APEX and NOEMA observations of H${}_2$S in nearby luminous galaxies and the ULIRG Mrk~231 -- Is there a relation between dense gas properties and molecular outflows?

Abstract

In order to understand the evolution and feedback of Active Galactic Nuclei (AGN) and star formation it is important to use molecular lines as probes of physical conditions and chemistry. We use H${}_2$S to investigate the impact of starburst and AGN activity on the chemistry of the molecular interstellar medium in luminous infrared galaxies. Using the APEX single dish telescope, we have observed the $1_{10}$--$1_{01}$ transition of ortho-H${}_2$S at 168 GHz towards the centres of twelve nearby luminous infrared galaxies. We have also observed the same line towards the ultra luminous infrared galaxy (ULIRG) Mrk~231 with the NOEMA interferometer. We have detected H${}_2$S towards NGC~253, NGC~1068, NGC~3256, NGC~4418, NGC~4826, NGC~4945, Circinus, M~83 and Mrk~231. Four galaxies show elevated H${}_2$S emission relative to HCN. We suggest that the high line ratios are caused by elevated H${}_2$S abundances in the dense gas. However, we do not find any clear connection between the H${}_2$S/HCN line intensity ratio, and the presence (or speed) of molecular outflows in the sample galaxies. Therefore H${}_2$S abundances do not seem to be globally affected by the large-scale outflows. We discuss possible mechanisms behind the suggested H${}_2$S abundance enhancements in NGC~4418, Circinus, NGC~3256 and NGC~4826. These include radiative processes (for example X-rays or cosmic-rays) or smaller scale shocks. We suggest that $L_{{\mathrm{H}}_2\mathrm{S}}$ serves as a tracer of the dense gas content, similar to $L_{\mathrm{HCN}}$, and that the correlation between $L_{{\mathrm{H}}_2\mathrm{S}}$ and $M_{\mathrm{outflow}}$(H${}_2$) implies a relation between the dense gas reservoir and the properties and evolution of the molecular feedback. This potential link requires further study since it holds important keys to our understanding of how the properties of molecular outflows relate to that of their host galaxies.

Accepted for publication in A&A.16 pages, 6 figures

References in corpus (29)

• Massive molecular outflows and negative feedback in ULIRGs observed by Herschel-PACS
• The Critical Density and the Effective Excitation Density of Commonly Observed Molecular Dense Gas Tracers
• Molecular line emission in NGC1068 imaged with ALMA. I An AGN-driven outflow in the dense molecular gas
• Cool Outflows in Galaxies and their Implications
• A Compendium of Far-Infrared Line and Continuum Emission for 227 Galaxies Observed by the Infrared Space Observatory
• Star formation in a galactic outflow
• Molecular outflows in local galaxies: Method comparison and a role of intermittent AGN driving
• UCLCHEM: A Gas-Grain Chemical Code
• Is HCN a True Tracer of Dense Molecular Gas in LIRGs and ULIRGs?
• High resolution observations of HCN and HCO+ J=3-2 in the disk and outflow of Mrk231 -Detection of vibrationally excited HCN in the warped nucleus
• Dense Molecular Gas Tracers in the Outflow of the Starburst Galaxy NGC 253
• Millimeter Interferometric HCN(1-0) and HCO+(1-0) Observations of Luminous Infrared Galaxies
• Sulphur-bearing species in the star forming region L1689N
• Dense Molecular Gas and the Role of Star Formation in the Host Galaxies of Quasi-Stellar Objects
• A new study of an old sink of sulfur in hot molecular cores: the sulfur residue
• A Luminous Infrared Merger with Two Bipolar Molecular Outflows: ALMA and SMA Observations of NGC 3256
• ALMA reveals optically thin, highly excited CO gas in the jet-driven winds of the galaxy IC5063
• Gas phase Elemental abundances in Molecular cloudS (GEMS). II. On the quest for the sulphur reservoir in molecular clouds: the $H_{2}S$ case
• Modelling the sulphur chemistry evolution in Orion KL
• Modeling the [Fe II]λ1.644μm outflow and comparison with H${}_2$ and H${}^{+}$ kinematics in the inner 200 pc of NGC 1068
• The hidden heart of the luminous infrared galaxy IC 860 I. A molecular inflow feeding opaque, extreme nuclear activity
• Resolved Structure of Arp 220 Nuclei at λ~3 mm
• Bottlenecks to interstellar sulfur chemistry: Sulfur-bearing hydrides in UV-illuminated gas and grains
• On the Formation of Molecular Clumps in QSO Outflows
• Molecular-Cloud-Scale Chemical Composition II: Mapping Spectral Line Survey toward W3(OH) in the 3 mm Band
• Hidden or missing outflows in highly obscured galaxy nuclei?
• ALMA resolves the remarkable molecular jet and rotating wind in the extremely radio-quiet galaxy NGC 1377
• Enhanced UV radiation and dense clumps in Mrk231's molecular outflow
• The outflow of gas from the Centaurus A circumnuclear disk: atomic spectral line maps from Herschel-PACS and APEX

Cited by in corpus (5)

• Theoretical modelling of the adsorption of neutral and charged sulphur-bearing species on to olivine nanoclusters
• Probing Jet-Torus Interaction in the Radio Galaxy NGC 1052 by Sulfur-Bearing Molecules
• An ALCHEMI inspection of sulphur-bearing species towards the central molecular zone of NGC 253
• A multi-scale investigation into the diagnostic potential of the HCN/HCO${}^{+}$ ratio for AGN and starburst activity in nearby galaxies
• High resolution ALMA observations of H${}_2$S in LIRGS (Dense gas and shocks in outflows and CNDs)