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arXiv 2103.08990astro-ph.GAastro-ph.SR
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大质量原恒星射电喷流的银河系巡天

A Galactic survey of radio jets from massive protostars

S. J. D. Purser, S. L. Lumsden, M. G. Hoare, S. Kurtz

备注：
To be published in MNRAS. 20 pages main text (4 tables, 14 figures), 90 pages appendices (6 tables, 66 figures)
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摘要：

结合以前的南半球的工作，我们提出了最大的无线电调查的喷气机从大规模的原恒星到目前为止，高分辨率，（$\sim 0.04^{\prime\prime}$）VLA观测对两个子样本的大规模恒星形成地区的不同的演化状态：48个红外明亮，大规模的YSO和8个IRDC包含16个发光（${\rm L_{bol}}>10^3\,{\rm L_\odot}$）的核心。对于MYSO样本的$94\%$，我们检测到热射电（$α\geq -0.1$，即$S_ν\propto ν^α$）源与原恒星一致，其中$84\%$（13个喷流和25个候选者）是喷流状的。射电光度被发现与${\rm L_{bol}}$的规模类似的低质量的情况下，支持一个共同的机制，在所有群众的喷流生产。相关的射电波瓣跟踪冲击被认为是对PDMATHAMT的喷气式物体，并优先检测到对更高的无线电和辐射热光度的喷气式飞机，由于我们的灵敏度限制。我们发现喷流质量损失率尺度与热光度为$\dot{m}_{\rm jet} \propto {\rm L_{bol}}^{0.9\pm0.2}$，从而放弃辐射，线驱动机制作为主要的喷气发射过程。计算的动量表明，大多数喷流是机械驱动的质量，分子外流现象，因为$p_{\rm jet}>p_{\rm outflow}$。最后，从它们的物理范围，我们表明，无线电发射不能起源于小，光学厚\textsc{Hii}区域。对IRDC核心，我们观察到随着年龄的增加发病率/无线电通量使用的代理增加亮度质量$\left( \frac{L}{M} \right)$和减少红外通量比$\left(\frac{S_{70 \rm μm}}{S_{24 \rm μm}}\right)$。在（$5.8{\rm GHz}$）射电光度$\sim1{\rm mJy\,kpc}^2$以上未检测到含$\frac{L}{M}<40\,{\rm L_{sol}}{\rm M_{sol}}^{-1}$的岩芯。

英文摘要：

In conjunction with a previous southern-hemisphere work, we present the largest radio survey of jets from massive protostars to date with high-resolution, ($\sim 0.04^{\prime\prime}$) VLA observations towards two subsamples of massive star-forming regions of different evolutionary statuses: 48 infrared-bright, massive YSOs and 8 IRDCs containing 16 luminous (${\rm L_{bol}}>10^3\,{\rm L_\odot}$) cores. For $94\%$ of the MYSO sample we detect thermal radio ($α\geq -0.1$ whereby $S_ν\propto ν^α$) sources coincident with the protostar, of which $84\%$ (13 jets and 25 candidates) are jet-like. Radio luminosity is found to scale with ${\rm L_{bol}}$ similarly to the low-mass case supporting a common mechanism for jet production across all masses. Associated radio lobes tracing shocks are seen towards $52\%$ of jet-like objects and are preferentially detected towards jets of higher radio and bolometric luminosities, resulting from our sensitivity limitations. We find jet mass loss rate scales with bolometric luminosity as $\dot{m}_{\rm jet} \propto {\rm L_{bol}}^{0.9\pm0.2}$, thereby discarding radiative, line-driving mechanisms as the dominant jet-launching process. Calculated momenta show that the majority of jets are mechanically capable of driving the massive, molecular outflow phenomena since $p_{\rm jet}>p_{\rm outflow}$. Finally, from their physical extent we show that the radio emission can not originate from small, optically-thick \textsc{Hii} regions. Towards the IRDC cores, we observe increasing incidence rates/radio fluxes with age using the proxy of increasing luminosity-to-mass $\left( \frac{L}{M} \right)$ and decreasing infrared flux ratios $\left(\frac{S_{70 \rm μm}}{S_{24 \rm μm}}\right)$. Cores with $\frac{L}{M}<40\,{\rm L_{sol}}{\rm M_{sol}}^{-1}$ are not detected above ($5.8{\rm GHz}$) radio luminosities of $\sim1{\rm mJy\,kpc}^2$.

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