An ALMA survey of the SCUBA-2 Cosmology Legacy Survey UKIDSS/UDS field: Halo Masses for Submillimetre Galaxies

Abstract We present an analysis of the spatial clustering of a large sample of high-resolution, interferometically identified, submillimetre galaxies (SMGs). We measure the projected cross-correlation function of ∼ 350 SMGs in the UKIDSS Ultra Deep-Survey Field across a redshift range of z = 1.5–3 utilising a method that incorporates the uncertainties in the redshift measurements for both the SMGs and cross-correlated galaxies through sampling their full probability distribution functions. By measuring the absolute linear bias of the SMGs we derive halo masses of $\log _{10}(M_{\rm halo}[{h^{-1}\, \rm M_{\odot }}])$ ∼ 12.8 with no evidence of evolution in the halo masses with redshift, contrary to some previous work. From considering models of halo mass growth rates we predict that the SMGs will reside in haloes of mass $\log _{10}(M_{\rm halo}[{h^{-1}\, \rm M_{\odot }}])$ ∼ 13.2 at z = 0, consistent with the expectation that the majority of z = 1.5–3 SMGs will evolve into present-day spheroidal galaxies. Finally, comparing to models of stellar-to-halo mass ratios, we show that SMGs may correspond to systems that are maximally efficient at converting their gas reservoirs into stars. We compare them to a simple model for gas cooling in halos that suggests that the unique properties of the SMG population, including their high levels of star-formation and their redshift distribution, are a result of the SMGs being the most massive galaxies that are still able to accrete cool gas from their surrounding intragalactic medium.

Download Full-text

What does strong gravitational lensing? The mass and redshift distribution of high-magnification lenses

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa1429 ◽

2020 ◽

Vol 495 (4) ◽

pp. 3727-3739 ◽

Cited By ~ 3

Author(s):

Andrew Robertson ◽

Graham P Smith ◽

Richard Massey ◽

Vincent Eke ◽

Mathilde Jauzac ◽

...

Keyword(s):

Gravitational Lensing ◽

Point Sources ◽

High Magnification ◽

Lower Mass ◽

Redshift Distribution ◽

Density Profiles ◽

Massive Galaxies ◽

Strong Gravitational Lensing ◽

Hydrodynamical Simulations ◽

Halo Masses

ABSTRACT Many distant objects can only be detected, or become more scientifically valuable, if they have been highly magnified by strong gravitational lensing. We use eagle and bahamas, two recent cosmological hydrodynamical simulations, to predict the probability distribution for both the lens mass and lens redshift when point sources are highly magnified by gravitational lensing. For sources at a redshift of 2, we find the distribution of lens redshifts to be broad, peaking at z ≈ 0.6. The contribution of different lens masses is also fairly broad, with most high-magnification lensing due to lenses with halo masses between 1012 and $10^{14} \mathrm{\, M_\odot }$. Lower mass haloes are inefficient lenses, while more massive haloes are rare. We find that a simple model in which all haloes have singular isothermal sphere density profiles can approximately reproduce the simulation predictions, although such a model overpredicts the importance of haloes with mass $\lt 10^{12} \mathrm{\, M_\odot }$ for lensing. We also calculate the probability that point sources at different redshifts are strongly lensed. At low redshift, high magnifications are extremely unlikely. Each z = 0.5 source produces, on average, 5 × 10−7 images with magnification greater than 10; for z = 2, this increases to about 2 × 10−5. Our results imply that searches for strongly lensed optical transients, including the optical counterparts to strongly lensed gravitational waves, can be optimized by monitoring massive galaxies, groups, and clusters rather than concentrating on an individual population of lenses.

Download Full-text

On the Formation of Small Groups of Galaxies at High Redshifts

International Astronomical Union Colloquium ◽

10.1017/s0252921100055391 ◽

2000 ◽

Vol 174 ◽

pp. 412-422

Author(s):

William C. Saslaw

Keyword(s):

Velocity Distribution ◽

Small Groups ◽

High Redshift ◽

Distribution Functions ◽

Many Body ◽

Redshift Distribution ◽

Groups Of Galaxies ◽

Velocity Distribution Functions ◽

Free Parameters

AbstractCosmological many-body clustering agrees with the spatial and velocity distribution functions of galaxies at low redshifts, and it can be extended to high redshifts z ≈ 3 or more. The high redshift distribution functions are predicted to have a particular form. In the simplest case, there are no free parameters in this prediction, but the degree of clustering depends sensitively on Ω0. Current observations of small groups at high redshifts suggest that Ω0 = 0.3 ± 0.2 for Einstein-Friedmann cosmologies.

Download Full-text

The XMM-Newton wide field survey in the COSMOS field: Clustering dependence of X-ray selected AGN on host galaxy properties

Astronomy and Astrophysics ◽

10.1051/0004-6361/201935186 ◽

2019 ◽

Vol 629 ◽

pp. A14 ◽

Cited By ~ 1

Author(s):

A. Viitanen ◽

V. Allevato ◽

A. Finoguenov ◽

A. Bongiorno ◽

N. Cappelluti ◽

...

Keyword(s):

Large Scale ◽

Accretion Rate ◽

Spatial Clustering ◽

Distribution Functions ◽

Active Galaxies ◽

Host Galaxy ◽

Wide Field ◽

Photometric Redshifts ◽

X Ray ◽

Massive Halos

Aims. We study the spatial clustering of 632 (1130) XMM-COSMOS active galactic nuclei (AGNs) with known spectroscopic or photometric redshifts in the range z = [0.1–2.5] in order to measure the AGN bias and estimate the typical mass of the hosting dark matter (DM) halo as a function of AGN host galaxy properties. Methods. We created AGN subsamples in terms of stellar mass, M*, and specific black hole accretion rate, LX/M*, to study how AGN environment depends on these quantities. Further, we derived the M*−Mhalo relation for our sample of XMM-COSMOS AGNs and compared it to results in literature for normal non-active galaxies. We measured the projected two-point correlation function wp(rp) using both the classic and the generalized clustering estimator, based on photometric redshifts, as probability distribution functions in addition to any available spectroscopic redshifts. We measured the large-scale (rp ≳ 1 h−1 Mpc) linear bias b by comparing the clustering signal to that expected of the underlying DM distribution. The bias was then related to the typical mass of the hosting halo Mhalo of our AGN subsamples. Since M* and LX/M* are correlated, we matched the distribution in terms of one quantity and we split the distribution in the other. Results. For the full spectroscopic AGN sample, we measured a typical DM halo mass of log (Mhalo/h−1 M⊙) = 12.79−0.43+0.26, similar to galaxy group environments and in line with previous studies for moderate-luminosity X-ray selected AGN. We find no significant dependence on specific accretion rate LX/M*, with log (Mhalo/h−1 M⊙) = 13.06−0.38+0.23 and log (Mhalo/h−1 M⊙) = 12.97−1.26+0.39 for low and high LX/M* subsamples, respectively. We also find no difference in the hosting halos in terms of M* with log (Mhalo/h−1 M⊙) = 12.93−0.62+0.31 (low) and log (Mhalo/h−1 M⊙) = 12.90−0.62+0.30 (high). By comparing the M*−Mhalo relation derived for XMM-COSMOS AGN subsamples with what is expected for normal non-active galaxies by abundance matching and clustering results, we find that the typical DM halo mass of our high M* AGN subsample is similar to that of non-active galaxies. However, AGNs in our low M* subsample are found in more massive halos than non-active galaxies. By excluding AGNs in galaxy groups from the clustering analysis, we find evidence that the result for low M* may be due to larger fraction of AGNs as satellites in massive halos.

Download Full-text

Spatially resolving the relics: The inferring the physics driving the quenching of massive galaxies from kinematics at z ∼ 1 and beyond

Proceedings of the International Astronomical Union ◽

10.1017/s1743921320001222 ◽

2019 ◽

Vol 15 (S352) ◽

pp. 267-267

Author(s):

Rachel Bezanson

Keyword(s):

Star Formation ◽

Galaxy Formation ◽

High Redshift ◽

Elliptical Galaxies ◽

Spectroscopic Studies ◽

Gas Reservoirs ◽

Massive Galaxies ◽

Spatially Resolved ◽

Galaxy Formation And Evolution ◽

Ordered Motion

AbstractToday's massive elliptical galaxies are primarily red-and-dead, dispersion supported ellipticals. The physical process(es) driving the shutdown or ‘quenching’ of star formation in these galaxies remains one of the least understood aspects of galaxy formation and evolution. Although today's spiral and elliptical galaxies exhibit a clear bimodality in their structures, kinematics, and stellar populations, it may be that the quenching and structural transformation do no occur simultaneously. In this talk I will present evidence that early quiescent galaxies, observed much closer to their quenching epoch at z ∼ 1, retain significant rotational support (∼ twice as much as local ellipticals). This suggests that the mechanisms responsible for shutting down star formation do not also have to destroy ordered motion in massive galaxies; the increased dispersion support could occur subsequently via hierarchical growth and minor merging. I will discuss this evidence in conjunction with recent ALMA studies of the dramatic range in molecular gas reservoirs of recently quenched high redshift galaxies to constrain quenching models. Finally, I will discuss prospects for extending spatially resolved spectroscopic studies of galaxies immediately following quenching with JWST and eventually 30-m class telescopes.

Download Full-text

The nature of submillimetre and highly star-forming galaxies in the EAGLE simulation

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz1692 ◽

2019 ◽

Vol 488 (2) ◽

pp. 2440-2454 ◽

Cited By ~ 16

Author(s):

Stuart McAlpine ◽

Ian Smail ◽

Richard G Bower ◽

A M Swinbank ◽

James W Trayford ◽

...

Keyword(s):

Reasonable Agreement ◽

Lower Mass ◽

Redshift Distribution ◽

Gas Reservoir ◽

Massive Galaxies ◽

Star Forming ◽

Hydrodynamical Simulation ◽

Galaxy Population ◽

Gas Fractions ◽

Selection Of

ABSTRACT We exploit EAGLE, a cosmological hydrodynamical simulation, to reproduce the selection of the observed submillimetre (submm) galaxy population by selecting the model galaxies at z ≥ 1 with mock submm fluxes $S_{850\, \mu \mathrm{m}}$ ≥ 1 mJy. We find a reasonable agreement between the model galaxies within this sample and the properties of the observed submm population, such as their star formation rates (SFRs) at z < 3, redshift distribution, and many integrated galaxy properties. We find that the median redshift of the $S_{850\, \mu \mathrm{m}}$ ≥ 1 mJy model population is z ≈ 2.5, and that they are massive galaxies (M* ∼ 1011 M⊙) with high dust masses (Mdust ∼ 108 M⊙), gas fractions (fgas ≈ 50 per cent), and SFRs ($\dot{M}_* \approx 100$ M⊙ yr−1). In addition, we find that they have major and minor merger fractions similar to the general population, suggesting that mergers are not the sole driver of the high SFRs in the model submm galaxies. Instead, the $S_{850\, \mu \mathrm{m}}$ ≥ 1 mJy model galaxies yield high SFRs primarily because they maintain a significant gas reservoir as a result of hosting an undermassive black hole relative to comparably massive galaxies. Not all ‘highly star-forming’ ($\dot{M}_* \ge 80$ M⊙ yr−1) eagle galaxies have submm fluxes $S_{850\, \mu \mathrm{m}}$ ≥ 1 mJy. We investigate the nature of these highly star-forming ‘Submm-Faint’ galaxies (i.e. $\dot{M}_* \ge 80$ M⊙ yr−1 but $S_{850\, \mu \mathrm{m}}$ < 1 mJy) and find that they are similar to the model submm galaxies, being gas rich and hosting undermassive black holes. However, they are also typically at higher redshifts (z > 4) and are lower mass (M* ∼ 1010 M⊙). These typically higher redshift galaxies show stronger evidence for having been triggered by major mergers, and critically, they are likely missed by most current submm surveys due to their higher dust temperatures and lower dust masses.

Download Full-text

Early Results from the VIMOS VLT Deep Survey

Symposium - International Astronomical Union ◽

10.1017/s0074180900196810 ◽

2005 ◽

Vol 216 ◽

pp. 381-389

Author(s):

O. Le Fèvre ◽

C. Adami ◽

O. Ilbert ◽

V. Le Brun ◽

C. Marinoni ◽

...

Keyword(s):

Large Scale ◽

Limited Sample ◽

Redshift Distribution ◽

Star Forming ◽

Large Scale Structures ◽

Early Results ◽

Main Challenge ◽

Deep Survey ◽

Scale Structures ◽

First Time

The VIMOS VLT Deep Survey (VVDS) is underway to study the evolution of galaxies, large scale structures and AGNs, from the measurement of more than 100 000 spectra of faint objects. We present here the results from the first epoch observations of more than 20000 spectra. The main challenge of the program, the redshift measurements, is described, in particular entering the “redshift desert” in the range 1.5 < z < 3 for which only very weak features are detected in the observed wavelength range. The redshift distribution of a magnitude limited sample brighter than IAB = 24 is presented for the first time, showing a peak at a low redshift z ∼ 0.7, and a tail extending all the way above z = 4. The evolution of the luminosity function out to z = 1.5 is presented, with the LF of blue star forming galaxies carrying most of the evolution, with L* changing by more than two magnitudes for this sub-sample.

Download Full-text

Quantized Redshifts - New Physics or Old Muddle?

Symposium - International Astronomical Union ◽

10.1017/s0074180900162126 ◽

1999 ◽

Vol 194 ◽

pp. 290-294

Author(s):

W.M. Napier

Keyword(s):

Energy Density ◽

Gravitational Lensing ◽

Confidence Level ◽

Spiral Galaxies ◽

New Physics ◽

Frame Of Reference ◽

High Confidence ◽

Redshift Distribution ◽

Massive Galaxies ◽

High Confidence Level

The HI redshift distribution of nearby spiral galaxies has been studied to test long-running but generally ignored claims that extragalactic redshifts are periodic or ‘quantized’. The existence of the phenomenon is confirmed at an extremely high confidence level, the quantization appearing in the galactocentric frame of reference. It is proposed that the energy density of the vacuum is a local, oscillating quantity associated with large masses such as spiral galaxies. A variety of ‘anomalies’ should then be detectable in massive galaxies, associated with their redshifts, their ambient gravitational lensing and their dynamics.

Download Full-text

Morphological properties of massive galaxies at high−z from GOODS

Proceedings of the International Astronomical Union ◽

10.1017/s1743921308018243 ◽

2007 ◽

Vol 3 (S245) ◽

pp. 407-410 ◽

Cited By ~ 1

Author(s):

Swara Ravindranath ◽

E. Daddi ◽

M. Giavalisco ◽

H. C. Ferguson ◽

M. E. Dickinson

Keyword(s):

Surface Brightness ◽

Morphological Diversity ◽

The Other ◽

Morphological Properties ◽

Redshift Range ◽

Large Sample ◽

Massive Galaxies ◽

Star Forming ◽

Wide Range ◽

Deep Survey

AbstractWe have used the BzK-selection to identify a composite population of passive, and star-forming galaxies at redshifts 1.4 ≤ z ≤ 2.5 from the Great Observatories Origins Deep Survey (GOODS). Using an unprecedented large sample of galaxies in this redshift range, we characterize the morphological diversity through the analysis of the surface-brightness profile shapes for 171 galaxies with passive SEDs, and 1068 star-forming galaxies. We find that the z ~ 2 galaxies display a wide range of morphologies, from spheroidals to disk-like. Interestingly, the galaxies with passively-evolving SEDs predominantly have steep profiles as seen for the classical bulges at low redshifts, although they are very compact with re < 3 kpc. The star-forming galaxies on the other hand exhibit mostly disk-like and merger morphologies, and have sizes comparable to their low−z counterparts. Our results emphasize the need for an unbiased selection in order to reveal the morphological diversities, and range of galaxy properties at high redshifts.

Download Full-text

Reconstruction of Star Formation and AGNs Activities in Galaxies Classified with the Balmer Break, 1.6 μm Bump and PAH Features up to z ≃2

Proceedings of the International Astronomical Union ◽

10.1017/s1743921311022733 ◽

2010 ◽

Vol 6 (S277) ◽

pp. 182-185

Author(s):

Hitoshi Hanami ◽

Tsuyoshi Ishigaki ◽

Keyword(s):

Star Formation ◽

Rest Frame ◽

Formation Rate ◽

Massive Galaxies ◽

Star Forming ◽

Luminous Infrared Galaxies ◽

The North ◽

Deep Survey ◽

Multi Wavelength ◽

Dusty Torus

AbstractWe have studied the star-forming and AGN activity of massive galaxies in the redshift range z = 0.4−2, which are detected in a deep survey field using the AKARI and Subaru telescopes toward the North Ecliptic Pole (NEP). The multi-wavelength survey allows us to select Mid-InfraRed (MIR) bright populations as Luminous InfraRed Galaxies (LIRGs) with L(IR) ≃ 1010–11 L⊙, which can be also sub-classified into Balmer Break Galaxies (BBGs) and Infra-Red (IR) Bump Galaxies (IRBGs). AKARI/IRC multiband photometry can distinguish their star-forming/AGN activity for LIRGs with/without the Polycyclic-Aromatic Hydrocarbon (PAH) emission bands at 6.2, 7.7 and 11.3 μm, and estimate the Star Formation Rate (SFR) from their total emitting InfraRed (IR) luminosities for star-formings and the emissions from dusty torus for AGNs. The results are summarised as below: 1) The rest-frame 7.7 μm luminosity is still a good tracer of the total IR (tIR) luminosity, as the PAH emission dominates for star-forming galaxies even up to z ≃ 2, 2) Rest-frame 5μm Luminosities may trace emissions from dusty torus of AGN in the LIRGs, 3) SFR of Starburst-AGN LIRGs (s/a-LIRGs) tends to quench at z < 0.8 more rapidly than that of Starburst dominated LIRGs (sb-LIRGs), 4) Intrinsic Stellar populations in the s/a-LIRGs show redder colours than those in the sb-LIRGs. These results suggest that Super Massive Black Holes (SMBH) could already have grown to ≃ 3 × 108M⊙ in the agn-LIRGs, with ≃ 1011L⊙ at z > 1.2, and the growth of SMBH tends to follow the star-forming activities around z = 1–2.

Download Full-text