Publication

Star Formation in Galaxies at z similar to 4-5 from the SMUVS Survey: A Clear Starburst/Main-sequence Bimodality for H alpha Emitters on the SFR-M* Plane

Caputi, K. I., Cowley, W. I., Deshmukh, S., Ashby, M. L. N., Bisigello, L., Fazio, G. G., Fynbo, J. P. U., Le Fèvre, O., Milvang-Jensen, B. & Ilbert, O., 1-Nov-2017, In : The Astrophysical Journal. 849, 1, 13 p., 45.

Research output: Contribution to journalArticleAcademicpeer-review

APA

Caputi, K. I., Cowley, W. I., Deshmukh, S., Ashby, M. L. N., Bisigello, L., Fazio, G. G., ... Ilbert, O. (2017). Star Formation in Galaxies at z similar to 4-5 from the SMUVS Survey: A Clear Starburst/Main-sequence Bimodality for H alpha Emitters on the SFR-M* Plane. The Astrophysical Journal, 849(1), [45]. https://doi.org/10.3847/1538-4357/aa901e

Author

Caputi, K. I. ; Cowley, W. I. ; Deshmukh, S. ; Ashby, M. L. N. ; Bisigello, L. ; Fazio, G. G. ; Fynbo, J. P. U. ; Le Fèvre, O. ; Milvang-Jensen, B. ; Ilbert, O. / Star Formation in Galaxies at z similar to 4-5 from the SMUVS Survey : A Clear Starburst/Main-sequence Bimodality for H alpha Emitters on the SFR-M* Plane. In: The Astrophysical Journal. 2017 ; Vol. 849, No. 1.

Harvard

Caputi, KI, Cowley, WI, Deshmukh, S, Ashby, MLN, Bisigello, L, Fazio, GG, Fynbo, JPU, Le Fèvre, O, Milvang-Jensen, B & Ilbert, O 2017, 'Star Formation in Galaxies at z similar to 4-5 from the SMUVS Survey: A Clear Starburst/Main-sequence Bimodality for H alpha Emitters on the SFR-M* Plane', The Astrophysical Journal, vol. 849, no. 1, 45. https://doi.org/10.3847/1538-4357/aa901e

Standard

Star Formation in Galaxies at z similar to 4-5 from the SMUVS Survey : A Clear Starburst/Main-sequence Bimodality for H alpha Emitters on the SFR-M* Plane. / Caputi, K. I.; Cowley, W. I.; Deshmukh, S.; Ashby, M. L. N.; Bisigello, L.; Fazio, G. G.; Fynbo, J. P. U.; Le Fèvre, O.; Milvang-Jensen, B.; Ilbert, O.

In: The Astrophysical Journal, Vol. 849, No. 1, 45, 01.11.2017.

Research output: Contribution to journalArticleAcademicpeer-review

Vancouver

Caputi KI, Cowley WI, Deshmukh S, Ashby MLN, Bisigello L, Fazio GG et al. Star Formation in Galaxies at z similar to 4-5 from the SMUVS Survey: A Clear Starburst/Main-sequence Bimodality for H alpha Emitters on the SFR-M* Plane. The Astrophysical Journal. 2017 Nov 1;849(1). 45. https://doi.org/10.3847/1538-4357/aa901e


BibTeX

@article{ecf9273ee82f4723a790d2bf419917ab,
title = "Star Formation in Galaxies at z similar to 4-5 from the SMUVS Survey: A Clear Starburst/Main-sequence Bimodality for H alpha Emitters on the SFR-M* Plane",
abstract = "We study a large galaxy sample from the Spitzer Matching Survey of the UltraVISTA ultra-deep Stripes (SMUVS) to search for sources with enhanced 3.6 μ {{m}} fluxes indicative of strong Hα emission at z=3.9{--}4.9. We find that the percentage of “Hα excess” sources reaches 37{\%}–40{\%} for galaxies with stellar masses {{log}}10({M}* /{M}ȯ )≈ 9{--}10 and decreases to <20 {\%} at {{log}}10({M}* /{M}ȯ )∼ 10.7. At higher stellar masses, however, the trend reverses, although this is likely due to active galactic nucleus contamination. We derive star formation rates (SFR) and specific SFR (sSFR) from the inferred Hα equivalent widths of our “Hα excess” galaxies. We show, for the first time, that the “Hα excess” galaxies clearly have a bimodal distribution on the SFR–M* plane: they lie on the main sequence of star formation (with {{log}}10({sSFR}/{{yr}}-1)<-8.05) or in a starburst cloud (with {{log}}10({sSFR}/{{yr}}-1)> -7.60). The latter contains ∼ 15 {\%} of all the objects in our sample and accounts for > 50 {\%} of the cosmic SFR density at z=3.9{--}4.9, for which we derive a robust lower limit of 0.066 {M}ȯ {{yr}}-1 {{Mpc}}-3. Finally, we identify an unusual > 50σ overdensity of z=3.9{--}4.9 galaxies within a 0.20× 0.20 arcmin2 region. We conclude that the SMUVS unique combination of area and depth at mid-IR wavelengths provides an unprecedented level of statistics and dynamic range that are fundamental to revealing new aspects of galaxy evolution in the young universe.",
keywords = "galaxies: evolution, galaxies: high-redshift, galaxies: star formation, galaxies: starburst, infrared: galaxies",
author = "Caputi, {K. I.} and Cowley, {W. I.} and S. Deshmukh and Ashby, {M. L. N.} and L. Bisigello and Fazio, {G. G.} and Fynbo, {J. P. U.} and {Le F{\`e}vre}, O. and B. Milvang-Jensen and O. Ilbert",
year = "2017",
month = "11",
day = "1",
doi = "10.3847/1538-4357/aa901e",
language = "English",
volume = "849",
journal = "The Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP PUBLISHING LTD",
number = "1",

}

RIS

TY - JOUR

T1 - Star Formation in Galaxies at z similar to 4-5 from the SMUVS Survey

T2 - A Clear Starburst/Main-sequence Bimodality for H alpha Emitters on the SFR-M* Plane

AU - Caputi, K. I.

AU - Cowley, W. I.

AU - Deshmukh, S.

AU - Ashby, M. L. N.

AU - Bisigello, L.

AU - Fazio, G. G.

AU - Fynbo, J. P. U.

AU - Le Fèvre, O.

AU - Milvang-Jensen, B.

AU - Ilbert, O.

PY - 2017/11/1

Y1 - 2017/11/1

N2 - We study a large galaxy sample from the Spitzer Matching Survey of the UltraVISTA ultra-deep Stripes (SMUVS) to search for sources with enhanced 3.6 μ {{m}} fluxes indicative of strong Hα emission at z=3.9{--}4.9. We find that the percentage of “Hα excess” sources reaches 37%–40% for galaxies with stellar masses {{log}}10({M}* /{M}ȯ )≈ 9{--}10 and decreases to <20 % at {{log}}10({M}* /{M}ȯ )∼ 10.7. At higher stellar masses, however, the trend reverses, although this is likely due to active galactic nucleus contamination. We derive star formation rates (SFR) and specific SFR (sSFR) from the inferred Hα equivalent widths of our “Hα excess” galaxies. We show, for the first time, that the “Hα excess” galaxies clearly have a bimodal distribution on the SFR–M* plane: they lie on the main sequence of star formation (with {{log}}10({sSFR}/{{yr}}-1)<-8.05) or in a starburst cloud (with {{log}}10({sSFR}/{{yr}}-1)> -7.60). The latter contains ∼ 15 % of all the objects in our sample and accounts for > 50 % of the cosmic SFR density at z=3.9{--}4.9, for which we derive a robust lower limit of 0.066 {M}ȯ {{yr}}-1 {{Mpc}}-3. Finally, we identify an unusual > 50σ overdensity of z=3.9{--}4.9 galaxies within a 0.20× 0.20 arcmin2 region. We conclude that the SMUVS unique combination of area and depth at mid-IR wavelengths provides an unprecedented level of statistics and dynamic range that are fundamental to revealing new aspects of galaxy evolution in the young universe.

AB - We study a large galaxy sample from the Spitzer Matching Survey of the UltraVISTA ultra-deep Stripes (SMUVS) to search for sources with enhanced 3.6 μ {{m}} fluxes indicative of strong Hα emission at z=3.9{--}4.9. We find that the percentage of “Hα excess” sources reaches 37%–40% for galaxies with stellar masses {{log}}10({M}* /{M}ȯ )≈ 9{--}10 and decreases to <20 % at {{log}}10({M}* /{M}ȯ )∼ 10.7. At higher stellar masses, however, the trend reverses, although this is likely due to active galactic nucleus contamination. We derive star formation rates (SFR) and specific SFR (sSFR) from the inferred Hα equivalent widths of our “Hα excess” galaxies. We show, for the first time, that the “Hα excess” galaxies clearly have a bimodal distribution on the SFR–M* plane: they lie on the main sequence of star formation (with {{log}}10({sSFR}/{{yr}}-1)<-8.05) or in a starburst cloud (with {{log}}10({sSFR}/{{yr}}-1)> -7.60). The latter contains ∼ 15 % of all the objects in our sample and accounts for > 50 % of the cosmic SFR density at z=3.9{--}4.9, for which we derive a robust lower limit of 0.066 {M}ȯ {{yr}}-1 {{Mpc}}-3. Finally, we identify an unusual > 50σ overdensity of z=3.9{--}4.9 galaxies within a 0.20× 0.20 arcmin2 region. We conclude that the SMUVS unique combination of area and depth at mid-IR wavelengths provides an unprecedented level of statistics and dynamic range that are fundamental to revealing new aspects of galaxy evolution in the young universe.

KW - galaxies: evolution

KW - galaxies: high-redshift

KW - galaxies: star formation

KW - galaxies: starburst

KW - infrared: galaxies

U2 - 10.3847/1538-4357/aa901e

DO - 10.3847/1538-4357/aa901e

M3 - Article

VL - 849

JO - The Astrophysical Journal

JF - The Astrophysical Journal

SN - 0004-637X

IS - 1

M1 - 45

ER -

ID: 50029646