Detailed study of the Bootes field using 300-500 MHz uGMRT observations: Source Properties and radio--infrared correlations

Abstract

The dominant source of radio continuum emissions at low frequencies is synchrotron radiation, which originates from star-forming regions in disk galaxies and from powerful jets produced by active galactic nuclei (AGN). We studied the Bootes field using the upgraded Giant Meterwave Radio Telescope (uGMRT) at 400 MHz, achieving a central minimum off-source RMS noise of 35$\mu$Jy beam${}^{-1}$ and a catalogue of 3782 sources in $\sim 6$ sq. degrees of the sky. The resulting catalogue was compared to other radio frequency catalogues, and the corrected normalised differential source counts were derived. We use standard multi-wavelength techniques to classify the sources in star-forming galaxies (SFGs), radio-loud (RL) AGN, and radio-quiet (RQ) AGN that confirm a boost in the SFGs and RQ\,AGN AGN populations at lower flux levels. For the first time, we investigated the properties of the radio--IR relations at 400\,MHz in this field. The $L_{400MHz}$--$L_{\mathrm{TIR}}$ relations for SFGs were found to show a strong correlation with non-linear slope values of $1.10\pm 0.01$, and variation of $q_{\mathrm{TIR}}$ with $z$ is given as, $q_{\mathrm{TIR}}=(2.19\pm 0.07)(1+z{)}^{-0.15\pm 0.08}$. This indicates that the non-linearity of the radio--IR relations can be attributed to the mild variation of $q_{\mathrm{TIR}}$ values with $z$. The derived relationships exhibit similar behaviour when applied to LOFAR at 150 MHz and also at 1.4 GHz. This emphasises the fact that other parameters like magnetic field evolution with $z$ or the number densities of cosmic ray electrons can play a vital role in the mild evolution of $q$ values.

18 pages, 18 Figures; Accepted for publication in MNRAS

References in corpus (22)

• The NumPy array: a structure for efficient numerical computation
• Cosmic Star Formation History
• WSClean: an implementation of a fast, generic wide-field imager for radio astronomy
• The LOFAR Two-metre Sky Survey - I. Survey Description and Preliminary Data Release
• An optimized algorithm for multi-scale wideband deconvolution of radio astronomical images
• The LOFAR Two Meter Sky Survey: Deep Fields, I -- Direction-dependent calibration and imaging
• The Radio-Loud Fraction of Quasars is a Strong Function of Redshift and Optical Luminosity
• The Spitzer Deep, Wide-Field Survey
• The faint radio sky: radio astronomy becomes mainstream
• The far-infrared/radio correlation and radio spectral index of galaxies in the SFR-M* plane up to z 2
• A new method to separate star forming from AGN galaxies at intermediate redshift: The submillijansky radio population in the VLA-COSMOS survey
• The VLA-COSMOS 3 GHz Large Project: Evolution of specific star formation rates out to $z\sim 5$
• The VLA-COSMOS Survey: III. Further Catalog Analysis and the Radio Source Counts
• The supernova-regulated ISM. I. The multi-phase structure
• The MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) Survey
• The non-linear infrared-radio correlation of low-z galaxies: implications for redshift evolution, a new radio SFR recipe, and how to minimize selection bias
• Synchrotron spectral index and interstellar medium densities of star-forming galaxies
• Extremely deep 150 MHz source counts from the LoTSS Deep Fields
• Discovery of Radio Jets in z~2 ULIRGs with Deep 9.7um Silicate Absorption
• Deep GMRT 610 MHz Observations of the ELAIS N1 Field : Catalogue and Source Counts
• Cosmic evolution of star-forming galaxies to $z\simeq 1.8$ in the faint low-frequency radio source population
• New insights into the interstellar medium of the dwarf galaxy IC 10: connection between magnetic fields, the radio--infrared correlation and star formation