ALMA: Liberal Sprinkling of Salt Discovered around a Young Star
Posted: Sat Feb 09, 2019 2:56 am
Liberal Sprinkling of Salt Discovered around a Young Star
ALMA | NRAO | NAOJ | ESO | 2019 Feb 08
Orion Source I's Disk Is Salty ~ Adam Ginsburg et al
ALMA | NRAO | NAOJ | ESO | 2019 Feb 08
New ALMA observations show there is ordinary table salt in a not-so-ordinary location: 1,500 light-years from Earth in the disk surrounding a massive young star. Though salts have been found in the atmospheres of old, dying stars, this is the first time they have been seen around young stars in stellar nurseries. The detection of this salt-encrusted disk may help astronomers study the chemistry of star formation as well as identify other similar protostars hidden inside dense cocoons of dust and gas.
A team of astronomers and chemists using the Atacama Large Millimeter/submillimeter Array (ALMA) has detected the chemical fingerprints of sodium chloride (NaCl) and other similar salty compounds emanating from the dusty disk surrounding Orion Source I, a massive, young star in a dusty cloud behind the Orion Nebula. ...Salty Protostar ~ New ALMA observations show there is ordinary table salt in a not-so-
ordinary location: 1,500 light-years from Earth in the disk surrounding a massive young
star. Credit: ALMA (NRAO/ESO/NAOJ); NRAO/AUI/NSF; Gemini Observatory/AURA
To detect molecules in space, astronomers use radio telescopes to search for their chemical signatures – telltale spikes in the spread-out spectra of radio and millimeter-wavelength light. Atoms and molecules emit these signals in several ways, depending on the temperature of their environments.
The new ALMA observations contain a bristling array of spectral signatures – or transitions, as astronomers refer to them – of the same molecules. To create such strong and varied molecular fingerprints, the temperature differences where the molecules reside must be extreme, ranging anywhere from 100 kelvin to 4,000 kelvin (about -175 Celsius to 3700 Celsius). An in-depth study of these spectral spikes could provide insights about how the star is heating the disk, which would also be a useful measure of the luminosity of the star. ...
The researchers speculate that these salts come from dust grains that collided and spilled their contents into the surrounding disk. Their observations confirm that the salty regions trace the location of the circumstellar disk. ...
Orion Source I's Disk Is Salty ~ Adam Ginsburg et al
- arXiv.org > astro-ph > arXiv:1901.04489 > 14 Jan 2019