A Caltech Library Service

A Study of Two Dwarf Irregular Galaxies with Asymmetrical Star Formation Distributions

Hunter, Deidre A. and Cook, David O. and Lee, Janice C. (2018) A Study of Two Dwarf Irregular Galaxies with Asymmetrical Star Formation Distributions. Astrophysical Journal, 855 (1). Art. No. 7. ISSN 1538-4357. doi:10.3847/1538-4357/aaa964.

[img] PDF - Published Version
See Usage Policy.

[img] PDF - Submitted Version
See Usage Policy.


Use this Persistent URL to link to this item:


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.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Hunter, Deidre A.0000-0002-3322-9798
Cook, David O.0000-0002-6877-7655
Lee, Janice C.0000-0002-2278-9407
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.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Space Telescope Science InstituteUNSPECIFIED
Swedish Research CouncilUNSPECIFIED
Swedish National Space Board (SNSB)UNSPECIFIED
Science and Technology Facilities Council (STFC)ST/P000541/1
2016 CAMPARE Scholar programUNSPECIFIED
Subject Keywords:galaxies: dwarf; galaxies: individual (DDO 187, NGC 3738) ; galaxies: star formation
Issue or Number:1
Record Number:CaltechAUTHORS:20180227-103610014
Persistent URL:
Official Citation:Deidre A. Hunter et al 2018 ApJ 855 7
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:84972
Deposited By: Ruth Sustaita
Deposited On:27 Feb 2018 18:56
Last Modified:15 Nov 2021 20:24

Repository Staff Only: item control page