New type I supernova discovered using JWST

Using the James Webb Space Telescope (JWST), an international team of astronomers observed the galaxy cluster PLCK G165.7+67.0. The observation campaign led to the discovery of a new type I supernova. The discovery was reported in a paper published September 13 on the preprint server arXiv. Supernovae (SNe) are powerful and luminous stellar explosions. They are important to the scientific community because they provide essential clues about the evolution of stars and galaxies. In general, SNe are divided into two groups based on their atomic spectra: type I (no hydrogen in the spectrum) and type II (showing hydrogen spectral lines).

Type Ia supernovae (SN Ia) are found in binary systems in which one of the stars is a white dwarf. Stellar explosions of this type are important to the scientific community because they provide essential clues about the evolution of stars and galaxies. A team of astronomers led by Brenda L. Frye of the Steward Observatory in Tucson, Arizona, recently observed PLCK G165.7+67.0 (or G165 for short) – a high-magnitude galaxy cluster. Redshift 0.35 and mass approximately 200– 300 trillion solar masses. During these observations, they discovered a supernova with a redshift of 1.78 using JWST’s Near Infrared Camera (NIRCam). The new supernova, named “SN H0pe,” was identified in Arc 2, a bright infrared galaxy gravitationally amplified by G165.

“The SN is located 1.5-2 kpc from the host galaxy Arc 2 and appears in three different positions due to the gravitational lensing of G165. These data can give a value for the Hubble constant using latency of SN Ia Many of these images we call ‘SN H0pe’,” the researchers wrote in the journal. SN H0pe is oriented to three distinct locations, designated SN 2a, 2b and 2c and thus offers a unique opportunity to determine the Hubble constant by measuring the delay between its multiple images. Further spectroscopic and photometric studies of SN H0pe confirmed that it is a Type Ia supernova. As for the host galaxy Arc 2, observations have revealed that it has a stellar mass of about 500 billion solar masses. The results show that it completed its star formation phase about a billion years ago and is now surrounded by star-forming satellite dwarf galaxies.

JWST observations also provide insight into the properties of G165. According to the paper, G165 has a mass of about 260 trillion solar masses and exhibits the brightest galaxy cluster (BCG) velocity shift relative to the system’s redshift. Summarizing the results, the study authors said they are examining the properties of SN H0pe further and more results will be published in the next research paper.

Source: arXiv (2023). DOI: 10.48550/arxiv.2309.07326