Examinando por Autor "Nadolny, J."

Mostrando 1 - 12 de 12

Acceso Abierto
A morphological study of galaxies in ZwCl0024+1652, a galaxy cluster at redshift z ∼ 0.4
(Oxford Academics: Oxford University Press, 2019-02-11) Beyoro Amado, Z.; Povic, M.; Sánchez Portal, M.; Tessema, S. B.; Bongiovanni, Á.; Cepa, J.; Cerviño, M.; González Serrano, J. I.; Nadolny, J.; Pérez García, A. M.; Pérez Martínez, R.; Pintos Castro, I.; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Bongiovanni, Á. [0000-0002-3557-3234]; Povic, M. [0000-0002-9766-6110]; Pérez García, A. M. [0000-0003-1634-3588]; Pérez Martínez, R. [0000-0002-9127-5522]; Pintos Castro, I. [0000-0002-9133-4457]; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFISICA DE ANDALUCIA (IAA), SEV-2017-0709; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
The well-known cluster of galaxies ZwCl0024+1652 at z ∼ 0.4 lacks an in-depth morphological classification of its central region. While previous studies provide a visual classification of a patched area, we used the public code called galaxy Support Vector Machine (GALSVM) and HST/ACS data as well as the WFP2 master catalogue to automatically classify all cluster members up to 1 Mpc. GALSVM analyses galaxy morphologies through support vector machine (SVM). From the 231 cluster galaxies, we classified 97 as early types (ETs) and 83 as late types (LTs). The remaining 51 stayed unclassified (or undecided). By cross-matching our results with the existing visual classification, we found an agreement of 81 per cent. In addition to previous Zwcl0024 morphological classifications, 121 of our galaxies were classified for the first time in this work. In addition, we tested the location of classified galaxies on the standard morphological diagrams, colour–colour and colour–magnitude diagrams. Out of all cluster members, ∼20 per cent are emission-line galaxies, taking into account previous GLACE results. We have verified that the ET fraction is slightly higher near the cluster core and decreases with the clustercentric distance, while the opposite trend has been observed for LT galaxies. We found a higher fraction of ETs (54 per cent) than LTs (46 per cent) throughout the analysed central region, as expected. In addition, we analysed the correlation between the five morphological parameters (Abraham concentration, Bershady–Concelice concentration, asymmetry, Gini, and M20 moment of light) and the clustercentric distance, without finding a clear trend. Finally, as a result of our work, the morphological catalogue of 231 galaxies containing all the measured parameters and the final classification is available in the electronic form of this paper.
Acceso Abierto
Galaxy classification: Deep learning on the OTELO and COSMOS databases
(EDP Sciences, 2020-06-25) De Diego, J. A.; Nadolny, J.; Bongiovanni, Á.; Cepa, J.; Povic, M.; Pérez García, A. M.; Padilla Torres, C. P.; Lara López, M. A.; Cerviño, M.; Pérez Martínez, R.; Alfaro, Emilio J.; Castañeda, H. O.; Fernández Lorenzo, M.; Gallego, J.; González, J. J.; González Serrano, J. I.; Pintos Castro, I.; Sánchez Portal, M.; Cedrés, B.; González Otero, M.; Jones, D. Heath; Bland Hawthorn, J.; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); De Diego, J. A. https://orcid.org/0000-0001-7040-069X; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFISICA DE ANDALUCIA (IAA), SEV-2017-0709; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
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.
Restringido
GLACE survey: Galaxy activity in ZwCl0024+1652 cluster from strong optical emission lines
(Oxford Academics: Oxford University Press, 2021-01-16) Beyoro Amado, Z.; Sánchez Portal, M.; Bongiovanni, Á.; Povic, M.; Tessema, S. B.; Pérez Martínez, R.; Pérez García, A. M.; Cerviño, M.; Nadolny, J.; Cepa, J.; González Serrano, J. I.; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Ethiopian Space Science and Technology Institute (ESSTI); Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFISICA DE ANDALUCIA (IAA), SEV-2017-0709; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Although ZwCl0024+1652 galaxy cluster at z ∼ 0.4 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 Hα emissionline galaxies (ELGs) were detected, most of them having [N II]. We reduced and analysed a set of [O III] andHβ tunable filter (TF) observations within GLACE survey. Using Hα priors, we identified [O III] and Hβ in 35 (∼20 per cent) and 59 (∼34 per cent) 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 per cent star-forming (SF), 55 per cent composites, and 5 per cent LINERs. Star formation rate (SFR) measured through extinction corrected Hα fluxes increases with stellar mass (M∗), attaining its peak at M∗ ∼ 109.8M⊙. We observed that the cluster centre to ∼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 M., confirming that star formation is highly suppressed in high-mass cluster galaxies. Finally, we determined that SFR correlates with M. while specific SFR (sSFR) anticorrelates with 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 Hβ and/or [O III] lines in ZwCl0024+1652 cluster.
Acceso Abierto
MaNGA galaxies with off-centered spots of enhanced gas velocity dispersion
(EDP Sciences, 2021-09-01) Pilyugin, L. S.; Cedrés, B.; Zinchenko, I. A.; Pérez García, A. M.; Lara López, M. A.; Nadolny, J.; Nefedyev, Y. A.; González Otero, M.; Vílchez, J. M.; Duarte Puertas, S.; Navarro Martínez, R.; Agencia Estatal de Investigación (AEI); National Academy of Sciences of Ukraine (NASU); Junta de Andalucía; Russian Science Foundation (RSF); Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFISICA DE ANDALUCIA (IAA), SEV-2017-0709
Off-centered spots of the enhanced gas velocity dispersion, σ, are revealed in some galaxies from the Mapping Nearby Galaxies at Apache Point Observatory survey (MaNGA). Aiming to clarify the origin of the spots of enhanced σ, we examine the distributions of the surface brightness, the line-of-sight velocity, the oxygen abundance, the gas velocity dispersion, and the Baldwin-Phillips-Terlevich spaxel classification in seven galaxies. We find that the enhanced σ spots in six galaxies can be attributed to a (minor) interaction with a satellite. Three galaxies in our sample have a very close satellite (the separation in the sky plane is comparable to the optical radius of the galaxy). The spots of enhanced σ in those galaxies are located at the edge of the galaxy close to the satellite. The spots of enhanced σ in three other galaxies are related to bright spots in the photometric B band within the galaxy, which can be due to the projection of a satellite in the line of sight of the galaxy. The oxygen abundances in the spots in these three galaxies are reduced. This suggests that the low-metallicity gas from the satellite is mixed with the interstellar medium of the disk, that is, the gas exchange between the galaxy and its satellite takes place. The spectra of the spaxels within a spot are usually H II-region-like, suggesting that the interaction (gas infall) in those galaxies does not result in appreciable shocks. In contrast, the spot of the enhanced σ in the galaxy M-8716-12703 is associated with an off-centered active galactic nucleus-like radiation distribution. One can suggest that the spot of the enhanced σ in the M-8716-12703 galaxy is different in origin, or that the characteristics of gas infall in this case differs from that in other galaxies.
Acceso Abierto
The OTELO survey as a morphological probe. Last ten Gyr of galaxy evolution The mass–size relation up to z = 2
(EDP Sciences, 2021-03-12) Nadolny, J.; Bongiovanni, Á.; Cepa, J.; Cerviño, M.; Pérez García, A. M.; Povic, M.; Pérez Martínez, M.; De Diego, J. A.; Pintos Castro, I.; Alfaro, Emilio J.; Castañeda, H. O.; Gallego, J.; González, J. J.; González Serrano, J. I.; Lara López, M. A.; Padilla Torres, C. P.; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); National Research Council (NRC); Ethiopian Space Science and Technology Institute (ESSTI); Nadolny, J. [0000-0003-1440-9061]; Centro de Excelencia Científica Severo Ochoa Instituto de Astrofísica de Andalucía CSIC, SEV-2017-0709; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Context. 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. Aims. 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 8000 sources. Methods. The morphological analysis is based on the single-Sérsic 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 GALFIT-M, and provides the best-fitting single-Sérsic 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. Results. A total of 8812 sources were successfully fitted with single-Sérsic profiles. The analysis of a carefully selected sample of ∼3000 sources up to zphot = 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. Compared to previous works on faint field galaxies, we found similarities regarding their rest-frame colours as well as the Sérsic and concentration indices.
Acceso Abierto
The OTELO survey as a morphological probe. Last ten Gyr of galaxy evolution The mass–size relation up to z = 2
(EDP Sciences, 2021-03-12) Nadolny, J.; Bongiovanni, Á.; Cepa, J.; Cerviño, M.; Pérez García, A. M.; Povic, M.; Pérez Martínez, R.; Sánchez Portal, M.; De Diego, J. A.; Pintos Castro, I.; Alfaro, Emilio J.; Castañeda, H. O.; Gallego, J.; González, J. J.; González Serrano, J. I.; Lara López, M. A.; Padilla Torres, P.; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Centre National de la Recherche Scientifique (CNRS); National Research Council (NRC); Ethiopian Space Science and Technology Institute (ESSTI); Nadolny, J. [0000-0003-1440-9061]; Pérez Martínez, R. [0000-0002-9127-5522]; González, J. J. [0000-0002-3724-1583]; Povic, M. [0000-0002-9766-6110]; Centro de Excelencia Científica Severo Ochoa Instituto de Astrofísica de Andalucía CSIC, SEV-2017-0709; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Context. 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. Aims. 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 8000 sources. Methods. The morphological analysis is based on the single-Sérsic 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 GALFIT-M, and provides the best-fitting single-Sérsic 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. Results. A total of 8812 sources were successfully fitted with single-Sérsic profiles. The analysis of a carefully selected sample of ∼3000 sources up to zphot = 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. Compared to previous works on faint field galaxies, we found similarities regarding their rest-frame colours as well as the Sérsic and concentration indices.
Acceso Abierto
The OTELO survey Faint end of the luminosity function of [O II]3727 emitters at ⟨z⟩ = 1.43
(EDP Sciences, 2021-05-13) Cedrés, B.; Bongiovanni, Á.; Cerviño, M.; Nadolny, J.; Cepa, J.; De Diego, J. A.; Pérez García, A. M.; Gallego, J.; Lara López, M. A.; Sánchez Portal, M.; González Serrano, J. I.; Alfaro, E. J.; Navarro Martínez, R.; Pérez Martínez, R.; González, J. J.; Padilla Torres, C. P.; Castañeda, H. O.; González Otero, Mauro; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Agence Nationale de la Recherche (ANR); Pérez Martínez, R. [0000-0002-9127-5522]; Lara López, M. A. [0000-0001-7327-3489]; Cedrés, B. [0000-0002-7382-6407]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC (MDM-2017-0737)
Aims. In this paper, we aim to study the main properties and luminosity function (LF) of the [O II]3727 emitters detected in the OTELO survey in order to characterise the star formation processes in low-mass galaxies at z ∼ 1.43 and to constrain the faint-end of the LF. Methods. 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). Results. We confirmed a total of 60 sources from a preliminary list of 332 candidates as [O II]3727 emitters. Approximately 93% of the emitters have masses in the range of 108 < M*/M⊙ < 109. All of our emitters are classified as late-type galaxies, with a lower value of (u − v) when compared with the rest of the emitters of the OTELO survey. We find that the cosmic variance strongly affects the normalisation (ϕ*) of the LF and explains the discrepancy of our results when compared with those obtained from surveys of much larger volumes. However, we are able to determine the faint-end slope of the LF, namely, α = −1.42 ± 0.06, by sampling the LF down to ∼1 dex lower than in previous works. We present our calculation of the SFRD of our sample and compare it to the value obtained in previous studies from the literature.
Acceso Abierto
The OTELO survey I. Description, data reduction, and multi-wavelength catalogue
(EDP Sciences, 2019-10-14) Ramón Pérez, M.; Pérez García, A. M.; Cepa, J.; Cerviño, M.; Nadolny, J.; Pérez Martínez, R.; Alfaro, Emilio J.; Castañeda, H. O.; De Diego, J. A.; Ederoclite, A.; Fernández Lorenzo, M.; Gallego, J.; González, J. J.; González Serrano, J. I.; Lara López, M. A.; Oteo Gómez, I.; Padilla Torres, C. P.; Pintos Castro, I.; Povic, M.; Sánchez Portal, M.; Jones, H.; Bland Hawthorn, J.; Cabrera Lavers, A.; Bongiovanni, Á.; Agence Nationale de la Recherche (ANR); Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Bongiovanni, Á. [0000-0002-3557-3234]
Context. The evolution of galaxies through cosmic time is studied observationally by means of extragalactic surveys. The usefulness of these surveys is greatly improved by increasing the cosmological volume, in either depth or area, and by observing the same targets in different wavelength ranges. A multi-wavelength approach using different observational techniques can compensate for observational biases. Aims. 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. Methods. 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 Å, which is free from strong sky emission lines, with a sampling interval of 6 Å and a bandwidth of 12 Å in the most deeply explored EGS 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. Results. The OTELO multi-wavelength catalogue contains 11 237 entries and is 50% complete at AB magnitude 26.38. Of these sources, 6600 have photometric redshifts with an uncertainty δ zphot better than 0.2 (1+zphot). 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 results will be released to the public on the second half of 2019.
Acceso Abierto
The OTELO survey II. The faint-end of the Hα luminosity function at z ∼ 0.40
(EDP Sciences, 2019-10-14) Ramón Pérez, M.; Bongiovanni, Á.; Pérez García, A. M.; Cepa, J.; Lara López, M. A.; De Diego, J. A.; Alfaro, Emilio J.; Castañeda, H. O.; Cerviño, M.; Fernández Lorenzo, M.; Gallego, J.; González, J. J.; González Serrano, J. I.; Nadolny, J.; Oteo Gómez, I.; Pérez Martínez, R.; Pintos Castro, I.; Povic, M.; Sánchez Portal, M.; Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Aims. We take advantage of the capability of the OTELO survey to obtain the Hα luminosity function (LF) at z ∼ 0.40. 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. Methods. We make use of the multiwavelength 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. Results. The Hα luminosity function at z ∼ 0.40 is obtained, which extends the current faint end by almost 1 dex, reaching minimal luminosities of log10Llim = 38.5 erg s−1 (or ∼0.002 M⊙ yr−1). The AGN contribution to the total Hα luminosity is estimated. We find that no AGN should be expected below a luminosity of log10L = 38.6 erg s−1. From the sample of non-AGN (presumably, pure SFG) at z ∼ 0.40 we estimated a star formation rate density of ρSFR = 0.012 ± 0.005 M⊙ yr−1 Mpc−3.
Acceso Abierto
The OTELO survey III. Demography, morphology, IR luminosity and environment of AGN hosts
(EDP Sciences, 2019-10-14) Ramón Pérez, M.; Bongiovanni, Á.; Pérez García, A. M.; Cepa, J.; Nadolny, J.; Pintos Castro, I.; Lara López, M. A.; Alfaro, Emilio J.; Castañeda, H. O.; Cerviño, M.; De Diego, J. A.; Fernández Lorenzo, M.; Gallego, J.; González, J. J.; González Serrano, J. I.; Oteo Martínez, R.; Povic, M.; Sánchez Portal, M.; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFISICA DE ANDALUCIA (IAA), SEV-2017-0709
Aims. We take advantage of the capabilities of the OSIRIS Tunable Emission Line Object (OTELO) survey to select and study the AGN population in the field. In particular, we aim to perform an analysis of the properties of these objects, including their demography, morphology, and IR luminosity. Focusing on the population of Hα emitters at z ∼ 0.4, we also aim to study the environments of AGN and non-AGN galaxies at that redshift. methods. We make use of the multiwavelength catalogue of objects in the field compiled by the OTELO survey, 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. Results. 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 characterise its members. At z ∼ 0.4, we find that up to 26% of our Hα 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 ∼ 1.6. We find that the proportion of LIRGs and ultra-luminous infraed galaxies (ULIRGs) is higher among the AGN population, and that ULIRGs show a higher fraction of AGNs than LIRGs.
Acceso Abierto
The OTELO survey. Nature and mass-metallicity relation for Hα emitters at z ∼ 0.4
(EDP Sciences, 2020-04-24) Nadolny, J.; Lara López, M. A.; Cerviño, M.; Bongiovanni, Á.; Cepa, J.; De Diego, J. A.; Pérez García, A. M.; Pérez Martínez, R.; Sánchez Portal, M.; Alfaro, Emilio J.; Castañeda, H. O.; Gallego, J.; González, J. J.; González Serrano, J. I.; Padilla Torres, C. P.; Pintos Castro, I.; Povic, M.; Ministerio de Economía y Competitividad (MINECO); Universidad Nacional Autónoma de México (UNAM); Agencia Estatal de Investigación (AEI); 0000-0003-1634-3588; 0000-0002-9127-5522; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Context. The OSIRIS Tunable Filter Emission Line Object (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. Aims. 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. Methods. The selection and analysis procedures of ELS candidates obtained using tunable filter 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. Results. From 541 preliminary emission-line source candidates selected around z & x2004;=& x2004;0.8, a total of 184 sources were confirmed as [O III] emitters. Consistent with simulations, the minimum detectable line flux and equivalent width in this ELS sample are similar to 5 x 10(-19) erg s(-1) cm(2) and similar to 6 angstrom, respectively. We are able to constrain the faint-end slope (alpha & x2004;=& x2004;-1.03 +/- 0.08) of the observed LF ([O III]) at a mean redshift of z & x2004;=& x2004;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-& x22c6;& x2004;< & x2004;10(10) M-circle dot.
Acceso Abierto
The OTELO Survey: The Star Formation Rate Evolution of Low-mass Galaxies
(IOP Science Publishing, 2021-07-01) Cedrés, B.; Pérez García, A. M.; Pérez Martínez, R.; Cerviño, M.; Gallego, J.; Bongiovanni, Á.; Cepa, J.; Navarro Martínez, R.; Nadolny, J.; Lara López, M. A.; Agence Nationale de la Recherche (ANR); Cedrés, B. [0000-0002-7382-6407]; Gallego, J. [0000-0003-1439-7697]; Nadolny, J. [0000-0003-1440-9061]; Lara López, M. A. [0000-0001-7327-3489]
We present the analysis of a sample of Hα, Hβ, and [O ii] emission line galaxies from the OTELO survey, with masses typically below $\mathrm{log}({M}_{* }/{M}_{\odot })\sim 9.4$ and redshifts between z ∼ 0.4 and 1.43. We study the star formation rate, star formation rate density, and their number density and 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 (SFRD) 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 ∼ 1.4. 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 SFRD in the redshift range of 0.4 < z < 1.43.