Stellar feedback impact on the ionized gas kinematics in the dwarf galaxy Sextans A

Abstract

Feedback from massive stars shapes the ISM and affects the evolution of galaxies, but its mechanisms acting at the small scales ($\sim 10$ pc) are still not well constrained observationally, especially in the low-metallicity environments. We present the analysis of the ionized gas (focusing on its kinematics, which were never studied before), and its connection to the massive stars in the nearby ($D\sim 1.4$ Mpc) star-forming very metal-poor ($Z\sim 0.07Z_{\odot }$) galaxy Sextans A. The analysis is based on the observations with a scanning Fabry-Perot interferometer, long-slit spectroscopy and imaging in emission lines with narrow-band tunable filters. We found 10 expanding superbubbles of ionized gas with ages of 1-3 Myr. We argue that 3 of them are probable supernovae remnants, while the pre-supernovae feedback is an important source of energy for blowing-out the remaining superbubbles. The two brightest sites of star formation exhibit signs of outflowing ionized gas, which is traced by its ionized and atomic gas kinematics and (in one case) by its emission line flux ratios. Overall, the ionized gas kinematics in Sextans A is highly affected by the feedback from several generations of massive stars and inconsistent with the mere solid-body rotation observed in atomic hydrogen.

19 pages, 12 figures, 5 tables. Accepted for publication in MNRAS

References in corpus (22)

• HyperLEDA. III. The catalogue of extragalactic distances
• The MAPPINGS III Library of Fast Radiative Shock Models
• The ACS Nearby Galaxy Survey Treasury
• An H-alpha Imaging Survey of Galaxies in the Local 11 Mpc Volume
• Modelling the nebular emission from primeval to present-day star-forming galaxies
• A Superbubble Feedback Model for Galaxy Simulations
• Inefficient Star Formation In Extremely Metal Poor Galaxies
• A Survey of Local Group Galaxies Currently Forming Stars: III. A Search for Luminous Blue Variables and Other H-alpha Emission-Lined Stars
• Associations of Dwarf Galaxies
• Testing massive star evolution, star-formation history and feedback at low metallicity : Spectroscopic analysis of OB stars in the SMC Wing
• What controls the ionized gas turbulent motions in dwarf galaxies?
• Which feedback mechanisms dominate in the high-pressure environment of the Central Molecular Zone?
• A New Diagnostic to Separate Line Emission from Star Formation, Shocks, and AGN Simultaneously in IFU Data
• Comparing the pre-SNe feedback and environmental pressures for 6000 HII regions across 19 nearby spiral galaxies
• The impact of pre-supernova feedback and its dependence on environment
• Complexes of triggered star formation in supergiant shell of Holmberg II
• The extended structure of the dwarf irregular galaxies Sextans A and Sextans B. Signatures of tidal distortion in the outskirts of the Local Group
• A Catalog of Holes and Shells in the Interstellar Medium of the LITTLE THINGS Dwarf Galaxies
• Ongoing star formation at the outskirts of Sextans A: Spectroscopic detection of early-O type stars
• Extremely metal-poor galaxy DDO 68: the LBV, H-alpha shells and the most luminous stars
• Scanning Fabry--Perot Interferometer of the 6-m SAO RAS Telescope
• Star formation in the nearby dwarf galaxy DDO 53: interplay between gas accretion and stellar feedback