First detection of the 448 GHz H2O transition in space

Abstract

We present the first detection of the ortho-H2O 4_23-3_30 transition at 448 GHz in space. We observed this transition in the local (z = 0.010) luminous infrared (IR) galaxy ESO 320-G030 (IRAS F11506-3851) using the Atacama Large Millimeter/submillimeter Array (ALMA). The water 4_23-3_30 emission, which originates in the highly obscured nucleus of this galaxy, is spatially resolved over a region of ~65 pc in diameter and shows a regular rotation pattern compatible with the global molecular and ionized gas kinematics. The line profile is symmetric and well fitted by a Gaussian with an integrated flux of 37.0 +- 0.7 Jy km s-1 . Models predict this water transition as a potential collisionally excited maser transition. On the contrary, in this galaxy, we find that the 4_23-3_30 emission is primarily excited by the intense far-IR radiation field present in its nucleus. According to our modeling, this transition is a probe of deeply buried galaxy nuclei thanks to the high dust optical depths (tau_100μm > 1, N_H > 1e24 cm-2) required to efficiently excite it.

arXiv commentAccepted for publication in A&A Letters; 4 pages, 5 figures

References in corpus (21)

• Herschel Space Observatory - An ESA facility for far-infrared and submillimetre astronomy
• The Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory
• Water, O2 and Ice in Molecular Clouds
• Interstellar water chemistry: from laboratory to observations
• Ionized gas outflows and global kinematics of low-z luminous star forming galaxies
• Herschel/PACS spectroscopy of NGC 4418 and Arp 220: H2O, H2^{18}O, OH, ^{18}OH, O I, HCN and NH3
• Molecular outflows in local ULIRGs: energetics from multi-transition OH analysis
• SMA Imaging of CO(3-2) Line and 860 micron Continuum of Arp 220 : Tracing the Spatial Distribution of Luminosity
• VLT/VIMOS integral field spectroscopy of luminous and ultraluminous infrared galaxies: 2D kinematic properties
• Local Luminous Infrared Galaxies. I. Spatially resolved observations with Spitzer/IRS
• The Physics of Water Masers observable with ALMA and SOFIA: Model Predictions for Evolved Stars
• The X-ray emission of local luminous infrared galaxies
• A spectral line survey of Orion KL in the bands 486-492 and 541-577 GHz with the Odin satellite II. Data analysis
• Neutral gas outflows in nearby [U]LIRGs via optical NaD feature
• Modeling the H2O submillimeter emission in extragalactic sources
• Spatially resolved kinematics, galactic wind, and quenching of star formation in the luminous infrared galaxy IRAS F11506-3851
• High-velocity extended molecular outflow in the star-formation dominated luminous infrared galaxy ESO 320-G030
• Inflowing gas onto a compact obscured nucleus in Arp 299A: Herschel spectroscopic studies of H2O and OH
• Distinguishing `disks' from `mergers': tracing the kinematic asymmetries in local (U)LIRGs using `kinemetry'-based criteria
• Non--local radiative transfer in strongly inverted masers
• The Hydroxyl-Water Megamaser Connection. I. Water Emission Toward OH Megamaser Hosts

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• First detection of the 448 GHz ortho-H2O line at high redshift: probing the structure of a starburst nucleus at z = 3.63
• A proto-pseudobulge in ESO 320-G030 fed by a massive molecular inflow driven by a nuclear bar
• NGC 7469 as seen by MEGARA: new results from high-resolution IFU spectroscopy
• z-GAL -- A NOEMA spectroscopic redshift survey of bright Herschel galaxies: [III] Physical properties
• SUNRISE: The rich molecular inventory of high-redshift dusty galaxies revealed by broadband spectral line surveys
• Excitation and acceleration of molecular outflows in LIRGs: The extended ESO 320-G030 outflow on 200-pc scales
• The importance of radiative pumping on the emission of the H_2O submillimeter lines in galaxies
• The Way of Water: ALMA resolves H2O emission lines in a strongly lensed dusty star-forming galaxy at z $\sim$ 3.1
• Collisional Pumping of H${}_2$O and CH${}_3$OH Masers in C-Type Shock Waves