EXPANDED VERY LARGE ARRAY DETECTION OF 44.1 GHz CLASS I METHANOL MASERS IN SAGITTARIUS A
We report on the detection of 44 GHz Class I methanol (CH[subscript 3]OH) maser emission in the Sagittarius A (Sgr A) complex with the Expanded Very Large Array (EVLA). These EVLA observations show that the Sgr A complex harbors at least four different tracers of shocked regions in the radio regime....
| Main Authors: | , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
IOP Publishing
2015
|
| Online Access: | http://hdl.handle.net/1721.1/95715 |
| _version_ | 1826193118535352320 |
|---|---|
| author | Sjouwerman, L. O. Fish, Vincent L. Pihlstrom, Y. M. |
| author2 | Haystack Observatory |
| author_facet | Haystack Observatory Sjouwerman, L. O. Fish, Vincent L. Pihlstrom, Y. M. |
| author_sort | Sjouwerman, L. O. |
| collection | MIT |
| description | We report on the detection of 44 GHz Class I methanol (CH[subscript 3]OH) maser emission in the Sagittarius A (Sgr A) complex with the Expanded Very Large Array (EVLA). These EVLA observations show that the Sgr A complex harbors at least four different tracers of shocked regions in the radio regime. The 44 GHz masers correlate with the positions and velocities of previously detected 36 GHz CH[subscript 3]OH masers, but less with 1720 MHz OH masers. Our detections agree with theoretical predictions that the densities and temperatures conducive for 1720 MHz OH masers may also produce 36 and 44 GHz CH[subscript 3]OH maser emission. However, many 44 GHz masers do not overlap with 36 GHz methanol masers, suggesting that 44 GHz masers also arise in regions too hot and too dense for 36 GHz masers to form. This agrees with the non-detection of 1720 MHz OH masers in the same area, which are thought to be excited under even cooler and less dense conditions. We speculate that the geometry of the 36 GHz masers outlines the current location of a shock front. |
| first_indexed | 2024-09-23T09:34:01Z |
| format | Article |
| id | mit-1721.1/95715 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T09:34:01Z |
| publishDate | 2015 |
| publisher | IOP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/957152022-09-30T15:20:34Z EXPANDED VERY LARGE ARRAY DETECTION OF 44.1 GHz CLASS I METHANOL MASERS IN SAGITTARIUS A Sjouwerman, L. O. Fish, Vincent L. Pihlstrom, Y. M. Haystack Observatory Fish, Vincent L. We report on the detection of 44 GHz Class I methanol (CH[subscript 3]OH) maser emission in the Sagittarius A (Sgr A) complex with the Expanded Very Large Array (EVLA). These EVLA observations show that the Sgr A complex harbors at least four different tracers of shocked regions in the radio regime. The 44 GHz masers correlate with the positions and velocities of previously detected 36 GHz CH[subscript 3]OH masers, but less with 1720 MHz OH masers. Our detections agree with theoretical predictions that the densities and temperatures conducive for 1720 MHz OH masers may also produce 36 and 44 GHz CH[subscript 3]OH maser emission. However, many 44 GHz masers do not overlap with 36 GHz methanol masers, suggesting that 44 GHz masers also arise in regions too hot and too dense for 36 GHz masers to form. This agrees with the non-detection of 1720 MHz OH masers in the same area, which are thought to be excited under even cooler and less dense conditions. We speculate that the geometry of the 36 GHz masers outlines the current location of a shock front. 2015-02-27T14:56:30Z 2015-02-27T14:56:30Z 2011-08 2011-04 Article http://purl.org/eprint/type/JournalArticle 2041-8205 2041-8213 http://hdl.handle.net/1721.1/95715 Pihlstrom, Y. M., L. O. Sjouwerman, and V. L. Fish. “EXPANDED VERY LARGE ARRAY DETECTION OF 44.1 GHz CLASS I METHANOL MASERS IN SAGITTARIUS A.” The Astrophysical Journal 739, no. 1 (August 30, 2011): L21. © 2011 The American Astronomical Society en_US http://dx.doi.org/10.1088/2041-8205/739/1/l21 The Astrophysical Journal. Letters 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 American Astronomical Society |
| spellingShingle | Sjouwerman, L. O. Fish, Vincent L. Pihlstrom, Y. M. EXPANDED VERY LARGE ARRAY DETECTION OF 44.1 GHz CLASS I METHANOL MASERS IN SAGITTARIUS A |
| title | EXPANDED VERY LARGE ARRAY DETECTION OF 44.1 GHz CLASS I METHANOL MASERS IN SAGITTARIUS A |
| title_full | EXPANDED VERY LARGE ARRAY DETECTION OF 44.1 GHz CLASS I METHANOL MASERS IN SAGITTARIUS A |
| title_fullStr | EXPANDED VERY LARGE ARRAY DETECTION OF 44.1 GHz CLASS I METHANOL MASERS IN SAGITTARIUS A |
| title_full_unstemmed | EXPANDED VERY LARGE ARRAY DETECTION OF 44.1 GHz CLASS I METHANOL MASERS IN SAGITTARIUS A |
| title_short | EXPANDED VERY LARGE ARRAY DETECTION OF 44.1 GHz CLASS I METHANOL MASERS IN SAGITTARIUS A |
| title_sort | expanded very large array detection of 44 1 ghz class i methanol masers in sagittarius a |
| url | http://hdl.handle.net/1721.1/95715 |
| work_keys_str_mv | AT sjouwermanlo expandedverylargearraydetectionof441ghzclassimethanolmasersinsagittariusa AT fishvincentl expandedverylargearraydetectionof441ghzclassimethanolmasersinsagittariusa AT pihlstromym expandedverylargearraydetectionof441ghzclassimethanolmasersinsagittariusa |