2 mm GISMO Observations of the Galactic Center. II. A Nonthermal Filament in the Radio Arc and Compact Sources
| dc.contributor.author | Staguhn, Johannes | |
| dc.contributor.author | Arendt, Richard | |
| dc.contributor.author | Dwek, Eli | |
| dc.contributor.author | Morris, Mark R | |
| dc.contributor.author | Yusef-Zadeh, Farhad | |
| dc.contributor.author | Benford, Dominic J | |
| dc.contributor.author | Kovacs, Attila | |
| dc.contributor.author | Gonzalez-Quiles, Junellie | |
| dc.date.accessioned | 2019-11-13T17:05:03Z | |
| dc.date.available | 2019-11-13T17:05:03Z | |
| dc.date.issued | 2019-11-01 | |
| dc.description.abstract | We have used the Goddard IRAM 2-Millimeter Observer (GISMO) with the 30 m IRAM telescope to carry out a 2 mm survey of the Galaxy’s central molecular zone (CMZ). These observations detect thermal emission from cold ISM dust, thermal free-free emission from ionized gas, and nonthermal synchrotron emission from relatively flat-spectrum sources. Archival data sets spanning 3.6 µm to 90 cm are used to distinguish different emission mechanisms. After the thermal emission of dust is modeled and subtracted, the remaining 2 mm emission is dominated by free-free emission, with the exception of the brightest nonthermal filament (NTF) that runs though the middle of the bundle of filaments known as the Radio Arc. This is the shortest wavelength at which any NTF has been detected. The GISMO observations clearly trace this NTF over a length of ∼ 0.2 ◦ , with a mean 2 mm spectral index which is steeper than at longer wavelengths. The 2 mm to 6 cm (or 20 cm) spectral index steepens from α ≈ −0.2 to −0.7 as a function distance from the Sickle H II region, suggesting that this region is directly related to the NTF. A number of unresolved (at 21′′) 2 mm sources are found nearby. One appears to be thermal dust emission from a molecular cloud that is associated with an enigmatic radio point source whose connection to the Radio Arc is still debated. The morphology and colors at shorter IR wavelengths indicate other 2 mm unresolved sources are likely to be compact H II regions. | en_US |
| dc.description.sponsorship | Based on observations carried out with the IRAM 30 m Telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain). | en_US |
| dc.description.uri | https://iopscience.iop.org/article/10.3847/1538-4357/ab451b | en_US |
| dc.format.extent | 14 pages | en_US |
| dc.genre | journal articles | en_US |
| dc.identifier.citation | Johannes Staguhn and Richard G. Arendt and Eli Dwek and Mark R. Morris and Farhad Yusef-Zadeh and Dominic J. Benford and Attila Kovács and Junellie Gonzalez-Quiles,2 mm GISMO Observations of the Galactic Center. II. A Nonthermal Filament in the Radio Arc and Compact Sources; The Astrophysical Journal 885,1 (2019 November 1) ; https://iopscience.iop.org/article/10.3847/1538-4357/ab451b | en_US |
| dc.identifier.uri | http://hdl.handle.net/11603/16278 | |
| dc.identifier.uri | https://doi.org/10.3847/1538-4357/ab451b | |
| dc.publisher | The American Astronomical Society | |
| dc.relation.isAvailableAt | The University of Maryland, Baltimore County (UMBC) | |
| dc.relation.ispartof | UMBC Center for Space Sciences and Technology | |
| dc.relation.ispartof | UMBC Faculty Collection | |
| dc.rights | This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law. | |
| dc.rights | CC0 1.0 Universal (CC0 1.0) Public Domain Dedication | |
| dc.rights.uri | https://creativecommons.org/publicdomain/zero/1.0/ | |
| dc.subject | Nonthermal Filament | en_US |
| dc.subject | Radio Arc | en_US |
| dc.subject | Compact Sources | en_US |
| dc.title | 2 mm GISMO Observations of the Galactic Center. II. A Nonthermal Filament in the Radio Arc and Compact Sources | en_US |
| dc.title.alternative | A Nonthermal Filament in the Radio Arc and Compact Sources | en_US |
| dc.type | Text | en_US |
| dcterms.creator | https://orcid.org/0000-0001-8403-8548 |