IMAGING AN EVENT HORIZON: MITIGATION OF SCATTERING TOWARD SAGITTARIUS A

被引：63

作者：

Fish, Vincent L. ^{[1
]}

Johnson, Michael D. ^{[2
]}

Lu, Ru-Sen ^{[1
]}

Doeleman, Sheperd S. ^{[1
,2
]}

Bouman, Katherine L. ^{[3
]}

Zoran, Daniel ^{[3
]}

Freeman, William T. ^{[3
]}

Psaltis, Dimitrios ^{[4
,5
]}

Narayan, Ramesh ^{[2
]}

Pankratius, Victor ^{[1
]}

Broderick, Avery E. ^{[6
,7
]}

Gwinn, Carl R. ^{[8
]}

Vertatschitsch, Laura E. ^{[2
]}

机构：

[1] MIT, Haystack Observ, Westford, MA 01886 USA

[2] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA

[3] MIT, Comp Sci & Artificial Intelligence Lab, Cambridge, MA 02139 USA

[4] Univ Arizona, Dept Astron, Tucson, AZ 85721 USA

[5] Univ Arizona, Dept Phys, Tucson, AZ 85721 USA

[6] Perimeter Inst Theoret Phys, Waterloo, ON N2L 2Y5, Canada

[7] Univ Waterloo, Dept Phys & Astron, Waterloo, ON N2L 3G1, Canada

[8] Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA

来源：

ASTROPHYSICAL JOURNAL | 2014年 / 795卷 / 02期

基金：

美国国家科学基金会; 加拿大自然科学与工程研究理事会;

关键词：

galaxies: individual (Sgr A*); Galaxy: center; scattering; techniques: image processing; techniques: interferometric; SGR-A-ASTERISK; SUPERMASSIVE BLACK-HOLE; NO-HAIR THEOREM; GALACTIC-CENTER; BROADENED IMAGE; INTRINSIC SIZE; VLBI OBSERVATIONS; RADIO; MILLIMETER; ACCRETION;

D O I：

10.1088/0004-637X/795/2/134

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

The image of the emission surrounding the black hole in the center of the Milky Way is predicted to exhibit the imprint of general relativistic (GR) effects, including the existence of a shadow feature and a photon ring of diameter similar to 50 mu as. Structure on these scales can be resolved by millimeter-wavelength very long baseline interferometry. However, strong-fieldGRfeatures of interest will be blurred at lambda >= 1.3 mm due to scattering by interstellar electrons. The scattering properties are well understood over most of the relevant range of baseline lengths, suggesting that the scattering may be (mostly) invertible. We simulate observations of a model image of Sgr A* and demonstrate that the effects of scattering can indeed be mitigated by correcting the visibilities before reconstructing the image. This technique is also applicable to Sgr A* at longer wavelengths.

引用

页数：7

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