Astro11.2-Active Galactic Nuclei (AGN)

These flashcards cover important vocabulary and concepts related to Active Galactic Nuclei and their characteristics discussed in the lecture.

AGN

Active Galactic Nuclei, the central region of a galaxy that is exceptionally bright due to the presence of supermassive black holes.

Elliptical Galaxies

Galaxies that are round to oval in shape with little to no gas and dust.

Starburst Galaxies

Galaxies with a significant amount of star formation occurring.

Radio Galaxies

Active galaxies that emit more light in the radio frequency than in the visible spectrum.

BL Lac Objects

Objects that appear star-like but have strong emission lines and polarization of light.

Quasars

Massive objects that radiate more energy than the entire galaxy they reside in, often a billion times the mass of the sun.

Redshift

The phenomenon where light from an object is increased in wavelength, usually due to the object moving away from the observer.

Flux

The amount of energy passing through a surface per unit area, significant in measuring the strength of an emission line.

Luminosity

The total amount of energy emitted by a star, galaxy, or quasar per unit of time.

Hubble's Law

A key relationship in cosmology that correlates the distance of galaxies to their recessional velocities.

Emission Lines

Bright lines in the spectrum of light that indicate the presence of specific elements and are produced by gas excited by energy.

C IV

A specific emission line relevant in quasar studies, typically used to trace the relationship between redshift and luminosity.

Graphical Analysis

A method used to analyze spectral data by graphing and comparing emission lines.

We determine the wavelengths of the emission lines

Identify wavelengths using spectral data analysis tools.

Ca II Break

A notable feature in the spectrum of celestial objects that indicates the presence of certain stellar compositions.