RUI: Dynamic Ultra-Compact Ionized Gas regions in the Star-Forming Region W49A: Continuing the Search for Flickering Sources

该团队将使用卡尔G。Jansky甚大阵列（VLA）用于寻找与大质量恒星相关的时变源。 这种在无线电波波长上闪烁的光源表明，恒星断断续续地吸积气体。 这种令人惊讶的行为是从模拟中预测出来的。 无线电信号的预期变化太小，无法逐年测量。 但它们足够大，可以从十年到十年进行衡量。 VLA的寿命意味着现在可以测试预测。 该团队将把他们新的VLA测量结果与20年前的测量结果进行比较。 最近对这个NSF设施的技术升级也将使该团队能够研究吸积气体的运动。 来自代表性不足群体的本科生将大量参与研究。 PI和他的本科生将为中学生制作教育海报。 他们还将在当地校园天文台的公共活动中演讲。 该天文台是一个著名的太阳系比例模型中心，该模型遍布格鲁吉亚的亚特兰大市。该研究小组将利用VLA精湛的空间分辨率和寿命来研究W 49 A，这是我们银河系中的一个巨大的恒星形成复合体。 他们的目标是（1）寻找其电离（HII）气体连续源的大小和通量密度的变化;（2）测试模拟的预测;（3）表征电离气体光谱线的特性;（4）寻找连续闪烁的运动学特征。

The team will use the Karl G. Jansky Very Large Array (VLA) to search for time-variable sources associated with massive stars. Such flickering sources at radio wavelengths suggest that the stars accrete gas in fits and starts. This surprising behavior was predicted from simulations. The expected changes in the radio signals are too small to measure from year to year. But they are big enough to measure from decade to decade. The longevity of the VLA means that the predictions can now be tested. The team will compare their new VLA measurements with those from two decades ago. Recent technical upgrades to this NSF facility will also let the team study the motions of the accreted gas. Undergraduates from underrepresented groups will be heavily involved in the research. The PI and his undergraduates will produce educational posters for middle-school students. They will also lecture at public events at the local campus observatory. The observatory is the well-known center of a scaled model of our Solar System spread throughout Atlanta, Georgia.The team will use the VLA's exquisite spatial resolution and longevity to study W49A, a massive star-forming complex in our Galaxy. Their goals are to (1) search for variations in the size and flux density of its continuum sources of ionized (HII) gas; (2) test the predictions of the simulations; (3) characterize the properties of the spectral lines from the ionized gas; and (4) look for kinematic signatures of continuum flickering.