Kent State Astronomical Research Society

1
Radio astronomy and astrophysics educationA
collaborative student-lead research effort
Aaron Slodov, Theodore Riffe, Mitchell Peters,
Justin Wheatcroft, Kevin Pospichel, Jeremy
Walmsley, Maeve Manion-Fischer, Jeremy Williams,
Kevin DiVincenzo Physics Department, Kent State
University
Introduction The Kent State physics department
is not active in astronomy or astrophysics
research. After a 2008 summer research
internship at the SETI Institute, senior physics
major Aaron Slodov recruited fellow students
Theodore Riffe, and Mitchell Peters to embark on
a revitalization campaign to re-introduce
astronomy to fellow students, the physics
department, and the university at large. The
proposal was eagerly met by members of the United
States node for the International Year of
Astronomy 2009 committee, as well as the
department chair Dr. Bryon Anderson who ensured
its progress and hopeful completion with a
generous grant. Now, after the donation of a
fully functional radio telescope thanks to MIT
and Wellesley College, we have the ability to
completely satisfy our goals.
Galactic Rotation Curves Galaxy rotation curves
(GRCs) are simple curves which represent a
galaxys orbital speed vs. its radius. These are
more than just a practical tool to measure the
mass of a galaxy, or your position in it. GRCs
were the first products of direct experimentation
that gave rise to dark matter theory. As seen
below, on a solar-system scale graph, the planets
obey Keplerian dynamics as the distance from the
sun increases. However, in the galactic scale
shown opposite, it can be seen there is a clear
discrepancy between the planetary, as the speed
from the center of the Milky Way remains
relatively constant. Current theory hinges
around this discrepancy, stating that in order to
maintain the velocities seen at longer distances,
there must be a huge amount of mass that is not
related to any light-emitting type of mass known
hence dark matter.
How does a radio telescope work? A standard
radio telescope is typically a single parabolic
dish which collects electromagnetic radiation in
the form of radio wavelengths from any celestial
object and focuses them into the feed. The
feed contains sensitive electronics which
includes a preamp, and a receiver. The signal
received is amplified, then sent through the
digital receiver which translates the waves
information into an electronic format that is
then processed by analytical spectrum software
and stored on a computer.
Resolution and Diffraction For small and single
dish radio telescopes, an inherent problem
becomes that of its resolution. As in optical
telescopes, the resolution is essentially the
ability to resolve an object at a particular
distance, as such, the same applies to radio
telescopes but the resolution depends on what
frequency is being observed as well as the
diameter of the dish. Resolution is ultimately
limited by diffraction, but still allows for
actual images to be generated based on data.
AimsThis project is a means to prepare junior
and senior level physics majors with a thorough
understanding of how a scientific research
project is carried out from concept to reality,
including but not limited to conceptual
planning, obtaining funding, instrumentation,
physics and calculations, and most importantly,
communications - in order to maintain a
progressive working environment. These aims are
ancillary of course to the development of our
experience and interests in astronomy and
astrophysics, as well as to leave Kent State with
an educational instrument for future students.
Radio Imaging Most commonly, celestial objects
are seen as a falsely colored visible light
image, which is rendered by taking the
information stored in each pixel and converting
it to an associated color. The same applies to
radio imaging, except each pixel contains a
different set of information and range of
color. Galaxy M31 or the
Andromeda Galaxy seen in both radio and
visible wavelengths.

• Radio Astronomy
• Radio astronomy is the study of the universe in
  the radio wavelength of the electromagnetic (EM)
  spectrum. Radio telescopes allow us to bypass
  dust, clouds, and light pollution which are
  inherently problematic for traditional optical
  telescopes. While radio astronomy comes with its
  own limitations, it is an extremely useful tool
  to observe phenomena that require a level of
  accuracy and certainty only found in this part of
  the EM spectrum. As seen below, radio astronomy
  is mostly concerned with a small range of
  wavelengths from 0.05 m to 20 m due to the
  opacity or visibility through the Earths
  atmosphere in this range.
• The most abundant element in the universe,
  Hydrogen, emits radio waves at exactly 21 cm in
  length (the Hydrogen emission line)
• The majority of celestial bodies in the
  universe, including the Sun, Jupiter, and the
  Milky Way are active radio sources
• The Hydrogen emission line has been used to
  calculate the mass of the galaxy, as well as our
  position in it
• Radio astronomy is still helping to determine
  some of the largest unanswered questions in
  cosmology today which includes answering
  questions from Big Bang theory

Rotation curves of both planetary and galactic
scales

• Organization
• Our group is composed of 9 physics majors
  currently, and overseen by Dr. Bryon Anderson,
  and Dr. Brett Ellman. Tasks are delegated on a
  first come first serve basis, we use a Google
  document on the web to communicate which tasks
  are available and completed. We have a weekly
  meeting to discuss progress, come up with new
  problems, and ways of solving them. Since the
  inception of the group last fall, it has come to
  be known as the Kent State Astronomical Research
  Society (KSARS).
• Current status
• Complete refurbishment of dish, hardware, and
  accessories
• Construction of the support platform
• Observatory wiring, burying of cables
• Calculations on visible sky from Kent, OH
• Assess any further costs for possible funding
  proposal
• Testing GCU, preamp, and digital receiver
• Assembly of the server for observatory use
• Start observing!

Small Radio Telescope (SRT) Pictured here at
MITs Haystack Observatory, this is the same
working model that is being used on Kents
campus. Specs Dish Diameter 2.3 m Preamp
frequency range 1400 1440 MHz Beam Width _at_
1420 MHz 7 degrees Focal length 85.7
cm The SRT will allow us to begin making
observations on many objects once we have it
placed at the observatory. We are currently
waiting on ground thaw in order to construct a
stable platform - atop which the dish will rest.
Once the platform is complete, we will run all
necessary cables and connect them inside the
observatory to the ground controller unit (GCU).
A data collection/manipulation server will also
be setup and directly connected to the GCU, this
server will be attached to the high-speed fiber
optic network in order to allow us remote access
and observing abilities. Java control software
will allow for easy interfacing with the
telescope from anywhere, provided an internet
connection. After initial calibrations are made,
and the dish is in good operational standing, we
will begin our first research objective to create
a rotation curvature map of the Milky Way using
hydrogen emission.
Acknowledgements This work is supported by the
Physics Department of Kent State University,
through a grant being overseen by chairperson Dr.
Bryon Anderson. The authors gratefully
acknowledge the support of both MIT and Wellesley
College for their generous donation. This
project is also supported by the United States
IYA2009 committee.
Electromagnetic spectrum for astronomy