University of Tasmania
Browse

File(s) not publicly available

Cosmic: Microarcsecond Resolution with a 30 Meter Radio Telescope

journal contribution
posted on 2023-05-16, 16:03 authored by Peter McCullochPeter McCulloch, Simon EllingsenSimon Ellingsen, Jauncey, DL, Steven CarterSteven Carter, Cimo, G, Lovell, JEJ, Dodson, R
Interstellar scintillation has been conclusively demonstrated to be the principal cause of the intraday variability (IDV) observed in the centimeter-wavelength emission of many active galactic nuclei. A few sources show large amplitude modulation in their flux density on a timescale of hours. However, the majority of IDV sources exhibit variability on timescales of a day or more. Some sources have been found to show an annual cycle in the pattern of their variability. Such an annual cycle occurs because the relative speeds of the Earth and the interstellar medium change as the Earth orbits the Sun. To search for these annual variations, as well as to follow the source evolution, requires a dedicated instrument; the necessary amounts of observing time are beyond the capability of the National Facility instruments. Here we describe the scientific motivation for and present an outline of the COSMIC (Continuous Single-Dish Monitoring of Intraday Variability at Ceduna) project, which uses the University of Tasmania's 30m diameter radio telescope at Ceduna, which has been monitoring the flux density of a number of the stronger southern scintillators at 6.65 GHz since 2003 March. © 2005. The American Astronomical Society. All rights reserved.

History

Publication title

The Astronomical Journal

Volume

129

Issue

4

Pagination

2034-2040

ISSN

0004-6256

Department/School

School of Natural Sciences

Publisher

Univ Chicago Press

Place of publication

Chicago, USA

Repository Status

  • Restricted

Socio-economic Objectives

Expanding knowledge in the physical sciences

Usage metrics

    University Of Tasmania

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC