Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 1003.4271

No Evolution in the IR-Radio Relation for IR-Luminous Galaxies at z<2 in the COSMOS Field

Mark T. Sargent·E. Schinnerer·E. Murphy·C. L. Carilli·G. Helou·H. Aussel·E. Le Floc'h·D. T. Frayer·O. Ilbert·P. Oesch·M. Salvato·V. Smolcic·J. Kartaltepe·D. B. Sanders
View original source ↗Read source document ↗Export metadata ↓

Abstract

Previous observational studies of the infrared (IR)-radio relation out to high redshift employed any detectable star forming systems at a given redshift within the restricted area of cosmological survey fields. Consequently, the evolution inferred relies on a comparison between the average IR/radio properties of (i) very IR-luminous high-z sources and (ii) more heterogeneous low(er)-z samples that often lack the strongest IR emitters. In this report we consider populations of objects with comparable luminosities over the last 10 Gyr by taking advantage of deep IR (esp. Spitzer 24 micron) and VLA 1.4 GHz observations of the COSMOS field. Consistent with recent model predictions, both Ultra Luminous Infrared Galaxies (ULIRGs) and galaxies on the bright end of the evolving IR luminosity function do not display any change in their average IR/radio ratios out to z~2 when corrected for bias. Uncorrected data suggested ~0.3 dex of positive evolution.

Explore related subjects

astro-ph.CO

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Mark T. Sargent, E. Schinnerer, E. Murphy, C. L. Carilli, G. Helou, H. Aussel, E. Le Floc'h, D. T. Frayer, O. Ilbert, P. Oesch, M. Salvato, V. Smolcic, J. Kartaltepe, D. B. Sanders. 2010-03-22. No Evolution in the IR-Radio Relation for IR-Luminous Galaxies at z<2 in the COSMOS Field. https://doi.org/10.1088/2041-8205%2F714%2F2%2Fl190

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

KSZ Velocity Reconstruction with ACT and DESI-LS using a Tomographic QML Power Spectrum Estimator

We perform kinetic Sunyaev-Zel'dovich (kSZ) velocity reconstruction on data from ACT DR6 and DESI-LS DR9. To estimate the cross-power between kSZ velocity reconstruction and galaxy density, we make use of a novel quadratic maximum likelihood (QML) power spectrum estimator in redshift binned spherical coordinates. We find a detection of the kSZ signal from the cross-correlation between the estimated velocity field and the large-scale galaxy field of $10 σ$. We estimate an amplitude $A=0.42 \pm 0.042$ of the kSZ signal relative to a halo model prediction, possibly indicating strong feedback in massive halos, in agreement with previous studies. We compare the result to the pseudo-$C_{\ell}$ analysis on the same dataset, finding a $\sim$20% improvement in the SNR. Our work demonstrates the feasibility of an optimal QML analysis at the required resolution, and will be a powerful tool for kSZ cosmology with upcoming high-resolution surveys.

astro-ph.CO↗
arXiv2026

The many boundaries of the stratified dark matter halo

We review the physics of halo collapse giving rise to various halo boundaries, as well as their identification, observation, and applications. The classical halo is typically defined as a monolithic, virialized object enclosed within its virial radius -- a definition which, however, does not account for ongoing halo growth. Continuous accretion causes the orbits of infalling particles to shrink over time, confining newly accreted material in a growing layer outside the virialized region. Several novel halo boundaries, such as the splashback and depletion radii, have recently been proposed to characterize this growth layer from different perspectives. Along with the turnaround radius, which operates on an even larger scale to enclose the entire infall region, these multiple boundaries comprise an extended view of a dark matter halo as a stratified structure. Theoretical models can largely explain the existence of various boundaries, while challenges remain in providing unified and quantitative predictions of their properties. The multiple boundaries open new avenues for observing halo growth and may substantially improve our understanding and modeling of cosmic structure formation. We provide a python package, SpheriC, implementing the key spherical collapse models.

astro-ph.CO↗
arXiv2026

A possible detection of gas rotation in galaxy groups via the kinetic Sunyaev-Zeldovich effect

We utilise the kinetic Sunyaev-Zeldovich effect (kSZ) to measure the rotation of ionised gas within galaxy groups defined in the SDSS-DR7 galaxy sample, via their dipolar imprint on the cosmic microwave background (CMB). We estimate the direction of the projected angular momentum for each of our selected fast-rotating groups by measuring the redshift dipole of satellite galaxies around their group centres. We find a clear redshift dipole in the stacked data for the selected SDSS groups. We then perform oriented stacking of the Planck CMB temperature map using the group centres and directions of angular momenta. We report a $2.3σ$ tentative detection of the dipolar rotational kSZ effect (rkSZ) within the virial radii of our fast-rotating groups from SDSS with an average mass of $10^{14}h^{-1} \rm M_{\odot}$ (corresponding to a null-hypothesis probability of 0.96%). We estimate the averaged rotational velocity of the sample to be $\sim 100-200 ~\rm km ~s^{-1}$, reaching a maximum value of $158.8\pm13.6 ~\rm km ~s^{-1}$. Our results are consistent within the errors with predictions based on the ELUCID constrained realisation simulation, with the predicted amplitude of the rkSZ signal being slightly lower near the centre. We also identify a systematic bias when estimating rotational velocities using the observed redshifts of galaxies, but find it to be subdominant for our analysis.

astro-ph.CO↗