shock waves articles
What primarily causes supernova remnants like SN 1987A to display bright rings instead of perfect spheres?
What type of star was the progenitor of Supernova 1987A?
How was the dense, equatorial ring surrounding the progenitor of SN 1987A likely formed?
If an observer views a dense, dusty torus surrounding a star, what viewing angle results in the appearance of a thin circle?
What phenomenon is responsible for the bright light observed in the ring structure of a supernova remnant?
What capability allows instruments like the James Webb Space Telescope (JWST) to better study supernova remnants?
Besides pre-ejected material, what intrinsic factor related to the progenitor star can cause a supernova remnant to be non-spherical?
What diagnostic technique allows astronomers to map the geometry of the pre-ejected material over several years for SN 1987A?
What fate awaits the bright ring structure as the supernova remnant ages beyond its initial interaction phase?
The text contrasts the intuitive expectation of a supernova explosion with the observed reality. What is the intuitive expectation?
What initial challenge baffled astronomers regarding spiral arms due to differential rotation?
Who developed the Density Wave Theory to explain long-lived spiral structures?
What are spiral structures described as in the traffic analogy on a freeway?
What defines the radius where the orbiting matter speed matches the pattern speed ($\Omega_{gp}$)?
Which two radii define the stable boundaries for a long-lived spiral structure?
What mechanism is responsible for triggering star formation within the spiral arms?
Why do the bright blue OB stars associated with the arms fade relatively quickly?
What mechanism transforms a minor density fluctuation into a much larger trailing wave pattern?
What term describes galaxies with clear, persistent, two-armed spiral structures?
Besides galactic disks, where was the mathematical description of density waves successfully applied?
Why do the luminous bands of spiral galaxies appear spectacularly bright?
What theory best explains the persistent, slowly rotating pattern of spiral arms?
What is the critical function performed by the density wave as it passes through the interstellar medium?
What characteristic links the color of newly formed stars to their surface temperature?
What do infrared observations effectively reveal within a spiral galaxy structure?
What happens to individual stars as they pass through the density wave front?
Which type of spiral galaxy classification lacks distinct, grand spiral patterns due to less dominant density wave influence?
What characteristic do older, longer-lived stars exhibit when located in the smoother inter-arm regions?
What light energy is specifically used to pinpoint the hottest, youngest stellar populations and very hot gas?