Astronomers investigate giant molecular clouds in the galaxy NGC 613

Utilizing the Atacama Massive Millimeter/sub-millimeter Array (ALMA), a world crew of astronomers has carried out high-resolution observations of a close-by galaxy often called NGC 613. Outcomes of the observational marketing campaign, published Might 30 on the preprint server arXiv, shed extra gentle on the quite a few big molecular clouds within the heart of this galaxy.

Molecular clouds are enormous complexes of interstellar gasoline and dust left over from the formation of galaxies, composed largely of molecular hydrogen. Molecular clouds with lots better than 100,000 solar lots are known as giant molecular clouds (GMCs). Basically, GMCs are 15–600 gentle years in diameter and are the coldest and densest elements of the interstellar medium.

GMCs are gasoline reservoirs the place most star formation takes place. Due to this fact, learning their lifecycle and traits is essential to advance our information concerning the formation and evolution of galaxies.

At a distance of some 57 million gentle years, NGC 613 is a close-by barred spiral galaxy with a total stellar mass of about 45 billion solar lots. The galaxy has a vibrant core and a star-forming nuclear ring.

Earlier observations of NGC 613 have discovered that it hosts GMCs in and round its nuclear ring. Lately, a bunch of astronomers led by Woorak Choi of the Yonsei College in South Korea, determined to take a better take a look at these GMCs, exploring their properties with ALMA.

“NGC 613 was noticed within the ¹²CO(1-0) line (relaxation frequency 115.271 GHz) utilizing the Atacama Massive Millimeter/sub-millimeter Array,” the researchers wrote.

ALMA observations allowed Choi’s crew to establish 356 GMCs in NGC 613, out of which 158 are spatially and spectrally resolved. It turned out that the GMCs on this galaxy have sizes between 49 and 244 light years, whereas their velocity dispersions vary from 2 to 36 km/s. The molecular gasoline lots of the GMCs within the pattern had been discovered to be 0.3–50 million solar lots, and their molecular gasoline mass floor densities had been estimated to be throughout the vary of 100–6,000 solar masses/laptop².

By evaluating the GMCs of NGC 613 to that of the Milky Way disk and Native Group galaxy GMCs, the astronomers discovered that these within the investigated galaxy have comparable sizes. Nonetheless, the GMCs reported within the paper have usually bigger velocity dispersions, molecular gasoline lots and molecular gasoline mass floor densities.

Analyzing the distribution of the recognized GMCs in NGC 613, the scientists discovered that sizes are comparable throughout the completely different areas of the galaxy. Nonetheless, the GMCs within the dust lanes of NGC 613 seem to have molecular gasoline lots, velocity dispersions and gasoline mass floor densities smaller than these of the GMCs within the different areas. The crew additionally discovered that the GMCs within the arcs are inclined to have gasoline lots and gasoline mass floor densities bigger than these of the GMCs within the different areas of NGC 613.

In keeping with the paper, the investigated big molecular clouds are marginally gravitationally sure, and the GMCs within the arcs are inclined to have smaller virial parameters than the GMCs within the different areas of the galaxy. The obtained outcomes additionally counsel that the attribute cloud lifetime of GMCs in NGC 613 is round 3-8 million years.

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