主要研究 今天

有时 you have to go to the extreme reaches of the planet to study the most extreme phenomena in space.

费边Kislat, 联合国大学物理学教授, recently spent two months in Antarctica with an international team of researchers to study neutron stars in our galaxy. 经过一系列的天气延误，在麦克默多站附近的冰面上, Kislat and the team launched a scientific balloon that carried with it a telescope aimed at two bright neutron stars in the Milky Way — Vela X-1 and GX 301-2 — in a bid to learn more about these intriguing space objects.  

中子星非常致密, perhaps only seven miles wide but with more mass than our own sun and a very strong magnetic field. 有时, 就像Vela X-1和GX 301-2一样, these neutron stars exist in a close orbit with another giant star that emits streams of charged particles similar to our solar wind. These particles accrete on the surface of the neutron stars because of their magnetic field — forces strong enough to draw out a near-constant flow of particles from the giant star.  

“Some of the strongest magnetic fields in the universe are found around neutron stars — something like 12 orders of magnitude stronger than the Earth’s magnetic field,基斯拉特解释道. “他们迷人的, and this research will help us to learn about how matter and radiation behave in these extreme magnetic fields,他补充道.

Neutron stars are somewhat difficult to study; they’re thousands of light years away from Earth and they’re small, 所以即使是最好的望远镜也只能捕捉到它们发出的一点光. 它们比普通恒星发出更多的x射线, 虽然, 这有助于科学家区分两者吗. 这些x射线在不同方向的平面上振荡，这种现象称为偏振. 这次任务的长度是27英尺., 3,500 lb. 望远镜,被称为 X-Calibur, was intended to measure the polarization of X-rays emitted from the two neutron stars to get a more accurate assessment of their geometry and how they behave.

"This research will help us to learn about how matter and radiation behave in these extreme magnetic fields."

X-Calibur团队，由来自 华盛顿大学. 路易, chose Antarctica for the launch location due in large part to the polar winds that make a full revolution above the continent every 12 days or so. The team expected that the telescope would stay afloat to record data for at least a week or possibly even longer. This would give the device ample time to capture the data needed to determine the X-ray polarization from Vela X-1 and GX 301-2.

然而，科学实地研究并不总是按计划进行. The balloon kept X-Calibur aloft for three days before descending rapidly and landing hours away on the continent’s 12,000 ft. 冰川，使得望远镜很难取回. X-Calibur在飞行过程中将数据发送给了团队, so the team members were able to salvage the information collected during the mission without needing hands-on access to the telescope. 没有人完全确定是什么原因导致了快速下降, 但基斯拉特说，他怀疑气球有漏洞. 尽管飞行时间很短, Kislat说 they are likely to have enough data to draw some conclusions in the coming months.

The lead-up to the launch in Antarctica was a long time in the making; Kislat has been involved in various aspects of the X-Calibur mission since 2012 during his post-doctoral position at 华盛顿大学. 路易. From writing the software for the flight and for data acquisition to hardware integration, 测试探测器, 开发数据分析方法, 基斯拉特参与了这次任务的大部分工作.

“What I like about the project itself is that it combines fundamental physics research and astrophysics with making and inventing the instruments to do this research,他说. “从很多方面来说，这是一个非常有创造性的过程.”

The team ran a few test flights from NASA’s Scientific Balloon Flight Facility in Fort Sumner, 新墨西哥, 在前往南极之前. Conducting the final mission in Antarctica provided Kislat with a wholly unique experience. “It’s a place unlike any other in the world — not just because it’s cold and you’re on ice and there are no plants and very few animals,基斯拉特说. “The scientific community that you find at McMurdo Station is very different than the scientists you might otherwise encounter elsewhere. 每年都有人因为热爱这里而回到这里工作, 他们是一个紧密结合的社区,他补充道.

目前还不清楚基斯拉特是否会在不久的将来返回南极洲, he is currently working with the X-Calibur mission team to develop a new project proposal for a larger, 更灵敏的望远镜将有一个大得多的反射镜. While a larger telescope will likely mean better data, there’s also the weight to consider. A scientific balloon can only carry so much weight and still achieve the necessary altitude to record data above the clouds, Kislat说. The engineering aspect of that project proposal and improvements to the X-ray detector are currently being discussed.  

Funding for the X-Calibur project was provided by NASA and the McDonnell Center for the Space Sciences at 华盛顿大学. 路易.