Multi-wavelength and Multi-CO View of The Minor Merger Driven Star Formation in the Nearby LIRG NGC 3110

Abstract

We present Atacama Large Millimeter/submillimeter Array observations of multiple CO(1-0), ${}^{13}$CO(1-0), and C${}^{18}$O(1-0) lines and 2.9 mm and 1.3 mm continuum emission toward the nearby interacting luminous infrared galaxy NGC 3110, supplemented with similar spatial resolution H$\alpha$, 1.4GHz continuum, and $K$-band data. We estimate the typical CO-to-H${}_2$ conversion factor of 1.7 $M_{\odot }$ (K km s${}^{-1}$ pc${}^2$)${}^{-1}$ within the disk using LTE-based and dust-based H${}_2$ column densities, and measure the 1-kpc scale surface densities of star formation rate (${\Sigma }_{\mathrm{SFR}}$), super star clusters (${\Sigma }_{\mathrm{SSC}}$), molecular gas mass, and star formation efficiency (SFE) toward the entire gas disk. These parameters show a peak at the southern part of the southern spiral arm (SFE $\sim$ 10${}^{-8.2}$ yr${}^{-1}$, ${\Sigma }_{\mathrm{SFR}}$ $\sim$ 10${}^{-0.6}$ $M_{\odot }$ kpc${}^{-2}$ yr${}^{-1}$, ${\Sigma }_{\mathrm{SSC}}$ $\sim$ 6.0 kpc${}^{-2}$), which is likely attributed to the on-going tidal interaction with the companion galaxy MCG-01-26-013, as well as toward the circumnuclear region. We also find that thermal free-free emission contributes to a significant fraction of the millimeter continuum emission at the southern peak position. Those measurements imply that the peak of the southern arm is an active and young star-forming region, whereas the central part of NGC 3110 is a site of long-continued star formation. We suggest that, during the early stage of the galaxy-galaxy interaction with large mass ratio that in NGC 3110, fragmentation along the main galaxy's arms is an important driver of merger-induced star formation and massive gas inflow results in dusty nuclear starbursts.

17 pages, 9 figures, 2 tables, accepted for publication in The Astrophysical Journal

References in corpus (10)

• Multi-Scale CLEAN deconvolution of radio synthesis images
• The effect of galaxy mass ratio on merger--driven starbursts
• New Constraints on the ${}^{12}$CO(2-1)/(1-0) Line Ratio Across Nearby Disc Galaxies
• Bars and spirals in tidal interactions with an ensemble of galaxy mass models
• Spectral Line Survey toward Spiral Arm of M51 in the 3 mm and 2 mm Bands
• ALMA Multi-line Observations of the IR-bright Merger VV 114
• CO excitation, molecular gas density and interstellar radiation field in local and high-redshift galaxies
• Spatially resolved CO SLED of the Luminous Merger Remnant NGC 1614 with ALMA
• Around the Ring We Go: The Cold, Dense Ring of Molecular Gas in NGC 1614
• Two Orders of Magnitude Variation in the Star Formation Efficiency Across the Pre-Merger Galaxy NGC 2276

Cited by in corpus (3)

• A sensitive APEX and ALMA CO(1-0), CO(2-1), CO(3-2), and [CI](1-0) spectral survey of 40 local (U)LIRGs
• CON-quest II. Spatially and spectrally resolved HCN/HCO+ line ratios in local luminous and ultraluminous infrared galaxies
• Measuring 60-pc-scale Star Formation Rate of the Nearby Seyfert Galaxy NGC 1068 with ALMA, HST, VLT/MUSE, and VLA