230 GHz VLBI OBSERVATIONS OF M87: EVENT‐HORIZON‐SCALE STRUCTURE DURING AN ENHANCED VERY‐HIGH‐ENERGY γ‐RAY STATE IN 2012
We report on 230 GHz (1.3 mm) very long baseline interferometry (VLBI) observations of M87 with the Event Horizon Telescope using antennas on Mauna Kea in Hawaii, Mt. Graham in Arizona, and Cedar Flat in California. For the first time, we have acquired 230 GHz VLBI interferometric phase information...
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| Format: | Article |
| Language: | en_US |
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IOP Publishing
2015
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| Online Access: | http://hdl.handle.net/1721.1/98305 https://orcid.org/0000-0003-1941-7458 |
| _version_ | 1826216179858931712 |
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| author | Lu, Rusen Fish, Vincent L. Doeleman, Sheperd Samuel Cappallo, Roger J. Crew, Geoffrey B. Rogers, Alan E. E. SooHoo, Jason G. Titus, Michael A. |
| author2 | Haystack Observatory |
| author_facet | Haystack Observatory Lu, Rusen Fish, Vincent L. Doeleman, Sheperd Samuel Cappallo, Roger J. Crew, Geoffrey B. Rogers, Alan E. E. SooHoo, Jason G. Titus, Michael A. |
| author_sort | Lu, Rusen |
| collection | MIT |
| description | We report on 230 GHz (1.3 mm) very long baseline interferometry (VLBI) observations of M87 with the Event Horizon Telescope using antennas on Mauna Kea in Hawaii, Mt. Graham in Arizona, and Cedar Flat in California. For the first time, we have acquired 230 GHz VLBI interferometric phase information on M87 through measurement of the closure phase on the triangle of long baselines. Most of the measured closure phases are consistent with 0° as expected by physically motivated models for 230 GHz structure such as jet models and accretion disk models. The brightness temperature of the event-horizon-scale structure is ~1 X 10[superscript 10] K derived from the compact flux density of ~1 Jy and the angular size of ~40 µas ~ 5.5 R[subscript s], which is broadly consistent with the peak brightness of the radio cores at 1–86 GHz located within ~10[superscript 2] R[subscript s]. Our observations occurred in the middle of an enhancement in very-high-energy (VHE) γ-ray flux, presumably originating in the vicinity of the central black hole. Our measurements, combined with results of multi-wavelength observations, favor a scenario in which the VHE region has an extended size of ~20–60 R[subscript s]. |
| first_indexed | 2024-09-23T16:43:14Z |
| format | Article |
| id | mit-1721.1/98305 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T16:43:14Z |
| publishDate | 2015 |
| publisher | IOP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/983052022-09-29T21:01:28Z 230 GHz VLBI OBSERVATIONS OF M87: EVENT‐HORIZON‐SCALE STRUCTURE DURING AN ENHANCED VERY‐HIGH‐ENERGY γ‐RAY STATE IN 2012 Lu, Rusen Fish, Vincent L. Doeleman, Sheperd Samuel Cappallo, Roger J. Crew, Geoffrey B. Rogers, Alan E. E. SooHoo, Jason G. Titus, Michael A. Haystack Observatory Lu, Rusen Fish, Vincent L. Doeleman, Sheperd Samuel Cappallo, Roger J. Crew, Geoffrey B. Rogers, Alan E. E. SooHoo, Jason G. Titus, Michael A. We report on 230 GHz (1.3 mm) very long baseline interferometry (VLBI) observations of M87 with the Event Horizon Telescope using antennas on Mauna Kea in Hawaii, Mt. Graham in Arizona, and Cedar Flat in California. For the first time, we have acquired 230 GHz VLBI interferometric phase information on M87 through measurement of the closure phase on the triangle of long baselines. Most of the measured closure phases are consistent with 0° as expected by physically motivated models for 230 GHz structure such as jet models and accretion disk models. The brightness temperature of the event-horizon-scale structure is ~1 X 10[superscript 10] K derived from the compact flux density of ~1 Jy and the angular size of ~40 µas ~ 5.5 R[subscript s], which is broadly consistent with the peak brightness of the radio cores at 1–86 GHz located within ~10[superscript 2] R[subscript s]. Our observations occurred in the middle of an enhancement in very-high-energy (VHE) γ-ray flux, presumably originating in the vicinity of the central black hole. Our measurements, combined with results of multi-wavelength observations, favor a scenario in which the VHE region has an extended size of ~20–60 R[subscript s]. 2015-09-01T19:40:35Z 2015-09-01T19:40:35Z 2015-07 2014-11 Article http://purl.org/eprint/type/JournalArticle 1538-4357 0004-637X http://hdl.handle.net/1721.1/98305 Akiyama, Kazunori, Ru-Sen Lu, Vincent L. Fish, Sheperd S. Doeleman, Avery E. Broderick, Jason Dexter, Kazuhiro Hada, et al. “230 GHz VLBI OBSERVATIONS OF M87: EVENT‐HORIZON‐SCALE STRUCTURE DURING AN ENHANCED VERY‐HIGH‐ENERGY γ‐RAY STATE IN 2012.” The Astrophysical Journal 807, no. 2 (July 9, 2015): 150. © 2015 The American Astronomical Society https://orcid.org/0000-0003-1941-7458 en_US http://dx.doi.org/10.1088/0004-637X/807/2/150 The Astrophysical Journal Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf IOP Publishing IOP Publishing |
| spellingShingle | Lu, Rusen Fish, Vincent L. Doeleman, Sheperd Samuel Cappallo, Roger J. Crew, Geoffrey B. Rogers, Alan E. E. SooHoo, Jason G. Titus, Michael A. 230 GHz VLBI OBSERVATIONS OF M87: EVENT‐HORIZON‐SCALE STRUCTURE DURING AN ENHANCED VERY‐HIGH‐ENERGY γ‐RAY STATE IN 2012 |
| title | 230 GHz VLBI OBSERVATIONS OF M87: EVENT‐HORIZON‐SCALE STRUCTURE DURING AN ENHANCED VERY‐HIGH‐ENERGY γ‐RAY STATE IN 2012 |
| title_full | 230 GHz VLBI OBSERVATIONS OF M87: EVENT‐HORIZON‐SCALE STRUCTURE DURING AN ENHANCED VERY‐HIGH‐ENERGY γ‐RAY STATE IN 2012 |
| title_fullStr | 230 GHz VLBI OBSERVATIONS OF M87: EVENT‐HORIZON‐SCALE STRUCTURE DURING AN ENHANCED VERY‐HIGH‐ENERGY γ‐RAY STATE IN 2012 |
| title_full_unstemmed | 230 GHz VLBI OBSERVATIONS OF M87: EVENT‐HORIZON‐SCALE STRUCTURE DURING AN ENHANCED VERY‐HIGH‐ENERGY γ‐RAY STATE IN 2012 |
| title_short | 230 GHz VLBI OBSERVATIONS OF M87: EVENT‐HORIZON‐SCALE STRUCTURE DURING AN ENHANCED VERY‐HIGH‐ENERGY γ‐RAY STATE IN 2012 |
| title_sort | 230 ghz vlbi observations of m87 event horizon scale structure during an enhanced very high energy γ ray state in 2012 |
| url | http://hdl.handle.net/1721.1/98305 https://orcid.org/0000-0003-1941-7458 |
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