Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/221579

Title

Scaling relations of star-forming regions: from kpc-sized clumps to Hii regions

Author(s)

Wisnioski, Emily;  Glazebrook, Karl;  Blake, Chris;  Poole, Gregory B.;  Green, Andrew W.;  Wyder, Ted;  Martin, Chris

Abstract

We present the properties of eight star-forming regions, or ‘clumps,’ in three galaxies at z∼ 1.3 from the WiggleZ Dark Energy Survey, which are resolved with the OH Suppressing InfraRed Imaging Spectrograph (OSIRIS) integral field spectrograph. Within turbulent discs, σ∼ 90 km s−1, clumps are measured with average sizes of 1.5 kpc and average Jeans masses of 4.2 × 109 M⊙, in total accounting for 40–60 per cent of the stellar mass of the discs. These findings lend observational support to models that predict larger clumps will form as a result of higher disc velocity dispersions driven-up by cosmological gas accretion. As a consequence of the changes in global environment, it may be predicted that star-forming regions at high redshift should not resemble star-forming regions locally. Yet despite the increased sizes and dispersions, clumps and H ii regions are found to follow tight scaling relations over the range z= 0–2 for Hα size, velocity dispersion, luminosity and mass when comparing >2000 H ii regions locally and 30 clumps at z > 1 (σ∝r0.42 ± 0.03, LHα∝r2.72 ± 0.04, LHα∝σ4.18 ± 0.21 and ). We discuss these results in the context of the existing simulations of clump formation and evolution, with an emphasis on the processes that drive-up the turbulent motions in the interstellar medium. Our results indicate that while the turbulence of discs may have important implications for the size and luminosity of regions which form within them, the same processes govern their formation from high redshift to the current epoch.

Publication type

Journal article

Research centre

Swinburne University of Technology. Faculty of Information and Communication Technologies. Centre for Astrophysics and Supercomputing

Source

Monthly Notices of the Royal Astronomical Society, Vol. 422, no. 4 (Jun 2012), pp. 3339-3355

Publication year

2012

FOR Code(s)

0201 Astronomical and Space Sciences

Keyword(s)

Dynamics;  Galaxy formation;  High-redshift;  Hii regions;  Kinematics;  Star clusters

Publisher

Wiley-Blackwell Publishing

ISSN

0035-8711

Publisher URL

http://dx.doi.org/10.1111/j.1365-2966.2012.20850.x

Copyright

Copyright © 2012 The Authors. Monthly Notices of the Royal Astronomical Society copyright © 2012 RAS.

Peer reviewed