Early Cenozoic denudation of central west Britain in response to transient and permanent uplift above a mantle plume

Upwelling mantle plumes beneath continental crust are predicted to produce difficult to quantify, modest uplift and denudation. The contribution of permanent and transient components to the uplift is also difficult to distinguish. A pulse of denudation in Britain in the Early Paleogene has been linked, although with some controversy, with the arrival of the proto-Iceland mantle plume. In this contribution we show that combining apatite and zircon (U-Th-Sm)/He and apatite fission track analyses from central west Britain with numerical modeling clearly identifies a pulse of early Cenozoic denudation. The data indicate that rock uplift and denudation were centered on the northern East Irish Sea Basin and 1.0–2.4 km of rocks were removed during the latest Cretaceous-early Paleogene. Uplift and erosion appears to have started a few million years before the earliest magmatism in the region. The regional denudation pattern mirrors the distribution of low-density magmatic rocks that has been imaged in the deep crust. However, the injection of the underplating melt is not enough to account for the total denudation. An additional regional uplift of at least 300 m is required, which is consistent with a transient thermal effect from the hot mantle plume. The rapid exhumation event ceased by ~40 Ma and the data do not require significant Neogene exhumation

One thousand plant transcriptomes and the phylogenomics of green plants

Abstract: Green plants (Viridiplantae) include around 450,000–500,000 species1, 2 of great diversity and have important roles in terrestrial and aquatic ecosystems. Here, as part of the One Thousand Plant Transcriptomes Initiative, we sequenced the vegetative transcriptomes of 1,124 species that span the diversity of plants in a broad sense (Archaeplastida), including green plants (Viridiplantae), glaucophytes (Glaucophyta) and red algae (Rhodophyta). Our analysis provides a robust phylogenomic framework for examining the evolution of green plants. Most inferred species relationships are well supported across multiple species tree and supermatrix analyses, but discordance among plastid and nuclear gene trees at a few important nodes highlights the complexity of plant genome evolution, including polyploidy, periods of rapid speciation, and extinction. Incomplete sorting of ancestral variation, polyploidization and massive expansions of gene families punctuate the evolutionary history of green plants. Notably, we find that large expansions of gene families preceded the origins of green plants, land plants and vascular plants, whereas whole-genome duplications are inferred to have occurred repeatedly throughout the evolution of flowering plants and ferns. The increasing availability of high-quality plant genome sequences and advances in functional genomics are enabling research on genome evolution across the green tree of life

The Tully-Fisher relation of COLD GASS galaxies

We present the stellar mass (M*) and Wide-Field Infrared Survey Explorer (WISE) absolute Band 1 magnitude (MW1) Tully-Fisher relations (TFRs) of subsets of galaxies from the CO Legacy Database for the Galex Arecibo SDSS Survey (COLD GASS). We examine the benefits and drawbacks of several commonly used fitting functions in the context of measuring CO(1-0) line widths (and thus rotation velocities), favouring the Gaussian Double Peak function. We find the MW1 and M* TFR, for a carefully selected sub-sample, to be MW1 = (-7.1 ± 0.6) [log(W50/sin i / km s^-1) - 23.83 ± 0.09 and log (M*/M⊙) = (3.3 ± 0.3) [log(W50/sin i / km s^-1) -2.58] + 10:51 ± 0.04, respectively, where W50 is the width of a galaxy's CO(1-0) integrated profile at 50% of its maximum and the inclination i is derived from the galaxy axial ratio measured on the SDSS r-band image. We find no evidence for any significant offset between the TFRs of COLD GASS galaxies and those of comparison samples of similar redshifts and morphologies. The slope of the COLD GASS M* TFR agrees with the relation of Pizagno et al. (2005). However, we measure a comparitively shallower slope for the COLD GASS MW1 TFR as compared to the relation of Tully and Pierce (2000). We attribute this to the fact that the COLD GASS sample comprises galaxies of various (late-type) morphologies. Nevertheless, our work provides a robust reference point with which to compare future CO TFR studies

Etude des mecanismes de conduction electrique et de l'anisotropie de resistivite dans les differentes phases magnetiques du compose La2CuO4

SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : TD 79312 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

K-CLASH: Strangulation and ram pressure stripping in galaxy cluster members at 0.3 < z < 0.6

Galaxy clusters have long been theorized to quench the star formation of their members. This study uses integral-field unit observations from the K-band MultiObject Spectrograph (KMOS) &#x2013; Cluster Lensing And Supernova survey with Hubble (CLASH) survey (K-CLASH) to search for evidence of quenching in massive galaxy clusters at redshifts 0.3 < z < 0.6. We first construct mass-matched samples of exclusively star-forming cluster and field galaxies, then investigate the spatial extent of their H&#x2009;&#x3B1; emission and study their interstellar medium conditions using emission line ratios. The average ratio of H&#x2009;&#x3B1; half-light radius to optical half-light radius ($r_{\mathrm{e}, {\rm {H}\,\alpha }}/r_{\mathrm{e}, R_{\mathrm{c} } }$) for all galaxies is 1.14&#xA0;&#xB1;&#xA0;0.06, showing that star formation is taking place throughout stellar discs at these redshifts. However, on average, cluster galaxies have a smaller $r_{\mathrm{e}, {\rm {H}\alpha }}/r_{\mathrm{e}, R_{\mathrm{c} } }$ ratio than field galaxies: &#x2329;$r_{\mathrm{e}, {\rm {H}\alpha }}/r_{\mathrm{e}, R_{\mathrm{c} } }$&#x232A;&#xA0;= 0.96&#xA0;&#xB1;&#xA0;0.09 compared to 1.22&#xA0;&#xB1;&#xA0;0.08 (smaller at a 98&#x2009;per&#x2009;cent credibility level). These values are uncorrected for the wavelength difference between H&#x2009;&#x3B1; emission and Rc-band stellar light but implementing such a correction only reinforces our results. We also show that whilst the cluster and field samples follow indistinguishable mass&#x2013;metallicity (MZ) relations, the residuals around the MZ relation of cluster members correlate with cluster-centric distance; galaxies residing closer to the cluster centre tend to have enhanced metallicities (significant at the 2.6&#x3C3; level). Finally, in contrast to previous studies, we find no significant differences in electron number density between the cluster and field galaxies. We use simple chemical evolution models to conclude that the effects of disc strangulation and ram-pressure stripping can quantitatively explain our observations

The resolved chemical abundance properties within the interstellar medium of star-forming galaxies at z≈ 1.5

We exploit the unprecedented depth of integral field data from the KMOS Ultra-deep Rotational Velocity Survey (KURVS) to analyse the strong (Hα) and forbidden ([NII], [SII]) emission line ratios in 22 main-sequence galaxies at z ≈ 1.5. Using the [NII]/Hα emission-line ratio, we confirm the presence of the stellar mass – gas-phase metallicity relation at this epoch, with galaxies exhibiting on average 0.13 ± 0.04 dex lower gas-phase metallicity (12 + log(O/H)M13 = 8.40 ± 0.03) for a given stellar mass (log10(M∗[M] = 10.1 ± 0.1) .than local main-sequence galaxies. We determine the galaxy-integrated [SII] doublet ratio, with a median value of [SII]λ6716/λ6731 = 1.26 ± 0.14 equivalent to an electron density of log10(ne[cm−3]) = 1.95 ± 0.12. Utilising CANDELS HST multi-band imaging we define the pixel surface-mass and star-formation rate density in each galaxy and spatially resolve the fundamental metallicity relation at z ≈ 1.5, finding an evolution of 0.05 ± 0.01 dex compared to the local relation. We quantify the intrinsic gas-phase metallicity gradient within the galaxies using the [NII]/Hα calibration, finding a median annuli-based gradient of Z/R = −0.015 ± 0.005 dex kpc−1. Finally, we examine the azimuthal variations in gas-phase metallicity, which show a negative correlation with the galaxy integrated star-formation rate surface density (rs = −0.40, ps = 0.07) but no connection to the galaxies kinematic or morphological properties nor radial variations in stellar mass surface density or star formation rate surface density. This suggests both the radial and azimuthal variations in interstellar medium properties are connected to the galaxy integrated density of recent star formation

KASHz: No evidence for ionised outflows instantaneously suppressing star formation in moderate luminosity AGN at z∼1.4–2.6

As part of our KMOS AGN Survey at High-redshift (KASHz), we present spatially-resolved VLT/KMOS and VLT/SINFONI spectroscopic data and ALMA 870μm continuum imaging of eight z=1.4–2.6 moderate AGN (⁠L 2−10kev L2−10kev = 1042 − 1045 ergs s−1). We map [O iii], Hα and rest-frame FIR emission to search for any spatial anti-correlation between ionised outflows (traced by the [O iii] line) and star formation (SF; traced by Hα and FIR), that has previously been claimed for some high-z AGN and used as evidence for negative and/or positive AGN feedback. Firstly, we conclude that Hα is unreliable to map SF inside our AGN host galaxies based on: (i) SF rates inferred from attenuation-corrected Hα can lie below those inferred from FIR; (ii) the FIR continuum is more compact than the Hα emission by a factor of ∼2 on average; (iii) in half of our sample, we observe significant spatial offsets between the FIR and Hα emission, with an average offset of 1.4 ± 0.6 kpc. Secondly, for the five targets with outflows we find no evidence for a spatial anti-correlation between outflows and SF using either Hα or FIR as a tracer. This holds for our re-analysis of a famous z=1.6 X-ray AGN (‘XID 2028’) where positive and negative feedback has been previously claimed. Based on our results, any impact on SF by ionised outflows must be subtle, either occurring on scales below our resolution, or on long timescales

K-CLASH: spatially-resolving star-forming galaxies in field and cluster environments at z ≈ 0.2-0.6

We present the KMOS-CLASH (K-CLASH) survey, a K-band Multi-Object Spectrograph (KMOS) survey of the spatially-resolved gas properties and kinematics of 191 (predominantly blue) Hα-detected galaxies at 0.2 ≲ z ≲ 0.6 in field and cluster environments. K-CLASH targets galaxies in four Cluster Lensing And Supernova survey with Hubble (CLASH) fields in the KMOS IZ-band, over 7′ radius (≈2–3 Mpc) fields-of-view. K-CLASH aims to study the transition of star-forming galaxies from turbulent, highly star-forming disc-like and peculiar systems at z ≈ 1–3, to the comparatively quiescent, ordered late-type galaxies at z ≈ 0, and to examine the role of clusters in the build-up of the red sequence since z ≈ 1. In this paper, we describe the K-CLASH survey, present the sample, and provide an overview of the K-CLASH galaxy properties. We demonstrate that our sample comprises star-forming galaxies typical of their stellar masses and epochs, residing both in field and cluster environments. We conclude K-CLASH provides an ideal sample to bridge the gap between existing large integral-field spectroscopy surveys at higher and lower redshifts. We find that star-forming K-CLASH cluster galaxies at intermediate redshifts have systematically lower stellar masses than their star-forming counterparts in the field, hinting at possible “downsizing” scenarios of galaxy growth in clusters at these epochs. We measure no difference between the star-formation rates of Hα-detected, star-forming galaxies in either environment after accounting for stellar mass, suggesting that cluster quenching occurs very rapidly during the epochs probed by K-CLASH, or that star-forming K-CLASH galaxies in clusters have only recently arrived there, with insufficient time elapsed for quenching to have occured