Constraints on the Cosmic Star Formation History via a new modeling of the SFG radio luminosity function
Wenjie WangZunli YuanHongwei YuJirong Mao
Wenjie WangZunli YuanHongwei YuJirong Mao
Nov 2023
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摘要原文
Context: Radio wavelengths offer a unique possibility of tracing the total star-formation rate (SFR) in galaxies, both obscured and unobscured. To prob the dust-unbiased star-formation history, an accurate measurement of the radio luminosity function (LF) for star-forming galaxies (SFGs) is crucial. Aims: We make use of an SFG sample (5915 sources) from the Very Large Array (VLA) COSMOS 3 GHz data to perform a new modeling of the radio LF. By integrating the analytical LF we aim to calculate the cosmic SFR density (SFRD) history since $z\sim5$. Methods: For the first time, we use both models of the pure luminosity evolution (PLE) and joint luminosity+density evolution (LADE) to fit the LFs directly to the radio data using a full maximum likelihood analysis, considering the sample completeness correction. We also incorporate the updated observations on local radio LFs and radio source counts into the fitting process to obtain additional constraints. Results: We find that the PLE model is not applicable to describe the evolution of the radio LF at high redshift ($z>2$). By construct, our LADE models can successfully fit a large amount of data on radio LFs and source counts of SFGs from recent observations. Our SFRD curve shows a good fit to the SFRD points derived by previous radio estimates. In view of that our radio LFs are not biased in contrast to previous studies performed by fitting the $1/V_{\rm max}$ LF points, our SFRD results should be an improvement to these previous estimates. Below $z<2$, our SFRD matches well with the multi-wavelength compilation from Madau \& Dickinson, while our SFRD turns over at a slightly higher redshift ($2<z<2.5$) and falls more rapidly out to high redshift.
