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