An international team of astronomers used the James Webb Space Telescope (JWST) to make detailed spectroscopic observations of a galaxy called COSMOS-1142. As a result, we discovered that neutral gas and ionized gas are flowing out in large quantities in multiple phases in this galaxy. The discovery was announced in his August 10th article on the preprint server arXiv. At redshift 2.445, COSMOS-11142 is a massive galaxy with a half-light radius of about 2,000 light-years. Previous observations of COSMOS-11142 indicate that it is in a ‘post-starburst’ phase, just after the rapid dimming of a star-forming episode. The galaxy’s current star formation rate is estimated to be between 1 and 10 solar masses per year. A group of astronomers led by Sirio Belli of the University of Bologna, Italy, recently observed his COSMOS-11142 using JWST’s Near-Infrared Spectrometer (NIRSpec). Observations to investigate the properties of this galaxy were made in December 2022 as part of the Blue Jay Survey.

“As part of the Blue Jay survey, a cycle 1 JWST program of about 150 galaxies uniformly distributed at redshift z (1.7 ∗ (log M∗/M ⊙ > 9)) , observed the galaxy COSMOS-11142,” the researchers said. wrote in the newspaper. Observations show that COSMOS-11142 is compact, elongated, and relatively dusty. The galaxy’s dynamic mass is about 70 billion solar masses, and its metallicity is estimated to be about 0.16. JWST imaging provides evidence of the outflow of neutral and ionized gas during the rapid star formation decay of COSMOS-11142. Mass flux rates for neutral and ionized gas outflows have been measured at about 100 and 1 solar mass per year, respectively. Astronomers have found that COSMOS-11142’s mass efflux rate is an order of magnitude larger than typical values ​​measured in local star-forming galaxies. Furthermore, the mass outflow rate is found to be higher than the rest of the star formation rate in COSMOS-11142. This indicates that gas eruptions may have a strong influence on the evolution of the studied galaxy. The researchers hypothesize that the observed outflow is caused by feedback from the active nucleus of the galaxy (AGN). Based on this result, the authors of the paper concluded that the observed efflux likely played an important role in the rapid elimination of COSMOS-11142. They added that feedback heating of the halo gas by radio-mode AGN is likely necessary to keep the galaxy stationary.

Source: , arXiv (2023). DOI: 10.48550/arxiv.2308.05795