Lecture

Radio Astronomy: The Hidden Universe

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Description

This lecture introduces the fascinating world of radio astronomy, highlighting how radio observations can unveil unexpected celestial objects and phenomena, from violent events to dark matter. The course explores the unique features of radio observations, the technology behind detecting radio waves, and the upcoming Square Kilometer Array project. Taught by experts in the field, students will delve into the physical processes generating radio emissions and study various astrophysical radio objects, including black holes, pulsars, galaxies, and the cosmic microwave background.

In MOOC

The Radio Sky I: Science and Observations

The serendipitous and unexpected discovery of radio emission from celestial objects opened up the possibility of studying a new and exciting view of the universe beyond the visible spectrum. Astronomers have been studying the cosmos in visible light since ancient Greece, but it is only in comparatively modern times that the universe beyond the visible spectrum has become accessible to us. In this course you will learn about the most important objects that emit in the radio regime, both within and beyond ou

Official source

Related concepts (31)

Radio astronomy

Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. The first detection of radio waves from an astronomical object was in 1933, when Karl Jansky at Bell Telephone Laboratories reported radiation coming from the Milky Way. Subsequent observations have identified a number of different sources of radio emission. These include stars and galaxies, as well as entirely new classes of objects, such as radio galaxies, quasars, pulsars, and masers.

Radio wave

Radio waves are a type of electromagnetic radiation with the longest wavelengths in the electromagnetic spectrum, typically with frequencies of 300 gigahertz (GHz) and below. At 300 GHz, the corresponding wavelength is 1mm, which is shorter than the diameter of a grain of rice. At 30 Hz the corresponding wavelength is ~, which is longer than the radius of the Earth. Wavelength of a radio wave is inversely proportional to its frequency, because its velocity is constant.

Radio

Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 3,000 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves, and received by another antenna connected to a radio receiver. Radio is widely used in modern technology, in radio communication, radar, radio navigation, remote control, remote sensing, and other applications.

Radio propagation

Radio propagation is the behavior of radio waves as they travel, or are propagated, from one point to another in vacuum, or into various parts of the atmosphere. As a form of electromagnetic radiation, like light waves, radio waves are affected by the phenomena of reflection, refraction, diffraction, absorption, polarization, and scattering. Understanding the effects of varying conditions on radio propagation has many practical applications, from choosing frequencies for amateur radio communications, international shortwave broadcasters, to designing reliable mobile telephone systems, to radio navigation, to operation of radar systems.

Shortwave radio

Shortwave radio is radio transmission using shortwave (SW) radio frequencies. There is no official definition of the band, but the range always includes all of the high frequency band (HF), which extends from 3 to 30 MHz (100 to 10 metres); above the medium frequency band (MF), to the bottom of the VHF band. Radio waves in the shortwave band can be reflected or refracted from a layer of electrically charged atoms in the atmosphere called the ionosphere.

Related lectures (61)

Cosmology Insights: The Hot Big Bang Theory

Covers the hot big bang theory, its origins, and implications for cosmology.

Radio Astronomy: The Hidden Universe

Explores the unique features of the radio sky and the technologies used in detecting radio waves.

Astroparticle Physics: Neutrinos and Dark Matter

Explores the dynamics of the Universe, neutrinos, relic neutrino background, dark matter candidates, and WIMPs.

Data Inspection: Visibility Data and CASA Software MOOC: The Radio Sky II: Observational Radio Astronomy

Covers the inspection of visibility data and the use of CASA software for radio astronomy.

Cosmology and the Milky Way: An Overview