Spatially-resolved Radio-to-Far-infrared SED of the Luminous Merger Remnant NGC 1614 with ALMA and VLA

Abstract

We present the results of Atacama Large Millimeter/Submillimeter Array (ALMA) 108, 233, 352, and 691 GHz continuum observations and Very Large Array (VLA) 4.81 and 8.36 GHz observations of the nearby luminous merger remnant NGC 1614. By analyzing the beam (1".0 * 1".0) and uv (> 45 kλ) matched ALMA and VLA maps, we find that the deconvolved source size of lower frequency emission (< 108 GHz) is more compact (420 pc * 380 pc) compared to the higher frequency emission (> 233 GHz) (560 pc * 390 pc), suggesting different physical origins for the continuum emission. Based on an SED model for a dusty starburst galaxy, it is found that the SED can be explained by three components, (1) non-thermal synchrotron emission (traced in the 4.81 and 8.36 GHz continuum), (2) thermal free-free emission (traced in the 108 GHz continuum), and (3) thermal dust emission (traced in the 352 and 691 GHz continuum). We also present the spatially-resolved (sub-kpc scale) Kennicutt-Schmidt relation of NGC 1614. The result suggests a systematically shorter molecular gas depletion time in NGC 1614 (average τ_gas of 49 - 77 Myr and 70 - 226 Myr at the starburst ring and the outer region, respectively) than that of normal disk galaxies (~ 2 Gyr) and a mid-stage merger VV 114 (= 0.1 - 1 Gyr). This implies that the star formation activities in U/LIRGs are efficiently enhanced as the merger stage proceeds, which is consistent with the results from high-resolution numerical merger simulations.

10 pages, 6 figures, accepted for publication in PASJ

References in corpus (13)

• The effect of galaxy mass ratio on merger--driven starbursts
• Luminous Infrared Galaxies with the Submillimeter Array: I. Survey Overview and the Central Gas to Dust Ratio
• SMA Imaging of CO(3-2) Line and 860 micron Continuum of Arp 220 : Tracing the Spatial Distribution of Luminosity
• Cold Molecular Gas in Merger Remnants: I. Formation of Molecular Gas Disks
• High-resolution imaging of the molecular outflows in two mergers: IRAS17208-0014 and NGC1614
• Far-Ultraviolet & X-ray Observations of VV 114: Feedback in a Local Analog to Lyman Break Galaxies
• Multiwavelength star formation indicators: Observations
• ALMA Multi-line Observations of the IR-bright Merger VV 114
• High-resolution ALMA Observations of SDP.81. II. Molecular Clump Properties of a Lensed Submillimeter Galaxy at z=3.042
• ALMA Observations of Warm Molecular Gas and Cold Dust in NGC 34
• Around the Ring We Go: The Cold, Dense Ring of Molecular Gas in NGC 1614
• Ground-based Pa$\alpha$ Narrow-band Imaging of Local Luminous Infrared Galaxies I: Star Formation Rates and Surface Densities
• A multi-wavelength view of the central kiloparsec region in the Luminous Infrared Galaxy NGC1614

Cited by in corpus (12)

• A diversity of starburst-triggering mechanisms in interacting galaxies and their signatures in CO emission
• Spatially resolved CO SLED of the Luminous Merger Remnant NGC 1614 with ALMA
• ALMA observations of HCN and HCO+ outflows in the merging galaxy NGC 3256
• Merger-induced Shocks in the Nearby LIRG VV 114 through Methanol Observations with ALMA
• Two Orders of Magnitude Variation in the Star Formation Efficiency Across the Pre-Merger Galaxy NGC 2276
• Molecular gas and Star Formation Properties in Early Stage Mergers: SMA CO(2-1) Observations of the LIRGs NGC 3110 and NGC 232
• Duality in spatially resolved star-formation relations in local LIRGs
• Extreme Variation in Star Formation Efficiency Across a Compact, Starbursting Disk Galaxy
• Star formation traced by optical and millimeter hydrogen recombination lines and free-free emissions in the dusty merging galaxy NGC 3256 -- MUSE/VLT and ALMA synergy
• No AGN evidence in NGC1614 from deep radio VLBI observations
• Measuring 60-pc-scale Star Formation Rate of the Nearby Seyfert Galaxy NGC 1068 with ALMA, HST, VLT/MUSE, and VLA
• Multi-wavelength and Multi-CO View of The Minor Merger Driven Star Formation in the Nearby LIRG NGC 3110