VLA AND ALMA IMAGING OF INTENSE GALAXY-WIDE STAR FORMATION IN z 2 GALAXIES Academic Article uri icon

abstract

  • ABSTRACT We present 0.4 resolution extinction-independent distributions of star formation and dust in 11 star-forming galaxies (SFGs) at z=1.33.0. These galaxies are selected from sensitive blank-field surveys of the 22 Hubble Ultra-Deep Field at =5 cm and 1.3 mm using the Karl G. Jansky Very Large Array and Atacama Large Millimeter/submillimeter Array. They have star formation rates (SFRs), stellar masses, and dust properties representative of massive main-sequence SFGs at z2. Morphological classification performed on spatially resolved stellar mass maps indicates a mixture of disk and morphologically disturbed systems; half of the sample harbor X-ray active galactic nuclei (AGNs), thereby representing a diversity of z2 SFGs undergoing vigorous mass assembly. We find that their intense star formation most frequently occurs at the location of stellar-mass concentration and extends over an area comparable to their stellar-mass distribution, with a median diameter of 4.21.8 kpc. This provides direct evidence of galaxy-wide star formation in distant blank-field-selected main-sequence SFGs. The typical galactic-average SFR surface density is 2.5 M yr1 kpc2, sufficiently high to drive outflows. In X-ray-selected AGN where radio emission is enhanced over the level associated with star formation, the radio excess pinpoints the AGNs, which are found to be cospatial with star formation. The median extinction-independent size of main-sequence SFGs is two times larger than those of bright submillimeter galaxies, whose SFRs are 38 times larger, providing a constraint on the characteristic SFR (300 M yr1) above which a significant population of more compact SFGs appears to emerge.

published proceedings

  • ASTROPHYSICAL JOURNAL

altmetric score

  • 8.33

author list (cited authors)

  • Rujopakarn, W., Dunlop, J. S., Rieke, G. H., Ivison, R. J., Cibinel, A., Nyland, K., ... Windhorst, R. A.

citation count

  • 115

complete list of authors

  • Rujopakarn, W||Dunlop, JS||Rieke, GH||Ivison, RJ||Cibinel, A||Nyland, K||Jagannathan, P||Silverman, JD||Alexander, DM||Biggs, AD||Bhatnagar, S||Ballantyne, DR||Dickinson, M||Elbaz, D||Geach, JE||Hayward, CC||Kirkpatrick, A||McLure, RJ||Michalowski, MJ||Miller, NA||Narayanan, D||Owen, FN||Pannella, M||Papovich, C||Pope, A||Rau, U||Robertson, BE||Scott, D||Swinbank, AM||van der Werf, P||van Kampen, E||Weiner, BJ||Windhorst, RA

publication date

  • December 2016