The missing metals problem. III How many metals are expelled from galaxies?

[Abridged] We revisit the metal budget at z~2. In the first two papers of this series, we already showed that ~30% (to <60% if extrapolating the LF) of the metals are observed in all z~2.5 galaxies detected in current surveys. Here, we extend our analysis to the metals outside galaxies, i.e. in intergalactic medium (IGM), using observational data and analytical calculations. Our results for the two are strikingly similar: (1) Observationally, we find that, besides the small (5%) contribution of DLAs, the forest and sub-DLAs contribute subtantially to make <30--45% of the metal budget, but neither of these appear to be sufficient to close the metal budget. The forest accounts for 15--30% depending on the UV background, and sub-DLAs for >2% to <17% depending on the ionization fraction. Together, the `missing metals' problem is substantially eased. (2) We perform analytical calculations based on the effective yield--mass relation. At z=2, we find that the method predicts that 2$--50% of the metals have been ejected from galaxies into the IGM, consistent with the observations. The metal ejection is predominantly by L<1/3L_B^*(z=2) galaxies, which are responsible for 90% the metal enrichment, while the 50 percentile is at L~1/10L^*_B(z=2). As a consequence, if indeed 50% of the metals have been ejected from galaxies, 3--5 bursts of star formation are required per galaxy prior to z=2. The ratio between the mass of metals outside galaxies to those in stars has changed from z=2 to z=0: it was 2:1 or 1:1 and is now 1:8 or 1:9. This evolution implies that a significant fraction of the IGM metals will cool and fall back into galaxies.Comment: 18pages, MNRAS, in press; small changes to match proofs; extended version with summary tabl

Multiphase Plasma in Sub-Damped Lyman Alpha Systems: A Hidden Metal Reservoir

We present a VLT/UVES spectrum of a proximate sub-damped Lyman-alpha (sub-DLA) system at z=2.65618 toward the quasar Q0331-4505 (z_qso=2.6785+/-0.0030). Absorption lines of O I, Si II, Si III, Si IV, C II, C III, C IV, Fe II, Al II, and O VI are seen in the sub-DLA, which has a neutral hydrogen column density log N(H I)=19.82+/-0.05. The absorber is at a velocity of 1820+/-250 km/s from the quasar; however, its low metallicity [O/H]=-1.64+/-0.07, lack of partial coverage, lack of temporal variations between observations taken in 2003 and 2006, and non-detection of N V imply the absorber is not a genuine intrinsic system. By measuring the O VI column density and assuming equal metallicities in the neutral and ionized gas, we determine the column density of hot ionized hydrogen in this sub-DLA, and in two other sub-DLAs with O VI drawn from the literature. Coupling this with determinations of the typical amount of warm ionized hydrogen in sub-DLAs, we confirm that sub-DLAs are a more important metal reservoir than DLAs, in total comprising at least 6-22% of the metal budget at z~2.5.Comment: 5 pages, 3 color figures, accepted for publication in ApJ

Optical properties and spatial distribution of MgII absorbers from SDSS image stacking

We present a statistical analysis of the photometric properties and spatial distribution of more than 2,800 MgII absorbers with 0.37<z<1 and rest equivalent width W_0(\lambda2796)>0.8\AA detected in SDSS quasar spectra. Using an improved image stacking technique, we measure the cross-correlation between MgII gas and light (in the g, r, i and z-bands) from 10 to 200 kpc and infer the light-weighted impact parameter distribution of MgII absorbers. Such a quantity is well described by a power-law with an index that strongly depends on W_0, ranging from ~-1 for W_0~ 1.5\AA. At redshift 0.37<z<0.55, we find the average luminosity enclosed within 100 kpc around MgII absorbers to be M_g=-20.65+-0.11 mag, which is ~0.5 L_g*. The global luminosity-weighted colors are typical of present-day intermediate type galaxies. However, while the light of weaker absorbers originates mostly from red passive galaxies, stronger systems display the colors of blue star-forming galaxies. Based on these observations, we argue that the origin of strong MgII absorber systems might be better explained by models of metal-enriched gas outflows from star-forming/bursting galaxies. Our analysis does not show any redshift dependence for both impact parameter and rest-frame colors up to z=1. However, we do observe a brightening of the absorbers related light at high redshift (~50% from z~0.4 to 1). We argue that MgII absorbers are a phenomenon typical of a given evolutionary phase that more massive galaxies experience earlier than less massive ones, in a downsizing fashion. (abridged)Comment: ApJ in press, 28 pages, 16 figures, using emulateapj. Only typo corrections wrt the original submission (v1

The History of Cosmological Star Formation: Three Independent Approaches and a Critical Test Using the Extragalactic Background Light

Taking three independent approaches, we investigate the simultaneous constraints set on the cosmic star formation history from various observations, including stellar mass density and extragalactic background light (EBL). We compare results based on: 1) direct observations of past light-cone, 2) a model using local fossil evidence constrained by SDSS observations at z~0 (the `Fossil' model), and 3) theoretical ab initio models from three calculations of cosmic star formation history: (a) new (1024)^3 Total Variation Diminishing (TVD) cosmological hydrodynamic simulation, (b) analytic expression of Hernquist & Springel based on cosmological Smoothed Particle Hydrodynamics (SPH) simulations, and (c) semi-analytic model of Cole et al. We find good agreement among the three independent approaches up to the order of observational errors, except that all the models predict bolometric EBL of I_tot ~= 37-52 nW m^-2 sr^-1, which is at the lower edge of the the observational estimate by Hauser & Dwek. We emphasize that the Fossil model that consists of two components -- spheroids and disks --, when normalized to the local observations, provides a surprisingly simple but accurate description of the cosmic star formation history and other observable quantities. Our analysis suggests that the consensus global parameters at z=0 are: Omega_* = 0.0023+-0.0004, I_EBL = 43+-7 nW m^-2 sr^-1 rho_SFR=(1.06+-0.22)e-2 Msun yr^-1 Mpc^-3, j_bol = (3.1+-0.2)e8 Lsun Mpc^-3.Comment: 40 page, 10 figures. ApJ in press. Matched to the accepted versio

Post-transcriptional gene silencing triggered by sense transgenes involves uncapped antisense RNA and differs from silencing intentionally triggered by antisense transgenes

Although post-transcriptional gene silencing (PTGS) has been studied for more than a decade, there is still a gap in our understanding of how de novo silencing is initiated against genetic elements that are not supposed to produce double-stranded (ds)RNA. Given the pervasive transcription occurring throughout eukaryote genomes, we tested the hypothesis that unintended transcription could produce antisense (as)RNA molecules that participate to the initiation of PTGS triggered by sense transgenes (S-PTGS). Our results reveal a higher level of asRNA in Arabidopsis thaliana lines that spontaneously trigger S-PTGS than in lines that do not. However, PTGS triggered by antisense transgenes (AS-PTGS) differs from S-PTGS. In particular, a hypomorphic ago1 mutation that suppresses S-PTGS prevents the degradation of asRNA but not sense RNA during AS-PTGS, suggesting a different treatment of coding and non-coding RNA by AGO1, likely because of AGO1 association to polysomes. Moreover, the intended asRNA produced during AS-PTGS is capped whereas the asRNA produced during S-PTGS derives from 3' maturation of a read-through transcript and is uncapped. Thus, we propose that uncapped asRNA corresponds to the aberrant RNA molecule that is converted to dsRNA by RNA-DEPENDENT RNA POLYMERASE 6 in siRNA-bodies to initiate S-PTGS, whereas capped asRNA must anneal with sense RNA to produce dsRNA that initiate AS-PTGS

SINFONI Integral Field Spectroscopy of z~2 UV-selected Galaxies: Rotation Curves and Dynamical Evolution

We present 0.5" resolution near-IR integral field spectroscopy of the Ha line emission of 14 z~2 UV-selected BM/BX galaxies obtained with SINFONI at ESO/VLT. The mean Ha half-light radius r_1/2 is about 4kpc and line emission is detected over > ~20kpc in several sources. In 9 sources, we detect spatially-resolved velocity gradients, from 40 to 410 km/s over ~10kpc. The observed kinematics of the larger systems are consistent with orbital motions. Four galaxies are well described by rotating disks with clumpy morphologies and we extract rotation curves out to radii > ~10kpc. One or two galaxies exhibit signatures more consistent with mergers. Analyzing all 14 galaxies in the framework of rotating disks, we infer mean inclination- and beam-corrected maximum circular velocities v_c of 180+-90 km/s and dynamical masses of (0.5-25)x10^10 Msun within r_1/2. On average, the dynamical masses are consistent with photometric stellar masses assuming a Chabrier/Kroupa IMF but too small for a 0.1-100 Msun Salpeter IMF. The specific angular momenta of our BM/BX galaxies are similar to those of local late-type galaxies. The specific angular momenta of their baryons are comparable to those of their dark matter halos. Extrapolating from the average v_c at 10kpc, the virial mass of the typical halo of a galaxy in our sample is 10^(11.7+-0.5) Msun. Kinematic modeling of the 3 best cases implies a ratio of v_c to local velocity dispersion of order 2-4 and accordingly a large geometric thickness. We argue that this suggests a mass accretion (alternatively, gas exhaustion) timescale of ~500Myr. We also argue that if our BM/BX galaxies were initially gas rich, their clumpy disks will subsequently lose their angular momentum and form compact bulges on a timescale of ~1 Gyr. [ABRIDGED]Comment: Accepted for publication in the Astrophysical Journal. 17 pages, 5 color figure

o.OM: Structured-Functional Communication between Computer Music Systems using OSC and Odot

International audienceO.—odot—is a portable media programming framework based on the OSC data encoding. It embeds a small expression language which allows writing and executing programs in OSC structures. The integration of programming and declarative functional descriptions within data transfer protocols enables structured and expressive communication in media systems: program snippets can be distributed in OSC messages, which evaluate to further OSC messages in the different communicating software. We present experiments using this framework in the OpenMusic computer-aided composition environment , and illustrate via case studies some advantages of such integrated system

Probabilistic analysis of the upwind scheme for transport

We provide a probabilistic analysis of the upwind scheme for multi-dimensional transport equations. We associate a Markov chain with the numerical scheme and then obtain a backward representation formula of Kolmogorov type for the numerical solution. We then understand that the error induced by the scheme is governed by the fluctuations of the Markov chain around the characteristics of the flow. We show, in various situations, that the fluctuations are of diffusive type. As a by-product, we prove that the scheme is of order 1/2 for an initial datum in BV and of order 1/2-a, for all a>0, for a Lipschitz continuous initial datum. Our analysis provides a new interpretation of the numerical diffusion phenomenon

The Effects of Kinesiotape on Scapular Kinematics in Symptomatic Baseball Players

Introduction Baseball players are at an increased risk for shoulder dysfunction due to repetitive overhead throwing. Patients with symptomatic shoulders present with altered scapular kinematics, with the greatest variations found in upward rotation and posterior tilt which modify subacromial space. Previous investigations of the effects of kinesiotape (KT) on scapular kinematics have been inconclusive. Objective To determine the effects of KT on scapular kinematics in symptomatic collegiate baseball players. Participants Six Division II and III baseball players between 21 and 25 years old (mean 22.7) with a symptomatic throwing shoulder. Four were right hand dominant. Methods Symptomatic was defined as a report or pain or dysfunction in their throwing shoulder Participants were screened by student physical therapists (SPTs) to determine if they fit the inclusion criteria Kinesiotape was applied via a mechanical correction stabilization technique by a certified KT practitioner (Figure 1) Scapular posterior tilting (PT) and upward rotation (UR) were collected by a designated SPT during three planes of shoulder humerothoracic (HT) elevation with the G4 electromagnetic motion capture system (Innsport , Chicago, IL) Scapular kinematics with and without KT were analyzed between 30-90 degree elevation Differences in PT and UR during the three planes of elevation were explored descriptively Differences between conditions were compared proportionally to the maximum range of motion available Results PT was consistently greater in the KT condition. The largest difference was in abduction, where PT was 2.92 degrees greater. UR was consistently less in the KT condition. The largest difference was in abduction, where UR was 3.22 degrees less. The difference in PT was a larger proportion of available motion in abduction and was an equal proportion of available motion in elevation in the scapular plane as compared to UR. The PT proportion in abduction was 16 percent. The UR proportion in scapular plane elevation was 13 percent. Conclusions Increased posterior tilting widens the subacromial space, which is thought to decrease risk of subacromial impingement in overhead athletes. 3 Kinesiotape increased posterior tilting in symptomatic subjects during elevation in all 3 elevation planes. This advantage is somewhat countered by the decrease in upward rotation. Future work with an increased sample size may determine if there are statistical or clinically significant differences. Matched pair t tests with a Bonferonni correction would be an appropriate analysis. Clinical Implications These results indicate that KT may be an effective non invasive intervention to improve scapular kinematics and/or decrease injury risk in individuals with symptomatic shoulders