On the 12th of April 2022, Marcus J. Turner II submitted this assignment for the SPST63 Winter 2022 – Astronomical Instrumentation course at the American Military University. The instructor for the course is Dr. Jeremy Wood.

1. Simplifying Radio Telescope Operations

Radio Telescopes (RTs) use three basic components to capture radio waves from the cosmos. The first component is one or more radio antennas pointed towards the sky used to collect radio waves from space. This process resembles the way regular radios on Earth pick up radio stations. The second component is the tuning of RTs to specific frequencies to capture radio waves from the cosmos. Once these waves are collected, computer programming is used to read and interpret the signals. Using this methodology, astronomers can gather information such as understanding star deaths, the location of dark matter, and other phenomena in the universe.

2. Appraising Infrared Imaging for Exoplanet Research

One of the topics of the National Radio Astronomy Observatory (NRAO) is Exoplanets. The Infrared Array Camera (IRAC), used during the Spitzer mission, is a four-channel camera that allows astronomers to measure light at a specific wavelength. This particular feature enables the imaging camera to detect photons at near and mid-range infrared wavelengths of 3.6 to 8.0 microns. These detectors, made from arsenic and indium, can take images simultaneously at four specific wavelengths. Kepler-442b, a rocky planet orbiting the K star Kepler-442, is considered an exoearth. The planet, approximately 1,194 light-years from Earth, inhabits a location where it would not be tidally locked to its star.

3. Acknowledging the Pioneers of Radio Astronomy

Grote Reber and Karl Jansky are pioneers of radio astronomy. In 1931, Reber constructed the first radio telescope in his backyard, equipped with a 9.6-meter parabolic dish mounted on an altazimuth. He and Jansky discovered cosmic radio waves coming from beyond our solar system. Jansky, who built his telescope in 1931, received signals from space, and concluded that the signals must be coming from outside the solar system. He later discovered radio waves coming from the Sagittarius constellation. Jansky was subsequently able to build a radio collecting telescope to categorize signals into three types - nearby thunderstorms, distant thunderstorms, and an unknown hiss with faint origins. Their contributions have been monumental for contemporary science in identifying celestial bodies using radio astronomy.

4. Discovering the Latest Scientific Progress in Radio Astronomy

The latest peer-reviewed science journal article that utilizes radio observations is "The Cold Dust Properties of Phases Identified in Herschel SPIRE Maps," published in The Astrophysical Journal. The paper explores the properties of the cold dust phase of self-regulated star formation cycles. Based on data from the Herschel Space Observatory, which observed wavelengths from 70 µm to 500 µm, researchers used submillimeter array radio observations to analyze star-forming regions' properties. The research shows the properties of the dust in the star-forming regions and indicates future prospects for observing dust through radio telescopes. This information enhances our understanding of star-forming regions, advancing the field of astrophysics.

In 1949, Centaurus A was established as the first extragalactic radio source. The comprehensive study of Centaurus A covered different wavelengths, including radio, infrared, optical, X-ray, and gamma-ray, utilizing various observatories. The central region of Centaurus A contains a black hole that has a mass of 55 million suns, which is intermediate between the black hole in Messier 87, which is six and a half billion suns, and the one in our Milky Way, which is four million suns. With higher frequency and resolving power, scientists have photographed the jet launched in Centaurus A. The new observations suggest that the black hole's probable position is the launching point of the Centaurus A jet. With this location, scientists anticipate that forthcoming examinations with smaller wavelengths and higher resolution could capture images of Centaurus A's central black hole.

Sources:

Arney, G. N. (2019). The K Dwarf advantage for biosignatures on directly imaged exoplanets. The Astrophysical Journal Letters, 873(1), L7.

Spitzer Space Telescope, (n.d.). The Infrared Array Camera (IRAC). https://www.spitzer.caltech.edu/mission/the-multiband-imaging-photometer-mips

Yang, J., Ji, W., & Zeng, Y. (2020). Transition from eyeball to snowball driven by sea-ice drift on tidally locked terrestrial planets. Nature Astronomy, 4(1), 58-66.

Jansky, K. G., & Reber, G. (2013). 6. On the Discovery of Extraterrestrial Radio Waves. In A Source Book in Astronomy and Astrophysics, 1900–1975 (pp. 30-35). Harvard University Press.

McKinley, B., Tingay, S. J., Gaspari, M., Kraft, R. P., Matherne, C., Offringa, A. R., & Johnston-Hollitt, M. (2022). Multi-scale feedback and feeding in the closest radio galaxy Centaurus A. Nature Astronomy, 6(1), 109-120.