What is the primary component of Giant Molecular Clouds (GMCs)?
Answer
Molecular hydrogen ($ ext{H}_2$)
Giant Molecular Clouds (GMCs) are the coldest, densest structures in the interstellar medium where stars initiate their lives. The primary constituent of these clouds is molecular hydrogen ($ ext{H}_2$). These massive reservoirs must overcome internal pressures and turbulence to begin collapsing under gravity, leading to the formation of stellar cores. While Carbon Monoxide (CO) is used as a vital tracer for this molecular gas because $ ext{H}_2$ itself is difficult to observe directly at the low temperatures present, $ ext{H}_2$ remains the dominant physical substance composing the cloud.
Related Questions
What is the primary component of Giant Molecular Clouds (GMCs)?What timescale does $ ext{UV}$ Luminosity ($L_{ ext{UV}}$) typically probe for star formation?Which molecule radiates strongly in the millimeter wave regime, serving as a proxy for $ ext{H}_2$?What process creates the characteristic red light of the $ ext{H} ext{alpha}$ line at $656.3 ext{ nm}$?In a galaxy undergoing steady-state star formation, what relationship should ideally exist between $L_{ ext{UV}}$ and total $L_{ ext{IR}}$?Which indicator traces star formation timescales significantly longer than $10^8$ years, representing the fuel supply?Which gas reservoir traces the *potential* for future star formation, observed via $21 ext{ cm}$ emission?What wavelength range specifically characterizes the Far-Infrared (FIR) useful for tracing dust re-radiation?What does a condition where $L_{ ext{UV}} ext{ extless extless} L_{ ext{IR}}$ strongly imply about current star formation?How does the energy absorbed by dust when blocking UV light manifest as a measurable output?