Detection of polarized millimeter and submillimeter emission from Sagittarius A

Citation
Dk. Aitken et al., Detection of polarized millimeter and submillimeter emission from Sagittarius A, ASTROPHYS J, 534(2), 2000, pp. L173-L176
Citations number
23
Categorie Soggetti
Space Sciences
Journal title
ASTROPHYSICAL JOURNAL
ISSN journal
0004637X → ACNP
Volume
534
Issue
2
Year of publication
2000
Part
2
Pages
L173 - L176
Database
ISI
SICI code
0004-637X(20000510)534:2<L173:DOPMAS>2.0.ZU;2-6
Abstract
We report the detection of linear polarization from Sgr A* at 750, 850, 135 0, and 2000 mu m which confirms the contribution elf synchrotron radiation. From the lack of polarization at longer wavelengths, it appears to arise i n the millimeter/submillimeter excess. There are large position angle chang es between the millimeter and submillimeter results, and these are discusse d in terms of a polarized dust contribution in the submillimeter and variou s synchrotron models. In the model that best explains the data, the synchro tron radiation from the excess is self-absorbed in the millimeter region an d becomes optically thin in the submillimeter. This implies that the excess arises in an extremely compact source of similar to 2 Schwarzschild radii.