English

K-Band Imaging of the Nearby, Clumpy Turbulent Disk Galaxy DYNAMO G04-1

Astrophysics of Galaxies 2022-02-23 v1

Abstract

We present a case study of stellar clumps in G04-1, a clumpy, turbulent disk galaxy located at zz = 0.13 from the DYNAMO sample, using adaptive optics enabled K-band imaging (2.25\sim2.25 kpc/arcsec) with Keck/NIRC2. We identify 15 stellar clumps in G04-1 with a range of masses from 3.6×1063.6 \times 10^{6} to 2.7×108 M2.7 \times 10^{8}\ \rm M_{\odot}, and with a median mass of 2.9×107 M\sim2.9 \times 10^{7}\ \rm M_{\odot}. Note that these masses decrease by about one-half when we apply a light correction for the underlying stellar disk. A majority (12 of 15) of clumps observed in the KPK_{P}-band imaging have associated components in Hα\alpha maps (2.75\sim2.75 kpc/arcsec; <<Rclump>_{clump}> \sim500 pc) and appear co-located (Δx0.1\overline{\Delta x} \sim 0.1 arcsec). Using Hubble Space Telescope WFC/ACS observations with the F336W and F467M filters, we also find evidence of radial trends in clump stellar properties: clumps closer to the centre of G04-1 are more massive (consistent with observations at high-zz) and appear more red, suggesting they may be more evolved. Using our high-resolution data, we construct a star forming main sequence for G04-1 in terms of spatially-resolved quantities and find that all regions (both clump and intra-clump) within the galaxy are experiencing an enhanced mode of star formation routinely observed in galaxies at high-zz. In comparison to recent simulations, our observation of a number of clumps with masses 107108 M10^{7}-10^{8}\ \rm M_{\odot} is not consistent with strong radiative feedback in this galaxy.

Keywords

Cite

@article{arxiv.2112.00764,
  title  = {K-Band Imaging of the Nearby, Clumpy Turbulent Disk Galaxy DYNAMO G04-1},
  author = {Heidi A. White and Deanne B. Fisher and Roberto G. Abraham and Karl Glazebrook and Danail Obreschkow},
  journal= {arXiv preprint arXiv:2112.00764},
  year   = {2022}
}

Comments

18 pages, 7 figures. Accepted to The Astrophysical Journal (ApJ)