A team of astronomers have searched for dust-extinguished supernovae in the nuclear regions of 40 ultra-luminous and luminous infrared galaxies some 652 million light-years away from Earth and have discovered five new supernovae among the data from NASA’s Spitzer Space Telescope. that remained hidden from optical light.
This accompanying image shows the Arp148 galaxy taken by the Spitzer Space Telescope and NASA’s Hubble Space Telescope. The Spitzer data, marked in a white circle, reveals infrared rays from a supernova hidden in the dust.
Playing cosmic hide and seek
Thanks to infrared telescopes like Spitzer, scientists can see through the haze and better understand the frequency with which these explosions occur in which the death of a giant star marks the brightest and most powerful explosion in the universe. Spitzer saw the universe with infrared rays penetrating through a cloud of dust that blocks optical light.
“These results with Spitzer show that optical studies we have long relied on to detect supernovae miss up to half of the stellar explosions in the universe,” Ori Fox said in a NASA statement. “It is very good news that the number of supernovae that we see with Spitzer is statistically in line with theoretical predictions.”
Where are all the supernovae?
For the study, the astronomers selected a local set of 40 dust-drowned galaxies, known as ultra-luminous and luminous infrared galaxies (LIRG and ULIRG, respectively). Cosmic dust absorbs optical light from objects like supernovae, but allows infrared light from these same objects to pass through unobstructed for telescopes like, in this case, Spitzer to detect . The astronomers detected nine supernovae, five of which had not been previously identified by optical studies.
“It is a testament to Spitzer’s discovery potential that the telescope was able to pick up the signal from hidden supernovae from these dusty galaxies,” Fox clarifies.
The type of supernova detected by Spitzer is known as a “core collapsed supernova” and involves a giant star with a mass at least eight times that of the Sun.
Description of a supernova: “As they age and their cores fill with iron, large stars can no longer produce enough energy to support their own gravity, and their cores suddenly and catastrophically collapse,” says NASA.
Next-generation telescopes, such as NASA’s Nancy Grace Roman Space Telescope (which will enable new sciences in all areas of astrophysics and offer new insights into the history and structure of the universe, including the mysterious “dark energy”) and the James Webb Space Telescope (a powerful ‘space time machine’ with which it is hoped to unravel the formation of the universe), which will be launched into space before the end of the year (scheduled for November 2021, after numerous delays) , detect infrared light similar to Spitzer’s.
Referencia: Ori D. Fox et al. 2021. A Spitzer survey for dust-obscured supernovae. MNRAS 506 (3): 4199-4209; doi: 10.1093/mnras/stab1740
