A Research about the locations of Jupiter's decametric sources by VLBI

VLBI对木星十米源位置的研究

• 批准号: 06640573
• 负责人: IMAI Kazumasa
• 金额: $ 1.28万
• 依托单位: Kochi National College of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06640573/
• 关键词: Jupiter; Radio Emissions; Decametric wave; VLBI; Polarization

The investigation of Jupiter's decameter-wavelength radio source locations and emission beam structure is very important for the study of the emission mechanism (Carr and Desch, 1976 ; Carr et al., 1983). Jupiter's rediation occurring during the so-called Io-B and Io-A storms is right-hand (RH) circularly or elliptically polarized. The Io-C storms, however, are often left-hand (LH) circularly polarized when observed in the vicinity of 18 MHz. Often a storm of long duration will begin in the Io-A region of central meridian longitude (CML) and end in the Io-C region, in which case it is not uncommon for the polarization sense to fluctuate back and forth between RH and LH in the transition region. It is generally believed that the Io-B and Io-A radiations are emitted in the extraordinary (X) mode, from within successive Io-energized flux tubes at the altitudes above the cloud-tops at which the wave frequency is only slightly higher than the electron gyrofrequency.Since it is known that the field lines of Jupiter's nearly-dipolar magnetic field are directed from the northern to the southern Jovigraphic polar regions, it follows that the RH polarized Io-B and Io-A emissions come from near the northern rather than the southern foot of the Io-energized flux tube. The question is where do the LH polarized Io-C emissions come from? With our dual-polarization interferometer we expect to be able to measure the angular separation of the sources of the LH polarized and RH polarized bursts that occur within a few time seconds of each other with sufficient accuracy to determine whether they were located in the same or in opposite polar hemispheres.

研究木星的分米波长射电源位置和发射束结构对于研究发射机制是非常重要的(Carr和Desch，1976；Carr等人，1983)。木星的辐射发生在所谓的Io-B和Io-A风暴期间，是右旋(RH)圆偏振或椭圆偏振。然而，在18兆赫附近观测到的Io-C风暴通常是左旋(Lh)圆偏振。通常，一场持续时间较长的风暴将开始于中央子午线经度(CML)的Io-A区，并在Io-C区结束，在这种情况下，在过渡区的相对湿度和相对湿度之间来回波动的偏振感并不少见。一般认为，Io-B和Io-A辐射是在连续的Io-充能通量管内以非常(X)模式发射的，在云顶以上的高度，波动频率仅略高于电子回转频率。由于已知木星近偶极磁场的场线从北向南引导，因此，RH极化的Io-B和Io-A辐射来自Io-充能通量管的北脚附近，而不是南脚。问题是，左旋体极化的IO-C排放从何而来？使用我们的双偏振干涉仪，我们希望能够以足够的精度测量发生在彼此几个时间秒内的左旋极化和右旋极化爆发的源的角度间隔，以确定它们是位于相同的极半球还是相反的极半球。

项目成果

Kazumasa Imai: "Observations of Jupiters Decametric Radio Sources by the Dual-Polarization Interferometer" Proceedings of Eights International Symposium on Solar Terrestial Physics. 49-49 (1994)

Kazumasa Imai：“双偏振干涉仪对木星十度射电源的观测”八人国际日地物理学研讨会论文集。

Kazumasa Imai, T.D.Carr^*, F.Reyes^*, Haruyori Matsuura^*: "Observations of Jupiter's Decametric Radio Sources by the Dudal-Polarization Interferometer" Proceedings of Eighth International Symposium on Solar Terrestrial Physics held at Sendai. 49 (1994)

Kazumasa Imai、T.D.Carr^*、F.Reyes^*、Haruyori Matsuura^*：“双偏振干涉仪对木星十米射电源的观测”在仙台举行的第八届国际日地物理学研讨会论文集。

今井一雅: "木星電波源のビーム構造" 地球惑星科学関連学会1995年合同大会予稿集. 262-262 (1995)

Kazumasa Imai：“木星射电源的光束结构”1995 年地球与行星科学相关学会联合会议记录 262-262 (1995)。

今井一雅: "UF50マイル干渉計による木星電波源の観測" 地球惑星科学関連学会1994年合同大会予稿集. 543-543 (1994)

Kazumasa Imai：“使用 UF50 英里干涉仪观测木星的射电源”1994 年地球与行星科学协会联合会议记录 543-543 (1994)。

今井一雅: "月面反射VLBIとその応用" VLBIシンポジウム集録(国立天文台). 174-175 (1994)

Kazumasa Imai：“月球反射 VLBI 及其应用”VLBI 研讨会论文集（日本国家天文台）174-175（1994 年）。