What Could You Use to Measure the Mass of the Dark

question 36

Multiple Choice

What could you use to measure the mass of the dark matter halo in a spiral galaxy?

• A) H \(\Pi\) emission from H II regions in the spiral disk
• B) The velocities of satellite dwarf galaxies surrounding a spiral galaxy
• C) Absorption lines in the spectra of its globular clusters
• D) All of the above

---

Definitions:

Recall, Recognition, And Relearning

Cognitive processes related to memory, where recall involves retrieving information without cues, recognition requires identifying information from available options, and relearning measures how much faster information is processed or learned again after it has been previously learned and forgotten.

Encoding

The initial process of transforming information into a form that can be stored in memory, an essential step in the creation of new memories.

Echoic Memory

A subtype of sensory memory that retains audio information for a brief period, usually up to several seconds after the original sound has ceased.

Iconic Memory

A type of visual sensory memory that holds an exact copy of the visual information it receives for a very short period of time.