Complex gas kinematics in compact, rapidly assembling star-forming galaxies

Abstract

Deep, high resolution spectroscopic observations have been obtained for six compact, strongly star-forming galaxies at redshift z~0.1-0.3, most of them also known as Green Peas. Remarkably, these galaxies show complex emission-line profiles in the spectral region including Hα, [NII]$\lambda \lambda 6548,6584$ and [SII]$\lambda \lambda 6717,6731$, consisting of the superposition of different kinematical components on a spatial extent of few kpc: a very broad line emission underlying more than one narrower component. For at least two of the observed galaxies some of these multiple components are resolved spatially in their 2D-spectra, whereas for another one a faint detached Hα blob lacking stellar continuum is detected at the same recessional velocity ~7 kpc away from the galaxy. The individual narrower Hα components show high intrinsic velocity dispersion (σ~30-80 km s${}^{-1}$), suggesting together with unsharped masking HST images that star formation proceeds in an ensemble of several compact and turbulent clumps, with relative velocities of up to ~500 km s${}^{-1}$. The broad underlying Hα components indicate in all cases large expansion velocities (full width zero intensity FWZI $\ge$ 1000 km s${}^{-1}$) and very high luminosities (up to ~10${}^{42}$ erg s${}^{-1}$), probably showing the imprint of energetic outflows from SNe. These intriguing results underline the importance of Green Peas for studying the assembly of low-mass galaxies near and far.

11 pages, 3 figures, and 1 Table. Accepted for publication in ApJ Letters

References in corpus (7)

• Cosmological Simulations of Intergalactic Medium Enrichment from Galactic Outflows
• Rapid formation of exponential disks and bulges at high redshift from the dynamical evolution of clump cluster and chain galaxies
• High star formation rates as the origin of turbulence in early and modern disk galaxies
• HST morphologies of local Lyman break galaxy analogs I: Evidence for starbursts triggered by merging
• Kinematics of gas and stars in the circumnuclear starforming ring of NGC 3351
• The effect of clouds in a galactic wind on the evolution of gas-rich dwarf galaxies
• Star-gas decoupling and a non-rotating stellar core in He 2-10: Integral field spectroscopy with FLAMES/ARGUS

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