Complex gas kinematics in compact, rapidly assembling star-forming galaxies
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]λλ6548, 6584Å, an...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2012 |
| País: | Argentina |
| Institución: | Universidad Nacional de La Plata |
| Repositorio: | SEDICI (UNLP) |
| Idioma: | inglés |
| OAI Identifier: | oai:sedici.unlp.edu.ar:10915/84688 |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/84688 |
| Access Level: | acceso abierto |
| Palabra clave: | Ciencias Astronómicas galaxies: dwarf galaxies: evolution galaxies: kinematics and dynamics galaxies: starburst |
| Sumario: | 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]λλ6548, 6584Å, and [SII]λλ6717, 6731Å, consisting of the superposition of different kinematical components on a spatial extent of few kiloparsecs: 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 two-dimensional spectra, whereas for another one a faint detached Hα blob lacking stellar continuum is detected at the same recessional velocity ∼ 7kpc away from the galaxy. The individual narrower Hα components show high intrinsic velocity dispersion (σ ∼30-80kms<sup>-1</sup>), suggesting together with unsharped masking Hubble Space Telescope images that star formation proceeds in an ensemble of several compact and turbulent clumps, with relative velocities of up to ∼500kms<sup>-1</sup>. The broad underlying Hα components indicate in all cases large expansion velocities (full width zero intensity ≥1000kms<sup>-1</sup>) and very high luminosities (up to ∼10<sup>42</sup> erg s<sup>-1</sup>), probably showing the imprint of energetic outflows from supernovae. These intriguing results underline the importance of green peas for studying the assembly of low-mass galaxies near and far. |
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