Netherlands Research School for Astronomy (NOVA) | 2014 Oct 28
An international team of astronomers under the guidance of graduate student Leah Morabito of Leiden Observatory has for the first time discovered the largest carbon atoms outside our Milky Way with the LOFAR radio telescope. In the future astronomers will be able to measure how cold and dense the gas around these atoms is that influences star formation and the evolution of a galaxy. The results are published in the journal Astrophysical Journal Letters on 28 October.[attachment=0]GrootsteKoolstofatomen_28oktober_1.jpg[/attachment]
"Carbon atoms are about half a million times smaller than the average thickness of a human hair, but they can be a billion times larger in the cold and sparse gas. The outermost electron is then orbiting the nucleus at a much larger distance," explains first author Morabito. The outermost electron can be captured by an atom that is missing an electron. A spectral line will then be visible in the light spectrum. All spectral lines form the chemical fingerprint of an atom such as carbon.
Astronomers predicted in the 70’s that the carbon spectral line would be detectable outside our galaxy. This first observation took 40 years to be made. The line is hard to detect because it is too faint when the gas that is surrounding the atoms is too warm or too dense. The cold, sparse gas is present in starburst galaxies - galaxies in which stars form at a high rate. For this reason the carbon spectral line is easier to detect in galaxies of this type. ...
Discovery of Carbon Radio Recombination Lines in M82 - Leah K. Morabito et al
- Astrophysical Journal Letters 795(2) L33 (2014 Nov 10) DOI: 10.1088/2041-8205/795/2/L33
arXiv.org > astro-ph > arXiv:1410.1544 > 06 Oct 2014