Question
Answer the following about the Square Kilometer Array, or SKA (“S-K-A”), an ambitious international project to build a radio telescope, for 10 points each.
[10m] The SKA will use this spectral feature to study the cosmic dark ages and the epoch of reionization. This spectral feature is created by a transition between hyperfine levels of the 1s (“one-S”) ground state.
ANSWER: 21-centimeter line [or 21 cm line; accept neutral hydrogen line or H I line (“H-one line”); prompt on hydrogen line or H line]
[10e] The SKA will use over 100,000 antennae to meet its requirements for sensitivity and this quantity. This quantity measures the angular distance between objects that a telescope can distinguish.
ANSWER: angular resolution [accept resolving power or minimum resolvable angle]
[10h] Like the Very Large Array, SKA will use this interferometric technique, which is based on the Van Cittert–Zernike (“vahn SIT-ert SAIR-nee-kuh”) theorem. This technique uses an array of paired telescopes to simulate a single telescope with higher resolution.
ANSWER: aperture synthesis [or synthesis imaging or aperture synthesis imaging]
<Other Science>
Summary
| 2024 ACF Nationals | 2024-04-21 | Y | 24 | 10.00 | 63% | 38% | 0% |
Data
| Claremont Colleges | Arizona State | 0 | 0 | 0 | 0 |
| Chicago C | Vanderbilt | 0 | 0 | 0 | 0 |
| Chicago A | Cornell A | 0 | 10 | 0 | 10 |
| Illinois | Georgia Tech | 10 | 10 | 0 | 20 |
| Kentucky | Harvard | 0 | 0 | 0 | 0 |
| Johns Hopkins | Iowa State | 10 | 10 | 0 | 20 |
| Maryland | Toronto A | 0 | 0 | 0 | 0 |
| Chicago D | Minnesota B | 10 | 0 | 0 | 10 |
| NYU | Michigan | 10 | 0 | 0 | 10 |
| North Carolina B | Cornell B | 10 | 10 | 0 | 20 |
| Northwestern | Brown | 0 | 10 | 0 | 10 |
| Penn | Ottawa | 0 | 0 | 0 | 0 |
| Indiana | Purdue | 10 | 10 | 0 | 20 |
| Florida | Rutgers | 0 | 10 | 0 | 10 |
| South Carolina | McGill | 0 | 10 | 0 | 10 |
| Stanford | Minnesota A | 0 | 10 | 0 | 10 |
| Texas | Columbia A | 10 | 10 | 0 | 20 |
| Duke | Toronto B | 0 | 10 | 0 | 10 |
| Berkeley B | Truman State | 0 | 10 | 0 | 10 |
| Yale B | Virginia | 0 | 0 | 0 | 0 |
| North Carolina A | WUSTL A | 10 | 10 | 0 | 20 |
| WUSTL B | Columbia B | 10 | 0 | 0 | 10 |
| Chicago B | Waterloo | 0 | 10 | 0 | 10 |
| Yale A | Berkeley A | 0 | 10 | 0 | 10 |