ISRO Missions and Discoveries

[pib] 3D distribution of Molecular & Atomic Hydrogen in Galaxies

Note4Students

From UPSC perspective, the following things are important :

Prelims level : Read the attached story

Mains level : Formation of stars

Indian scientists have estimated the three-dimensional distribution of molecular and atomic hydrogen in a nearby galaxy which can help lead to clues to the star formation processes and the evolution of the galaxy.

Study on Hydrogen distribution

  • Galaxies like the one we reside in, the Milky Way, consist of discs containing stars, molecular and atomic hydrogen, and helium.
  • The molecular hydrogen gas collapses on itself in distinct pockets, forming stars, its temperature was found to be low –close to 10 kelvin, or -263 ºC, and thickness is about 60 to 240 light-years.
  • The atomic hydrogen extends both above and below the discs.
  • Indian scientists have estimated that molecular hydrogen extends farther from the disc in both directions, up to about 3000 light-years.
  • This gaseous component is warmer than the one straddling the disc and has comparatively lesser densities, thus escaping earlier observations.
  • They called it the ‘diffuse’ component of the molecular disc.

Answer this PYQ in the comment box:

Q. Which one of the following sets of elements was primarily responsible for the origin of life on the Earth?

(a) Hydrogen, Oxygen, Sodium

(b) Carbon, Hydrogen, Nitrogen

(c) Oxygen, Calcium, Phosphorous

(d) Carbon, Hydrogen, Potassium

Why does this study matter?

  • The molecular hydrogen gas converts to individual stars under the pull of gravity, thus holding clues to the star formation processes and the evolution of the galaxy.
  • If a significant part of the gas extends beyond the thin disc of a few hundred light-years, it may explain why astronomers also observe stars at a few thousand light-years perpendicular to the galactic disc.
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Karthik Jayaram
Karthik Jayaram
4 months ago

Carbon, Hydrogen, Nitrogen