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| Main Authors: | , , , |
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| Format: | Preprint |
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2025
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| Online Access: | https://arxiv.org/abs/2511.19650 |
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| _version_ | 1866912923897561088 |
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| author | Contreras, Ana León Amorín, Ricardo Llerena, Mario Fernández, Vital |
| author_facet | Contreras, Ana León Amorín, Ricardo Llerena, Mario Fernández, Vital |
| contents | We present a study of the ionized gas kinematics and feedback properties in a sample of 14 low-mass, UV-luminous Lyman Break Analogs (LBAs) at redshifts z~0.1-0.3. These compact, strongly star-forming galaxies serve as local analogs of high-redshift starbursts. Using high-resolution VLT/X-shooter spectra, we model the optical emission-line profiles, including [O III] 4959,5007 and the Balmer lines, with multi-component Gaussian fits. All galaxies show complex kinematics that require both narrow (sigma < 90 km/s) and broad (sigma > 90 km/s) components. The narrow components trace highly turbulent gas associated with massive star-forming regions, while the broad components indicate ionized outflows driven by stellar winds and supernova feedback, with outflow velocities of about 200-500 km/s. Estimated mass outflow rates range from 0.20 to 2.72 solar masses per year, with mass-loading factors between 0.03 and 0.81. We find a mild increase in mass loading toward lower stellar masses, as well as a strong correlation between mass loading and star-formation-rate surface density, suggesting that more compact starbursts drive more powerful outflows. These trends are consistent with those seen in star-forming galaxies at higher redshifts. Our results highlight the importance of local UV-compact starbursts for understanding feedback processes in low-mass, rapidly star-forming galaxies. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2511_19650 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Tracing ionized gas kinematics in Lyman-Break Analogs. Implications for star formation compactness and outflow properties Contreras, Ana León Amorín, Ricardo Llerena, Mario Fernández, Vital Astrophysics of Galaxies Cosmology and Nongalactic Astrophysics We present a study of the ionized gas kinematics and feedback properties in a sample of 14 low-mass, UV-luminous Lyman Break Analogs (LBAs) at redshifts z~0.1-0.3. These compact, strongly star-forming galaxies serve as local analogs of high-redshift starbursts. Using high-resolution VLT/X-shooter spectra, we model the optical emission-line profiles, including [O III] 4959,5007 and the Balmer lines, with multi-component Gaussian fits. All galaxies show complex kinematics that require both narrow (sigma < 90 km/s) and broad (sigma > 90 km/s) components. The narrow components trace highly turbulent gas associated with massive star-forming regions, while the broad components indicate ionized outflows driven by stellar winds and supernova feedback, with outflow velocities of about 200-500 km/s. Estimated mass outflow rates range from 0.20 to 2.72 solar masses per year, with mass-loading factors between 0.03 and 0.81. We find a mild increase in mass loading toward lower stellar masses, as well as a strong correlation between mass loading and star-formation-rate surface density, suggesting that more compact starbursts drive more powerful outflows. These trends are consistent with those seen in star-forming galaxies at higher redshifts. Our results highlight the importance of local UV-compact starbursts for understanding feedback processes in low-mass, rapidly star-forming galaxies. |
| title | Tracing ionized gas kinematics in Lyman-Break Analogs. Implications for star formation compactness and outflow properties |
| topic | Astrophysics of Galaxies Cosmology and Nongalactic Astrophysics |
| url | https://arxiv.org/abs/2511.19650 |