The connection between the peaks in velocity dispersion and star-forming clumps of turbulent galaxies

Abstract

We present Keck/OSIRIS adaptive optics observations with 150-400 pc spatial sampling of 7 turbulent, clumpy disc galaxies from the DYNAMO sample ($0.07<z<0.2$). DYNAMO galaxies have previously been shown to be well matched in properties to main sequence galaxies at $z\sim 1.5$. Integral field spectroscopy observations using adaptive optics are subject to a number of systematics including a variable PSF and spatial sampling, which we account for in our analysis. We present gas velocity dispersion maps corrected for these effects, and confirm that DYNAMO galaxies do have high gas velocity dispersion ($\sigma =40-80$\kms), even at high spatial sampling. We find statistically significant structure in 6 out of 7 galaxies. The most common distance between the peaks in velocity dispersion and emission line peaks is $\sim 0.5$~kpc, we note this is very similar to the average size of a clump measured with HST H$\alpha$ maps. This could suggest that the peaks in velocity dispersion in clumpy galaxies likely arise due to some interaction between the clump and the surrounding ISM of the galaxy, though our observations cannot distinguish between outflows, inflows or velocity shear. Observations covering a wider area of the galaxies will be needed to confirm this result.

Accepted for publication in MNRAS

References in corpus (21)

• Cosmic Star Formation History
• Formation of Massive Galaxies at High Redshift: Cold Streams, Clumpy Disks and Compact Spheroids
• The SAMI Galaxy Survey: instrument specification and target selection
• The rapid formation a large rotating disk galaxy three billion years after the Big Bang
• Bulge Formation by the Coalescence of Giant Clumps in Primordial Disk Galaxies
• Kinemetry of SINS High-Redshift Star-Forming Galaxies: Distinguishing Rotating Disks from Major Mergers
• Clumpy Galaxies in CANDELS. I. The Definition of UV Clumps and the Fraction of Clumpy Galaxies at 0.5<z<3
• A method to remove residual OH emission from near infrared spectra
• GHASP : An Halpha kinematic survey of spiral and irregular galaxies - VI. New Halpha data cubes for 108 galaxies
• Resolved spectroscopy of gravitationally lensed galaxies: global dynamics and star-forming clumps on ~100pc scales
• High star formation rates as the origin of turbulence in early and modern disk galaxies
• Observations and modelling of a clumpy galaxy at z=1.6: Spectroscopic clues to the origin and evolution of chain galaxies
• Shocked Superwinds from the z~2 Clumpy Star-forming Galaxy, ZC406690
• DYNAMO-HST Survey: Clumps in Nearby Massive Turbulent Disks and the Effects of Clump Clustering on Kiloparsec Scale Measurements of Clumps
• Gemini GMOS/IFU spectroscopy of NGC 1569 - I: Mapping the properties of a young star cluster and its environment
• Gemini/GMOS IFU stellar kinematics of the nuclear region of six nearby active galaxies
• Studying the galactic outflow in NGC 1569
• Extreme gas fractions in clumpy, turbulent disk galaxies at z~0.1
• IROCKS: Spatially resolved kinematics of z~1 star forming galaxies
• Gas Content and Kinematics in Clumpy, Turbulent Star-forming Disks
• VIMOS-VLT Integral Field Kinematics of the Giant Low Surface Brightness Galaxy ESO 323-G064

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• SDSS-IV MaNGA: Modeling the Spectral Line Spread Function to Sub-Percent Accuracy
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• Spatially resolved dust properties and quasar-galaxy decomposition of a HyLIRG at z = 4.4
• SDSS-IV MaNGA: Understanding Ionized Gas Turbulence using Integral Field Spectroscopy of 4500 Star-Forming Disk Galaxies
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• The SAMI Galaxy Survey: Bayesian Inference for Gas Disk Kinematics using a Hierarchical Gaussian Mixture Model
• Instability analysis for spiral arms of local galaxies: M51, NGC3627 and NGC628
• Stellar Masses of Clumps in Gas-rich, Turbulent Disk Galaxies
• CO Excitation in High-z Main Sequence Analogues: Resolved CO(4-3)/CO(3-2) Line Ratios in DYNAMO Galaxies
• K-Band Imaging of the Nearby, Clumpy Turbulent Disk Galaxy DYNAMO G04-1
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