A) Plasma B) Rock formations C) Gas and dust D) Liquid water
A) Radio waves B) Gamma rays C) X-rays D) Visible light
A) Microwave heating B) Heat conduction C) Radiative torque alignment D) Ionization imbalance
A) H II regions B) Molecular clouds C) Supernova remnants D) Reflection nebulae
A) Oxygen B) Helium C) Hydrogen D) Carbon
A) Diamonds B) Platinum C) Gold D) Silicates
A) Carbon dioxide (CO2) B) Methane (CH4) C) Polycyclic aromatic hydrocarbons (PAHs) D) Carbon monoxide (CO)
A) Green B) Blue C) Red D) Yellow
A) Supernova remnant B) Dark nebula C) Reflection nebula D) H II region
A) 1 trillion (1012) molecules/m3 B) 100 ions/m3 C) 10 quadrillion (1016) molecules/m3 D) 1 billion (109) molecules/m3
A) Coronal gas B) Photodissociation region C) Warm ionized medium D) Cold dense phase
A) 50% B) 5% C) 1% D) 10%
A) Neutron stars B) Red giants C) OB stars D) White dwarfs
A) ~ 104 K B) < 300 K C) ~ 106 K D) O(105 K)
A) ~ 1025 molecules/m3 B) ~ 100 ions/m3 C) ~ 1012 molecules/m3 D) ~ 1016 molecules/m3
A) Warm intercloud phase B) Cold dense phase C) Photodissociation region D) Very hot gas (T ~ 106 K)
A) All phases have equal density. B) Thermal pressure is more important than magnetic fields. C) Pressure varies significantly across different regions. D) The phases are roughly in pressure balance over most of the Galactic disk.
A) René Descartes B) Francis Bacon C) William Huggins D) Edward Barnard
A) Spectral lines from CO B) Forbidden lines of O III C) 21-cm line of H I D) Ly-α photon from hydrogen
A) Interstellar dust B) Stellar nucleosynthesis during stellar evolution. C) Cosmic rays D) Primordial nucleosynthesis
A) They reduce the number of hydrogen atoms. B) They convert surrounding gas into the warm ionized phase, increasing temperature. C) They decrease the density of the ISM. D) They create cold neutral medium.
A) Bremsstrahlung radiation B) Inverse Compton scattering C) Photon emission from de-excitation D) Synchrotron radiation
A) Dipole radiation B) Far infrared quasi-blackbody emission C) Millimetre wavelength lines D) 21-cm line emission
A) O III B) H2 (molecular hydrogen) C) N II D) CO (carbon monoxide)
A) Collision with atomic nuclei B) Bremsstrahlung cooling C) Synchrotron radiation D) Inverse Compton scattering
A) It has no effect on the ISM. B) It prevents star formation in spiral arms. C) It compresses all ISM into a thin disk. D) It influences their dynamics and structure.
A) It only contains cold gas. B) It remains unchanged from the rest of the galaxy. C) It becomes entirely in the coronal phase. D) It is profoundly modified by the central supermassive black hole.
A) Synchrotron radiation B) Far infrared quasi-blackbody emission C) Millimetre wavelength lines D) 21-cm line emission
A) Bremsstrahlung radiation B) Synchrotron radiation C) Inverse Compton scattering D) Quasi-blackbody emission
A) 2040 B) 2025 C) 2020 D) 2030
A) Absorption lines B) Reddening C) Scattering D) Emission lines
A) Carbon monoxide. B) Only hydrogen and helium molecules. C) Buckminsterfullerene (C60) or 'buckyballs'. D) Simple hydrocarbons.
A) Edward Barnard B) Slipher C) Victor Hess D) Mary Lea Heger
A) Telescope lens B) Refraction C) Spectroscopy D) Photography
A) Fine structure cooling B) Inverse Compton scattering C) Synchrotron radiation D) Bremsstrahlung radiation
A) They reduce the number of photons with energy below the Lyman limit. B) They increase the density of molecular clouds. C) They cool down the ionized gas. D) They contribute to the heating of the warm neutral medium.
A) Brackett-alpha transition B) Paschen-alpha transition C) Balmer-alpha transition D) Lyman-alpha transition
A) Far infrared quasi-blackbody emission B) Bremsstrahlung radiation C) Synchrotron radiation D) Dipole radiation from spinning nanometre-sized grains
A) Infrared emission B) Synchrotron radiation C) Gamma-ray photons D) Bremsstrahlung radiation
A) 10,000 parsecs B) 30,000 parsecs C) 100 parsecs (300 light years) D) 500 parsecs
A) 50 km/s B) 1000 km/s C) 200 km/s D) 500 km/s |