2021-07-22

Research to explain the formation of negative ions in interstellar space

By yqqlm yqqlm

Research to explain the formation of negative ions in interstellar space

“In short, our ion trap allows us to The conditions in space are reproduced in the laboratory,” Roland Wester explained. “This instrument allows us to study the formation of compounds in detail.” Scientists working with Roland Wester have now found an explanation for how negatively charged molecules are formed in space.

An idea based on theory

Before the discovery of the first negatively charged carbon molecule in space in 2006, it was thought that interstellar clouds contained only positively charged ions. Since then, how negatively charged ions are formed has been an open question. The Italian theorist Franco A. Gianturco worked as a scientist at the University of Innsbruck for 8 years. He developed a theoretical framework several years ago that can provide a possible explanation: the existence of weakly bonded states, the so-called dipole bonding State, it should enhance the attachment of free electrons to linear molecules. Such a molecule has a permanent dipole moment, which strengthens the interaction at a relatively far distance from the neutral nucleus and increases the capture rate of free electrons.

Research to explain the formation of negative ions in interstellar space(1)

In their experiment, because Sbruck’s physicists created molecules composed of three carbon atoms and one nitrogen atom, ionized them, and bombarded them in ion traps with lasers at extremely low temperatures. They keep changing the frequency of light until the energy is large enough to eject an electron from the molecule.

Albert Einstein described this so-called photoelectric effect 100 years ago. The in-depth analysis of measurement data by Malcolm Simpson, an early researcher from the doctoral training program “Atoms, Light and Molecules” at the University of Innsbruck, finally revealed this difficult-to-observe phenomenon. He compared the data with theoretical models and finally provided clear evidence of the existence of dipole binding states.

Research to explain the formation of negative ions in interstellar space(2)

“Our explanation is that these dipoles The sub-bound state represents a way of opening the door for the combination of free electrons and molecules, thereby promoting the generation of negative ions in space,” Roland Wester said. “Without this intermediate step, it would be extremely unlikely that electrons would truly bind to molecules.”