Dying star reveals distant galaxy`s interstellar environment
An international research team made use of a dying star`s fury to probe a distant galaxy some 9.5 billion light-years distant.
Washington: An international research team made use of a dying star`s fury to probe a distant galaxy some 9.5 billion light-years distant.
The dying star, which lit the galactic scene, is the most distant stellar explosion of its kind ever studied.
“It`s like someone turned on a flashlight in a dark room and suddenly allowed us to see, for a short time, what this far-off galaxy looks like, what it is composed of,” according to Edo Berger of Harvard-Smithsonian Center for Astrophysics, who led the team.
The study describes how the researchers used the exploding star`s light (called an ultra-luminous core-collapse supernova) as a probe to study the gas conditions in the space between the host galaxy`s stars.
Berger said the findings reveal that the distant galaxy`s interstellar conditions appear “reassuringly normal” when compared to those seen in the galaxies of our local universe.
“This shows the enormous potential of using the most luminous supernovae to study the early universe. Ultimately it will help us understand how galaxies like our Milky Way came to be,” he said.
The discovery of the dying star in this distant galaxy was made using images from the Pan-STARRS1 survey telescope on Haleakala in Maui, Hawai`i.
After the Pan-STARRS discovery, spectroscopic follow-up studies using the Multiple Mirror Telescope in Arizona and the 8-meter Gemini North telescope on Mauna Kea, Hawai`i provided the data used by the team to probe the gas of the distant galaxy`s interstellar environment.
The spectra revealed the signatures of a distant ultra-luminous supernova, and equally important, the unique fingerprints of iron and magnesium within the distant galaxy that hosted the explosion. The galaxy itself contains a very young population of stars (~15 to 45 million years old) with a mass totaling some 2 billon Suns.
The study by Berger and his team provides the first direct demonstration that ultra-luminous supernovae can serve as probes of distant galaxies.
Their results suggest that with the future combination of large survey and spectroscopic telescopes ultra-luminous supernovae could be used to probe galaxies 90 percent of the way back to the Big Bang.
The study was published recently in The Astrophysical Journal.