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Kinematics and Feedback in H ii Regions in the Dwarf Starburst Galaxy IC 10

Cosens, Maren and Wright, Shelley A. and Murray, Norman and Armus, Lee and Sandstrom, Karin and Do, Tuan and Larson, Kirsten and Martinez, Gregory and Sabhlok, Sanchit and Vayner, Andrey and Wiley, James (2022) Kinematics and Feedback in H ii Regions in the Dwarf Starburst Galaxy IC 10. Astrophysical Journal, 929 (1). Art. No. 74. ISSN 0004-637X. doi:10.3847/1538-4357/ac52f3.

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We present a survey of the central region of the nearest starburst galaxy, IC 10, using the W. M. Keck Observatory Keck Cosmic Web Imager (KCWI) at high spectral and spatial resolution. We map the central starburst of IC 10 to sample the kinematic and ionization properties of the individual star-forming regions. Using the low spectral resolution mode of KCWI, we map the oxygen abundance, and with the high spectral resolution mode, we identify 46 individual H II regions. These H II regions have an average radius of 4.0 pc, star formation rate ∼1.3 × 10⁻⁴ M⊙ yr⁻¹, and velocity dispersion ∼16 km s⁻¹. None of the H II regions appear to be virialized (α_(vir) ≫ 1), and on average, they show evidence of ongoing expansion. IC 10's H II regions are offset from the star-forming-region size–luminosity scaling relationships, as well as Larson's Law that relates size and velocity dispersion. We investigate the balance of inward and outward pressure, P_(in) and P_(out), finding P_(out) > P_(in) in 89% of H II regions, indicating feedback-driven expansion even in these low-mass H II regions. We find warm gas pressure (P_(gas)) provides the dominant contribution to the outward pressure (P_(out)). This counteracts the inward pressure, which is dominated by turbulence in the surrounding gas rather than self-gravity. Five H II regions show evidence of outflows that are most likely supported by either stellar winds (two regions) or champagne flows (three regions). These observations provide new insights into the state of the star-forming regions in IC 10 and negative feedback from low-mass clusters.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Cosens, Maren0000-0002-2248-6107
Wright, Shelley A.0000-0003-1034-8054
Armus, Lee0000-0003-3498-2973
Sandstrom, Karin0000-0002-4378-8534
Do, Tuan0000-0001-9554-6062
Larson, Kirsten0000-0003-3917-6460
Sabhlok, Sanchit0000-0002-8780-8226
Vayner, Andrey0000-0002-0710-3729
Wiley, James0000-0003-2687-9618
Additional Information:© 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2021 October 13; revised 2022 January 20; accepted 2022 February 5; published 2022 April 14. We thank the anonymous referee for their comments that helped improve the quality of this paper. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. Facility: Keck: II (KCWI). - Software: astrodendro (Thomas et al. 2013), Astropy (Astropy Collaboration et al. 2013; Price-Whelan et al. 2018), IPython (Perez & Granger 2007) Matplotlib (Hunter 2007), NumPy (Harris et al. 2020), pandas (McKinney 2010; The Pandas Development Team 2016), photutils (Bradley et al. 2019), PyStan (Stan Development Team 2017), reproject (Robitaille et al. 2020), and SHAPE (Steffen et al. 2011).
Funding AgencyGrant Number
W. M. Keck FoundationUNSPECIFIED
Subject Keywords:Starburst galaxies; Star forming regions; H II regions; Galaxy kinematics; Galaxy dynamics; Spectroscopy; Dwarf irregular galaxies; Ground-based astronomy; Scaling relations
Issue or Number:1
Classification Code:Unified Astronomy Thesaurus concepts: Starburst galaxies (1570); Star forming regions (1565); H II regions (694); Galaxy kinematics (602); Galaxy dynamics (591); Spectroscopy (1558); Dwarf irregular galaxies (417); Groundbased astronomy (686)
Record Number:CaltechAUTHORS:20220512-165916100
Persistent URL:
Official Citation:Maren Cosens et al 2022 ApJ 929 74
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:114698
Deposited By: Tony Diaz
Deposited On:12 May 2022 19:01
Last Modified:12 May 2022 19:01

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