Towards a census of super-compact massive galaxies in the Kilo Degree Survey

Abstract

The abundance of compact, massive, early-type galaxies (ETGs) provides important constraints to galaxy formation scenarios. Thanks to the area covered, depth, excellent spatial resolution and seeing, the ESO Public optical Kilo Degree Survey (KiDS), carried out with the VLT Survey Telescope (VST), offers a unique opportunity to conduct a complete census of the most compact galaxies in the Universe. This paper presents a first census of such systems from the first 156 square degrees of KiDS. Our analysis relies on g-, r-, and i-band effective radii ($R_{\mathrm{e}}$), derived by fitting galaxy images with PSF-convolved Sérsic models, high-quality photometric redshifts, $z_{\mathrm{phot}}$, estimated from machine learning techniques, and stellar masses, $M_{\star }$, calculated from KiDS aperture photometry. After massiveness ($M_{\star }>8\times 10^{10}{\mathrm{M}}_{\odot }$) and compactness ($R_{\mathrm{e}}<1.5\mathrm{kpc}$ in g-, r- and i-bands) criteria are applied, a visual inspection of the candidates plus near-infrared photometry from VIKING-DR1 are used to refine our sample. The final catalog, to be spectroscopically confirmed, consists of 92 systems in the redshift range $z\sim 0.2-0.7$. This sample, which we expect to increase by a factor of ten over the total survey area, represents the first attempt to select massive super-compact ETGs (MSCGs) in KiDS. We investigate the impact of redshift systematics in the selection, finding that this seems to be a major source of contamination in our sample. A preliminary analysis shows that MSCGs exhibit negative internal colour gradients, consistent with a passive evolution of these systems. We find that the number density of MSCGs is only mildly consistent with predictions from simulations at $z>0.2$, while no such system is found at $z<0.2$.

11 pages, 6 figures, MNRAS in press, revised and improved version, figures and text have been updated

References in corpus (19)

• From rings to bulges: evidence for rapid secular galaxy evolution at z~2 from integral field spectroscopy in the SINS survey
• The first and second data releases of the Kilo-Degree Survey
• The Formation of Massive, Compact Galaxies at z=2 in the Illustris Simulation
• The dramatic size evolution of elliptical galaxies and the quasar feedback
• The Majority of Compact Massive Galaxies at z~2 are Disk Dominated
• Superdense massive galaxies in the Nearby Universe
• The diverse evolutionary paths of simulated high-z massive, compact galaxies to z=0
• Luminous K-band Selected Quasars from UKIDSS
• Massive relic galaxies challenge the co-evolution of SMBHs and their host galaxies
• The initial mass function of a massive relic galaxy
• 2DPHOT: A Multi-purpose Environment for the Two-dimensional Analysis of Wide-field Images
• A catalogue of photometric redshifts for the SDSS-DR9 galaxies
• The Number Density of Quiescent Compact Galaxies at Intermediate Redshift
• MRK 1216 & NGC 1277 - An orbit-based dynamical analysis of compact, high velocity dispersion galaxies
• Machine Learning based photometric redshifts for the KiDS ESO DR2 galaxies
• Dozens of compact and high velocity-dispersion early-type galaxies in Sloan Digital Sky Survey
• Evolution of central dark matter of early-type galaxies up to z ~ 0.8
• The Environment of Massive Quiescent Compact Galaxies at $0.1<z<0.4$ in the COSMOS Field
• A cosmological context for compact massive galaxies

Cited by in corpus (36)

• The first and second data releases of the Kilo-Degree Survey
• The third data release of the Kilo-Degree Survey and associated data products
• Two new confirmed massive relic galaxies: red nuggets in the present-day Universe
• The structural and dynamical properties of compact elliptical galaxies
• METAPHOR: A machine learning based method for the probability density estimation of photometric redshifts
• Photometric redshifts for the Kilo-Degree Survey. Machine-learning analysis with artificial neural networks
• Evolution of galaxy size--stellar mass relation from the Kilo Degree Survey
• KiDS-SQuaD: The KiDS Strongly lensed Quasar Detection project
• Red nuggets grow inside-out: evidence from gravitational lensing
• A cooperative approach among methods for photometric redshifts estimation: an application to KiDS data
• A duality in the origin of bulges and spheroidal galaxies
• INSPIRE: INvestigating Stellar Population In RElics -- I. Survey presentation and pilot program
• The first sample of spectroscopically confirmed ultra-compact massive galaxies in the Kilo Degree Survey
• Return of the features. Efficient feature selection and interpretation for photometric redshifts
• Quiescent Galaxy Size and Spectroscopic Evolution: Combining HSC Imaging and Hectospec Spectroscopy
• The abundance of compact quiescent galaxies since z ~ 0.6
• Galaxy and Mass Assembly (GAMA): Accurate number densities & environments of massive ultracompact galaxies at 0.02 < z < 0.3
• Building the largest spectroscopic sample of ultra-compact massive galaxies with the Kilo Degree Survey
• Statistical analysis of probability density functions for photometric redshifts through the KiDS-ESO-DR3 galaxies
• Ultramassive dense early-type galaxies: velocity dispersions and number density evolution since z=1.6
• Massive relic galaxies prefer dense environments
• Star formation quenching imprinted on the internal structure of naked red nuggets
• INSPIRE: INvestigating Stellar Population In RElics III. Second data release (DR2): testing the systematics on the stellar velocity dispersion
• The Evolution of Sizes and Specific Angular Momenta in Hierarchical Models of Galaxy Formation and Evolution
• The first catalogue of spectroscopically confirmed red nuggets at z~0.7 from the VIPERS survey. Linking high-z red nuggets and local relics
• Relic galaxy analogues in Illustris TNG50: the formation pathways of surviving red nuggets in a cosmological simulation
• Compact galaxies and the size-mass galaxy distribution from a colour-selected sample at 0.04 < z < 0.15 supplemented by ugrizYJHK photometric redshifts
• Nature versus nurture: relic nature and environment of the most massive passive galaxies at $z<0.5$
• The supermassive black hole merger driven evolution of high-redshift red nuggets into present-day cored early-type galaxies
• Environments of red nuggets at z~0.7 from the VIPERS survey
• The central dark matter fraction of massive early-type galaxies
• Toward a stellar population catalog in the Kilo Degree Survey: the impact of stellar recipes on stellar masses and star formation rates
• Total and dark mass from observations of galaxy centers with Machine Learning
• Rejection criteria based on outliers in the KiDS photometric redshifts and PDF distributions derived by machine learning
• INSPIRE: INvestigating Stellar Populations In RElics. IX. KiDS J0842+0059: the first fully confirmed relic beyond the local Universe
• Cooperative photometric redshift estimation