SDSSJ143244.91+301435.3 at VLBI: a compact radio galaxy in a narrow-line Seyfert 1

We present VLBI observations, carried out with the European Very Long Baseline Interferometry Network (EVN), of SDSSJ143244.91+301435.3, a radio-loud narrow-line Seyfert 1 (RLNLS1) characterized by a steep radio spectrum. The source, compact at Very Large Array (VLA) resolution, is resolved on the milliarcsec scale, showing a central region plus two extended structures. The relatively high brightness temperature of all components (5x10^6-1.3x10^8 K) supports the hypothesis that the radio emission is non-thermal and likely produced by a relativistic jet and/or small radio lobes. The observed radio morphology, the lack of a significant core and the presence of a low frequency (230 MHz) spectral turnover are reminiscent of the Compact Steep Spectrum sources (CSS). However, the linear size of the source (~0.5kpc) measured from the EVN map is lower than the value predicted using the turnover/size relation valid for CSS sources (~6kpc). This discrepancy can be explained by an additional component not detected in our observations, accounting for about a quarter of the total source flux density, combined to projection effects. The low core-dominance of the source (CD<0.29) confirms that SDSSJ143244.91+301435.3 is not a blazar, i.e. the relativistic jet is not pointing towards the observer. This supports the idea that SDSSJ143244.91+301435.3 may belong to the "parent population" of flat-spectrum RLNLS1 and favours the hypothesis of a direct link between RLNLS1 and compact, possibly young, radio galaxies.Comment: 8 pages, 3 figures, accepted for publication in MNRA

RETRACTED: A Novel Approavh to Discover Web Services Using WSDL and UDDI

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).This article has been retracted at the request of the scientific committee of International Conference on Computer, Communication and Convergence (ICCC 2015). The authors have plagiarized part of a paper that had already appeared in the International Journal of Information Technology and Computer Science(IJITCS), 6 (2014) 56–62, DOI: 10.5815/ijitcs.2014.10.08. (http://www.mecs-press.org/ijitcs/ijitcs-v6-n10/v6n10-8.html). One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents an abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the ICCC 2015 submission process

From the molecular hallmarks to motor behavior: characterization of a new transgenic mouse model for spinocerebellar ataxia type 2

Spinocerebellar ataxia type 2 (SCA2) is a rare disease with no cure, and therefore patients depend on symptomatic and supportive treatments. It is a highly debilitating disease affecting predominantly the brain with symptoms that include motor and coordination impairment. SCA2 is caused by an abnormal expansion of the CAG triplet in the coding region of the ATXN2 gene. When it has above 33 CAG repeats, it originates a protein with an abnormally expanded glutamine tract. The mutant protein impairs several cellular functions, leading to neuronal degeneration and death. Several rodent models were developed to study the neuropathology and potential therapies for SCA2. However, most of them fail to mimic a complete SCA2 phenotype, taking too long to develop diseaserelated symptoms or failing to display neuronal-associated deficits.info:eu-repo/semantics/publishedVersio

SDSSJ143244.91+301435.3: a link between radio-loud narrow-line Seyfert 1 galaxies and compact steep-spectrum radio sources?

We present SDSSJ143244.91+301435.3, a new case of radio-loud narrow line Seyfert 1 (RL NLS1) with a relatively high radio power (P1.4GHz=2.1x10^25 W Hz^-1) and large radioloudness parameter (R1.4=600+/-100). The radio source is compact with a linear size below ~1.4 kpc but, contrary to most of the RL NLS1 discovered so far with such a high R1.4, its radio spectrum is very steep (alpha=0.93) and not supporting a 'blazar-like' nature. Both the small mass of the central super-massive black-hole and the high accretion rate relative to the Eddington limit estimated for this object (3.2x10^7 Msun and 0.27, respectively, with a formal error of ~0.4 dex on both quantities) are typical of the class of NLS1. Through a modeling of the spectral energy distribution of the source we have found that the galaxy hosting SDSSJ143244.91+301435.3 is undergoing a quite intense star-formation (SFR=50 Msun y^-1) which, however, is expected to contribute only marginally (~1 per cent) to the observed radio emission. The radio properties of SDSSJ143244.91+301435.3 are remarkably similar to those of compact steep spectrum (CSS) radio sources, a class of AGN mostly composed by young radio galaxies. This may suggest a direct link between these two classes of AGN, with the CSS sources possibly representing the misaligned version (the so-called parent population) of RL NLS1 showing blazar characteristics.Comment: 14 pages, 7 figures, 4 tables, accepted for publication in MNRA

z~2-9 Galaxies magnified by the Hubble Frontier Field Clusters I: Source Selection and Surface Density-Magnification Constraints from >2500 galaxies

We assemble a large comprehensive sample of 2534 z~2, 3, 4, 5, 6, 7, 8, and 9 galaxies lensed by the six clusters from the Hubble Frontier Fields (HFF) program. Making use of the availability of multiple independent magnification models for each of the HFF clusters and alternatively treating one of the models as the "truth," we show that the median magnification factors from the v4 parametric models are typically reliable to values of 30 to 50, and in one case to 100. Using the median magnification factor from the latest v4 models, we estimate the UV luminosities of the 2534 lensed z~2-9 galaxies, finding sources as faint as -12.4 mag at z~3 and -12.9 mag at z~7. We explicitly demonstrate the power of the surface density-magnification relations Sigma(z) vs. mu in the HFF clusters to constrain both distant galaxy properties and cluster lensing properties. Based on the Sigma(z) vs. mu relations, we show that the median magnification estimates from existing public models must be reliable predictors of the true magnification mu to mu<15 (95% confidence). We also use the observed Sigma(z) vs. mu relations to derive constraints on the evolution of the luminosity function faint-end slope from z~7 to z~2, showing that faint-end slope results can be consistent with blank-field studies if, and only if, the selection efficiency shows no strong dependence on the magnification factor mu. This can only be the case if very low luminosity galaxies are very small, being unresolved in deep lensing probes.Comment: 22 pages, 13 figures, 6 tables, accepted for publication in the Astrophysical Journa

Confirmation of double peaked Lyα emission at z = 6.593. Witnessing a galaxy directly contributing to the reionisation of the Universe

Large scale structure and cosmolog

Slicing COSMOS with SC4K:the evolution of typical Lya emitters and the Lya escape fraction from z~2 to z~6

We present and explore deep narrow- and medium-band data obtained with the Subaru and the Isaac Newton telescopes in the ~2 deg$^2$ COSMOS field. We use these data as an extremely wide, low-resolution (R~20-80) IFU survey to slice through the COSMOS field and obtain a large sample of ~4000 Lyman-$\alpha$ (Lya) emitters from z~2 to z~6 in 16 redshift slices (SC4K). We present new Lya luminosity functions (LFs) covering a co-moving volume of ~10$^8$Mpc$^3$. SC4K extensively complements ultra-deep surveys, jointly covering over 4 dex in Lya luminosity and revealing a global (2.5z 3.5, likely linked with the evolution of the AGN population. The Lya luminosity density rises by a factor ~2 from z~2 to z~3 but is then found to be roughly constant (~$1.1\times10^{40}$ erg s$^{-1}$ Mpc$^{-3}$) to z~6, despite the ~0.7 dex drop in UV luminosity density. The Lya/UV luminosity density ratio rises from $4\pm1$% to $30\pm6$% from z~2.2 to z~6. Our results imply a rise of a factor of ~2 in the global ionisation efficiency ($\xi_{\rm ion}$) and a factor ~$4\pm1$ in the Lya escape fraction from z~2 to z~6, hinting for evolution in both the typical burstiness/stellar populations and even more so in the typical ISM conditions allowing Ly$\alpha$ photons to escape

Resolved UV and [C II] Structures of Luminous Galaxies within the Epoch of Reionization

We present new deep ALMA and HST/WFC3 observations of MASOSA and VR7, two luminous Ly$\alpha$ emitters (LAEs) at $z=6.5$, for which the UV continuum level differ by a factor four. No IR dust continuum emission is detected in either, indicating little amounts of obscured star formation and/or high dust temperatures. MASOSA, with a UV luminosity M$_{1500}=-20.9$, compact size and very high Ly$\alpha$ EW$_{0}\approx145$ A, is undetected in [CII] to a limit of L$_{\rm [CII]

The evolution of the UV luminosity and stellar mass functions of Lyman-α emitters from z ~2 to z ~6

We measure the evolution of the rest-frame UV luminosity function (LF) and the stellar mass function (SMF) of Lyman-α (Ly α) emitters (LAEs) from z ~ 2 to z ~ 6 by exploring ~4000 LAEs from the SC4K sample. We find a correlation between Ly α luminosity (LLy α) and rest-frame UV (MUV), with best fit MUV = -1.6+0.2-0.3 log10(LLy α/erg s-1) + 47+12-11 and a shallower relation between LLy α and stellar mass (M∗), with best fit log10(M∗/M·) = 0.9+0.1-0.1 log10(LLy α/erg s-1) - 28+4.0-3.8. An increasing LLy α cut predominantly lowers the number density of faint MUV and low M∗ LAEs. We estimate a proxy for the full UV LFs and SMFs of LAEs with simple assumptions of the faint end slope. For the UV LF, we find a brightening of the characteristic UV luminosity (M∗UV) with increasing redshift and a decrease of the characteristic number density (Φ∗). For the SMF, we measure a characteristic stellar mass (M∗∗/M·) increase with increasing redshift, and a Φ∗ decline. However, if we apply a uniform luminosity cut of log10(LLy α/erg s-1) ≥ 43.0, we find much milder to no evolution in the UV and SMF of LAEs. The UV luminosity density (ρUV) of the full sample of LAEs shows moderate evolution and the stellar mass density (ρM) decreases, with both being always lower than the total ρUV and ρM of more typical galaxies but slowly approaching them with increasing redshift. Overall, our results indicate that both ρUV and ρM of LAEs slowly approach the measurements of continuum-selected galaxies at z > 6, which suggests a key role of LAEs in the epoch of reionization

The Synchrony of Production & Escape:Half the Bright Lyαα Emitters at z≈2z\approx2 have Lyman Continuum Escape Fractions ≈50%\approx50\%

The ionizing photon escape fraction (LyC $f_{\rm{esc}}$) of star-forming galaxies is the single greatest unknown in the reionization budget. Stochastic sightline effects prohibit the direct separation of LyC leakers from non-leakers at significant redshift. Here we circumvent this uncertainty by inferring $f_{\rm{esc}}$ with resolved (R>4000) LyA profiles from the X-SHOOTER LyA survey at z=2 (XLS-z2). We select leakers ($f_{\rm{esc}}>20$%) and non-leakers ($f_{\rm{esc}}0.2 L^{*}$ LyA emitters (LAEs). With median stacked spectra of these subsets covering 1000-8000 {\AA} (rest-frame) we investigate the conditions for LyC $f_{\rm{esc}}$. We find the following differences between leakers vs. non-leakers: (i) strong nebular CIV and HeII emission vs. non-detections, (ii) O32~8.5 vs. ~3, (iii) Ha/Hb indicating no dust vs. E(B-V)~0.3, (iv) MgII emission close to the systemic velocity vs. redshifted, optically thick MgII, (v) LyA $f_{\rm{esc}}$ of ~50% vs. ~10%. The extreme EWs in leakers (O3+Hb~1100 {\AA}) constrain the characteristic timescale of LyC escape to ~3-10 Myr bursts when short-lived stars with the hardest ionizing spectra shine. The defining traits of leakers -- extremely ionizing stellar populations, low column densities, a dust-free, high ionization state ISM -- occur simultaneously in the $f_{\rm{esc}}>20\%$ stack, suggesting they are causally connected, and motivating why indicators like O32 may suffice to constrain $f_{\rm{esc}}$ at z>6 with JWST. The leakers comprise half our sample, have a median LyC $f_{\rm{esc}}$~50%, and an ionising production efficiency $\log({\xi_{\rm{ion}}/\rm{Hz\ erg^{-1}}})$~25.9. These results show LAEs -- the type of galaxies rare at z=2, but that become the norm at higher redshift -- are highly efficient ionizers, with extreme $\xi_{\rm{ion}}$ and prolific $f_{\rm{esc}}$ occurring in sync. (ABRIDGED