Trident: A three-pronged galaxy survey. I. Lyman alpha emitting galaxies at z~2 in GOODS North

Context. Lyman alpha emitting galaxies (LAEs) are used to probe the distant universe and are therefore important for galaxy evolution studies and for providing clues to the nature of the epoch of reionization, but the exact circumstances under which Lyman alpha escapes a galaxy are still not fully understood. Aims. The Trident project is designed to simultaneously examine Lyman alpha, H-alpha and Lyman Continuum emission from galaxies at redshift z~2, thus linking together these three aspects of ionising radiation in galaxies. In this paper, we outline the strategy of this project and examine the properties of LAEs in the GOODS North field. Methods. We performed a narrowband LAE survey in GOODS North using existing and two custom made filters at the Nordic Optical Telescope with MOSCA. We use complementary broad band archival data in the field to make a careful candidate selection and perform optical to near-IR SED fitting. We also estimate far-infrared luminosities by matching our candidates to detections in Spitzer/MIPS 24{\mu}m and Herschel/PACS catalogs. Results. We find a total of 25 LAE candidates, probing mainly the bright end of the LAE luminosity function with L_Ly {\alpha} ~ 1-15e42 erg/s. They display a range of masses of ~0.5-50e9 M_solar, and average ages from a few tens of Myr to 1 Gyr when assuming a constant star formation history. The majority of our candidates also show signs of recent elevated star formation. Three candidates have counterparts in the GOODS-Herschel far-IR catalogue, with luminosities consistent with ultra-luminous infrared galaxies (ULIRGs). Conclusions. The wide range of parameters derived from our SED fitting, as well as part of our sample being detected as ULIRGs, seems to indicate that at these Lyman alpha luminosities, LAEs do not necessarily have to be young dwarfs, and that a lack of dust is not required for Lyman alpha to escape.Comment: 16 pages, 12 figures. Accepted version for publication in A&

Estimulación motora en niños con déficit visual: plan de actividades para alumnos de 1º de Primaria

A partir de la experiencia realizada con un niño con baja visión, escolarizado en 1.º de Primaria, la autora plantea una propuesta de intervención, con la finalidad de demostrar que la práctica psicomotriz es necesaria, entre los 4 y los 6 años de edad, en niños con deficiencia visual. El objetivo fundamental es mejorar el entorno social y educativo de los alumnos, a través del aprendizaje motor. El programa se aplica a lo largo del curso escolar, conjuntamente con la asignatura de Educación Física. El plan de actividades trata de lograr la estimulación motora mediante tareas de lateralidad, conocimiento del propio cuerpo, equilibrio, autonomía en la vida diaria, higiene postural y juegos de expresión

Peering through the holes: the far UV color of star-forming galaxies at z~3-4 and the escaping fraction of ionizing radiation

We aim to investigate the effect of the escaping ionizing radiation on the color selection of high redshift galaxies and identify candidate Lyman continuum (LyC) emitters. The intergalactic medium prescription of Inoue et al.(2014) and galaxy synthesis models of Bruzual&Charlot (2003) have been used to properly treat the ultraviolet stellar emission, the stochasticity of the intergalactic transmission and mean free path in the ionizing regime. Color tracks are computed by turning on/off the escape fraction of ionizing radiation. At variance with recent studies, a careful treatment of IGM transmission leads to no significant effects on the high-redshift broad-band color selection. The decreasing mean free path of ionizing photons with increasing redshift further diminishes the contribution of the LyC to broad-band colors. We also demonstrate that prominent LyC sources can be selected under suitable conditions by calculating the probability of a null escaping ionizing radiation. The method is applied to a sample of galaxies extracted from the GOODS-S field. A known LyC source at z=3.795 is successfully recovered as a LyC emitter candidate and another convincing candidate at z=3.212 is reported. A detailed analysis of the two sources (including their variability and morphology) suggests a possible mixture of stellar and non-stellar (AGN) contribution in the ultraviolet. Conclusions: Classical broad-band color selection of 2.5<z<4.5 galaxies does not prevent the inclusion of LyC emitters in the selected samples. Large fesc in relatively bright galaxies (L>0.1L*) could be favored by the presence of a faint AGN not easily detected at any wavelength. A hybrid stellar and non-stellar (AGN) ionizing emission could coexist in these systems and explain the tensions found among the UV excess and the stellar population synthesis models reported in literature.Comment: Accepted for publication in Astronomy & Astrophysics. 13 pages, 7 figure

Use of polyaspartates for the tartaric stabilisation of white and red wines and side effects on wine characteristics

Aim: The stabilising efficacy against tartaric precipitations of polyaspartates-based products (PAs), in particular potassium polyaspartate (KPA), was tested with six different wines (three white and three red). Some side effects on wine characteristics (white wine colour stability, wine turbidity and filterability) were also studied. Results and conclusions: All PAs showed good stabilising efficacy against tartaric precipitations according to the cold test. With the same test, the PAs were stable in wine for 1 year of storage, which was the total duration of the study. The dose of 100 mg/L was sufficient to stabilise the tested wines. No differences in filterability were observed in comparison with MTA (metatartaric acid). The hypothesised protective effect against colour browning in white wines was not observed. Significance and impact of the study: The international wine trade requires stable wines. This paper provides information to support wineries in managing the use of KPA, as little information is available to date in the literature on this stabilising additive

Constraining Lyman-alpha spatial offsets at 3<z<5.53<z<5.5 from VANDELS slit spectroscopy

We constrain the distribution of spatially offset Lyman-alpha emission (Ly$\alpha$) relative to rest-frame ultraviolet emission in $\sim300$ high redshift ($3<z<5.5$) Lyman-break galaxies (LBGs) exhibiting Ly$\alpha$ emission from VANDELS, a VLT/VIMOS slit-spectroscopic survey of the CANDELS Ultra Deep Survey and Chandra Deep Field South fields (${\simeq0.2}~\mathrm{deg}^2$ total). Because slit spectroscopy compresses two-dimensional spatial information into one spatial dimension, we use Bayesian inference to recover the underlying Ly$\alpha$ spatial offset distribution. We model the distribution using a 2D circular Gaussian, defined by a single parameter $\sigma_{r,\mathrm{Ly}\alpha}$, the standard deviation expressed in polar coordinates. Over the entire redshift range of our sample ($3<z<5.5$), we find $\sigma_{r,\mathrm{Ly}\alpha}=1.70^{+0.09}_{-0.08}$ kpc ($68\%$ conf.), corresponding to $\sim0.25$ arcsec at $\langle z\rangle=4.5$. We also find that $\sigma_{r,\mathrm{Ly}\alpha}$ decreases significantly with redshift. Because Ly$\alpha$ spatial offsets can cause slit-losses, the decrease in $\sigma_{r,\mathrm{Ly}\alpha}$ with redshift can partially explain the increase in the fraction of Ly$\alpha$ emitters observed in the literature over this same interval, although uncertainties are still too large to reach a strong conclusion. If $\sigma_{r,\mathrm{Ly}\alpha}$ continues to decrease into the reionization epoch, then the decrease in Ly$\alpha$ transmission from galaxies observed during this epoch might require an even higher neutral hydrogen fraction than what is currently inferred. Conversely, if spatial offsets increase with the increasing opacity of the IGM, slit losses may explain some of the drop in Ly$\alpha$ transmission observed at $z>6$. Spatially resolved observations of Ly$\alpha$ and UV continuum at $6<z<8$ are needed to settle the issue.Comment: Submitted to MNRA

Clustering and descendants of MUSYC galaxies at z<1.5

We measure the evolution of galaxy clustering out to a redshift of z~1.5 using data from two MUSYC fields, the Extended Hubble Deep Field South (EHDF-S) and the Extended Chandra Deep Field South (ECDF-S). We use photometric redshift information to calculate the projected-angular correlation function, omega(sigma), from which we infer the projected correlation function Xi(sigma). We demonstrate that this technique delivers accurate measurements of clustering even when large redshift measurement errors affect the data. To this aim we use two mock MUSYC fields extracted from a LambdaCDM simulation populated with GALFORM semi-analytic galaxies which allow us to assess the degree of accuracy of our estimates of Xi(sigma) and to identify and correct for systematic effects in our measurements. We study the evolution of clustering for volume limited subsamples of galaxies selected using their photometric redshifts and rest-frame r-band absolute magnitudes. We find that the real-space correlation length r_0 of bright galaxies, M_r<-21 (rest-frame) can be accurately recovered out to z~1.5, particularly for ECDF-S given its near-infrared photometric coverage. There is mild evidence for a luminosity dependent clustering in both fields at the low redshift samples (up to =0.57), where the correlation length is higher for brighter galaxies by up to 1Mpc/h between median rest-frame r-band absolute magnitudes of -18 to -21.5. As a result of the photometric redshift measurement, each galaxy is assigned a best-fit template; we restrict to E and E+20%Sbc types to construct subsamples of early type galaxies (ETGs). Our ETG samples show a strong increase in r_0 as the redshift increases, making it unlikely (95% level) that ETGs at median redshift z_med=1.15 are the direct progenitors of ETGs at z_med=0.37 with equivalent passively evolved luminosities. (ABRIDGED)Comment: 16 pages, 12 figures, 2 tables, accepted for publication in MNRA