Universal Sirens: Gamma Ray Bursts Astronomy Quiz

If a massive star collapses or two neutron stars merge, then a massive amount of energy is released. If this energy is concentrated into beams of gamma rays, then we detect a sudden "burst" on Earth. Therefore, GRBs are the most powerful explosions in the universe.

If we look at the electromagnetic spectrum, then gamma rays have the highest frequency. If energy is proportional to frequency (E=hf), then gamma rays must carry significantly more energy than visible light. Therefore, the statement is true.

If gamma rays hit the nitrogen and oxygen atoms in our air, then they are absorbed or scattered. If this happens, the signal never reaches telescopes on the ground. Therefore, sensors must be placed in space, above the atmosphere, to "see" the burst.

If the explosion hits the gas surrounding the star, it creates a second, longer-lasting glow. If this glow is seen in X-rays, visible light, and radio waves after the main burst, then it is called the afterglow. Therefore, the answer is afterglow.

If a detector is in space, it is hit by random particles and background radiation. If these random hits are recorded alongside the actual GRB, then they make the data "messy." Therefore, signal processing must filter out this noise to see the true burst.

If a very massive star reaches the end of its life, it collapses into a black hole and shoots out jets. If these jets take several seconds or minutes to finish their initial blast, then the burst is classified as "long." Therefore, long GRBs are associated with "super-massive" star deaths.

If the universe is expanding, then the space through which the light travels is stretching. If the space stretches, then the waves of light are also stretched. If the waves stretch, then the wavelength becomes longer. Therefore, this is known as Cosmological Redshift.

If a signal hits three different satellites at slightly different times, then we can calculate the distance to the source from each. If we find where those distances intersect, then we have the location. Therefore, this technique is called triangulation.

If a burst happens in a fraction of a second, then electronics must be extremely fast to record it. If there is background noise, then we must filter it. If they happen randomly, we must watch the whole sky at once. Therefore, A, B, and D are the main technical hurdles.

If we record the number of gamma rays hitting the sensor every millisecond, then we can plot those numbers on a graph. If the X-axis is time and the Y-axis is brightness, then the resulting line shows how the burst "evolved." Therefore, this graph is called a light curve.

If two extremely dense neutron stars spiral into each other, then they merge in a very fast explosion. If this explosion releases a burst of gamma rays that lasts less than 2 seconds, then it is a "short" GRB. Therefore, the statement is true.

If a signal changes very quickly, then we must check the sensor many times every second. If we only check once a second, then we miss the details of a millisecond-long burst. Therefore, a high sampling rate is necessary to capture the fast "wiggles" in a GRB signal.

If we have a mix of "real" data and "noise," then we need to separate them. If we use a mathematical rule to throw away the noise and keep the signal, then we are cleaning the data. Therefore, this process is called filtering.

If gamma-ray detectors have poor "vision" (resolution), then they only give a rough area of the sky. If we find the visible light (optical) afterglow with a traditional telescope, then we can see the exact star or galaxy. Therefore, the optical counterpart provides the precise location.

If we spread the light into a spectrum, then we can see how much it was stretched (distance). If there are gaps in the spectrum, then we know what gas clouds are between us and the burst. Therefore, A, B, and C are all useful data points.

If a short GRB is caused by the merger of two objects, then those objects must have been orbiting each other first. If two objects orbit each other, then it is a binary system. Therefore, the statement is true.

If we recorded every second of empty space, then we would run out of memory. If the computer is programmed to ignore the "quiet" sky but start saving data when the brightness suddenly jumps, then it is "triggered" by the burst. Therefore, the trigger ensures we only save important data.

If a computer processes a signal, then it turns the signal into 1s and 0s. If each 1 or 0 represents a single choice or value, then it is a "binary digit" or bit. Therefore, the bit is the basic building block of digital data.

If the real signal is very strong and the noise is very weak, then the SNR is high. If the SNR is high, then the data is very clear and easy to read. Therefore, the SNR is a measure of how good the data quality is.

If a massive star collapses or two neutron stars merge, then the resulting gravity is so strong that it crushes the matter into a single point. If this point is so dense that light cannot escape, then it is a black hole. Therefore, the "central engine" of a GRB is almost always the birth of a black hole.