1.3 mm wavelength VLBI of sagittarius A*: Detection of time-variable emission on event horizon scales

Vincent L. Fish; Sheperd S. Doeleman; Christopher Beaudoin; Ray Blundell; David E. Bolin; Geoffrey C. Bower; Richard Chamberlin; Robert Freund; Per Friberg; Mark A. Gurwell; Mareki Honma; Makoto Inoue; Thomas P. Krichbaum; James Lamb; Daniel P. Marrone; James M. Moran; Tomoaki Oyama; Richard Plambeck; Rurik Primiani; Alan E.E. Rogers; Daniel L. Smythe; Jason Soohoo; Peter Strittmatter; Remo P.J. Tilanus; Michael Titus; Jonathan Weintroub; Melvyn Wright; David Woody; Ken H. Young; Lucy M. Ziurys

doi:10.1088/2041-8205/727/2/L36

1.3 mm wavelength VLBI of sagittarius A^*: Detection of time-variable emission on event horizon scales

Vincent L. Fish, Sheperd S. Doeleman, Christopher Beaudoin, Ray Blundell, David E. Bolin, Geoffrey C. Bower, Richard Chamberlin, Robert Freund, Per Friberg, Mark A. Gurwell, Mareki Honma, Makoto Inoue, Thomas P. Krichbaum, James Lamb, Daniel P. Marrone, James M. Moran, Tomoaki Oyama, Richard Plambeck, Rurik Primiani, Alan E.E. RogersDaniel L. Smythe, Jason Soohoo, Peter Strittmatter, Remo P.J. Tilanus, Michael Titus, Jonathan Weintroub, Melvyn Wright, David Woody, Ken H. Young, Lucy M. Ziurys

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176 Scopus citations

Abstract

Sagittarius A^*, the ∼4 × 10⁶ M _⊙ black hole candidate at the Galactic center, can be studied on Schwarzschild radius scales with (sub)millimeter wavelength very long baseline interferometry (VLBI). We report on 1.3 mm wavelength observations of Sgr A ^* using a VLBI array consisting of the JCMT on Mauna Kea, the Arizona Radio Observatory's Submillimeter Telescope on Mt. Graham in Arizona, and two telescopes of the CARMA array at Cedar Flat in California. Both Sgr A^* and the quasar calibrator 1924-292 were observed over three consecutive nights, and both sources were clearly detected on all baselines. For the first time, we are able to extract 1.3 mm VLBI interferometer phase information on Sgr A^* through measurement of closure phase on the triangle of baselines. On the third night of observing, the correlated flux density of Sgr A^* on all VLBI baselines increased relative to the first two nights, providing strong evidence for time-variable change on scales of a few Schwarzschild radii. These results suggest that future VLBI observations with greater sensitivity and additional baselines will play a valuable role in determining the structure of emission near the event horizon of Sgr A^*.

Original language	English (US)
Journal	Astrophysical Journal Letters
Volume	727
Issue number	2 PART II
DOIs	https://doi.org/10.1088/2041-8205/727/2/L36
State	Published - Feb 1 2011

Keywords

Galaxy: center
Submillimeter: general
Techniques: high angular resolution
Techniques: interferometric

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

Access to Document

10.1088/2041-8205/727/2/L36

Cite this

Fish, V. L., Doeleman, S. S., Beaudoin, C., Blundell, R., Bolin, D. E., Bower, G. C., Chamberlin, R., Freund, R., Friberg, P., Gurwell, M. A., Honma, M., Inoue, M., Krichbaum, T. P., Lamb, J., Marrone, D. P., Moran, J. M., Oyama, T., Plambeck, R., Primiani, R., ... Ziurys, L. M. (2011). 1.3 mm wavelength VLBI of sagittarius A^*: Detection of time-variable emission on event horizon scales. Astrophysical Journal Letters, 727(2 PART II). https://doi.org/10.1088/2041-8205/727/2/L36

Fish, VL, Doeleman, SS, Beaudoin, C, Blundell, R, Bolin, DE, Bower, GC, Chamberlin, R, Freund, R, Friberg, P, Gurwell, MA, Honma, M, Inoue, M, Krichbaum, TP, Lamb, J, Marrone, DP, Moran, JM, Oyama, T, Plambeck, R, Primiani, R, Rogers, AEE, Smythe, DL, Soohoo, J, Strittmatter, P , Tilanus, RPJ, Titus, M, Weintroub, J, Wright, M, Woody, D, Young, KH & Ziurys, LM 2011, '1.3 mm wavelength VLBI of sagittarius A^*: Detection of time-variable emission on event horizon scales', Astrophysical Journal Letters, vol. 727, no. 2 PART II. https://doi.org/10.1088/2041-8205/727/2/L36

@article{abaf875590e94438afc9a526fa33745e,

title = "1.3 mm wavelength VLBI of sagittarius A*: Detection of time-variable emission on event horizon scales",

abstract = "Sagittarius A*, the ∼4 × 106 M ⊙ black hole candidate at the Galactic center, can be studied on Schwarzschild radius scales with (sub)millimeter wavelength very long baseline interferometry (VLBI). We report on 1.3 mm wavelength observations of Sgr A * using a VLBI array consisting of the JCMT on Mauna Kea, the Arizona Radio Observatory's Submillimeter Telescope on Mt. Graham in Arizona, and two telescopes of the CARMA array at Cedar Flat in California. Both Sgr A* and the quasar calibrator 1924-292 were observed over three consecutive nights, and both sources were clearly detected on all baselines. For the first time, we are able to extract 1.3 mm VLBI interferometer phase information on Sgr A* through measurement of closure phase on the triangle of baselines. On the third night of observing, the correlated flux density of Sgr A* on all VLBI baselines increased relative to the first two nights, providing strong evidence for time-variable change on scales of a few Schwarzschild radii. These results suggest that future VLBI observations with greater sensitivity and additional baselines will play a valuable role in determining the structure of emission near the event horizon of Sgr A*.",

keywords = "Galaxy: center, Submillimeter: general, Techniques: high angular resolution, Techniques: interferometric",

author = "Fish, {Vincent L.} and Doeleman, {Sheperd S.} and Christopher Beaudoin and Ray Blundell and Bolin, {David E.} and Bower, {Geoffrey C.} and Richard Chamberlin and Robert Freund and Per Friberg and Gurwell, {Mark A.} and Mareki Honma and Makoto Inoue and Krichbaum, {Thomas P.} and James Lamb and Marrone, {Daniel P.} and Moran, {James M.} and Tomoaki Oyama and Richard Plambeck and Rurik Primiani and Rogers, {Alan E.E.} and Smythe, {Daniel L.} and Jason Soohoo and Peter Strittmatter and Tilanus, {Remo P.J.} and Michael Titus and Jonathan Weintroub and Melvyn Wright and David Woody and Young, {Ken H.} and Ziurys, {Lucy M.}",

note = "Funding Information: High-frequency VLBI work at MIT Haystack Observatory is supported by grants from the National Science Foundation (NSF). ARO receives partial support from the NSF ATI program. The Submillimeter Array is a joint project between the Smith-sonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics and is funded by the Smithsonian Institution and the Academia Sinica. Funding for ongoing CARMA development and operations is supported by the NSF and the CARMA partner universities. D.E.B. acknowledges support from the NSF Research Experiences for Undergraduates program. Facilities: CARMA (), HHT (), JCMT (), SMA (), CSO ()",

year = "2011",

month = feb,

day = "1",

doi = "10.1088/2041-8205/727/2/L36",

language = "English (US)",

volume = "727",

journal = "Astrophysical Journal Letters",

issn = "2041-8205",

publisher = "American Astronomical Society",

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TY - JOUR

T1 - 1.3 mm wavelength VLBI of sagittarius A*

T2 - Detection of time-variable emission on event horizon scales

AU - Fish, Vincent L.

AU - Doeleman, Sheperd S.

AU - Beaudoin, Christopher

AU - Blundell, Ray

AU - Bolin, David E.

AU - Bower, Geoffrey C.

AU - Chamberlin, Richard

AU - Freund, Robert

AU - Friberg, Per

AU - Gurwell, Mark A.

AU - Honma, Mareki

AU - Inoue, Makoto

AU - Krichbaum, Thomas P.

AU - Lamb, James

AU - Marrone, Daniel P.

AU - Moran, James M.

AU - Oyama, Tomoaki

AU - Plambeck, Richard

AU - Primiani, Rurik

AU - Rogers, Alan E.E.

AU - Smythe, Daniel L.

AU - Soohoo, Jason

AU - Strittmatter, Peter

AU - Tilanus, Remo P.J.

AU - Titus, Michael

AU - Weintroub, Jonathan

AU - Wright, Melvyn

AU - Woody, David

AU - Young, Ken H.

AU - Ziurys, Lucy M.

N1 - Funding Information: High-frequency VLBI work at MIT Haystack Observatory is supported by grants from the National Science Foundation (NSF). ARO receives partial support from the NSF ATI program. The Submillimeter Array is a joint project between the Smith-sonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics and is funded by the Smithsonian Institution and the Academia Sinica. Funding for ongoing CARMA development and operations is supported by the NSF and the CARMA partner universities. D.E.B. acknowledges support from the NSF Research Experiences for Undergraduates program. Facilities: CARMA (), HHT (), JCMT (), SMA (), CSO ()

PY - 2011/2/1

Y1 - 2011/2/1

N2 - Sagittarius A*, the ∼4 × 106 M ⊙ black hole candidate at the Galactic center, can be studied on Schwarzschild radius scales with (sub)millimeter wavelength very long baseline interferometry (VLBI). We report on 1.3 mm wavelength observations of Sgr A * using a VLBI array consisting of the JCMT on Mauna Kea, the Arizona Radio Observatory's Submillimeter Telescope on Mt. Graham in Arizona, and two telescopes of the CARMA array at Cedar Flat in California. Both Sgr A* and the quasar calibrator 1924-292 were observed over three consecutive nights, and both sources were clearly detected on all baselines. For the first time, we are able to extract 1.3 mm VLBI interferometer phase information on Sgr A* through measurement of closure phase on the triangle of baselines. On the third night of observing, the correlated flux density of Sgr A* on all VLBI baselines increased relative to the first two nights, providing strong evidence for time-variable change on scales of a few Schwarzschild radii. These results suggest that future VLBI observations with greater sensitivity and additional baselines will play a valuable role in determining the structure of emission near the event horizon of Sgr A*.

AB - Sagittarius A*, the ∼4 × 106 M ⊙ black hole candidate at the Galactic center, can be studied on Schwarzschild radius scales with (sub)millimeter wavelength very long baseline interferometry (VLBI). We report on 1.3 mm wavelength observations of Sgr A * using a VLBI array consisting of the JCMT on Mauna Kea, the Arizona Radio Observatory's Submillimeter Telescope on Mt. Graham in Arizona, and two telescopes of the CARMA array at Cedar Flat in California. Both Sgr A* and the quasar calibrator 1924-292 were observed over three consecutive nights, and both sources were clearly detected on all baselines. For the first time, we are able to extract 1.3 mm VLBI interferometer phase information on Sgr A* through measurement of closure phase on the triangle of baselines. On the third night of observing, the correlated flux density of Sgr A* on all VLBI baselines increased relative to the first two nights, providing strong evidence for time-variable change on scales of a few Schwarzschild radii. These results suggest that future VLBI observations with greater sensitivity and additional baselines will play a valuable role in determining the structure of emission near the event horizon of Sgr A*.

KW - Galaxy: center

KW - Submillimeter: general

KW - Techniques: high angular resolution

KW - Techniques: interferometric

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U2 - 10.1088/2041-8205/727/2/L36

DO - 10.1088/2041-8205/727/2/L36

M3 - Article

AN - SCOPUS:84889884648

SN - 2041-8205

VL - 727

JO - Astrophysical Journal Letters

JF - Astrophysical Journal Letters

IS - 2 PART II

ER -

1.3 mm wavelength VLBI of sagittarius A^*: Detection of time-variable emission on event horizon scales

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1.3mm VLBI observations of Sagittarius A*

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1.3 mm wavelength VLBI of sagittarius A*: Detection of time-variable emission on event horizon scales

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1.3mm VLBI observations of Sagittarius A*

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1.3 mm wavelength VLBI of sagittarius A^*: Detection of time-variable emission on event horizon scales