Highly turbulent gas on GMC scales in NGC 3256, the nearest luminous infrared galaxy
Journal article, 2021

We present the highest resolution CO (2-1) observations obtained to date (0.25 arcsec) of NGC 3256 and use them to determine the detailed properties of the molecular interstellar medium in the central 6 kpc of this merger. Distributions of physical quantities are reported from pixel-by-pixel measurements at 55 and 120 pc scales and compared to disc galaxies observed by PHANGS-ALMA (Physics at High Angular resolution in Nearby GalaxieS with Atacama Large Millimeter/Submillimeter Array). Mass surface densities range from 8 to 5500 M-circle dot pc(-2) and velocity dispersions from 10 to 200 km s(-1). Peak brightness temperatures as large as 37 K are measured, indicating the gas in NGC 3256 may be hotter than all regions in nearby disc galaxies measured by PHANGS-ALMA. Brightness temperatures even surpass those in the overlap region of NGC 4038/9 at the same scales. The majority of the gas appears unbound with median virial parameters of 7-19, although external pressure may bind some of the gas. High internal turbulent pressures of 10(5)-10(10) K cm(-3) are found. Given the lack of significant trends in surface density, brightness temperature, and velocity dispersion with physical scale we argue the molecular gas is made up of a smooth medium down to 55 pc scales, unlike the more structured medium found in the PHANGS-ALMA disc galaxies.

ISM: kinematics and dynamics

galaxies: jets

ISM: jets and outflows

galaxies: interactions

galaxies: ISM

ISM: clouds


Nathan Brunetti

McMaster University

Christine D. Wilson

McMaster University

Kazimierz Sliwa

Max Planck Society

Eva Schinnerer

Max Planck Society

Susanne Aalto

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

Alison B. Peck

Gemini Observatory North

Monthly Notices of the Royal Astronomical Society

0035-8711 (ISSN) 1365-2966 (eISSN)

Vol. 500 4 4730-4748

Subject Categories

Energy Engineering

Meteorology and Atmospheric Sciences

Astronomy, Astrophysics and Cosmology



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