Extreme dust disks in Arp 220 as revealed by ALMA

Abstract

We present new images of Arp 220 from the Atacama Large Millimeter/submillimeter Array with the highest combination of frequency (691 GHz) and resolution ($0.36\times 0.20^{\prime \prime }$) ever obtained for this prototypical ultraluminous infrared galaxy. The western nucleus is revealed to contain warm (200 K) dust that is optically thick (${\tau }_{434\mu m}=5.3$), while the eastern nucleus is cooler (80 K) and somewhat less opaque (${\tau }_{434\mu m}=1.7$). We derive full-width half-maximum diameters of $76\times \le 70$ pc and $123\times 79$ pc for the western and eastern nucleus, respectively. The two nuclei combined account for ($83_{-38}^{+65}$ (calibration) ${}_{-34}^{+0}$ (systematic))% of the total infrared luminosity of Arp 220. The luminosity surface density of the western nucleus ($\log (\sigma T^4)=14.3\pm 0.2_{-0.7}^{+0}$ in units of L${}_{\odot }$ kpc${}^{-2}$) appears sufficiently high to require the presence of an AGN or a "hot starburst", although the exact value depends sensitively on the brightness distribution adopted for the source. Although the role of any central AGN remains open, the inferred mean gas column densities of $0.6-1.8\times 10^{25}$ cm${}^{-2}$ mean that any AGN in Arp 220 must be Compton-thick.

arXiv commentAccepted to ApJ Letters

References in corpus (22)

• Rotating Nuclear Rings and Extreme Starbursts in Ultraluminous Galaxies
• What Powers Ultra-luminous IRAS Galaxies?
• Radiation Pressure Supported Starburst Disks and AGN Fueling
• Observations of Ultraluminous Infrared Galaxies with the Infrared Spectrograph on the Spitzer Space Telescope II: The IRAS Bright Galaxy Sample
• Observations of Arp 220 using Herschel-SPIRE: An Unprecedented View of the Molecular Gas in an Extreme Star Formation Environment
• Planck Early Results: Thermal dust in Nearby Molecular Clouds
• Counterrotating Nuclear Disks in Arp 220
• SMA Imaging of CO(3-2) Line and 860 micron Continuum of Arp 220 : Tracing the Spatial Distribution of Luminosity
• NICMOS Imaging of the Nuclei of Arp 220
• Black hole in the West Nucleus of Arp 220
• Assessing Radiation Pressure as a Feedback Mechanism in Star-Forming Galaxies
• The radio spectra of the compact sources in Arp 220: A mixed population of supernovae and supernova remnants
• The role of nuclear activity as the power source of ultraluminous infrared galaxies
• High Spatial Resolution Imaging of Arp 220 from 3 - 25 microns
• Chandra Observations of Arp 220: The Nuclear Source
• SMA CO(J=6-5) and 435 micron interferometric imaging of the nuclear region of Arp 220
• Resolution of the Compact Radio Continuum Sources in Arp220
• High-resolution HNC 3-2 SMA observations of Arp220
• Arp220: extinction and merger-induced star formation
• VLA H53alpha radio recombination line observations of the ultraluminous infrared galaxy Arp 220
• The Arp 220 merger on kpc scales
• The merger Seyfert galaxy Arp 220. Line and continuum absorption and emission

Cited by in corpus (57)

• ISM masses and the star formation law at Z = 1 to 6 // ALMA observations of dust continuum in 145 galaxies in the COSMOS survey field
• A Herschel/PACS Far Infrared Line Emission Survey of Local Luminous Infrared Galaxies
• An ALMA survey of the SCUBA-2 CLS UDS field: Physical properties of 707 Sub-millimetre Galaxies
• Compact starbursts in z~3-6 submillimeter galaxies revealed by ALMA
• The SCUBA-2 Cosmology Legacy Survey: Multi-wavelength Properties of ALMA-identified Submillimeter Galaxies in UKIDSS-UDS
• ALMA Imaging of HCN, CS and dust in Arp 220 and NGC 6240
• ALMA Resolves the Nuclear Disks of Arp 220
• Discovery of four apparently cold dusty galaxies at z=3.62-5.85 in the COSMOS field: direct evidence of CMB impact on high-redshift galaxy observables
• Driving gas shells with radiation pressure on dust in radiation-hydrodynamic simulations
• High-Resolution Radio Continuum Measurements of the Nuclear Disks of Arp 220
• The Kennicutt-Schmidt Law and Gas Scale Height in Luminous and Ultra-Luminous Infrared Galaxies
• Subarcsecond international LOFAR radio images of Arp 220 at 150 MHz: A kpc-scale star forming disk surrounding nuclei with shocked outflows
• The unbearable opaqueness of Arp 220
• MUSE view of Arp220: Kpc-scale multi-phase outflow and evidence for positive feedback
• Are Starburst Galaxies Proton Calorimeters?
• ALMA Multi-line Observations of the IR-bright Merger VV 114
• Clumpy and Extended Starbursts in the Brightest Unlensed Submillimeter Galaxies
• Are local ULIRGs powered by AGN? The sub-kpc view of the 220 GHz continuum. PUMA II
• Radio Jet Feedback and Star Formation in Heavily Obscured Quasars at Redshifts ~0.3-3, I: ALMA Observations
• Resolved Structure of Arp 220 Nuclei at λ~3 mm
• The scaling relations and star formation laws of ministarburst complexes
• Chemically Distinct Nuclei and Outflowing Shocked Molecular Gas in Arp 220
• Molecular line emission in NGC 4945, imaged with ALMA
• Magnetically elevated accretion disks in active galactic nuclei: broad emission line regions and associated star formation
• On the redshift distribution and physical properties of ACT-selected DSFGs
• Gamma-Ray Emission from Arp 220: Indications of an Active Galactic Nucleus
• ALMACAL II: Extreme star-formation-rate densities in a pair of dusty starbursts at $z=3.442$ revealed by ALMA 20-milliarcsec resolution imaging
• The Greenhouse Effect in Buried Galactic Nuclei and the Resonant HCN Vibrational Emission
• Dusty Cloud Acceleration by Radiation Pressure in Rapidly Star-Forming Galaxies
• Spatially resolved CO SLED of the Luminous Merger Remnant NGC 1614 with ALMA
• Cosmic Rays, Gamma-Rays, and Neutrinos in the Starburst Nuclei of Arp 220
• Morphology and Kinematics of Warm Molecular Gas in the Nuclear Region of Arp 220 as Revealed by ALMA
• Inverse Compton Signatures of Gamma-Ray Burst Afterglows
• Luminous, pc-scale CO 6-5 emission in the obscured nucleus of NGC1377
• Sub-arcsecond imaging of the water emission in Arp 220
• The VLA Frontier Field Survey: A Comparison of the Radio and UV/optical size of $0.3\lesssim z\lesssim 3$ star-forming galaxies
• Planck's Dusty GEMS. VIII. Dense-gas reservoirs in the most active dusty starbursts at z~3
• PdBI U/LIRG Survey (PULS): Dense Molecular Gas in Arp 220 and NGC 6240
• SOFIA/HAWC+ View of an Extremely Luminous Infrared Galaxy, WISE1013+6112
• Evolution of Molecular Clouds in the Superwind Galaxy NGC 1808 Probed by ALMA Observations
• Vibrationally excited HC3N emission in NGC1068: Tracing the recent star formation in the starburst ring
• Search for High-Energy Neutrinos from Ultra-Luminous Infrared Galaxies with IceCube
• Breaking the Radio - Gamma-Ray Connection in Arp 220
• Arp 220: New Observational Insights into the Structure and Kinematics of the Nuclear Molecular Disks and Surrounding Gas
• Deeply Buried Nuclei in the Infrared-Luminous Galaxies NGC 4418 and Arp 220: I. ALMA Observations at $\lambda =$1.4-0.4 mm and Continuum Analysis
• Dust masses, compositions, and luminosities in the nuclear disks and the diffuse circumnuclear medium of Arp220
• HST/WFC3 Observations of an Off-Nuclear Superbubble in Arp 220
• The Opaque Heart of the Galaxy IC 860: Analogous Protostellar, Kinematics, Morphology, and Chemistry
• Obscured flat spectrum radio AGN as sources of high-energy neutrinos
• Gas, dust, and the CO-to-molecular gas conversion factor in low-metallicity starbursts
• SMA Observations of the Extended CO(6-5) Emission in the Starburst Galaxy NGC253
• Obscured AGNs in Bulgeless Hosts discovered by WISE: The Case Study of SDSS J1224+5555
• Revisiting the formaldehyde masers
• One of Everything: The Breakthrough Listen Exotica Catalog
• Comparison of Low-Mass and High-Mass Star Formation
• ALMA Observation of NGC5135: The Circumnuclear CO(6-5) and Dust Continuum Emission at 45 Parsec Resolution[$\star$]
• The magnetic fields of the dusty nuclei and molecular outflows of Arp 220