of Dark Object Masses (WISDOM) project, we present an estimate of the mass of the supermassive black hole (SMBH) in the nearby fast-rotator early-type galaxy NGC 3665. We obtained Combined Array for Research in Millimeter Astronomy (CARMA) B and C array observations of the $^{12}$CO$(J=2-1)$ emission line with a combined angular resolution of $0".59$. We analysed and modelled the three-dimensional molecular gas kinematics, obtaining a best-fit SMBH mass $M_{\rm BH}=5.75^{+1.49}_{-1.18} \times 10^{8}$ $M_{\odot}$, a mass-to-light ratio at $H$-band $(M/L)_{H}=1.45\pm0.04$ $(M/L)_{\odot, H}$, and other parameters describing the geometry of the molecular gas disc (statistical errors, all at $3\sigma$ confidence). We estimate the systematic uncertainties on the stellar $M/L$ to be $\approx0.2$ $(M/L)_{\odot, H}$, and on the SMBH mass to be $\approx0.4\times10^{8}$ $M_{\odot}$. The measured SMBH mass is consistent with that estimated from the latest correlations with galaxy properties. Following our older works, we also analysed and modelled the kinematics using only the major-axis position-velocity diagram, and conclude that the two methods are consistent., Comment: Accepted to MNRAS

Published
2017
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5. 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., Wood, S. J., 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.

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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6. 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

7. 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

8. 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., Wood, S. J., 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.

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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9. Giant Molecular Clouds and Star Formation in the Tidal Molecular Arm of NGC 4039

Author

Espada, D., Komugi, S., Muller, E., Nakanishi, K., Saito, M., Tatematsu, K., Iguchi, S., Hasegawa, T., Mizuno, N., Iono, D., Matsushita, S., Trejo, A., Chapillon, E., Takahashi, S., Su, Y. N., Kawamura, A., Akiyama, E., Hiramatsu, M., Nagai, H., Miura, R. E., Kurono, Y., Sawada, T., Higuchi, A. E., Tachihara, K., Saigo, K., Kamazaki, T., Espada, D., Komugi, S., Muller, E., Nakanishi, K., Saito, M., Tatematsu, K., Iguchi, S., Hasegawa, T., Mizuno, N., Iono, D., Matsushita, S., Trejo, A., Chapillon, E., Takahashi, S., Su, Y. N., Kawamura, A., Akiyama, E., Hiramatsu, M., Nagai, H., Miura, R. E., Kurono, Y., Sawada, T., Higuchi, A. E., Tachihara, K., Saigo, K., and Kamazaki, T.

Abstract

The properties of tidally induced arms provide a means to study molecular cloud formation and the subsequent star formation under environmental conditions which in principle are different from quasi stationary spiral arms. We report the properties of a newly discovered molecular gas arm of likely tidal origin at the south of NGC 4039 and the overlap region in the Antennae galaxies, with a resolution of 1"68 x 0"85, using the Atacama Large Millimeter/submillimeter Array science verification CO(2-1) data. The arm extends 3.4 kpc (34") and is characterized by widths of ~ 200 pc (2") and velocity widths of typically \DeltaV ~ 10-20 km/s . About 10 clumps are strung out along this structure, most of them unresolved, with average surface densities of \Sigma_gas ~ 10-100 Msun pc^{-2}, and masses of (1-8) x 10^6 Msun. These structures resemble the morphology of beads on a string, with an almost equidistant separation between the beads of about 350 pc, which may represent a characteristic separation scale for giant molecular associations. We find that the star formation efficiency at a resolution of 6" (600 pc) is in general a factor of 10 higher than in disk galaxies and other tidal arms and bridges. This arm is linked, based on the distribution and kinematics, to the base of the western spiral arm of NGC 4039, but its morphology is different to that predicted by high-resolution simulations of the Antennae galaxies., Comment: Accepted in ApJL, 8 pages, 5 figures

Published
2012
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10. The parsec-scale jet of PKS 1749+096

Author

Lu, R. -S., Shen, Z. -Q., Krichbaum, T. P., Iguchi, S., Lee, S. -S., Zensus, J. A., Lu, R. -S., Shen, Z. -Q., Krichbaum, T. P., Iguchi, S., Lee, S. -S., and Zensus, J. A.

Abstract

PKS 1749+096 is a BL Lac object showing weak extended jet emission to the northeast of the compact VLBI core on parsec scales. We aim at better understanding the jet kinematics and variability of this source and finding clues that may applicable to other BL Lac objects. The jet was studied with multi-epoch multi-frequency high-resolution VLBI observations. The jet is characterized by a one-sided curved morphology at all epochs and all frequencies. The VLBI core, located at the southern end of the jet, was identified based on its spectral properties. The equipartition magnetic field of the core was investigated, through which we derived a Doppler factor of 5, largely consistent with that derived from kinematics (component C5). The study of the detailed jet kinematics at 22 and 15 GHz, spanning a period of more than 10 years, indicates the possible existence of a bimodal distribution of the jet apparent speed. Ballistic and non-ballistic components are found to coexist in the jet. Superluminal motions in the range of 5-21 c were measured in 11 distinct components. We estimated the physical jet parameters with the minimum Lorentz factor of 10.2 and Doppler factors in the range of 10.2-20.4 (component C5). The coincidence in time of the component's ejection and flares supports the idea that, at least in PKS 1749+096, ejection of new jet components is connected with major outbursts in flux density. For the best-traced component (C5) we found that the flux density decays rapidly as it travels downstream the jet, accompanied by a steepening of its spectra, which argues in favor of a contribution of inverse Compton cooling. These properties make PKS 1749+096 a suitable target for an intensive monitoring to decipher the variability phenomenon of BL Lac objects., Comment: Replaced to match published version

Published
2012
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11. Giant Molecular Clouds and Star Formation in the Tidal Molecular Arm of NGC 4039

Author

Espada, D., Komugi, S., Muller, E., Nakanishi, K., Saito, M., Tatematsu, K., Iguchi, S., Hasegawa, T., Mizuno, N., Iono, D., Matsushita, S., Trejo, A., Chapillon, E., Takahashi, S., Su, Y. N., Kawamura, A., Akiyama, E., Hiramatsu, M., Nagai, H., Miura, R. E., Kurono, Y., Sawada, T., Higuchi, A. E., Tachihara, K., Saigo, K., Kamazaki, T., Espada, D., Komugi, S., Muller, E., Nakanishi, K., Saito, M., Tatematsu, K., Iguchi, S., Hasegawa, T., Mizuno, N., Iono, D., Matsushita, S., Trejo, A., Chapillon, E., Takahashi, S., Su, Y. N., Kawamura, A., Akiyama, E., Hiramatsu, M., Nagai, H., Miura, R. E., Kurono, Y., Sawada, T., Higuchi, A. E., Tachihara, K., Saigo, K., and Kamazaki, T.

Abstract

The properties of tidally induced arms provide a means to study molecular cloud formation and the subsequent star formation under environmental conditions which in principle are different from quasi stationary spiral arms. We report the properties of a newly discovered molecular gas arm of likely tidal origin at the south of NGC 4039 and the overlap region in the Antennae galaxies, with a resolution of 1"68 x 0"85, using the Atacama Large Millimeter/submillimeter Array science verification CO(2-1) data. The arm extends 3.4 kpc (34") and is characterized by widths of ~ 200 pc (2") and velocity widths of typically \DeltaV ~ 10-20 km/s . About 10 clumps are strung out along this structure, most of them unresolved, with average surface densities of \Sigma_gas ~ 10-100 Msun pc^{-2}, and masses of (1-8) x 10^6 Msun. These structures resemble the morphology of beads on a string, with an almost equidistant separation between the beads of about 350 pc, which may represent a characteristic separation scale for giant molecular associations. We find that the star formation efficiency at a resolution of 6" (600 pc) is in general a factor of 10 higher than in disk galaxies and other tidal arms and bridges. This arm is linked, based on the distribution and kinematics, to the base of the western spiral arm of NGC 4039, but its morphology is different to that predicted by high-resolution simulations of the Antennae galaxies., Comment: Accepted in ApJL, 8 pages, 5 figures

Published
2012
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12. The parsec-scale jet of PKS 1749+096

Author

Lu, R. -S., Shen, Z. -Q., Krichbaum, T. P., Iguchi, S., Lee, S. -S., Zensus, J. A., Lu, R. -S., Shen, Z. -Q., Krichbaum, T. P., Iguchi, S., Lee, S. -S., and Zensus, J. A.

Abstract

PKS 1749+096 is a BL Lac object showing weak extended jet emission to the northeast of the compact VLBI core on parsec scales. We aim at better understanding the jet kinematics and variability of this source and finding clues that may applicable to other BL Lac objects. The jet was studied with multi-epoch multi-frequency high-resolution VLBI observations. The jet is characterized by a one-sided curved morphology at all epochs and all frequencies. The VLBI core, located at the southern end of the jet, was identified based on its spectral properties. The equipartition magnetic field of the core was investigated, through which we derived a Doppler factor of 5, largely consistent with that derived from kinematics (component C5). The study of the detailed jet kinematics at 22 and 15 GHz, spanning a period of more than 10 years, indicates the possible existence of a bimodal distribution of the jet apparent speed. Ballistic and non-ballistic components are found to coexist in the jet. Superluminal motions in the range of 5-21 c were measured in 11 distinct components. We estimated the physical jet parameters with the minimum Lorentz factor of 10.2 and Doppler factors in the range of 10.2-20.4 (component C5). The coincidence in time of the component's ejection and flares supports the idea that, at least in PKS 1749+096, ejection of new jet components is connected with major outbursts in flux density. For the best-traced component (C5) we found that the flux density decays rapidly as it travels downstream the jet, accompanied by a steepening of its spectra, which argues in favor of a contribution of inverse Compton cooling. These properties make PKS 1749+096 a suitable target for an intensive monitoring to decipher the variability phenomenon of BL Lac objects., Comment: Replaced to match published version

Published
2012
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13. Digital Spectro-Correlator System for the Atacama Compact Array of the Atacama Large Millimeter/submillimeter Array

Author

Kamazaki, T., Okumura, S. K., Chikada, Y., Okuda, T., Kurono, Y., Iguchi, S., Mitsuishi, S., Murakami, Y., Nishimuta, N., Mita, H., Sano, R., Kamazaki, T., Okumura, S. K., Chikada, Y., Okuda, T., Kurono, Y., Iguchi, S., Mitsuishi, S., Murakami, Y., Nishimuta, N., Mita, H., and Sano, R.

Abstract

We have developed an FX-architecture digital spectro-correlator for the Atacama Compact Array (ACA) of the Atacama Large Millimeter/submillimeter Array. The correlator is able to simultaneously process four pairs of dual polarization signals with the bandwidth of 2 GHz, which are received by up to sixteen antennas. It can calculate auto- and cross-correlation spectra including cross-polarization in all combinations of all the antennas, and output correlation spectra with flexible spectral configuration such as multiple frequency ranges and multiple frequency resolutions. Its spectral dynamic range is estimated to be higher than 10^4 relative to Tsys from processing results of thermal noise for eight hours with a typical correlator configuration. The sensitivity loss is also confirmed to be 0.9 % with the same configuration. In this paper, we report the detailed design of the correlator and the verification results of the developed hardware., Comment: To be published in PASJ, 64

Published
2011
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14. Digital Spectro-Correlator System for the Atacama Compact Array of the Atacama Large Millimeter/submillimeter Array

Author

Kamazaki, T., Okumura, S. K., Chikada, Y., Okuda, T., Kurono, Y., Iguchi, S., Mitsuishi, S., Murakami, Y., Nishimuta, N., Mita, H., Sano, R., Kamazaki, T., Okumura, S. K., Chikada, Y., Okuda, T., Kurono, Y., Iguchi, S., Mitsuishi, S., Murakami, Y., Nishimuta, N., Mita, H., and Sano, R.

Abstract

We have developed an FX-architecture digital spectro-correlator for the Atacama Compact Array (ACA) of the Atacama Large Millimeter/submillimeter Array. The correlator is able to simultaneously process four pairs of dual polarization signals with the bandwidth of 2 GHz, which are received by up to sixteen antennas. It can calculate auto- and cross-correlation spectra including cross-polarization in all combinations of all the antennas, and output correlation spectra with flexible spectral configuration such as multiple frequency ranges and multiple frequency resolutions. Its spectral dynamic range is estimated to be higher than 10^4 relative to Tsys from processing results of thermal noise for eight hours with a typical correlator configuration. The sensitivity loss is also confirmed to be 0.9 % with the same configuration. In this paper, we report the detailed design of the correlator and the verification results of the developed hardware., Comment: To be published in PASJ, 64

Published
2011
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15. Portable intelligent drilling machine for visualising roof-rock geostructure.

Author

Itakura K., Rockbolting in mining and injection technology and roadway support systems Aachen, Germany 14-15 May 2008, Goto T., Ichihara Y., Iguchi S., Mastalir P., Tomita S., Yoshida Y., Itakura K., Rockbolting in mining and injection technology and roadway support systems Aachen, Germany 14-15 May 2008, Goto T., Ichihara Y., Iguchi S., Mastalir P., Tomita S., and Yoshida Y.

Abstract

A logging system is described which displays changes in strata and crack distributions in a roof-rock structure. The system is used to aid in preventing rock falls, for roof and cable bolting, and to provide information about the rock along the roadway of underground coal mines. Four sensors are attached to a portable pneumatic drilling machine to obtain mechanical data including torque, thrust, revolution and stroke. The sensor data are recorded on a USB memory, with sampling time of 10 or 100 ms, after passing through the amplifier and barrier circuit. Feasibility studies were carried out at the Gujarat mine in Australia, in which 48 holes for roof bolts were drilled along the roadway and the geostructure along the roadway displayed three-dimensionally on a personal computer., A logging system is described which displays changes in strata and crack distributions in a roof-rock structure. The system is used to aid in preventing rock falls, for roof and cable bolting, and to provide information about the rock along the roadway of underground coal mines. Four sensors are attached to a portable pneumatic drilling machine to obtain mechanical data including torque, thrust, revolution and stroke. The sensor data are recorded on a USB memory, with sampling time of 10 or 100 ms, after passing through the amplifier and barrier circuit. Feasibility studies were carried out at the Gujarat mine in Australia, in which 48 holes for roof bolts were drilled along the roadway and the geostructure along the roadway displayed three-dimensionally on a personal computer.

Published
2008

16. Performance Measurements of 8-Gsps 1-bit ADCs Developed for Wideband Radio Astronomical Observations

Author

Okuda, T., Iguchi, S., Okuda, T., and Iguchi, S.

Abstract

8-Gsps 1-bit Analog-to-Digital Converters (ADCs) were newly developed toward the realization of the wideband observation. The development of the wideband ADCs is one of the most essential developments for the radio interferometer. To evaluate its performance in interferometric observations, the time (phase) stability and frequency response were measured with a noise source and a signal generator. The results of these measurements show that the developed ADCs can achieve the jitter time less than 0.05 psec at the time interval of 1 sec, the passband frequency response with the slope less than 0.73 dB/GHz and the ripple less than 1.8 dB, and the aperture time less than 20 psec. The details of the developed ADC design, the measurement methods, and the results of these measurements are presented in this paper., Comment: Accepted for publication in PASJ. 19 pages, 15 figures

Published
2008
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17. Performance Measurements of 8-Gsps 1-bit ADCs Developed for Wideband Radio Astronomical Observations

Author

Okuda, T., Iguchi, S., Okuda, T., and Iguchi, S.

Abstract

8-Gsps 1-bit Analog-to-Digital Converters (ADCs) were newly developed toward the realization of the wideband observation. The development of the wideband ADCs is one of the most essential developments for the radio interferometer. To evaluate its performance in interferometric observations, the time (phase) stability and frequency response were measured with a noise source and a signal generator. The results of these measurements show that the developed ADCs can achieve the jitter time less than 0.05 psec at the time interval of 1 sec, the passband frequency response with the slope less than 0.73 dB/GHz and the ripple less than 1.8 dB, and the aperture time less than 20 psec. The details of the developed ADC design, the measurement methods, and the results of these measurements are presented in this paper., Comment: Accepted for publication in PASJ. 19 pages, 15 figures

Published
2008
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18. Performance Measurements of 8-Gsps 1-bit ADCs Developed for Wideband Radio Astronomical Observations

Author

Okuda, T., Iguchi, S., Okuda, T., and Iguchi, S.

Abstract

8-Gsps 1-bit Analog-to-Digital Converters (ADCs) were newly developed toward the realization of the wideband observation. The development of the wideband ADCs is one of the most essential developments for the radio interferometer. To evaluate its performance in interferometric observations, the time (phase) stability and frequency response were measured with a noise source and a signal generator. The results of these measurements show that the developed ADCs can achieve the jitter time less than 0.05 psec at the time interval of 1 sec, the passband frequency response with the slope less than 0.73 dB/GHz and the ripple less than 1.8 dB, and the aperture time less than 20 psec. The details of the developed ADC design, the measurement methods, and the results of these measurements are presented in this paper., Comment: Accepted for publication in PASJ. 19 pages, 15 figures

Published
2008
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19. Multi-epoch VLBA observations of 3C 66A

Author

Cai, H. -B., Shen, Z. -Q., Sudou, H., Shang, L. -L., Iguchi, S., Murata, Y., Taniguchi, Y., Wakamatsu, K., Takaba, H., Cai, H. -B., Shen, Z. -Q., Sudou, H., Shang, L. -L., Iguchi, S., Murata, Y., Taniguchi, Y., Wakamatsu, K., and Takaba, H.

Abstract

We present the results of six-epoch Very Long Baseline Array (VLBA) observations of 3C~66A. The high-resolution Very Long Baseline Interferometer (VLBI) maps obtained at multi-frequency (2.3, 8.4, and 22.2 GHz) simultaneously enabled us to identify the brightest compact component with the core. We find that the spectrum of the core can be reasonably fitted by the synchrotron self-absorption model. Our VLBA maps show that the jet of 3C~66A has two bendings at about 1.2 and 4 mas from the core. We also give possible identifications of our jet components with the components in previous VLBA observations by analysing their proper motions. We find consistent differences of the position from the core in one component between different frequencies at six epochs., Comment: 10 pages, 5 figures, received 30 January 2007, accepted 22 March 2007

Published
2007
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20. Multi-epoch VLBA observations of 3C 66A

Author

Cai, H. -B., Shen, Z. -Q., Sudou, H., Shang, L. -L., Iguchi, S., Murata, Y., Taniguchi, Y., Wakamatsu, K., Takaba, H., Cai, H. -B., Shen, Z. -Q., Sudou, H., Shang, L. -L., Iguchi, S., Murata, Y., Taniguchi, Y., Wakamatsu, K., and Takaba, H.

Abstract

We present the results of six-epoch Very Long Baseline Array (VLBA) observations of 3C~66A. The high-resolution Very Long Baseline Interferometer (VLBI) maps obtained at multi-frequency (2.3, 8.4, and 22.2 GHz) simultaneously enabled us to identify the brightest compact component with the core. We find that the spectrum of the core can be reasonably fitted by the synchrotron self-absorption model. Our VLBA maps show that the jet of 3C~66A has two bendings at about 1.2 and 4 mas from the core. We also give possible identifications of our jet components with the components in previous VLBA observations by analysing their proper motions. We find consistent differences of the position from the core in one component between different frequencies at six epochs., Comment: 10 pages, 5 figures, received 30 January 2007, accepted 22 March 2007

Published
2007
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21. Multi-epoch VLBA observations of 3C 66A

Author

Cai, H. -B., Shen, Z. -Q., Sudou, H., Shang, L. -L., Iguchi, S., Murata, Y., Taniguchi, Y., Wakamatsu, K., Takaba, H., Cai, H. -B., Shen, Z. -Q., Sudou, H., Shang, L. -L., Iguchi, S., Murata, Y., Taniguchi, Y., Wakamatsu, K., and Takaba, H.

Abstract

We present the results of six-epoch Very Long Baseline Array (VLBA) observations of 3C~66A. The high-resolution Very Long Baseline Interferometer (VLBI) maps obtained at multi-frequency (2.3, 8.4, and 22.2 GHz) simultaneously enabled us to identify the brightest compact component with the core. We find that the spectrum of the core can be reasonably fitted by the synchrotron self-absorption model. Our VLBA maps show that the jet of 3C~66A has two bendings at about 1.2 and 4 mas from the core. We also give possible identifications of our jet components with the components in previous VLBA observations by analysing their proper motions. We find consistent differences of the position from the core in one component between different frequencies at six epochs., Comment: 10 pages, 5 figures, received 30 January 2007, accepted 22 March 2007

Published
2007
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22. Orbital Motion in the Radio Galaxy 3C 66B: Evidence for a Supermassive Black Hole Binary

Author

Sudou, H., Iguchi, S., Murata, Y., Taniguchi, Y., Sudou, H., Iguchi, S., Murata, Y., and Taniguchi, Y.

Abstract

Supermassive black hole binaries may exist in the centers of active galactic nuclei like quasars and radio galaxies and mergers between galaxies may result in the formation of supermassive binaries during the course of galactic evolution. Using the very-long-baseline interferometer, we imaged the radio galaxy 3C 66B at radio frequencies and found that the unresolved radio core of 3C 66B shows well-defined elliptical motions with a period of 1.05 +/- 0.03 years, which provides a direct detection of a supermassive black hole binary., Comment: 8 pages, 3 figures, to appear in the Science

Published
2003
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23. Orbital Motion in the Radio Galaxy 3C 66B: Evidence for a Supermassive Black Hole Binary

Author

Sudou, H., Iguchi, S., Murata, Y., Taniguchi, Y., Sudou, H., Iguchi, S., Murata, Y., and Taniguchi, Y.

Abstract

Supermassive black hole binaries may exist in the centers of active galactic nuclei like quasars and radio galaxies and mergers between galaxies may result in the formation of supermassive binaries during the course of galactic evolution. Using the very-long-baseline interferometer, we imaged the radio galaxy 3C 66B at radio frequencies and found that the unresolved radio core of 3C 66B shows well-defined elliptical motions with a period of 1.05 +/- 0.03 years, which provides a direct detection of a supermassive black hole binary., Comment: 8 pages, 3 figures, to appear in the Science

Published
2003
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24. Pair Plasma Dominance in the Parsec-Scale Relativistic Jet of 3C345

Author

Hirotani, K., Iguchi, S., Kimura, M., Wajima, K., Hirotani, K., Iguchi, S., Kimura, M., and Wajima, K.

Abstract

We investigate whether a pc-scale jet of 3C345 is dominated by a normal plasma or an electron-positron plasma. We present a general condition that a jet component becomes optically thick for synchrotron self-absorption, by extending the method originally developed by Reynolds et al. The general condition gives a lower limit of the electron number density, with the aid of the surface brightness condition, which enables us to compute the magnetic field density. Comparing the lower limit with another independent constraint for the electron density that is deduced from the kinetic luminosity, we can distinguish the matter content. We apply the procedure to the five components of 3C345 (C2, C3, C4, C5, and C7) of which angular diameters and radio fluxes at the peak frequencies were obtainable from literature. Evaluating the representative values of Doppler beaming factors by their equipartition values, we find that all the five components are likely dominated by an electron-positron plasma. The conclusion does not depend on the lower cutoff energy of the power-law distribution of radiating particles., Comment: 17 pages

Published
2000
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25. Pair Plasma Dominance in the Parsec-Scale Relativistic Jet of 3C345

Author

Hirotani, K., Iguchi, S., Kimura, M., Wajima, K., Hirotani, K., Iguchi, S., Kimura, M., and Wajima, K.

Abstract

We investigate whether a pc-scale jet of 3C345 is dominated by a normal plasma or an electron-positron plasma. We present a general condition that a jet component becomes optically thick for synchrotron self-absorption, by extending the method originally developed by Reynolds et al. The general condition gives a lower limit of the electron number density, with the aid of the surface brightness condition, which enables us to compute the magnetic field density. Comparing the lower limit with another independent constraint for the electron density that is deduced from the kinetic luminosity, we can distinguish the matter content. We apply the procedure to the five components of 3C345 (C2, C3, C4, C5, and C7) of which angular diameters and radio fluxes at the peak frequencies were obtainable from literature. Evaluating the representative values of Doppler beaming factors by their equipartition values, we find that all the five components are likely dominated by an electron-positron plasma. The conclusion does not depend on the lower cutoff energy of the power-law distribution of radiating particles., Comment: 17 pages

Published
2000
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26. Development of Short-Distance Optical Transmission Cord

Author

SUMITOMO ELECTRIC INDUSTRIES LTD YOKOHAMA (JAPAN), Yuto,M., Hayashi,Y., Mukunashi,H., Iguchi,S., SUMITOMO ELECTRIC INDUSTRIES LTD YOKOHAMA (JAPAN), Yuto,M., Hayashi,Y., Mukunashi,H., and Iguchi,S.

Abstract

Two types of optical fiber cords designed for short-distance optical transmission are described. One of them uses plastic fiber as its core material. Its thermal resistance, solvent resistance, and mechanical properties are improved by coating it with a special resin sheathing. The other type is an improved version of the plastic clad silica fiber, in which the protrusion of the core at the ends of the cord has been minimized by selecting the optimal cladding material. Either type is characterized by its large core diameter and high numerical aperture. The ease with which cord ends, including connector attachments can be treated affords them broad applicability as short-distance optical links. (Author), This article is from 'Proceedings of the International Wire and Cable Symposium (32nd) Held at Cherry Hill, New Jersey on November 15, 16 and 17, 1983', AD-A136 749, p422-428.

Published
1983

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