A Widespread, Clumpy Starburst in the Isolated Ongoing Dwarf Galaxy Merger dm1647+21

G. C. Privon, S. Stierwalt, D. R. Patton, G. Besla, S. Pearson, M. Putman, K. E. Johnson, N. Kallivayalil, S. Liss

Research output: Research - peer-reviewArticle

Abstract

Interactions between pairs of isolated dwarf galaxies provide a critical window into low-mass hierarchical, gas-dominated galaxy assembly and the build-up of stellar mass in low-metallicity systems. We present the first Very Large Telescope/Multi Unit Spectroscopic Explorer (VLT/MUSE) optical integral field unit (IFU) observations of the interacting dwarf pair dm1647+21 selected from the TiNy Titans survey. The Hα emission is widespread and corresponds to a total unobscured star formation rate (SFR) of 0.44 M o yr-1, which is 2.7 times higher than the SFR inferred from Sloan Digital Sky Survey (SDSS) data. The implied specific SFR (sSFR) for the system is elevated by more than an order of magnitude above non-interacting dwarfs in the same mass range. This increase is dominated by the lower-mass galaxy, which has a sSFR enhancement of >50. Examining the spatially resolved maps of classic optical line diagnostics, we find that the interstellar medium (ISM) excitation can be fully explained by star formation. The velocity field of the ionized gas is not consistent with simple rotation. Dynamical simulations indicate that the irregular velocity field and the stellar structure is consistent with the identification of this system as an ongoing interaction between two dwarf galaxies. The widespread, clumpy enhancements in the star formation in this system point to important differences in the effect of mergers on dwarf galaxies, compared to massive galaxies; rather than the funneling of gas to the nucleus and giving rise to a nuclear starburst, starbursts in low-mass galaxy mergers may be triggered by large-scale ISM compression, and thus may be more distributed.

LanguageEnglish (US)
Article number74
JournalAstrophysical Journal
Volume846
Issue number1
DOIs
StatePublished - Sep 1 2017

Fingerprint

dwarf galaxies
galaxies
merger
gas
star formation rate
star formation
velocity distribution
augmentation
gases
interactions
rate
stellar structure
Titan
ionized gases
stellar mass
metallicity
assembly
telescopes
nuclei
excitation

Keywords

  • galaxies: dwarf
  • galaxies: individual (SDSS J164710.66+210514.5, SDSS J164711.12+210514.8)
  • galaxies: interactions
  • galaxies: ISM
  • galaxies: starburst

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Privon, G. C., Stierwalt, S., Patton, D. R., Besla, G., Pearson, S., Putman, M., ... Liss, S. (2017). A Widespread, Clumpy Starburst in the Isolated Ongoing Dwarf Galaxy Merger dm1647+21. Astrophysical Journal, 846(1), [74]. DOI: 10.3847/1538-4357/aa8560

A Widespread, Clumpy Starburst in the Isolated Ongoing Dwarf Galaxy Merger dm1647+21. / Privon, G. C.; Stierwalt, S.; Patton, D. R.; Besla, G.; Pearson, S.; Putman, M.; Johnson, K. E.; Kallivayalil, N.; Liss, S.

In: Astrophysical Journal, Vol. 846, No. 1, 74, 01.09.2017.

Research output: Research - peer-reviewArticle

Privon, GC, Stierwalt, S, Patton, DR, Besla, G, Pearson, S, Putman, M, Johnson, KE, Kallivayalil, N & Liss, S 2017, 'A Widespread, Clumpy Starburst in the Isolated Ongoing Dwarf Galaxy Merger dm1647+21' Astrophysical Journal, vol 846, no. 1, 74. DOI: 10.3847/1538-4357/aa8560
Privon GC, Stierwalt S, Patton DR, Besla G, Pearson S, Putman M et al. A Widespread, Clumpy Starburst in the Isolated Ongoing Dwarf Galaxy Merger dm1647+21. Astrophysical Journal. 2017 Sep 1;846(1). 74. Available from, DOI: 10.3847/1538-4357/aa8560
Privon, G. C. ; Stierwalt, S. ; Patton, D. R. ; Besla, G. ; Pearson, S. ; Putman, M. ; Johnson, K. E. ; Kallivayalil, N. ; Liss, S./ A Widespread, Clumpy Starburst in the Isolated Ongoing Dwarf Galaxy Merger dm1647+21. In: Astrophysical Journal. 2017 ; Vol. 846, No. 1.
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