J/A+A/694/A261 Mock catalog of extragalactic radio background (Gao+, 2025)
An empirical model of the extragalactic radio background.
Gao F., Wang T., Wang Y.
<Astron. Astrophys. 694, A261 (2025)>
=2025A&A...694A.261G 2025A&A...694A.261G (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, radio ; Photometry, infrared ; Optical ;
Photometry, millimetric/submm ; Morphology
Keywords: galaxies: evolution - galaxies: luminosity function, mass function -
galaxies: photometry - radio continuum: galaxies
Abstract:
Radio observations provide a powerful tool to constrain the assembly
of galaxies over cosmic time. Recent deep and wide radio continuum
surveys have improved significantly our understanding on radio
emission properties of active galactic nuclei (AGNs) and star-forming
galaxies (SFGs) across 0<z<4. This allows us to derive an empirical
model of the radio continuum emission of galaxies based on their star
formation rates and the probability of hosting an radio AGN.
Here we verify how well this empirical model can reproduce the
extragalactic radio background (ERB), which can provide new insights
into the contribution to the ERB from galaxies of different masses and
redshifts.We make use of the Empirical Galaxy Generator (EGG) to
generate a near-infrared (NIR)-selected, flux-limited multi-wavelength
catalog to mimic real observations. Then we assign radio continuum
flux densities to galaxies based on their star formation rates and the
probability of hosting a radio-AGN of specific 1.4GHz luminosity. We
also apply special treatments to reproduce the clustering signal of
radio AGNs.Our empirical model successfully recovers the observed
1.4GHz radio luminosity functions (RLFs) of both AGN and SFG
populations, as well as the differential number counts at various
radio bands. The uniqueness of this approach also allows us to
directly link radio flux densities of galaxies to other properties,
including redshifts, stellar masses, and magnitudes at various
photometric bands. We find that roughly half of the radio continuum
sources to be detected by the Square Kilometer Array (SKA) at z∼4-6
will be too faint to be detected in the optical survey (r∼27.5)
carried out by Rubin observatory.Unlike previous studies which
utilized (extrapolations of) RLFs to reproduce ERB, our work starts
from a simulated galaxy catalog with realistic physical properties. It
has the potential to simultaneously, and self-consistently reproduce
physical properties of galaxies across a wide range of wavelengths,
from optical, NIR, far-infrared (FIR) to radio wavelengths. Our
empirical model can shed light on the contribution of different
galaxies to the extragalactic background light, and greatly
facilitates designing future multiwavelength galaxy surveys.
Description:
This catalog presents mock catalog generated in our paper, starting
from generating mock catalog using EGG covering 4 square degrees, then
we assign radio AGNs and assigning 1.4GHz rest-frame luminosity for
radio AGNs and SFGs.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 550 4232416 Mock catalog with multi-wavelength information
and radio properties
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Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 7 I7 --- ID Identification number generated by EGG
9- 23 F15.11 deg RAdeg [] Right Ascension (J2000)
25- 39 F15.11 deg DEdeg Declination (J2000)
41- 49 F9.6 --- z Redshift
51- 58 F8.5 [Msun] logMass log stellar mass
60- 71 E12.6 Msun/yr SFR star formation rates
73 I1 --- Passive [0/1] 1 if passive galaxies
75- 86 E12.6 Lsun LIR Infrared luminosity
88- 99 E12.6 Jy Fu SDSS u band flux density
101-112 E12.6 Jy Fg SDSS g band flux density
114-125 E12.6 Jy Fr SDSS r band flux density
127-138 E12.6 Jy Fi SDSS i band flux density
140-151 E12.6 Jy Fz SDSS z band flux density
153-164 E12.6 Jy FF606W HST F606W band flux density
166-177 E12.6 Jy FF775W HST F775W band flux density
179-190 E12.6 Jy FF814W HST F814W band flux density
192-203 E12.6 Jy FF140W JWST F140W band flux density
205-216 E12.6 Jy FF160W JWST F160W band flux density
218-229 E12.6 Jy FF444W JWST F444W band flux density
231-242 E12.6 Jy FKs WIRCAM Ks band flux density
244-255 E12.6 Jy FIRAC1 Spitzer 3.6um band flux density
257-268 E12.6 Jy FIRAC2 Spitzer 4.5um band flux density
270-281 E12.6 Jy FIRAC3 Spitzer 5um band flux density
283-294 E12.6 Jy FIRAC4 Spitzer 8um band flux density
296-307 E12.6 Jy FMIPS Spitzer mips 24um
309-320 E12.6 Jy FS250 Herschel SPIRE 250um
322-333 E12.6 Jy FS350 Herschel SPIRE 350um
335-346 E12.6 Jy FS500 Herschel SPIRE 500um
348-362 F15.11 deg RANdeg ?=-99 New Right Ascension for
galaxies>1010M☉ (1)
364-378 F15.11 deg DENdeg ?=-99 New Declination for
galaxies>1010M☉ (1)
380-381 I2 --- AGN [1]?=-1 1 if radio AGN
383-394 E12.6 W/Hz L1.4GHz Rest-frame 1.4GHz luminosity
396-407 E12.6 --- qir Ratio between IR luminosity and rest-frame
1.4GHz radio luminosity (qIR) value
for non-AGNs
409-420 E12.6 --- alphalow Spectral slope at 150 and 350MHz (2)
422-433 E12.6 --- alphahigh Spectral slope at 1.4, 3, 10 and 15GHz (2)
435-446 E12.6 Jy F150MHz 150MHz flux density
448-459 E12.6 Jy F350MHz 350MHz flux density
461-472 E12.6 Jy F1.4GHz 1.4GHz flux density
474-485 E12.6 Jy F3GHz 3GHz flux density
487-498 E12.6 Jy F10GHz 10GHz flux density
500-511 E12.6 Jy F15GHz 15GHz flux density
513-524 E12.6 deg theta ?=-99 Position angle
526-537 E12.6 --- ellip Ellipticity of non-AGNs
539-550 E12.6 kph Reff Effective radius of non-AGNs
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Note (1): For galaxies with stellar mass above 1010solar masses, we
redistribute their positions in order to create clustering signal.
Note (2): The spectral slope at low and high frequency end for radio AGNs are
the same.
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Acknowledgements:
Fangyou Gao, gfymargaret(at)gmail.com
(End) Patricia Vannier [CDS] 17-Dec-2024