%0 Generic %1 safarzadeh2017topheavy %A Safarzadeh, Mohammadtaher %A Lu, Yu %A Hayward, Christopher C. %D 2017 %K counts galaxy imf smg submm %T Is a top-heavy initial mass function needed to reproduce the submillimeter galaxy number counts? %U http://arxiv.org/abs/1705.05377 %X Matching the number counts and redshift distribution of submillimeter galaxies (SMGs) without invoking modifications to the initial mass function (IMF) has proved challenging for semi-analytic models (SAMs) of galaxy formation. We adopt a previously developed SAM that is constrained to match the $z = 0$ galaxy stellar mass function and implement three simple prescriptions to predict the submillimeter flux densities of the model galaxies; two depend solely on star formation rate, whereas the other also depends on the dust mass. By comparing the predictions of the models, we find that taking into account the dust mass, which affects the dust temperature and thus influences the far-infrared spectral energy distribution, is crucial for matching the number counts and redshift distribution of SMGs. Moreover, despite using a standard IMF, our model can match the observed SMG number counts and redshift distribution reasonably well, which contradicts the conclusions of some previous studies that a top-heavy IMF is needed to match these observations. Our results suggest that differences in the treatments of processes such as stellar feedback may enable some SAMs to reproduce the properties of the SMG population without IMF variation.

@misc{safarzadeh2017topheavy, abstract = {Matching the number counts and redshift distribution of submillimeter galaxies (SMGs) without invoking modifications to the initial mass function (IMF) has proved challenging for semi-analytic models (SAMs) of galaxy formation. We adopt a previously developed SAM that is constrained to match the $z = 0$ galaxy stellar mass function and implement three simple prescriptions to predict the submillimeter flux densities of the model galaxies; two depend solely on star formation rate, whereas the other also depends on the dust mass. By comparing the predictions of the models, we find that taking into account the dust mass, which affects the dust temperature and thus influences the far-infrared spectral energy distribution, is crucial for matching the number counts and redshift distribution of SMGs. Moreover, despite using a standard IMF, our model can match the observed SMG number counts and redshift distribution reasonably well, which contradicts the conclusions of some previous studies that a top-heavy IMF is needed to match these observations. Our results suggest that differences in the treatments of processes such as stellar feedback may enable some SAMs to reproduce the properties of the SMG population without IMF variation.}, added-at = {2017-05-17T10:05:10.000+0200}, author = {Safarzadeh, Mohammadtaher and Lu, Yu and Hayward, Christopher C.}, biburl = {https://www.bibsonomy.org/bibtex/223d920482296e2226548f18101f94aa9/miki}, description = {[1705.05377] Is a top-heavy initial mass function needed to reproduce the submillimeter galaxy number counts?}, interhash = {07724b5572730cf7d1a3383967e4a642}, intrahash = {23d920482296e2226548f18101f94aa9}, keywords = {counts galaxy imf smg submm}, note = {cite arxiv:1705.05377Comment: 6 pages, 3 figures, submitted to ApJL}, timestamp = {2017-05-17T10:05:10.000+0200}, title = {Is a top-heavy initial mass function needed to reproduce the submillimeter galaxy number counts?}, url = {http://arxiv.org/abs/1705.05377}, year = 2017 }