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## Extended H$\alpha$ over compact far-infrared continuum in dusty submillimeter galaxies -- Insights into dust distributions and star-formation rates at $z\sim2$

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Extended H$\alpha$ over compact far-infrared continuum in dusty submillimeter galaxies -- Insights into dust distributions and star-formation rates at $z\sim2$. / Chen, Chian-Chou; Harrison, C. M.; Smail, I.; Swinbank, A. M.; Turner, O. J.; Wardlow, J. L.; Brandt, W. N.; Calistro Rivera, G.; Chapman, S. C.; Cooke, E. A.; Dannerbauer, H.; Dunlop, J. S.; Farrah, D.; Michałowski, M. J.; Schinnerer, E.; Simpson, J. M.; Thomson, A. P.; van der Werf, P. P.

In: Astronomy and Astrophysics, Vol. 635, A119, 31.03.2020.

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### Harvard

Chen, C-C, Harrison, CM, Smail, I, Swinbank, AM, Turner, OJ, Wardlow, JL, Brandt, WN, Calistro Rivera, G, Chapman, SC, Cooke, EA, Dannerbauer, H, Dunlop, JS, Farrah, D, Michałowski, MJ, Schinnerer, E, Simpson, JM, Thomson, AP & van der Werf, PP 2020, 'Extended H$\alpha$ over compact far-infrared continuum in dusty submillimeter galaxies -- Insights into dust distributions and star-formation rates at $z\sim2$', Astronomy and Astrophysics, vol. 635, A119. https://doi.org/10.1051/0004-6361/201936286

### APA

Chen, C-C., Harrison, C. M., Smail, I., Swinbank, A. M., Turner, O. J., Wardlow, J. L., Brandt, W. N., Calistro Rivera, G., Chapman, S. C., Cooke, E. A., Dannerbauer, H., Dunlop, J. S., Farrah, D., Michałowski, M. J., Schinnerer, E., Simpson, J. M., Thomson, A. P., & van der Werf, P. P. (2020). Extended H$\alpha$ over compact far-infrared continuum in dusty submillimeter galaxies -- Insights into dust distributions and star-formation rates at $z\sim2$. Astronomy and Astrophysics, 635, [A119]. https://doi.org/10.1051/0004-6361/201936286

### Author

Chen, Chian-Chou ; Harrison, C. M. ; Smail, I. ; Swinbank, A. M. ; Turner, O. J. ; Wardlow, J. L. ; Brandt, W. N. ; Calistro Rivera, G. ; Chapman, S. C. ; Cooke, E. A. ; Dannerbauer, H. ; Dunlop, J. S. ; Farrah, D. ; Michałowski, M. J. ; Schinnerer, E. ; Simpson, J. M. ; Thomson, A. P. ; van der Werf, P. P. / Extended H$\alpha$ over compact far-infrared continuum in dusty submillimeter galaxies -- Insights into dust distributions and star-formation rates at $z\sim2$. In: Astronomy and Astrophysics. 2020 ; Vol. 635.

### Bibtex

title = "Extended H$\alpha$ over compact far-infrared continuum in dusty submillimeter galaxies -- Insights into dust distributions and star-formation rates at $z\sim2$",
abstract = "Using data from ALMA and near-infrared (NIR) integral field spectrographs including both SINFONI and KMOS on the VLT, we investigate the two-dimensional distributions of H$\alpha$ and rest-frame far-infrared (FIR) continuum in six submillimeter galaxies at $z\sim2$. At a similar spatial resolution ($\sim$0.5{"} FWHM; $\sim$4.5 kpc at $z=2$), we find that the half-light radius of H$\alpha$ is significantly larger than that of the FIR continuum in half of the sample, and on average H$\alpha$ is a median factor of $2.0\pm0.4$ larger. Having explored various ways to correct for the attenuation, we find that the attenuation-corrected H$\alpha$-based SFRs are systematically lower than the IR-based SFRs by at least a median factor of $3\pm1$, which cannot be explained by the difference in half-light radius alone. In addition, we find that in 40% of cases the total $V$-band attenuation ($A_V$) derived from energy balance modeling of the full ultraviolet(UV)-to-FIR spectral energy distributions (SEDs) is significantly higher than that derived from SED modeling using only the UV-to-NIR part of the SEDs, and the discrepancy appears to increase with increasing total infrared luminosity. Finally, considering all our findings along with the studies in the literature, we postulate that the dust distributions in SMGs, and possibly also in less IR luminous $z\sim2$ massive star-forming galaxies, can be decomposed into three main components; the diffuse dust heated by older stellar populations, the more obscured and extended young star-forming HII regions, and the heavily obscured central regions that have a low filling factor but dominate the infrared luminosity in which the majority of attenuation cannot be probed via UV-to-NIR emissions.",
keywords = "Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics",
author = "Chian-Chou Chen and Harrison, {C. M.} and I. Smail and Swinbank, {A. M.} and Turner, {O. J.} and Wardlow, {J. L.} and Brandt, {W. N.} and {Calistro Rivera}, G. and Chapman, {S. C.} and Cooke, {E. A.} and H. Dannerbauer and Dunlop, {J. S.} and D. Farrah and Micha{\l}owski, {M. J.} and E. Schinnerer and Simpson, {J. M.} and Thomson, {A. P.} and {van der Werf}, {P. P.}",
year = "2020",
month = mar,
day = "31",
doi = "10.1051/0004-6361/201936286",
language = "English",
volume = "635",
journal = "Astronomy and Astrophysics",
issn = "1432-0746",
publisher = "EDP Sciences",

}

### RIS

TY - JOUR

T1 - Extended H$\alpha$ over compact far-infrared continuum in dusty submillimeter galaxies -- Insights into dust distributions and star-formation rates at $z\sim2$

AU - Chen, Chian-Chou

AU - Harrison, C. M.

AU - Smail, I.

AU - Swinbank, A. M.

AU - Turner, O. J.

AU - Wardlow, J. L.

AU - Brandt, W. N.

AU - Calistro Rivera, G.

AU - Chapman, S. C.

AU - Cooke, E. A.

AU - Dannerbauer, H.

AU - Dunlop, J. S.

AU - Farrah, D.

AU - Michałowski, M. J.

AU - Schinnerer, E.

AU - Simpson, J. M.

AU - Thomson, A. P.

AU - van der Werf, P. P.

PY - 2020/3/31

Y1 - 2020/3/31

N2 - Using data from ALMA and near-infrared (NIR) integral field spectrographs including both SINFONI and KMOS on the VLT, we investigate the two-dimensional distributions of H$\alpha$ and rest-frame far-infrared (FIR) continuum in six submillimeter galaxies at $z\sim2$. At a similar spatial resolution ($\sim$0.5" FWHM; $\sim$4.5 kpc at $z=2$), we find that the half-light radius of H$\alpha$ is significantly larger than that of the FIR continuum in half of the sample, and on average H$\alpha$ is a median factor of $2.0\pm0.4$ larger. Having explored various ways to correct for the attenuation, we find that the attenuation-corrected H$\alpha$-based SFRs are systematically lower than the IR-based SFRs by at least a median factor of $3\pm1$, which cannot be explained by the difference in half-light radius alone. In addition, we find that in 40% of cases the total $V$-band attenuation ($A_V$) derived from energy balance modeling of the full ultraviolet(UV)-to-FIR spectral energy distributions (SEDs) is significantly higher than that derived from SED modeling using only the UV-to-NIR part of the SEDs, and the discrepancy appears to increase with increasing total infrared luminosity. Finally, considering all our findings along with the studies in the literature, we postulate that the dust distributions in SMGs, and possibly also in less IR luminous $z\sim2$ massive star-forming galaxies, can be decomposed into three main components; the diffuse dust heated by older stellar populations, the more obscured and extended young star-forming HII regions, and the heavily obscured central regions that have a low filling factor but dominate the infrared luminosity in which the majority of attenuation cannot be probed via UV-to-NIR emissions.

AB - Using data from ALMA and near-infrared (NIR) integral field spectrographs including both SINFONI and KMOS on the VLT, we investigate the two-dimensional distributions of H$\alpha$ and rest-frame far-infrared (FIR) continuum in six submillimeter galaxies at $z\sim2$. At a similar spatial resolution ($\sim$0.5" FWHM; $\sim$4.5 kpc at $z=2$), we find that the half-light radius of H$\alpha$ is significantly larger than that of the FIR continuum in half of the sample, and on average H$\alpha$ is a median factor of $2.0\pm0.4$ larger. Having explored various ways to correct for the attenuation, we find that the attenuation-corrected H$\alpha$-based SFRs are systematically lower than the IR-based SFRs by at least a median factor of $3\pm1$, which cannot be explained by the difference in half-light radius alone. In addition, we find that in 40% of cases the total $V$-band attenuation ($A_V$) derived from energy balance modeling of the full ultraviolet(UV)-to-FIR spectral energy distributions (SEDs) is significantly higher than that derived from SED modeling using only the UV-to-NIR part of the SEDs, and the discrepancy appears to increase with increasing total infrared luminosity. Finally, considering all our findings along with the studies in the literature, we postulate that the dust distributions in SMGs, and possibly also in less IR luminous $z\sim2$ massive star-forming galaxies, can be decomposed into three main components; the diffuse dust heated by older stellar populations, the more obscured and extended young star-forming HII regions, and the heavily obscured central regions that have a low filling factor but dominate the infrared luminosity in which the majority of attenuation cannot be probed via UV-to-NIR emissions.

KW - Astrophysics - Astrophysics of Galaxies

KW - Astrophysics - Solar and Stellar Astrophysics

U2 - 10.1051/0004-6361/201936286

DO - 10.1051/0004-6361/201936286

M3 - Journal article

VL - 635

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

SN - 1432-0746

M1 - A119

ER -