NICMOS Coronagraphic Observations of the GM Aurigae Circumstellar Disk
NICMOS Coronagraphic Observations of the GM Aurigae Circumstellar Disk
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GM Aurigae 环星盘的 NICMOS 日冕观测
DOI：
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发表时间：
2003
期刊：
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通讯作者：
P. Lowrance
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作者：
G. Schneider;Kenneth Wood;M. Silverstone;D. Hines;D. Koerner;B. Whitney;J. Bjorkman;P. Lowrance
我们介绍了哈勃太空望远镜近红外相机和多目标光谱仪(NICMOS)对年轻的恒星-盘系统GM-Aurigae区域环境的日冕观测。在两个光谱带(F110W=1.1μm和F160W=1.6μm)上的散射近红外光追踪到距离恒星∼700AU的恒星周围尘埃的形态。在∼图像中可以看到一个半径为300AU的向外张开的圆盘，与天空平面成50°-55°的倾角，周围环绕着一个稀薄的包层，这证实了先前CO和光学观测所提出的圆盘的大小和可能的耀斑性质。NICMOS图像探测的圆盘区域的空间分辨率为∼0.“1，径向距离为0.35至∼4.”5-5.0，距离大体上没有遮挡的中央恒星。来自GM Aurigae的圆盘1的中平面3在轮廓中显露出来，相对于先前看不到的沿其短轴(如投影到天空上的那样)的被照亮的圆盘的“下”部分。我们评论了沿圆盘长轴和短轴的表面亮度分布，以及圆盘的等高线图。根据这些光度数据，我们测量了仪器内径为0.025“35以外的磁盘的积分通量密度，在F110W和F160W分别为8.0mJy和9.3mJy(±20%)，对应于这两个波段的磁盘散射分数LDisk/L*=0.025(±20%)。通过将圆盘的光度学性质与散射光模型进行拟合，我们估计圆盘的质量为∼0.04M⊙。此外，我们还发现两个沿圆盘短轴扩散的红色极叶，很可能是双极外流的结果，距离为±3。“8距离GM Aurigae(∼900AU，我们推断的倾角)，H带表面峰值亮度为∼14μJy arcsec-2。我们还注意到NICMOS视场内存在一个宽的(∼3“宽)蓝色物质带，在空间上与圆盘长轴的东北外部区域重合并延伸至少12”。
We present Hubble Space Telescope Near Infrared Camera and Multi-Object Spectrometer (NICMOS) coronagraphic observations of the environment in the region of the young star-disk system GM Aurigae. Scattered near-infrared light in two spectral bands (F110W = 1.1 μm and F160W = 1.6 μm) trace the morphology of circumstellar dust to a distance of ∼700 AU from the star. An ∼300 AU radius outwardly flared disk inclined 50°–55° to the plane of the sky surrounded by a tenuous envelope is seen in the NICMOS images, confirming the size and suspected flared nature of the disk suggested by earlier CO and optical observations. The NICMOS images probe the disk region with spatial resolutions of ∼0.″1 at radial distances of 0.″35 to ∼4.″5–5.″0 from the largely unobscured (Av < 0.5) central star. The midplane of the disk 1.″3 from GM Aurigae is revealed in silhouette against the previously unseen "lower" portion of the illuminated disk along its minor axis (as projected onto the sky). We comment on surface brightness profiles along the disk major and minor axes, as well as isophotal maps of the disk. From these photometric data we have measured the integrated flux density of the disk, beyond the instrumental inner radius of 0.″35, as 8.0 and 9.3 mJy (±20%) at F110W and F160W, respectively, corresponding to disk scattering fractions of Ldisk/L* = 0.025 (±20%) in both bands. By fitting the photometric properties of the disk to a scattered-light model, we estimate the disk mass to be ∼0.04 M⊙. Additionally, we find two diffuse red polar lobes along the disk minor axis, likely the result of a bipolar outflow, at distances of ±3.″8 from GM Aurigae (∼900 AU with our inferred inclination) with peak H-band surface brightnesses of ∼14 μJy arcsec-2. We also note the existence of a broad (∼3″ wide) band of blue material within the NICMOS field of view, spatially coincident with and extending at least 12″ from the northeast outer region of the disk major axis.