Search

We consider polynomials of the form $\operatorname{h}_m(y_1^{[\varkappa_1]},\ldots,y_n^{[\varkappa_n]})$, where $\operatorname{h}_m$ is the complete homogeneous polynomial of degree $m$ and $y_j^{[\varkappa_j]}$ denotes $y_j$ repeated $\varkappa_j$ times. Using the decomposition of the generating function into partial fractions we represent such polynomials in the form \[ \operatorname{h}_m(y_1^{[\varkappa_1]},\ldots,y_n^{[\varkappa_n]}) =\sum_{j=1}^n \sum_{r=1}^{\varkappa_j} \binom{r+m-1}{r-1} A_{y,\varkappa,j,r} y_j^m, \] where $A_{y,\varkappa,j,r}$ are some coefficients that do not depend on $m$. We also provide an alternative proof using the inverse of the confluent Vandermonde matrix., Comment: 28 pages

Methods.We applied distinct selection criteria to attain an SFG sample with minimal AGN contamination. Multiple approaches were used to estimate the intrinsic extinction, SFR and gas-phase metallicity for the SFGs. In conjunction with findings in the literature, we examined the correlation between SFRs and stellar masses ($M_*$), as well as the metallicity evolution depending on $M_*$. Finally, the 3D relationship between $M_*$, SFR and metallicity, is also studied.} Results. From the initial spectroscopic sample of 409 FIR-selected objects from the Lockman--SpReSO catalogue, 69 (17\%) AGNs have been identified and excluded, which is nearly double the percentage found in local studies, leaving a sample of 340 SFGs. The analysis of the $M_*$--SFR relationship revealed that Lockman--SpReSO IR-selected SFGs show signs of evolution at redshifts $z>0.4$, shifting above the main sequence, with a mean value of $\sim0.4$ dex. They are located within the starburst galaxy region since 78\% of the galaxies fall into this category. In addition, no evident flattening was found in the relation to specific SFR with redshift for $\log M_* (M_\odot) \gtrsim 10.5$. In line with the $M_*$--metallicity relation (MZR) outcomes published in previous studies for optically selected SFGs, however, during the analysis of the MZR, it was found that IR-selected SFGs exhibit lower metallicities than those anticipated on the basis of their $M_*$ and redshift. During the investigation of the 3D $M_*$--SFR--metallicity relation (FP), it was established that the research sample is consistent with relations in the existing literature, with an average scatter of $\sim0.2$ dex. However, a re-calibration of the FP when using the SFR obtained from the IR luminosity is required and, in this case, no attenuation in the correlation for $\log M_* (M_\odot) \gtrsim 10.5$ is observed., Comment: 21 pages, 17 figures, accepted in A&A

In this paper, we revisit the data for the galaxy cluster ZwCl 0024.0+1652 provided by the GLACE survey and study the mass--metallicity function and its relationship with the environment. Here we describe an alternative way to reduce the data from OSIRIS tunable filters. This method gives us better uncertainties in the fluxes of the emission lines and the derived quantities. We present an updated catalogue of cluster galaxies with emission in H$\alpha$ and [N\,{\sc{ii}}] $\lambda\lambda$6548,6583. We also discuss the biases of these new fluxes and describe the way in which we calculated the mass--metallicity relationship and its uncertainties. We generated a new catalogue of 84 emission-line galaxies with reliable fluxes in [N\,{\sc{ii}}] and H$\alpha$ lines from a list of 174 galaxies. We find a relationship between the clustercentric radius and the density of galaxies. We derived the mass--metallicity relationship for ZwCl 0024.0+1652 and compared it with clusters and field galaxies from the literature. We find a difference in the mass--metallicity relationship when compared to more massive clusters, with the latter showing on average higher values of abundance. This could be an effect of the quenching of the star formation, which seems to be more prevalent in low-mass galaxies in more massive clusters. We find little to no difference between ZwCl 0024.0+1652 galaxies and field galaxies located at the same redshift., Comment: 13 pages, 17 figures, accepted for publication in Astronomy and Astrophysics

Methods. We performed measurements of the \MgII, \MgI, \FeIIa, \FeIIb, and \FeIIc\ spectral lines present in the spectra of the selected sample to determine the EW and velocity of the flows observed in the star-forming galaxies. Subsequently, we conducted $10^7$ bootstrap simulations using Spearman's rank correlation coefficient ($\rho_s$) to explore correlations with galaxy properties. Furthermore, we calculated the covering factor, gas density, and optical depth for the measured \ion{Fe}{II} doublets. Results. Our analysis revealed strong correlations between the EW of \ion{Mg}{II} lines and both $M_{*}$ ($\rho_s=0.43$, 4.5$\sigma$) and SFR ($\rho_s=0.42$, 4.4$\sigma$). For the \ion{Fe}{II} lines, we observed strong correlations between the EW and SFR ($\rho_s\sim0.65$, $>3.9\sigma$), with a weaker correlation for $M_{*}$ ($\rho_s\sim0.35$, $>1.9\sigma$). No notable correlations were found between velocity measurements of \ion{Mg}{II} line and $M_{*}$, SFR, or sSFR of the objects ($\rho_s\sim0.1)$. However, a negative strong correlation was found between the velocity of the \ion{Fe}{II} lines and the SFR of the galaxies ($\rho_s\sim-0.45$, $\sim3\sigma$). Our results align with previous studies but studying FIR-selected objects. Finally, we detected a candidate \textit{loitering outflow}, a recently discovered subtype of FeLoBAL quasar, at redshift of $z=1.4399$, exhibiting emission in \ion{C}{III}] and low line velocities ($|v|\lesssim$ 200 km/s)., Comment: 25 pages, 31 figures

We consider polynomials of the form $\operatorname{s}_\lambda(y_1^{[\varkappa_1]},\ldots,y_n^{[\varkappa_n]})$, where $\lambda$ is an integer partition, $\operatorname{s}_\lambda$ is the Schur polynomial associated to $\lambda$, and $y_j^{[\varkappa_j]}$ denotes $y_j$ repeated $\varkappa_j$ times. We represent $\operatorname{s}_\lambda(y_1^{[\varkappa_1]},\ldots,y_n^{[\varkappa_n]})$ as a quotient whose the denominator is the determinant of the confluent Vandermonde matrix, and the numerator is the determinant of some generalized confluent Vandermonde matrix. We give three algebraic proofs of this formula., Comment: 26 pages

Context. Extragalactic surveys are a key tool for better understanding the evolution of galaxies. Both deep and wide-field surveys serve to provide a clearer emerging picture of the physical processes that take place in and around galaxies, and to identify which of these processes are the most important in shaping the properties of galaxies. Aims. The Lockman Spectroscopic Redshift Survey using Osiris (Lockman-SpReSO) aims to provide one of the most complete optical spectroscopic follow-ups of the far-infrared (FIR) sources detected by the \textit{Herschel} Space Observatory in the Lockman Hole (LH) field. The optical spectroscopic study of the FIR-selected galaxies supplies valuable information about the relation between fundamental FIR and optical parameters, including extinction, star formation rate, and gas metallicity. In this article, we introduce and provide an in-depth description of the Lockman-SpReSO project and of its early results. Methods. We selected FIR sources from \textit{Herschel} observations of the central 24 arcmin $\times$ 24 arcmin of the LH field with an optical counterpart up to 24.5 $R_{\rm C}$(AB). The sample comprises 956 \textit{Herschel} FIR sources, plus 188 additional interesting objects in the field. These are point X-ray sources, cataclysmic variable star candidates, high-velocity halo star candidates, radio sources, very red quasi-stellar objects, and optical counterparts of sub-millimetre galaxies. The faint component of the catalogue ($R_{\rm C}(\mathrm{AB})\geq20$) was observed using the OSIRIS instrument on the 10.4 m Gran Telescopio Canarias in multi-object spectroscopy (MOS) mode. The bright component was observed using two multi-fibre spectrographs: the AF2-WYFFOS at the William Herschel Telescope and the HYDRA instrument at the WYIN telescope., Comment: 22 pages, 12 figures

Context. Computational techniques are essential for mining large databases produced in modern surveys with value-added products. Aims. This paper presents a machine learning procedure to carry out simultaneously galaxy morphological classification and photometric redshift estimates. Currently, only spectral energy distribution (SED) fitting has been used to obtain these results all at once. Methods. We used the ancillary data gathered in the OTELO catalog and designed a non-sequential neural network that accepts optical and near-infrared photometry as input. The network transfers the results of the morphological classification task to the redshift fitting process to ensure consistency between both procedures. Results. The results successfully recover the morphological classification and the redshifts of the test sample, reducing catastrophic redshift outliers produced by SED fitting and avoiding possible discrepancies between independent classification and redshift estimates. Our technique may be adapted to include galaxy images to improve the classification., Comment: Astronomy and Astrophysics (A&A) accepted

We present the analysis of a sample of \ha\,, \hb\ and \oii\ emission line galaxies from the \otelo\ survey, with masses typically below $log(M_*/M_\sun) \sim 9.4$ and redshifts between $z \sim 0.4$ and 1.43. We study the star formation rate, star formation rate density, and number density and their evolution with redshift. We obtain a robust estimate of the specific star formation rate -- stellar mass relation based on the lowest mass sample published so far. We also determine a flat trend of the star formation rate density and number density with redshift. Our results suggest a scenario of no evolution of the number density of galaxies, regardless of their masses, up to redshift $z\sim1.4$. This implies a gradual change of the relative importance of the star forming processes, from high-mass galaxies to low-mass galaxies, with decreasing redshift. We also find little or no variation of the star formation rate density in the redshift range of $0.4

We study a sample of H$\beta$ emission line sources at $z\sim$0.9 to identify the star-forming (SF) galaxies sample and characterise them in terms of line luminosity, stellar mass, SFR, and morphology. The final aim is to obtain the H$\beta$ luminosity function (LF) of the SF galaxies at this redshift. We used the instrument OSIRIS at GTC to obtain the pseudo spectra of emission line sources in the OTELO field. From these pseudo spectra, we identified the objects with H$\beta$ emission. As the resolution of the pseudo spectra allowed us to separate H$\beta$ from O[III], we derive the H$\beta$ flux without contamination. Using data from the extended OTELO catalogue, we discriminated AGNs and studied the SFR, the stellar mass, and the morphology of the SF galaxies. We find that our sample is located on the main sequence of SF galaxies. The sources are morphologically classified, mostly as disc-like galaxies (76%), and 90% of the sample are low-mass galaxies ($M_*<10^{10}\;\mathrm{M}_\odot$). The low-mass SF galaxies at $z \sim 0.9$ that were detected by OTELO present similar properties as low-mass SF galaxies in the local universe, suggesting that these kinds of objects do not have a favorite epoch of formation and star formation enhancement from $z \sim 1$ to now. Our sample of 40 H$\beta$ SF galaxies includes the faintest H$\beta$ emitters detected so far. This allows us to constrain the faint end of the LF for the H$\beta$ line alone with a minimum luminosity of $\log L = 39 \;\mathrm{erg\,s}^{-1}$, which is a hundred times fainter than previous surveys. The dust-corrected OTELO H$\beta$ LF established the faint-end slope as $\alpha =-1.36\pm 0.15$. We increased the scope of the analysis to the bright end by adding ancillary data from the literature, which was not dust-corrected in this case. The obtained slope for this extended LF is $\alpha = -1.43\pm 0.12$., Comment: 12 pages, 6 figures, accepted by A&A

In this paper, we aim to study the main properties and luminosity function (LF) of the [OII] emitters detected in the OTELO survey in order to characterise the star formation processes in low-mass galaxies at $z\sim1.43$ and to constrain the faint-end of the LF. Here, we describe the selection method and analysis of the emitters obtained from narrow-band scanning techniques. In addition, we present several relevant properties of the emitters and discuss the selection biases and uncertainties in the determination of the LF and the star formation rate density (SFRD). We confirmed a total of 60 sources from a preliminary list of 332 candidates as [OII] emitters. Approximately 93% of the emitters have masses in the range of $10^{8}

The morphology of galaxies provide us with a unique tool for relating and understanding other physical properties and their changes over the course of cosmic time. It is only recently that we have been afforded access to a wealth of data for an unprecedented number galaxies thanks to large and deep surveys, We present the morphological catalogue of the OTELO survey galaxies detected with the Hubble Space Telescope (HST)-ACS F814W images. We explore various methods applied in previous works to separate early-type (ET) and late-type (LT) galaxies classified via spectral energy distribution (SED) fittings using galaxy templates. Together with this article, we are releasing a catalogue containing the main morphological parameters in the F606W and F814W bands derived for more than 8\,000 sources. The morphological analysis is based on the single-S\'ersic profile fit. We used the GALAPAGOS2 software to provide multi-wavelength morphological parameters fitted simultaneously in two HST-ACS bands. The GALAPAGOS2 software detects, prepares guess values for GALFTI-M, and provides the best-fitting single-S\'ersic model in both bands for each source. Stellar masses were estimated using synthetic rest-frame magnitudes recovered from SED fittings of galaxy templates. The morphological catalogue is complemented with concentration indexes from a separate SExtractor dual, high dynamical range mode. A total of 8,812 sources were successfully fitted with single-S\'ersic profiles. The analysis of a carefully selected sample of ~3,000 sources up to phot_z=2 is presented in this work, of which 873 sources were not detected in previous studies. We found no statistical evidence for the evolution of the low-mass end of mass-size relation for ET and LT since z=2. Furthermore, we found a good agreement for the median size evolution for ET and LT galaxies, for a given stellar mass, with the data from the literature., Comment: 16 pages, 16 figures, Accepted in Astronomy & Astrphysics

Although ZwCl0024+1652 galaxy cluster at $z\sim0.4$ has been thoroughly analysed, it lacks a comprehensive study of star formation and nuclear activity of its members. With GaLAxy Cluster Evolution (GLACE) survey, a total of 174 H$\alpha$ emission-line galaxies (ELGs) were detected, most of them having [NII}]. We reduced and analysed a set of [OIII] and H$\beta$ tunable filter (TF) observations within GLACE survey. Using H$\alpha$ priors, we identified [OIII] and H$\beta$ in 35 ($\sim$20%) and 59 ($\sim$34%) sources, respectively, with 21 of them having both emission lines, and 20 having in addition [NII]. Applying BPT-NII diagnostic diagram, we classified these ELGs into 40% star-forming (SF), 55% composites, and 5% LINERs. Star formation rate (SFR) measured through extinction corrected H$\alpha$ fluxes increases with stellar mass ($\mathrm{M}_{*}$), attaining its peak at $\mathrm{M}_{*}\sim10^{9.8}\mathrm{M}_\odot$. We observed that the cluster centre to $\sim$1.3Mpc is devoid of SF galaxies and AGN. Our results suggest that the star formation efficiency declines as the local density increases in the cluster medium. Moreover, the SF and AGN fractions drop sharply towards high-density environments. We observed a strong decline in SF fraction in high $\mathrm{M}_*$, confirming that star formation is highly suppressed in high-mass cluster galaxies. Finally, we determined that SFR correlates with $\mathrm{M}_*$ while specific SFR (sSFR) anti-correlates with $\mathrm{M}_*$, both for cluster and field. This work shows the importance and strength of TF observations when studying ELGs in clusters at higher redshifts. We provide with this paper a catalogue of ELGs with H$\beta$ and/or [OIII] lines in ZwCl0024+1652 cluster., Comment: Accepted for publication in MNRAS main journal, 22 pages, 21 figures

The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) will soon start to scan thousands of square degrees of the northern extragalactic sky with a unique set of $56$ optical filters from a dedicated $2.55$m telescope, JST, at the Javalambre Astrophysical Observatory. Before the arrival of the final instrument (a 1.2 Gpixels, 4.2deg$^2$ field-of-view camera), the JST was equipped with an interim camera (JPAS-Pathfinder), composed of one CCD with a 0.3deg$^2$ field-of-view and resolution of 0.23 arcsec pixel$^{-1}$. To demonstrate the scientific potential of J-PAS, with the JPAS-Pathfinder camera we carried out a survey on the AEGIS field (along the Extended Groth Strip), dubbed miniJPAS. We observed a total of $\sim 1$ deg$^2$, with the $56$ J-PAS filters, which include $54$ narrow band (NB, $\rm{FWHM} \sim 145$Angstrom) and two broader filters extending to the UV and the near-infrared, complemented by the $u,g,r,i$ SDSS broad band (BB) filters. In this paper we present the miniJPAS data set, the details of the catalogues and data access, and illustrate the scientific potential of our multi-band data. The data surpass the target depths originally planned for J-PAS, reaching $\rm{mag}_{\rm {AB}}$ between $\sim 22$ and $23.5$ for the NB filters and up to $24$ for the BB filters ($5\sigma$ in a $3$~arcsec aperture). The miniJPAS primary catalogue contains more than $64,000$ sources extracted in the $r$ detection band with forced photometry in all other bands. We estimate the catalogue to be complete up to $r=23.6$ for point-like sources and up to $r=22.7$ for extended sources. Photometric redshifts reach subpercent precision for all sources up to $r=22.5$, and a precision of $\sim 0.3$% for about half of the sample. (Abridged), Comment: The miniJPAS data and associated value added catalogues are publicly accessible via this url: http://archive.cefca.es/catalogues/minijpas-pdr201912

Context. The accurate classification of hundreds of thousands of galaxies observed in modern deep surveys is imperative if we want to understand the universe and its evolution. Aims. Here, we report the use of machine learning techniques to classify early- and late-type galaxies in the OTELO and COSMOS databases using optical and infrared photometry and available shape parameters: either the Sersic index or the concentration index. Methods. We used three classification methods for the OTELO database: 1) u-r color separation , 2) linear discriminant analysis using u-r and a shape parameter classification, and 3) a deep neural network using the r magnitude, several colors, and a shape parameter. We analyzed the performance of each method by sample bootstrapping and tested the performance of our neural network architecture using COSMOS data. Results. The accuracy achieved by the deep neural network is greater than that of the other classification methods, and it can also operate with missing data. Our neural network architecture is able to classify both OTELO and COSMOS datasets regardless of small differences in the photometric bands used in each catalog. Conclusions. In this study we show that the use of deep neural networks is a robust method to mine the cataloged data, Comment: 20 pages, 10 tables, 14 figures, Astronomy and Astrophysics (in press)

A sample of low-mass H$\alpha$ emission line sources (ELS) at $z\,\sim\,0.4$ was studied in the context of the mass-metallicty relation (MZR) and its possible evolution. We drew our sample from the OSIRIS Tunable Emission Line Object (OTELO) survey, which exploits the red tunable filter of OSIRIS at the Gran Telescopio Canarias to perform a blind narrow-band spectral scan in a selected field of the Extended Groth Strip. We were able to directly measure emission line fluxes and equivalent widths from the analysis of OTELO pseudo-spectra. This study aims to explore the MZR in the very low-mass regime. Our sample reaches stellar masses ($M_*$) as low as $10^{6.8}\,M_\odot$, where 63\% of the sample have $M_*\,<10^9\,M_\odot$. We also explore the relation of the star formation rate (SFR) and specific SFR (sSFR) with $M_*$ and gas-phase oxygen abundances, as well as the $M_*$-size relation and the morphological classification. The $M_*$ were estimated using synthetic rest-frame colours. Using an $\chi^2$ minimization method, we separated the contribution of \Nii$\lambda$6583 to the H$\alpha$ emission lines. Using the N2 index, we separated active galactic nuclei from star-forming galaxies (SFGs) and estimated the gas metallicity. We studied the morphology of the sampled galaxies qualitatively (visually) and quantitatively (automatically) using high-resolution data from the \textit{Hubble Space Telescope}-ACS. The physical size of the galaxies was derived from the morphological analysis using \texttt{GALAPAGOS2/GALFIT}, where we fit a single-S\'ersic 2D model to each source., Comment: 17 Pages, 14 Figures, Accepted in Astronomy & Astrophysics

The OTELO survey is a very deep, blind exploration of a selected region of the Extended Groth Strip and is designed for finding emission-line sources (ELSs). The survey design, observations, data reduction, astrometry, and photometry, as well as the correlation with ancillary data used to obtain a final catalogue, including photo-z estimates and a preliminary selection of ELS, were described in a previous contribution. Here, we aim to determine the main properties and luminosity function (LF) of the [O III] ELS sample of OTELO as a scientific demonstration of its capabilities, advantages, and complementarity with respect to other surveys. The selection and analysis procedures of ELS candidates obtained using tunable filter (TF) pseudo-spectra are described. We performed simulations in the parameter space of the survey to obtain emission-line detection probabilities. Relevant characteristics of [O III] emitters and the LF([O III]), including the main selection biases and uncertainties, are presented. A total of 184 sources were confirmed as [O III] emitters at a mean redshift z=0.83. The minimum detectable line flux and equivalent width (EW) in this ELS sample are $\sim$5 $\times$ 10$^{-19}$ erg s$^{-1}$ cm$^{2}$ and $\sim$6 \AA, respectively. We are able to constrain the faint-end slope ($\alpha = -1.03\pm0.08$) of the observed LF([O III]) at z=0.83. This LF reaches values that are approximately ten times lower than those from other surveys. The vast majority (84\%) of the morphologically classified [O III] ELSs are disc-like sources, and 87\% of this sample is comprised of galaxies with stellar masses of M$_\star$ $<$ 10$^{10}$ M$_{\odot}$., Comment: v1: 16 pages, 6 figures. Accepted in Astronomy \& Astrophysics. v2: Author added in metadata

We take advantage of the capabilities of the OTELO survey to select and study the AGN population in the field. We performed an analysis of the properties of these objects, including their demography, morphology, and IR luminosity. Focusing on the population of H$\alpha$ emitters at $z \sim 0.4$, we also aim to study the environments of AGN and non-AGN galaxies at that redshift. We make use of the multiwavelength catalog of objects in the field compiled by the OTELO survey, unique in terms of minimum line flux and equivalent width. The OTELO pseudo-spectra allow the identification of emission lines and the spectral classification of the sources. We obtained a sample of 72 AGNs in the field of OTELO, selected with four different methods in the optical, X-rays, and mid-infrared bands. We find that using X-rays is the most efficient way to select AGNs. An analysis was performed on the AGN population of OTELO in order to characterize its members. At $z \sim 0.4$, we find that up to 26\% of our H$\alpha$ emitters are AGNs. At that redshift, AGNs are found in identical environments to non-AGNs, although they represent the most clustered group when compared to passive and star-forming galaxies. The majority of our AGNs at any redshift were classified as late-type galaxies, including a 16\% proportion of irregulars. Another 16\% of AGNs show signs of interactions or mergers. Regarding the infrared luminosity, we are able to recover all the luminous infrared galaxies (LIRGs) in the field of OTELO up to $z\sim 1.6$. We find that the proportion of LIRGs and ultra-luminous infrared galaxies (ULIRGs) is higher among the AGN population, and that ULIRGs show a higher fraction of AGNs than LIRGs., Comment: 31 pages, 32 figures. Published in Astronomy \& Astrophysics

We take advantage of the capability of the OTELO survey to obtain the H$\alpha$ luminosity function (LF) at ${\rm z}\sim0.40$. Because of the deepest coverage of OTELO, we are able to determine the faint end of the LF, and thus better constrain the star formation rate and the number of galaxies at low luminosities. The AGN contribution to this LF is estimated as well. We make use of the multi-wavelength catalogue of objects in the field compiled by the OTELO survey, which is unique in terms of minimum flux and equivalent width. We also take advantage of the pseudo-spectra built for each source, which allow the identification of emission lines and the discrimination of different types of objects. The H$\alpha$ luminosity function at $z\sim0.40$ is obtained, which extends the current faint end by almost 1 dex, reaching minimal luminosities of $\log_{10}L_{\rm lim}=38.5$ erg s$^{-1}$ (or $\sim0.002\, \text{M}_\odot\text{ yr}^{-1})$. The AGN contribution to the total H$\alpha$ luminosity is estimated. We find that no AGN should be expected below a luminosity of $\log_{10}L=38.6$ erg s$^{-1}$. From the sample of non-AGN (presumably, pure SFG) at $z\sim0.40$ we estimated a star formation rate density of $\rho_{\rm SFR}=0.012\pm0.005\ {\rm \text{M}_{\odot}\ yr^{-1}\ Mpc^{-3}}$., Comment: 8 pages, 5 figures. Published in Astronomy \& Astrophysics

The evolution of galaxies through cosmic time is studied observationally by means of extragalactic surveys. The OTELO survey aims to provide the deepest narrow-band survey to date in terms of minimum detectable flux and emission line equivalent width in order to detect the faintest extragalactic emission line systems. In this way, OTELO data will complements other broad-band, narrow-band, and spectroscopic surveys. The red tunable filter of the OSIRIS instrument on the 10.4 m Gran Telescopio Canarias (GTC) is used to scan a spectral window centred at $9175 \AA$, which is free from strong sky emission lines, with a sampling interval of $6 \AA$ and a bandwidth of $12 \AA$ in the most deeply explored Extended Groth Strip region. Careful data reduction using improved techniques for sky ring subtraction, accurate astrometry, photometric calibration, and source extraction enables us to compile the OTELO catalogue. This catalogue is complemented with ancillary data ranging from deep X-ray to far-infrared, including high resolution HST images, which allow us to segregate the different types of targets, derive precise photometric redshifts, and obtain the morphological classification of the extragalactic objects detected. The OTELO multi-wavelength catalogue contains 11237 entries and is 50\% complete at AB magnitude 26.38. Of these sources, 6600 have photometric redshifts with an uncertainty $z_{phot}$ better than $0.2 (1+z_{phot})$. A total of 4336 of these sources correspond to preliminary emission line candidates, which are complemented by 81 candidate stars and 483 sources that qualify as absorption line systems. The OTELO survey products were released to the public on 2019., Comment: v1: 29 pages, 29 figures. Published in Astronomy \& Astrophysics. v2: author's affiliation and final statement in Abstract updated

Given a symmetric polynomial $P$ in $2n$ variables, there exists a unique symmetric polynomial $Q$ in $n$ variables such that \[ P(x_1,\ldots,x_n,x_1^{-1},\ldots,x_n^{-1}) =Q(x_1+x_1^{-1},\ldots,x_n+x_n^{-1}). \] We denote this polynomial $Q$ by $\Phi_n(P)$ and show that $\Phi_n$ is an epimorphism of algebras. We compute $\Phi_n(P)$ for several families of symmetric polynomials $P$: symplectic and orthogonal Schur polynomials, elementary symmetric polynomials, complete homogeneous polynomials, and power sums. Some of these formulas were already found by Elouafi (2014) and Lachaud (2016). The polynomials of the form $\Phi_n(\operatorname{s}_{\lambda/\mu}^{(2n)})$, where $\operatorname{s}_{\lambda/\mu}^{(2n)}$ is a skew Schur polynomial in $2n$ variables, arise naturally in the study of the minors of symmetric banded Toeplitz matrices, when the generating symbol is a palindromic Laurent polynomial, and its roots can be written as $x_1,\ldots,x_n,x^{-1}_1,\ldots,x^{-1}_n$. Trench (1987) and Elouafi (2014) found efficient formulas for the determinants of symmetric banded Toeplitz matrices. We show that these formulas are equivalent to the result of Ciucu and Krattenthaler (2009) about the factorization of the characters of classical groups., Comment: 38 pages

J-PLUS is an ongoing 12-band photometric optical survey, observing thousands of square degrees of the Northern hemisphere from the dedicated JAST/T80 telescope at the Observatorio Astrof\'isico de Javalambre. T80Cam is a 2 sq.deg field-of-view camera mounted on this 83cm-diameter telescope, and is equipped with a unique system of filters spanning the entire optical range. This filter system is a combination of broad, medium and narrow-band filters, optimally designed to extract the rest-frame spectral features (the 3700-4000\AA\ Balmer break region, H$\delta$, Ca H+K, the G-band, the Mgb and Ca triplets) that are key to both characterize stellar types and to deliver a low-resolution photo-spectrum for each pixel of the sky observed. With a typical depth of AB $\sim 21.25$ mag per band, this filter set thus allows for an indiscriminate and accurate characterization of the stellar population in our Galaxy, it provides an unprecedented 2D photo-spectral information for all resolved galaxies in the local universe, as well as accurate photo-z estimates ($\Delta\,z\sim 0.01-0.03$) for moderately bright (up to $r\sim 20$ mag) extragalactic sources. While some narrow band filters are designed for the study of particular emission features ([OII]/$\lambda$3727, H$\alpha$/$\lambda$6563) up to $z < 0.015$, they also provide well-defined windows for the analysis of other emission lines at higher redshifts. As a result, J-PLUS has the potential to contribute to a wide range of fields in Astrophysics, both in the nearby universe (Milky Way, 2D IFU-like studies, stellar populations of nearby and moderate redshift galaxies, clusters of galaxies) and at high redshifts (ELGs at $z\approx 0.77, 2.2$ and $4.4$, QSOs, etc). With this paper, we release $\sim 36$ sq.deg of J-PLUS data, containing about $1.5\times 10^5$ stars and $10^5$ galaxies at $r<21$ mag., Comment: Submitted to A&A

We present the results of a multi-wavelength study of a sample of high-redshift Radio Loud (RL) Broad Absorption Line (BAL) quasars. This way we extend to higher redshift previous studies on the radio properties, and broadband optical colors of these objects. We have se- lected a sample of 22 RL BAL quasars with 3.6 z 4.8 cross-correlating the FIRST radio survey with the SDSS. Flux densities between 1.25 and 9.5 GHz have been collected with the JVLA and Effelsberg-100m telescopes for 15 BAL and 14 non-BAL quasars used as compar- ison sample. We determine the synchrotron peak frequency, constraining their age. A large number of GigaHertz Peaked Spectrum (GPS) and High Frequency Peakers (HFP) sources has been found in both samples (80% for BAL and 71% for non-BAL QSOs), not suggesting a younger age for BAL quasars. The spectral index distribution provides information about the orientation of these sources, and we find statistically similar distributions for the BAL and non-BAL quasars in contrast to work done on lower redshift samples. Our sample may be too small to convincingly find the same effect, or might represent a real evolutionary effect based on the large fraction of young sources. We also study the properties of broadband colors in both optical (SDSS) and near- and mid-infrared (UKIDSS and WISE) bands, finding that also at high redshift BAL quasars tend to be optically redder than non-BAL quasars. However, these differences are no more evident at longer wavelength, when comparing colors of the two samples by mean of the WISE survey., Comment: Accepted for publication on MNRAS, 2017 February 6. 14 pages, 10 figures

Microvariability (intra-night variability) is a low amplitude flux change at short time scales (i.e. hours). It has been detected in unobscured type 1 AGNs and blazars. However in type 2 AGNs, the detection is hampered by the low contrast between the presumably variable nucleus and the host galaxy. In this paper, we present a search for microvariability in a sample of four type 2 quasars as an astrostatistical problem. We are exploring the use of a newly introduced enhanced F-test, proposed by de Diego 2014. The presented results show that out of our four observed targets, we were able to apply this statistical method to three of them. Evidence of microvariations is clear in the case of quasar J0802+2552 in all used filters (g',r' and i') during both observing nights, the microvariations are present in one of the nights of observations of J1258+5239 in one filter (i'), while for the J1316+4452, there is evidence for microvariability within our detection levels during one night and two filters (r' and i'). We demonstrate the feasibility of the enhanced F-test to detect microvariability in obscured type 2 quasars. At the end of this paper, we discuss possible causes of microvariability. One of the options is the misclassification of the targets. A likely scenario for explanation of the phenomenon involves optically thin gaps in a clumpy obscuring medium, in accordance with the present view of the circumnuclear region. There is a possible interesting connection between the merging state of the targets and detection of microvariability., Comment: 11 pages, 8 figures, accepted to MNRAS

Broad absorption line quasars are among the objects presenting the fastest outflows. The launching mechanism itself is not completely understood. Models in which they could be launched from the accretion disk, and then curved and accelerated by the effect of the radiation pressure, have been presented. We conducted an extensive observational campaign, from radio to optical band, to collect information about their nature and test the models present in the literature, the main dichotomy being between a young scenario and an orientation one. We found a variety of possible orientations, morphologies, and radio ages, not converging to a particular explanation for the BAL phenomenon. From our latest observations in the m- and mm-band, we obtained an indication of a lower dust abundance with respect to normal quasars, thus suggesting a possible feedback process on the host galaxy. Also, in the low-frequency regime we confirmed the presence of CSS components, sometime in conjunction with a GPS one already detected at higher frequencies. Following this, about 70% of our sample turns out to be in a GPS or CSS+GPS phase. We conclude that fast outflows, responsible for the BAL features, can be more easily present among objects going through a restarting or just-started radio phase, where radiation pressure can substantially contribute to their acceleration., Comment: accepted for publication on AN

Broad absorption line quasars (BAL QSOs) are objects showing absorption from relativistic outflows, with velocities up to 0.2c. These manifest, in about 15% of quasars, as absorption troughs on the blue side of UV emission lines, such as C iv and Mg ii. In this work, we complement the information collected in the cm band for our previously presented sample of radio loud BAL QSOs with new observations at m and mm bands. Our aim is to verify the presence of old, extended radio components in the MHz range, and probe the emission of dust (linked to star formation) in the mm domain. We observed 5 sources from our sample, already presenting hints of low-frequency emission, with the GMRT at 235 and 610 MHz. Other 17 sources (more than half the sample) were observed with bolometer cameras at IRAM-30m and APEX. All sources observed with the GMRT present extended emission at a scale of tens of kpc. In some cases these measurements allow us to identify a second component in the SED, at frequencies below 1.4 GHz, beyond the one already studied in the GHz domain. In the mm-band, only one source shows emission clearly ascribable to dust. Upper limits were obtained for the remaining targets. These findings confirm that BAL QSOs can also be present in old radio sources, or even in restarting ones, where favourable conditions for the outflow launching/acceleration are present. A suggestion that these outflows could be precursors of the jet comes from the fact that ~70% of our sample can be considered in a GigaHertz Peaked Spectrum (GPS) or Compact Steep Spectrum (CSS)+GPS phase. This would confirm the idea proposed by other authors that these outflows could be recollimated to form the jet. Comparing with previous works in the literature, dust emission seems to be weaker than the what expected in 'normal' QSOs, suggesting that a feedback mechanism could inhibit star formation in radio-loud BAL QSOs., Comment: Accepted for publication in A&A

The Square Kilometre Array (SKA) is called to revolutionise essentially all areas of Astrophysics. With a collecting area of about a square kilometre, the SKA will be a transformational instrument, and its scientific potential will go beyond the interests of astronomers. Its technological challenges and huge cost requires a multinational effort, and Europe has recognised this by putting the SKA on the roadmap of the European Strategy Forum for Research Infrastructures (ESFRI). The Spanish SKA White Book is the result of the coordinated effort of 120 astronomers from 40 different research centers. The book shows the enormous scientific interest of the Spanish astronomical community in the SKA and warrants an optimum scientific exploitation of the SKA by Spanish researchers, if Spain enters the SKA project., Comment: Editors: Miguel A. Perez-Torres (Editor-in-chief), L. Verdes-Montenegro, J. C. Guirado, A. Alberdi, J. Martin-Pintado, R. Bachiller, D. Herranz, J. M. Girart, J. Gorgas, C. Hernandez-Monteagudo, S. Migliari and J. M. Rodriguez Espinosa; 289 pages, published in June 2015 by Sociedad Espa\~nola de Astronom\'ia

Fast brightness variations are a unique tool to probe the innermost regions of active galactic nuclei (AGN). These variations are called microvariability or intra-night variability, and this phenomenon has been monitored in samples of blazars and unobscured AGNs. Detecting optical microvariations in targets hidden by the obscuring torus is a challenging task because the region responsible for the variations is hidden from our sight. However, there have been reports of fast variations in obscured Seyfert galaxies in X-rays, which rises the question whether microvariations can also be detected in obscured AGNs in the optical regime. Because the expected variations are very small and can easily be lost within the noise, the analysis requires a statistical approach. We report the use of a one-way analysis of variance, ANOVA, with which we searched for microvariability. ANOVA was successfully employed in previous studies of unobscured AGNs. As a result, we found microvariable events during three observing blocks: in two we observed the same object (Mrk 477), and in another, J0759+5050. The results on Mrk 477 confirm previous findings. However, since Mrk 477 is quite a peculiar target with hidden broad-line regions, we cannot rule out the possibility that we have serendipitously chosen a target prone to variations., Comment: Research note, 5 pages, 2 figures, accepted for publication in Astronomy and Astrophysics

The cores of clusters at 0 $\lesssim$ z $\lesssim$ 1 are dominated by quiescent early-type galaxies, whereas the field is dominated by star-forming late-type ones. Galaxy properties, notably the star formation (SF) ability, are altered as they fall into overdense regions. The critical issues to understand this evolution are how the truncation of SF is connected to the morphological transformation and the responsible physical mechanism. The GaLAxy Cluster Evolution Survey (GLACE) is conducting a study on the variation of galaxy properties (SF, AGN, morphology) as a function of environment in a representative sample of clusters. A deep survey of emission line galaxies (ELG) is being performed, mapping a set of optical lines ([OII], [OIII], H$\beta$ and H$\alpha$/[NII]) in several clusters at z $\sim$ 0.40, 0.63 and 0.86. Using the Tunable Filters (TF) of OSIRIS/GTC, GLACE applies the technique of TF tomography: for each line, a set of images at different wavelengths are taken through the TF, to cover a rest frame velocity range of several thousands km/s. The first GLACE results target the H$\alpha$/[NII] lines in the cluster ZwCl 0024.0+1652 at z = 0.395 covering $\sim$ 2 $\times$ r$_{vir}$. We discuss the techniques devised to process the TF tomography observations to generate the catalogue of H$\alpha$ emitters of 174 unique cluster sources down to a SFR below 1 M$_{\odot}$/yr. The AGN population is discriminated using different diagnostics and found to be $\sim$ 37% of the ELG population. The median SFR is 1.4 M$_{\odot}$/yr. We have studied the spatial distribution of ELG, confirming the existence of two components in the redshift space. Finally, we have exploited the outstanding spectral resolution of the TF to estimate the cluster mass from ELG dynamics, finding M$_{200}$ = 4.1 $\times$ 10$^{14}$ M$_{\odot} h^{-1}$, in agreement with previous weak-lensing estimates., Comment: 23 pages, 13 figures, accepted for publication in A&A. Astro-ph abstract abridged

We obtain a sample of 87 radio-loud QSOs in the redshift range 3.6 1 mJy with star-like objects having r <20.2 in SDSS Data Release 7. Of these 87 QSOs, 80 are spectroscopically classified in previous work (mainly SDSS), and form the training set for a search for additional such sources. We apply our selection to 2,916 FIRST-DR7 pairs and find 15 likely candidates. Seven of these are confirmed as high-redshift quasars, bringing the total to 87. The candidates were selected using a neural-network, which yields 97% completeness (fraction of actual high-z QSOs selected as such) and an efficiency (fraction of candidates which are high-z QSOs) in the range of 47 to 60%. We use this sample to estimate the binned optical luminosity function of radio-loud QSOs at $z\sim 4$, and also the LF of the total QSO population and its comoving density. Our results suggest that the radio-loud fraction (RLF) at high z is similar to that at low-z and that other authors may be underestimating the fraction at high-z. Finally, we determine the slope of the optical luminosity function and obtain results consistent with previous studies of radio-loud QSOs and of the whole population of QSOs. The evolution of the luminosity function with redshift was for many years interpreted as a flattening of the bright end slope, but has recently been re-interpreted as strong evolution of the break luminosity for high-z QSOs, and our results, for the radio-loud population, are consistent with this., Comment: 20 pages. Accepted for publication in MNRAS on 3 March 2015

OTELO is an emission-line object survey carried out with the red tunable filter of the instrument OSIRIS at the GTC, whose aim is to become the deepest emission-line object survey to date. With 100% of the data of the first pointing finally obtained in June 2014, we present here some aspects of the processing of the data and the very first results of the OTELO survey. We also explain the next steps to be followed in the near future., Comment: Oral contribution presented in the XI Scientific Meeting of the Spanish Astronomical Society held on September 8-12, in Teruel, Spain (7 pages, 2 figures, 1 table). To appear in Highlights of Spanish Astrophysics VIII, Proceedings of the XI Scientific Meeting of the Spanish Astronomical Society. Eds. A. J. Cenarro, F. Figueras, C. Hern\'andez-Monteagudo, J. Trujillo, L. Valdivielso

Broad absorption lines (BALs) are present in the spectra of ~20% of quasars (QSOs); this indicates fast outflows (up to 0.2c) that intercept the observer's line of sight. These QSOs can be distinguished again into radio-loud (RL) BAL QSOs and radio-quiet (RQ) BAL QSOs. The first are very rare, even four times less common than RQ BAL QSOs. The reason for this is still unclear and leaves open questions about the nature of the BAL-producing outflows and their connection with the radio jet. We explored the spectroscopic characteristics of RL and RQ BAL QSOs with the aim to find a possible explanation for the rarity of RL BAL QSOs. We identified two samples of genuine BAL QSOs from SDSS optical spectra, one RL and one RQ, in a suitable redshift interval (2.5$

Tunable filters are a powerful way of implementing narrow-band imaging mode over wide wavelength ranges, without the need of purchasing a large number of narrow-band filters covering all strong emission or absorption lines at any redshift. However, one of its main features is a wavelength variation across the field of view, sometimes termed the phase effect. In this work, an anomalous phase effect is reported and characterized for the OSIRIS instrument at the 10.4m Gran Telescopio Canarias. The transmitted wavelength across the field of view of the instrument depends, not only on the distance to the optical centre, but on wavelength. This effect is calibrated for the red tunable filter of OSIRIS by measuring both normal-incidence light at laboratory and spectral lamps at the telescope at non-normal incidence. This effect can be explained by taking into account the inner coatings of the etalon. In a high spectral resolution etalon, the gap between plates is much larger than the thickness of the inner reflective coatings. In the case of a tunable filter, like that in OSIRIS, the coatings thickness could be of the order of the cavity, which changes drastically the effective gap of the etalon. We show that by including thick and dispersive coatings into the interference equations, the observed anomalous phase effect can be perfectly reproduced. In fact, we find that, for the OSIRIS red TF, a two-coatings model fits the data with a rms of 0.5\AA\ at all wavelengths and incidence angles. This is a general physical model that can be applied to other tunable-filter instruments., Comment: Accepted for publication in MNRAS (June 30th, 2014); 15 pages; 16 figures

The Javalambre-Physics of the Accelerated Universe Astrophysical Survey (J-PAS) is a narrow band, very wide field Cosmological Survey to be carried out from the Javalambre Observatory in Spain with a purpose-built, dedicated 2.5m telescope and a 4.7 sq.deg. camera with 1.2Gpix. Starting in late 2015, J-PAS will observe 8500sq.deg. of Northern Sky and measure $0.003(1+z)$ photo-z for $9\times10^7$ LRG and ELG galaxies plus several million QSOs, sampling an effective volume of $\sim 14$ Gpc$^3$ up to $z=1.3$ and becoming the first radial BAO experiment to reach Stage IV. J-PAS will detect $7\times 10^5$ galaxy clusters and groups, setting constrains on Dark Energy which rival those obtained from its BAO measurements. Thanks to the superb characteristics of the site (seeing ~0.7 arcsec), J-PAS is expected to obtain a deep, sub-arcsec image of the Northern sky, which combined with its unique photo-z precision will produce one of the most powerful cosmological lensing surveys before the arrival of Euclid. J-PAS unprecedented spectral time domain information will enable a self-contained SN survey that, without the need for external spectroscopic follow-up, will detect, classify and measure $\sigma_z\sim 0.5\%$ redshifts for $\sim 4000$ SNeIa and $\sim 900$ core-collapse SNe. The key to the J-PAS potential is its innovative approach: a contiguous system of 54 filters with $145\AA$ width, placed $100\AA$ apart over a multi-degree FoV is a powerful "redshift machine", with the survey speed of a 4000 multiplexing low resolution spectrograph, but many times cheaper and much faster to build. The J-PAS camera is equivalent to a 4.7 sq.deg. "IFU" and it will produce a time-resolved, 3D image of the Northern Sky with a very wide range of Astrophysical applications in Galaxy Evolution, the nearby Universe and the study of resolved stellar populations., Comment: 215 pages, 70 figures. J-PAS "Red Book", containing a description of the technical aspects of the Survey and its main scientific goals