How can you tell a quasar from a star?

How can you tell a quasar from a star?

Answer: With even the larger optical telescopes that astronomers have at their disposal, one cannot tell the difference between a star and a quasar as they both look like bright points of light in an image made with an optical telescope. The name “quasar”, in fact, means “quasi-stellar radio source”.

What are broad absorption lines called?

INTRODUCTION. The most luminous active galactic nuclei (AGN) are known as quasars. Broad absorption line (BAL) quasars are those quasars which show ultraviolet (UV) absorption troughs thousands of km s−1 wide (e.g. Lynds 1967; Allen et al.

What are broad emission lines?

Abstract Broad emission lines hold fundamental clues about the kinematics and structure of the central regions in AGN. There is growing evidence that a fundamental parameter underlying Eigenvector 1 may be the luminosity-to-mass ratio of the active nucleus (L/M), with source orientation playing a concomitant role.

Are quasars redshifted or Blueshifted?

But observations show no metal deficiency as a function of redshift. Quasars enviroments, based on their emission lines, are generally metal rich with metallicities near or above the solar value.

What is natural line width?

The line width ΔνL is also called natural line width and is connected with the decay time τ which is also known as natural life time. Typical values of ΔνL for single and undisturbed molecules that perform transitions within the visible range of the electromagnetic spectrum are between one and 10 Megahertz.

What is the most powerful thing in the Universe?

Quasars inhabit the centers of active galaxies and are among the most luminous, powerful, and energetic objects known in the universe, emitting up to a thousand times the energy output of the Milky Way, which contains 200–400 billion stars.

What is the largest object in the Universe?

Hercules-Corona Borealis Great Wall
The largest known ‘object’ in the Universe is the Hercules-Corona Borealis Great Wall. This is a ‘galactic filament’, a vast cluster of galaxies bound together by gravity, and it’s estimated to be about 10 billion light-years across!