New Observations of NGC 3627 Reveal Its Dust and Star Formation
A three-dimensional analysis of the spiral galaxy NGC 3627, using data from the IMEGIN program of the NIKA2 instrument, unravels the components of its electromagnetic emission. Astronomers process signals ranging from infrared to radio waves to isolate the contributions from cosmic dust, free-free radiation, and synchrotron. This innovative technique allows direct investigation of how interstellar medium features link to star-forming processes. 🔭
Mapping Dust and Gas with Millimeter Precision
The study identifies that the emission captured at 1.15 mm is the best tracer for calculating the total dust mass. In contrast, the emission at 160 microns shows a very strong correlation with the presence of molecular gas, the primary material for forming new stars. This distinction is crucial for creating precise maps of matter distribution in the galaxy.
Key Findings on Radio Emission:- The contribution of radio emission to the total observed at 2 mm is approximately 10%.
- This percentage increases to 18% at the southern end of the galactic bar, a zone of intense stellar activity.
- An isolated region, beyond this hotspot, proves to be the most efficient in the entire galaxy.
A simple model simulating dust evolution predicts for this isolated region higher efficiency in producing it and high effective yield.
Galactic Dynamics as the Main Sculptor
The research also quantifies that small dust grains, representing 13% of the total mass, are consumed in intense radiation environments. This depletion is particularly notable in the southern tidal tail. Gas flows driven by the rotation of the galactic bar, along with tidal interactions with nearby galaxies, emerge as decisive factors.
Impact of Dynamics on the Galaxy:- Shapes the large-scale structure of NGC 3627.
- Directly influences how efficiently stars can form in different regions.
- Determines how dust is distributed and recycled throughout the interstellar medium.