Asteroids and comets (planetesimals) are created in gas- and dust-rich protoplanetary discs. The presence of these planetesimals around main-sequence stars is usually inferred from the detection of excess continuum emission at infrared wavelengths from dust grains produced by destructive processes within these discs. Modelling of the disc structure and dust grain properties for those discs is often hindered by the absence of any meaningful constraint on the location and spatial extent of the disc. Multi-wavelength, spatially resolved imaging is thus invaluable in refining the interpretation of these systems. Observations of HD 48682 at far-infrared (Spitzer, Herschel) and sub-millimetre (JCMT, SMA) wavelengths indicated the presence of an extended, cold debris disc with a blackbody temperature of 57.9 ± 0.7 K. Here, we combined these data to perform a comprehensive study of the disc architecture and its implications for the dust grain properties. The deconvolved images revealed a cold debris belt, verified by combining a 3D radiative transfer dust continuum model with image analysis to replicate the structure using a single, axisymmetric annulus. A Markov chain Monte Carlo analysis calculated the maximum likelihood of HD48682's disc radius ( $R_{\rm disc} = 89^{+17}_{-20}~$ au), fractional width ( $\Delta R_{\rm disc} = 0.41^{+0.27}_{-0.20}$ ), position angle ( $\theta = 66{_{.}^{\circ}} 3^{+4.5}_{-4.9}$ ), and inclination ( $\phi = 112{_{.}^{\circ}} 5^{+4.2}_{-4.2}$ ). HD 48682 has been revealed to host a collisionally active, broad disc whose emission is dominated by small dust grains, smin ∼ 0.6 μm, and a size distribution exponent of 3.60 ± 0.02.

中文翻译：

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HD 48682 碎片盘的多波长空间解析建模

小行星和彗星（小行星）是在富含气体和尘埃的原行星盘中产生的。这些星子在主序星周围的存在通常是通过检测到这些圆盘内破坏性过程产生的尘埃颗粒在红外波长下过度连续发射而推断出来的。由于对圆盘的位置和空间范围没有任何有意义的约束，对这些圆盘的圆盘结构和尘埃颗粒特性的建模常常受到阻碍。因此，多波长、空间分辨成像对于完善这些系统的解释是非常宝贵的。在远红外（Spitzer、Herschel）和亚毫米（JCMT、SMA）波长下对 HD 48682 的观察表明存在一个扩展的冷碎片盘，黑体温度为 57.9 ± 0.7 K。这里，我们结合这些数据对圆盘结构及其对尘埃颗粒特性的影响进行了全面研究。解卷积图像显示了一条冷碎片带，通过将 3D 辐射转移尘埃连续体模型与图像分析相结合以使用单个轴对称环复制结构来验证。马尔可夫链蒙特卡罗分析计算了 HD48682 的圆盘半径（$R_{\rm disc} = 89^{+17}_{-20}~$ au）、分数宽度（ $\Delta R_{\rm disc } = 0.41^{+0.27}_{-0.20}$ ），位置角（ $\theta = 66{_{.}^{\circ}} 3^{+4.5}_{-4.9}$ ），和倾角（ $\phi = 112{_{.}^{\circ}} 5^{+4.2}_{-4.2}$ ）。已发现 HD 48682 拥有一个碰撞活跃的宽盘，其发射主要是小尘埃颗粒，smin ∼ 0.6 μm，尺寸分布指数为 3.60 ± 0.02。