A Study of Two Dwarf Irregular Galaxies with Asymmetrical Star Formation Distributions
Abstract
Two dwarf irregular galaxies, DDO 187 and NGC 3738, exhibit a striking pattern of star formation: intense star formation is taking place in a large region occupying roughly half of the inner part of the optical galaxy. We use data on the H i distribution and kinematics and stellar images and colors to examine the properties of the environment in the high star formation rate (HSF) halves of the galaxies in comparison with the low star formation rate halves. We find that the pressure and gas density are higher on the HSF sides by 30%–70%. In addition we find in both galaxies that the H i velocity fields exhibit significant deviations from ordered rotation and there are large regions of high-velocity dispersion and multiple velocity components in the gas beyond the inner regions of the galaxies. The conditions in the HSF regions are likely the result of large-scale external processes affecting the internal environment of the galaxies and enabling the current star formation there.
Additional Information
© 2018 American Astronomical Society. Received 2017 October 13. Accepted 2018 January 17. Published 2018 February 27. Some of the results presented here are based on observations made with the NASA/ESA Hubble Space Telescope under the LEGUS survey. Support for Program number 13364 was provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. A.A. acknowledges the support of the Swedish Research Council (Vetenskapsrdet) and the Swedish National Space Board (SNSB). M.F. acknowledges support by the UK Science and Technology Facilities Council (grant number ST/P000541/1). S.G. appreciates funding from the National Science Foundation grant AST-1461200 to Northern Arizona University for Research Experiences for Undergraduates summer internships and Drs. Kathy Eastwood and David Trilling for running the NAU REU program in 2016. S.G. also appreciates the support of the 2016 CAMPARE Scholar program and Dr. Alexander Rudolph for directing that program.Attached Files
Published - Hunter_2018_ApJ_855_7.pdf
Submitted - 1802.02060.pdf
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Additional details
- Eprint ID
- 84972
- Resolver ID
- CaltechAUTHORS:20180227-103610014
- Space Telescope Science Institute
- NAS5-26555
- NASA
- Swedish Research Council
- Swedish National Space Board (SNSB)
- ST/P000541/1
- Science and Technology Facilities Council (STFC)
- AST-1461200
- NSF
- 2016 CAMPARE Scholar program
- Created
-
2018-02-27Created from EPrint's datestamp field
- Updated
-
2021-11-15Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)