Morehead State University
Defining Antenna Gain and System Temperature of the Morehead State University 21-Meter Space Tracking Antenna and Initial Observations of Microvariabilty in Active Galactic Nuclei at 1420 MHz
Institution
Morehead State University
Faculty Advisor/ Mentor
Benjamin Malphrus
Abstract
The Morehead State University 21-Meter Space Tracking Antenna and Radio Telescope is a centimeter-wavelength radio telescope designed to permit the investigation of a wide variety of astronomical phenomena at different frequencies, (L-Band, S-Band, and Ku-Bands), and also to provide telemetry, tracking, and control services for space missions. The performance of this instrument is highly dependent upon the antenna’s radio frequency (RF) performance characteristics. Primary among these are antenna gain and system temperature, both of which can be numerically derived from G/T. The value of G/T serves as a predictor of the instrument’s ability to detect and measure characteristics of distant astronomical sources. Active Galactic Nuclei (AGNs) are some of the most distant objects known in the universe and, as such, require optimum instrumental sensitivity and gain. One of the interesting characteristics of AGNs is that they vary in brightness over a variety of time scales including long term (years or decades), intraday (days or weeks), and very short periods (hours or minutes). By monitoring the microvariability in the atomic hydrogen line at 1420 MHz, we may be able to determine if the variability is due the internal processes of these objects or due to the intervening medium, and to provide insight into the nature and process of the AGN central engines. Using the Morehead State University 21-Meter Space Tracking Antenna, we can measure short-term variations (microvariability) of the radio frequency radiation of these distant objects. Herein we report baseline measurements of G/T and initial observations of microvariability of a set of AGNs.
Defining Antenna Gain and System Temperature of the Morehead State University 21-Meter Space Tracking Antenna and Initial Observations of Microvariabilty in Active Galactic Nuclei at 1420 MHz
The Morehead State University 21-Meter Space Tracking Antenna and Radio Telescope is a centimeter-wavelength radio telescope designed to permit the investigation of a wide variety of astronomical phenomena at different frequencies, (L-Band, S-Band, and Ku-Bands), and also to provide telemetry, tracking, and control services for space missions. The performance of this instrument is highly dependent upon the antenna’s radio frequency (RF) performance characteristics. Primary among these are antenna gain and system temperature, both of which can be numerically derived from G/T. The value of G/T serves as a predictor of the instrument’s ability to detect and measure characteristics of distant astronomical sources. Active Galactic Nuclei (AGNs) are some of the most distant objects known in the universe and, as such, require optimum instrumental sensitivity and gain. One of the interesting characteristics of AGNs is that they vary in brightness over a variety of time scales including long term (years or decades), intraday (days or weeks), and very short periods (hours or minutes). By monitoring the microvariability in the atomic hydrogen line at 1420 MHz, we may be able to determine if the variability is due the internal processes of these objects or due to the intervening medium, and to provide insight into the nature and process of the AGN central engines. Using the Morehead State University 21-Meter Space Tracking Antenna, we can measure short-term variations (microvariability) of the radio frequency radiation of these distant objects. Herein we report baseline measurements of G/T and initial observations of microvariability of a set of AGNs.