Home > Research > Publications & Outputs > Evolution of Dust-obscured Star Formation and G...

### Electronic data

• 1702.06182v1

Rights statement: © 2017 American Astronomical Society This is an author-created, un-copyedited version of an article accepted for publication/published in The Astrophysical Journal. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi:10.103847/1538-4357/aa6116

Accepted author manuscript, 711 KB, PDF document

## Evolution of Dust-obscured Star Formation and Gas to z=2.2 from HiZELS

Research output: Contribution to journalJournal articlepeer-review

Published

### Standard

Evolution of Dust-obscured Star Formation and Gas to z=2.2 from HiZELS. / Thomson, Alasdair; Simpson, James; Smail, Ian; Swinbank, Mark; Best, Philip; Sobral, David; Geach, James; Ibar, Edo; Johnson, Helen.

In: The Astrophysical Journal, Vol. 838, No. 2, 119, 31.03.2017.

Research output: Contribution to journalJournal articlepeer-review

### Harvard

Thomson, A, Simpson, J, Smail, I, Swinbank, M, Best, P, Sobral, D, Geach, J, Ibar, E & Johnson, H 2017, 'Evolution of Dust-obscured Star Formation and Gas to z=2.2 from HiZELS', The Astrophysical Journal, vol. 838, no. 2, 119. https://doi.org/10.3847/1538-4357/aa61a6

### APA

Thomson, A., Simpson, J., Smail, I., Swinbank, M., Best, P., Sobral, D., Geach, J., Ibar, E., & Johnson, H. (2017). Evolution of Dust-obscured Star Formation and Gas to z=2.2 from HiZELS. The Astrophysical Journal, 838(2), [119]. https://doi.org/10.3847/1538-4357/aa61a6

### Vancouver

Thomson A, Simpson J, Smail I, Swinbank M, Best P, Sobral D et al. Evolution of Dust-obscured Star Formation and Gas to z=2.2 from HiZELS. The Astrophysical Journal. 2017 Mar 31;838(2). 119. https://doi.org/10.3847/1538-4357/aa61a6

### Author

Thomson, Alasdair ; Simpson, James ; Smail, Ian ; Swinbank, Mark ; Best, Philip ; Sobral, David ; Geach, James ; Ibar, Edo ; Johnson, Helen. / Evolution of Dust-obscured Star Formation and Gas to z=2.2 from HiZELS. In: The Astrophysical Journal. 2017 ; Vol. 838, No. 2.

### Bibtex

@article{37a7d98df99f487685e540c5d7fa60a8,
title = "Evolution of Dust-obscured Star Formation and Gas to z=2.2 from HiZELS",
abstract = "We investigate the far-infrared properties of galaxies selected via deep, narrow-band imaging of the H$\alpha$ emission line in four redshift slices from $z=0.40$--$2.23$ over $\sim 1$deg$^2$ as part of the High-redshift Emission Line Survey (HiZELS). We use a stacking approach in the Herschel PACS/SPIRE bands, along with $850\,\mu$m imaging from SCUBA-2 to study the evolution of the dust properties of H$\alpha$-emitters selected above an evolving characteristic luminosity threshold, $0.2L^\star_{{\rm H}\alpha}(z)$. We investigate the relationship between the dust temperatures and the far-infrared luminosities of our stacked samples, finding that H$\alpha$-selection identifies cold, low-$L_{\rm IR}$ galaxies ($T_{\rm dust}\sim 14$k; $\log[L_{\rm IR}/{\rm L}_\odot]\sim 9.9$) at $z=0.40$, and more luminous, warmer systems ($T_{\rm dust}\sim 34$k; $\log[L_{\rm IR}/{\rm L}_\odot]\sim 11.5$) at $z=2.23$. Using a modified greybody model, we estimate {"}characteristic sizes{"} for the dust-emitting regions of HiZELS galaxies of $\sim 0.5$kpc, nearly an order of magnitude smaller than their stellar continuum sizes, which may provide indirect evidence of clumpy ISM structure. Lastly, we measure the dust masses from our far-IR SEDs along with metallicity-dependent gas-to-dust ratios ($\delta_{\rm GDR}$) to measure typical molecular gas masses of $\sim 10^{10}$M$_\odot$ for these bright H$\alpha$-emitters. The gas depletion timescales are shorter than the Hubble time at each redshift, suggesting probable replenishment of their gas reservoirs from the intergalactic medium. Based on the number density of H$\alpha$-selected galaxies, we find that typical star-forming galaxies brighter than $0.2L^{\star}_{{\rm H}\alpha}(z)$ host a significant fraction ($35\pm10$%) of the total gas content of the Universe, consistent with the predictions of the latest cosmological simulations.",
keywords = "galaxies: evolution , galaxies: high-redshift, galaxies: ISM , galaxies: star formation",
author = "Alasdair Thomson and James Simpson and Ian Smail and Mark Swinbank and Philip Best and David Sobral and James Geach and Edo Ibar and Helen Johnson",
note = "{\textcopyright} 2017 American Astronomical Society This is an author-created, un-copyedited version of an article accepted for publication/published in The Astrophysical Journal. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi:10.103847/1538-4357/aa6116",
year = "2017",
month = mar,
day = "31",
doi = "10.3847/1538-4357/aa61a6",
language = "English",
volume = "838",
journal = "The Astrophysical Journal",
issn = "0004-637X",
publisher = "Institute of Physics Publishing",
number = "2",

}

### RIS

TY - JOUR

T1 - Evolution of Dust-obscured Star Formation and Gas to z=2.2 from HiZELS

AU - Thomson, Alasdair

AU - Simpson, James

AU - Smail, Ian

AU - Swinbank, Mark

AU - Best, Philip

AU - Sobral, David

AU - Geach, James

AU - Ibar, Edo

AU - Johnson, Helen

N1 - © 2017 American Astronomical Society This is an author-created, un-copyedited version of an article accepted for publication/published in The Astrophysical Journal. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi:10.103847/1538-4357/aa6116

PY - 2017/3/31

Y1 - 2017/3/31

N2 - We investigate the far-infrared properties of galaxies selected via deep, narrow-band imaging of the H$\alpha$ emission line in four redshift slices from $z=0.40$--$2.23$ over $\sim 1$deg$^2$ as part of the High-redshift Emission Line Survey (HiZELS). We use a stacking approach in the Herschel PACS/SPIRE bands, along with $850\,\mu$m imaging from SCUBA-2 to study the evolution of the dust properties of H$\alpha$-emitters selected above an evolving characteristic luminosity threshold, $0.2L^\star_{{\rm H}\alpha}(z)$. We investigate the relationship between the dust temperatures and the far-infrared luminosities of our stacked samples, finding that H$\alpha$-selection identifies cold, low-$L_{\rm IR}$ galaxies ($T_{\rm dust}\sim 14$k; $\log[L_{\rm IR}/{\rm L}_\odot]\sim 9.9$) at $z=0.40$, and more luminous, warmer systems ($T_{\rm dust}\sim 34$k; $\log[L_{\rm IR}/{\rm L}_\odot]\sim 11.5$) at $z=2.23$. Using a modified greybody model, we estimate "characteristic sizes" for the dust-emitting regions of HiZELS galaxies of $\sim 0.5$kpc, nearly an order of magnitude smaller than their stellar continuum sizes, which may provide indirect evidence of clumpy ISM structure. Lastly, we measure the dust masses from our far-IR SEDs along with metallicity-dependent gas-to-dust ratios ($\delta_{\rm GDR}$) to measure typical molecular gas masses of $\sim 10^{10}$M$_\odot$ for these bright H$\alpha$-emitters. The gas depletion timescales are shorter than the Hubble time at each redshift, suggesting probable replenishment of their gas reservoirs from the intergalactic medium. Based on the number density of H$\alpha$-selected galaxies, we find that typical star-forming galaxies brighter than $0.2L^{\star}_{{\rm H}\alpha}(z)$ host a significant fraction ($35\pm10$%) of the total gas content of the Universe, consistent with the predictions of the latest cosmological simulations.

AB - We investigate the far-infrared properties of galaxies selected via deep, narrow-band imaging of the H$\alpha$ emission line in four redshift slices from $z=0.40$--$2.23$ over $\sim 1$deg$^2$ as part of the High-redshift Emission Line Survey (HiZELS). We use a stacking approach in the Herschel PACS/SPIRE bands, along with $850\,\mu$m imaging from SCUBA-2 to study the evolution of the dust properties of H$\alpha$-emitters selected above an evolving characteristic luminosity threshold, $0.2L^\star_{{\rm H}\alpha}(z)$. We investigate the relationship between the dust temperatures and the far-infrared luminosities of our stacked samples, finding that H$\alpha$-selection identifies cold, low-$L_{\rm IR}$ galaxies ($T_{\rm dust}\sim 14$k; $\log[L_{\rm IR}/{\rm L}_\odot]\sim 9.9$) at $z=0.40$, and more luminous, warmer systems ($T_{\rm dust}\sim 34$k; $\log[L_{\rm IR}/{\rm L}_\odot]\sim 11.5$) at $z=2.23$. Using a modified greybody model, we estimate "characteristic sizes" for the dust-emitting regions of HiZELS galaxies of $\sim 0.5$kpc, nearly an order of magnitude smaller than their stellar continuum sizes, which may provide indirect evidence of clumpy ISM structure. Lastly, we measure the dust masses from our far-IR SEDs along with metallicity-dependent gas-to-dust ratios ($\delta_{\rm GDR}$) to measure typical molecular gas masses of $\sim 10^{10}$M$_\odot$ for these bright H$\alpha$-emitters. The gas depletion timescales are shorter than the Hubble time at each redshift, suggesting probable replenishment of their gas reservoirs from the intergalactic medium. Based on the number density of H$\alpha$-selected galaxies, we find that typical star-forming galaxies brighter than $0.2L^{\star}_{{\rm H}\alpha}(z)$ host a significant fraction ($35\pm10$%) of the total gas content of the Universe, consistent with the predictions of the latest cosmological simulations.

KW - galaxies: evolution

KW - galaxies: high-redshift

KW - galaxies: ISM

KW - galaxies: star formation

U2 - 10.3847/1538-4357/aa61a6

DO - 10.3847/1538-4357/aa61a6

M3 - Journal article

VL - 838

JO - The Astrophysical Journal

JF - The Astrophysical Journal

SN - 0004-637X

IS - 2

M1 - 119

ER -