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We present an analysis using the MOSFIRE Deep Evolution Field (MOSDEF) survey on the nature of MIR-excess galaxies, which have star formation rates (SFR) inferred from mid-infrared (MIR) data that is substantially elevated relative to that estimated from dust-corrected UV data. We use a sample of $sim$200 galaxies and AGN at $1.40<z<2.61$ with 24 $mu$m detections (rest-frame 8$mu$m) from MIPS/textit{Spitzer}. We find that the identification of MIR-excess galaxies strongly depends on the methodologies used to estimate IR luminosity ($rm L_{IR}$) and to correct the UV light for dust attenuation. We find that extrapolations of the SFR from the observed 24 $mu$m flux, using luminosity-dependent templates based on local galaxies, substantially overestimate $rm L_{IR}$ in $zsim2$ galaxies. By including textit{Herschel} observations and using a stellar mass-dependent, luminosity-independent $rm L_{IR}$, we obtain more reliable estimates of the SFR and a lower fraction of MIR-excess galaxies. Once stellar mass selection biases are taken into account, we identify $sim24%$ of our galaxies as MIR-excess. However, $rm SFR_{Halpha}$ is not elevated in MIR-excess galaxies compared to MIR-normal galaxies, indicating that the intrinsic fraction of MIR-excess may be lower. Using X-ray, IR, and optically-selected AGN in MOSDEF, we do not find a higher prevalence for AGN in MIR-excess galaxies relative to MIR-normal galaxies. A stacking analysis of X-ray undetected galaxies does not reveal a harder spectrum in MIR-excess galaxies relative to MIR-normal galaxies. Our analysis indicates that AGN activity does not contribute substantially to the MIR excess and instead implies that it is likely due to the enhanced PAH emission.
The complex structure of gas, metals, and dust in the interstellar and circumgalactic medium (ISM and CGM, respectively) in star-forming galaxies can be probed by Ly$alpha$ emission and absorption, low-ionization interstellar (LIS) metal absorption,
We make use of sensitive (9.3 microJy/beam RMS) 1.2mm-continuum observations from the ASPECS ALMA large program of the Hubble Ultra Deep Field (HUDF) to probe dust-enshrouded star formation from 1362 Lyman-break galaxies spanning the redshift range z
We present a comparative study of a set of star-formation rate tracers based on mid-infrared emission in the 12.81$mu$m [Ne II] line, the 15.56$mu$m [Ne III] line, and emission features from polycyclic aromatic hydrocarbons (PAHs) between 5.2 and 14.
We make use of deep 1.2mm-continuum observations (12.7microJy/beam RMS) of a 1 arcmin^2 region in the Hubble Ultra Deep Field to probe dust-enshrouded star formation from 330 Lyman-break galaxies spanning the redshift range z=2-10 (to ~2-3 Msol/yr at
We investigate the evolution of the galaxy Star Formation Rate Function (SFRF) and Cosmic Star Formation Rate Density (CSFRD) of $zsim 0-8 $ galaxies in the Evolution and Assembly of GaLaxies and their Environments (EAGLE) simulations. In addition, w