Search

Your search keyword '"Viironen, Kerttu"' showing total 24 results
Start Over Author "Viironen, Kerttu" Search Limiters Full Text
24 results on '"Viironen, Kerttu"'

1. J-PLUS: Unveiling the brightest-end of the Ly{\alpha} luminosity function at 2.0<z<3.3 over 1000 deg^2

Author

Spinoso, Daniele, Orsi, Alvaro, López-Sanjuan, Carlos, Bonoli, Silvia, Viironen, Kerttu, Izquierdo-Villalba, David, Sobral, David, Gurung-López, Siddhartha, Hernán-Caballero, Antonio, Ederoclite, Alessandro, Varela, Jesús, Overzier, Roderik, Miralda-Escudé, Jordi, Muniesa, David J., Alcaniz, Jailson, Angulo, Raul E., Cenarro, A. Javier, Cristóbal-Hornillos, David, Dupke, Renato A., Hernández-Monteagudo, Carlos, Marín-Franch, Antonio, Moles, Mariano, Sodré Jr, Laerte, and Vázquez-Ramió, Héctor

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present the photometric determination of the bright-end (L_Lya>10^43.5 erg/s) of the Lya luminosity function (LF) within four redshifts windows in the interval 2.210^43.3 erg/s) Lya-emitting candidates. We test our selection with two spectroscopic follow-up programs at the GTC telescope, confirming ~89% of the targets as line-emitting sources, with ~64% being genuine z~2.2 QSOs. We extend the 2.22 AGN/QSOs (likely dominant in our samples) are described by a structurally different LF than z>2 star-forming LAEs, namely with L^*_QSOs ~ 100 L^*_LAEs and Phi^*_QSOs ~ 10^-3 Phi^*_LAEs. Finally, our method identifies very efficiently as high-z line-emitters sources without previous spectroscopic confirmation, currently classified as stars (~2000 objects in each redshift bin, on average). Assuming a large predominance of Lya-emitting AGN/QSOs in our samples, this supports the scenario by which these are the most abundant class of z>2 Lya emitters at L_Lya>10^43.3 erg/s., Comment: 27 pages (6 in appendix), 21 figures (5 in appendix), submitted to A&A

Published
2020
Full Text
View/download PDF

2. ELDAR, a new method to identify AGN in multi-filter surveys: the ALHAMBRA test-case

Author

Chaves-Montero, Jonás, Bonoli, Silvia, Salvato, Mara, Greisel, Natascha, Díaz-García, Luis A., López-Sanjuan, Carlos, Viironen, Kerttu, Fernández-Soto, Alberto, Pović, Mirjana, Ascaso, Begoña, Arnalte-Mur, Pablo, Masegosa, Josefa, Matute, Israel, Márquez, Isabel, Cenarro, A. Javier, Abramo, L. Raul, Ederoclite, Alessandro, and Alfaro, Emilio J.

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present ELDAR, a new method that exploits the potential of medium- and narrow-band filter surveys to securely identify active galactic nuclei (AGN) and determine their redshifts. Our methodology improves on traditional approaches by looking for AGN emission lines expected to be identified against the continuum, thanks to the width of the filters. To assess its performance, we apply ELDAR to the data of the ALHAMBRA survey, which covered an effective area of $2.38\,{\rm deg}^2$ with 20 contiguous medium-band optical filters down to F814W$\simeq 24.5$. Using two different configurations of ELDAR in which we require the detection of at least 2 and 3 emission lines, respectively, we extract two catalogues of type-I AGN. The first is composed of 585 sources ($79\,\%$ of them spectroscopically-unknown) down to F814W$=22.5$ at $z_{\rm phot}>1$, which corresponds to a surface density of $209\,{\rm deg}^{-2}$. In the second, the 494 selected sources ($83\,\%$ of them spectroscopically-unknown) reach F814W$=23$ at $z_{\rm phot}>1.5$, for a corresponding number density of $176\,{\rm deg}^{-2}$. Then, using samples of spectroscopically-known AGN in the ALHAMBRA fields, for the two catalogues we estimate a completeness of $73\,\%$ and $67\,\%$, and a redshift precision of $1.01\,\%$ and $0.86\,\%$ (with outliers fractions of $8.1\,\%$ and $5.8\,\%$). At $z>2$, where our selection performs best, we reach $85\,\%$ and $77\,\%$ completeness and we find no contamination from galaxies., Comment: 23 pages, 18 figures, submitted to MNRAS

Published
2017
Full Text
View/download PDF

3. An Accurate Cluster Selection Function for the J-PAS Narrow-Band wide-field survey

Author

Ascaso, Begoña, Benítez, Narciso, Dupke, Renato, Cypriano, Eduardo, Lima-Neto, Gastao, López-Sanjuan, Carlos, Varela, Jesús, Alcaniz, Jailson S., Broadhurst, Tom, Cenarro, Javier, Devi, N. Chandrachani, Díaz-García, Luis A., Fernandes, Cristina A. C., Hernández-Monteagudo, Carlos, Mei, Simona, de Oliveira, Claudia Mendes, Molino, Alberto, Oteo, Ivan, Schoenell, William, Sodré, Laerte, Viironen, Kerttu, and Marín-Franch, Antonio

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The impending Javalambre Physics of the accelerating universe Astrophysical Survey (J-PAS) will be the first wide-field survey of $\gtrsim$ 8500 deg$^2$ to reach the `stage IV' category. Because of the redshift resolution afforded by 54 narrow-band filters, J-PAS is particularly suitable for cluster detection in the range z$<$1. The photometric redshift dispersion is estimated to be only $\sim 0.003$ with few outliers $\lesssim$ 4\% for galaxies brighter than $i\sim23$ AB, because of the sensitivity of narrow band imaging to absorption and emission lines. Here we evaluate the cluster selection function for J-PAS using N-body+semi-analytical realistic mock catalogues. We optimally detect clusters from this simulation with the Bayesian Cluster Finder, and we assess the completeness and purity of cluster detection against the mock data. The minimum halo mass threshold we find for detections of galaxy clusters and groups with both $>$80\% completeness and purity is $M_h \sim 5 \times 10^{13}M_{\odot}$ up to $z\sim 0.7$. We also model the optical observable, $M^*_{\rm CL}$-halo mass relation, finding a non-evolution with redshift and main scatter of $\sigma_{M^*_{\rm CL} | M_{\rm h}}\sim 0.14 \,dex$ down to a factor two lower in mass than other planned broad-band stage IV surveys, at least. For the $M_{\rm h} \sim 1 \times 10^{14}M_{\odot}$ Planck mass limit, J-PAS will arrive up to $z\sim 0.85$ with a $\sigma_{M^*_{\rm CL} | M_{\rm h}}\sim 0.12 \, dex$. Therefore J-PAS will provide the largest sample of clusters and groups up to $z\sim 0.8$ with a mass calibration accuracy comparable to X-ray data., Comment: 16 pages, 15 figures, accepted for publication in MNRAS

Published
2016
Full Text
View/download PDF

4. Galaxy clusters and groups in the ALHAMBRA Survey

Author

Ascaso, Begoña, Benítez, Narciso, Fernández-Soto, Alberto, Arnalte-Mur, Pablo, López-Sanjuan, Carlos, Molino, Alberto, Schoenell, William, Jiménez-Teja, Yolanda, Merson, Alexander I., Huertas-Company, Marc, Díaz-García, Luis Alberto, Martínez, Vicent J., Cenarro, A. Javier, Dupke, Renato, Márquez, Isabel, Masegosa, Josefa, Nieves-Seoane, Lorena, Povic, Mirjana, Varela, Jesús, Viironen, Kerttu, Aguerri, J. Alfonso L., Del Olmo, Ascensión, Moles, Mariano, Perea, Jaime, Alfaro, Emilio, Aparicio-Villegas, Teresa, Broadhurst, Tom, Cabrera-Caño, Jesús, Castander, Francisco J., Cepa, Jordi, Cerviño, Miguel, González~Delgado, Rosa M., Cristóbal-Hornillos, David, Hurtado-Gil, Lluis, Husillos, Cesar, Infante, Leopoldo, Prada, Francisco, and Quintana, Jose María

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present a catalogue of 348 galaxy clusters and groups with $0.2

Published
2015
Full Text
View/download PDF

5. New candidate Planetary Nebulae in the IPHAS survey: the case of PNe with ISM interaction

Author

Sabin, Laurence, Zijlstra, Albert A., Wareing, Christopher, Corradi, Romano L. M., Mampaso, Antonio, Viironen, Kerttu, Wright, Nicholas J., and Parker, Quentin A.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

We present the results of the search for candidate Planetary Nebulae interacting with the interstellar medium (PN-ISM) in the framework of the INT Photometric H$\alpha$ Survey (IPHAS) and located in the right ascension range 18h-20h. The detection capability of this new Northern survey, in terms of depth and imaging resolution, has allowed us to overcome the detection problem generally associated to the low surface brightness inherent to PNe-ISM. We discuss the detection of 21 IPHAS PN-ISM candidates. Thus, different stages of interaction were observed, implying various morphologies i.e. from the unaffected to totally disrupted shapes. The majority of the sources belong to the so-called WZO2 stage which main characteristic is a brightening of the nebula's shell in the direction of motion. The new findings are encouraging as they would be a first step into the reduction of the scarcity of observational data and they would provide new insights into the physical processes occurring in the rather evolved PNe., Comment: 8 pages, 8 figures, presentation at the workshop on the Legacies of the Macquarie/AAO/Strasbourg H-alpha Planetary Nebula project, accepted by the Publications of the Astronomical Society of Australia (PASA)

Published
2009
Full Text
View/download PDF

6. Light curves and polarization of accretion- and nuclear-powered millisecond pulsars

Author

Viironen, Kerttu and Poutanen, Juri

Subjects
Astrophysics
Abstract

We study theoretical X-ray light curves and polarization properties of accretion-powered millisecond pulsars. We assume that the radiation is produced in two antipodal spots at the neutron star surface which are associated with the magnetic poles. We compute the angle-dependent intensity and polarization produced in an electron-scattering dominated plane-parallel accretion shock in the frame of the shock. The observed flux, polarization degree and polarization angle are calculated accounting for special and general relativistic effects. The calculations also extended to the case of nuclear-powered millisecond pulsars -- X-ray bursts. In this case, we consider one spot and the radiation is assumed to be produced in the atmosphere of the infinite Thomson optical depth. The light curves and polarization profiles show a large diversity depending on the model parameters. Presented results can be used as a first step to understand the observed pulse profiles of accretion- and nuclear-powered millisecond pulsars. Future observations of the X-ray polarization will provide a valuable tool to test the geometry of the emission region and its physical characteristics., Comment: 14 pages, 11 figures, A&A, in press

Published
2004
Full Text
View/download PDF

7. The ALHAMBRA survey: Tight dependence of the optical mass-to-light ratio on galaxy colour up to z = 1.5

Author

Ministry of Science and Technology (Ethiopia), Governo Brasil, Generalitat de Catalunya, Junta de Andalucía, Generalitat Valenciana, European Commission, Fundación Agencia Aragonesa para la Investigación y el Desarrollo, Ministerio de Ciencia e Innovación (España), Fondo de Inversiones de Teruel, López-Sanjuan, Carlos, Díaz-García, L. A., Cenarro, A. J., Fernández-Soto, Alberto, Viironen, Kerttu, Molino, Alberto, Benítez, Narciso, Cristóbal-Hornillos, David, Moles, Mariano, Varela, Jesús, Arnalte-Mur, P., Ascaso, Begoña, Cerviño, Miguel, González Delgado, Rosa M., Husillos, César, Márquez, Isabel, Masegosa, Josefa, Olmo, Ascensión del, Pović, Mirjana, Perea, Jaime, Castander, Francisco J., Ministry of Science and Technology (Ethiopia), Governo Brasil, Generalitat de Catalunya, Junta de Andalucía, Generalitat Valenciana, European Commission, Fundación Agencia Aragonesa para la Investigación y el Desarrollo, Ministerio de Ciencia e Innovación (España), Fondo de Inversiones de Teruel, López-Sanjuan, Carlos, Díaz-García, L. A., Cenarro, A. J., Fernández-Soto, Alberto, Viironen, Kerttu, Molino, Alberto, Benítez, Narciso, Cristóbal-Hornillos, David, Moles, Mariano, Varela, Jesús, Arnalte-Mur, P., Ascaso, Begoña, Cerviño, Miguel, González Delgado, Rosa M., Husillos, César, Márquez, Isabel, Masegosa, Josefa, Olmo, Ascensión del, Pović, Mirjana, Perea, Jaime, and Castander, Francisco J.

Abstract

[Aims] Our goal is to characterise the dependence of the optical mass-to-light ratio on galaxy colour up to z = 1.5, expanding the redshift range explored in previous work. [Methods] From the redshifts, stellar masses, and rest-frame luminosities of the ALHAMBRA multi-filter survey, we derive the mass-to-light ratio versus colour relation for quiescent and for star-forming galaxies. The intrinsic relation and its physical dispersion are derived with a Bayesian inference model. [Results] The rest-frame i-band mass-to-light ratio of quiescent and star-forming galaxies presents a tight correlation with the rest-frame (g - i) colour up to z = 1.5. The mass-to-light ratio versus colour relation is linear for quiescent galaxies and quadratic for star-forming galaxies. The intrinsic dispersion in these relations is 0.02 dex for quiescent galaxies and 0.06 dex for star-forming ones. The derived relations do not present a significant redshift evolution and are compatible with previous local results in the literature. Finally, these tight relations also hold for g- and r-band luminosities. [Conclusions] The derived mass-to-light ratio versus colour relations in ALHAMBRA can be used to predict the mass-to-light ratio from a rest-frame optical colour up to z = 1.5. These tight correlations do not change with redshift, suggesting that galaxies have evolved along the derived relations during the last 9 Gyr.

Published
2019

8. The ALHAMBRA survey: 2D analysis of the stellar populations in massive early-type galaxies at z < 0.3

Author

Fondo de Inversiones de Teruel, European Commission, Gobierno de Aragón, Ministerio de Economía y Competitividad (España), Ministry of Science and Technology (Ethiopia), San Roman, I., Cenarro, A. J., Díaz-García, L. A., López-Sanjuan, Carlos, Varela, Jesús, González Delgado, Rosa M., Sánchez-Blázquez, P., Alfaro, Emilio J., Ascaso, Begoña, Bonoli, Silvia, Borlaff, Alejandro, Castander, Francisco J., Cerviño, Miguel, Fernández-Soto, Alberto, Márquez, Isabel, Masegosa, Josefa, Muniesa, David, Pović, Mirjana, Viironen, Kerttu, Aguerri, J.A.L., Benítez, Narciso, Broadhurst, Tom, Cabrera-Caño, Jesús, Cepa, Jordi, Cristóbal-Hornillos, David, Infante, Leopoldo, Martínez, Vicente J., Moles, Mariano, Olmo, Ascensión del, Perea, Jaime, Prada, Francisco, Quintana, José María, Fondo de Inversiones de Teruel, European Commission, Gobierno de Aragón, Ministerio de Economía y Competitividad (España), Ministry of Science and Technology (Ethiopia), San Roman, I., Cenarro, A. J., Díaz-García, L. A., López-Sanjuan, Carlos, Varela, Jesús, González Delgado, Rosa M., Sánchez-Blázquez, P., Alfaro, Emilio J., Ascaso, Begoña, Bonoli, Silvia, Borlaff, Alejandro, Castander, Francisco J., Cerviño, Miguel, Fernández-Soto, Alberto, Márquez, Isabel, Masegosa, Josefa, Muniesa, David, Pović, Mirjana, Viironen, Kerttu, Aguerri, J.A.L., Benítez, Narciso, Broadhurst, Tom, Cabrera-Caño, Jesús, Cepa, Jordi, Cristóbal-Hornillos, David, Infante, Leopoldo, Martínez, Vicente J., Moles, Mariano, Olmo, Ascensión del, Perea, Jaime, Prada, Francisco, and Quintana, José María

Abstract

We present a technique that permits the analysis of stellar population gradients in a relatively low-cost way compared to integral field unit (IFU) surveys. We developed a technique to analyze unresolved stellar populations of spatially resolved galaxies based on photometric multi-filter surveys. This technique allows the analysis of vastly larger samples and out to larger galactic radii. We derived spatially resolved stellar population properties and radial gradients by applying a centroidal Voronoi tessellation and performing a multicolor photometry spectral energy distribution fitting. This technique has been successfully applied to a sample of 29 massive (M > 10M) early-type galaxies at z < 0.3 from the ALHAMBRA survey. We produced detailed 2D maps of stellar population properties (age, metallicity, and extinction), which allow us to identify galactic features. Radial structures were studied, and luminosity-weighted and mass-weighted gradients were derived out to 2-3.5 R. We find that the spatially resolved stellar population mass, age, and metallicity are well represented by their integrated values. We find the gradients of early-type galaxies to be on average flat in age (⇠log Age = 0.02 ± 0.06 dex/R) and negative in metallicity (⇠[Fe/H] = -0.09 ± 0.06 dex/R). Overall,the extinction gradients are flat (⇠A = -0.03 ± 0.09 mag/R) with a wide spread. These results are in agreement with previous studies that used standard long-slit spectroscopy, and with the most recent IFU studies. According to recent simulations, these results are consistent with a scenario where early-type galaxies were formed through major mergers and where their final gradients are driven by the older ages and higher metallicity of the accreted systems. We demonstrate the scientific potential of multi-filter photometry to explore the spatially resolved stellar populations of local galaxies and confirm previous spectroscopic trends from a complementary technique.

Published
2018

9. J-Plus: Measuring Ha Emission Line Flux In The Nearby Universe

Author

Logroño-García, Rafael, Vilella-Rojo, Gonzalo, López-San Juan, Carlos, Varela, Jesús, and Viironen, Kerttu

Subjects
data analysis photometry star formation low z, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

In the present presentation we aim to validate the methodology designed to extract the Ha emission line flux from J-PLUS data, a twelve optical filter survey carried out with the 2 deg² field of view T80Cam camera, mounted at the JAST/T80 telescope in the OAJ, Teruel, Spain. We use the information of the twelve J-PLUS bands, including the J0660 narrow-band filter located at rest-frame Ha, over 42 deg² to extract de-reddened and [NII] decontaminated Ha emission line fluxes of 46 star-forming regions with previous SDSS and/or CALIFA spectroscopic information. The agreement of the J-PLUS photometric Ha flux and the spectroscopic one is remarkable, with a ratio R = 1,01 +/- 0,27. This demonstrates that we are able to recover reliable Ha fluxes from J-PLUS photometric data. With an expected final area of 8,500 deg2, the large J-PLUS footprint will permit the study of the spatially resolved star formation rate of thousands nearby galaxies at z~0,015, as well as the influence of the close environment. As an illustrative example, we looked to the close pair of interacting galaxies NGC3994 and NGC3995, finding an enhancement of the star formation rate not only in the central part of NGC3994 but also in outer parts of the disc.

Published
2017
Full Text
View/download PDF

10. Lyman-Alpha Emitters At Z~2.2 In J-Plus Edr

Author

Daniele Spinoso, Orsi, Alvaro, Bonoli, Silvia, and Viironen, Kerttu

Subjects
Lyman-alpha emitters, high-redshift, galaxy evolution, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

This presentation explains the method used to select bright z~2.2 Lyman-alpha emitters in J-PLUS data and show the preliminary results obtained when applying the selection on the J-PLUS EDR. The combination of J-PLUS wide survey volume and filter set configuration allows to look for z~2.2 bright Lyman-alpha emitters (LAEs) over an unprecedentedly wide area. Preliminary results on J-PLUS EDR show that, despite the relatively shallowness of the survey, it is possible to detect ~1/sq.deg bright LAE, thus allowing to constrain the bright-end of z~2.2 LAEs luminosity function over a wide cosmological volume. Residual contamination from quasars (both and z~2.2 and other redshifts) does not allow to either disentangle between relative contribution of z~2.2 star forming galaxies and quasars to the LAEs luminosity function or to properly asses the contamination from interlopers in our candidates sample. Spectroscopic follow-up of our candidates is thus needed to assess the performance of our selection method before applying it to the future J-PLUS data releases.

Published
2017
Full Text
View/download PDF

11. ELDAR, a new method to identify AGN in multi-filter surveys: the ALHAMBRA test case

Author

Fondo de Inversiones de Teruel, Ministry of Science and Technology (Ethiopia), Fundação para a Ciência e a Tecnologia (Portugal), European Commission, Ministerio de Economía y Competitividad (España), Ibercaja, Chaves-Montero, Jonás, Bonoli, Silvia, Salvato, Mara, Greisel, N., Díaz-García, L. A., López-Sanjuan, Carlos, Viironen, Kerttu, Fernández-Soto, Alberto, Pović, Mirjana, Ascaso, Begoña, Arnalte-Mur, P., Masegosa, Josefa, Matute, Israel, Márquez, Isabel, Cenarro, A. J., Abramo, L. R., Ederoclite, Alessandro, Alfaro, Emilio J., Marín-Franch, Antonio, Varela, Jesús, Cristóbal-Hornillos, David, Fondo de Inversiones de Teruel, Ministry of Science and Technology (Ethiopia), Fundação para a Ciência e a Tecnologia (Portugal), European Commission, Ministerio de Economía y Competitividad (España), Ibercaja, Chaves-Montero, Jonás, Bonoli, Silvia, Salvato, Mara, Greisel, N., Díaz-García, L. A., López-Sanjuan, Carlos, Viironen, Kerttu, Fernández-Soto, Alberto, Pović, Mirjana, Ascaso, Begoña, Arnalte-Mur, P., Masegosa, Josefa, Matute, Israel, Márquez, Isabel, Cenarro, A. J., Abramo, L. R., Ederoclite, Alessandro, Alfaro, Emilio J., Marín-Franch, Antonio, Varela, Jesús, and Cristóbal-Hornillos, David

Abstract

We present ELDAR, a new method that exploits the potential of medium- and narrow-band filter surveys to securely identify active galactic nuclei (AGN) and determine their redshifts. Our methodology improves on traditional approaches by looking for AGN emission lines expected to be identified against the continuum, thanks to the width of the filters. To assess its performance, we apply ELDAR to the data of the ALHAMBRA (Advance Large Homogeneous Area Medium Band Redshift Astronomical) survey, which covered an effective area of 2.38 deg2 with 20 contiguous medium-band optical filters down to F814W ≃ 24.5. Using two different configurations of ELDAR in which we require the detection of at least two and three emission lines, respectively, we extract two catalogues of type-I AGN. The first is composed of 585 sources (79 per cent of them spectroscopically unknown) down to F814W = 22.5 at zphot > 1, which corresponds to a surface density of 209 deg−2. In the second, the 494 selected sources (83 per cent of them spectroscopically unknown) reach F814W = 23 at zphot > 1.5, for a corresponding number density of 176 deg−2. Then, using samples of spectroscopically known AGN in the ALHAMBRA fields, for the two catalogues we estimate a completeness of 73 per cent and 67 per cent, and a redshift precision of 1.01 per cent and 0.86 per cent (with outliers fractions of 8.1 per cent and 5.8 per cent). At z > 2, where our selection performs best, we reach 85 per cent and 77 per cent completeness and we find no contamination from galaxies.

Published
2017

12. ELDAR, a new method to identify AGN in multi-filter surveys: the ALHAMBRA test case

Author

Chaves-Montero, Jonás, primary, Bonoli, Silvia, additional, Salvato, Mara, additional, Greisel, Natascha, additional, Díaz-García, Luis A., additional, López-Sanjuan, Carlos, additional, Viironen, Kerttu, additional, Fernández-Soto, Alberto, additional, Pović, Mirjana, additional, Ascaso, Begoña, additional, Arnalte-Mur, Pablo, additional, Masegosa, Josefa, additional, Matute, Israel, additional, Márquez, Isabel, additional, Cenarro, A. Javier, additional, Abramo, L. Raul, additional, Ederoclite, Alessandro, additional, Alfaro, Emilio J., additional, Marin-Franch, Antonio, additional, Varela, Jesus, additional, and Cristobal-Hornillos, David, additional

Published
2017
Full Text
View/download PDF

13. High redshift galaxies in the ALHAMBRA survey

Author

Viironen, Kerttu, López-Sanjuan, C., Varela, Jesús, Cristóbal-Hornillos, David, Molino, Alberto, Fernández-Soto, Alberto, Ascaso, Begoña, Cenarro, A.J., Cerviño, Miguel, Cepa, Jordi, Ederoclite, A., Márquez, Isabel, Masegosa, Josefa, Moles, Mariano, Oteo, I., Pović, Mirjana, Aguerri, J.A.L., Alfaro, Emilio J., Aparicio Villegas, Teresa, Benítez, Narciso, Broadhurst, T., Cabrera-Caño, Jesús, Castander, Francisco J., Olmo, Ascensión del, González Delgado, Rosa M., Husillos, César, Infante, Leopoldo, Martínez, Vicente J., Perea, Jaime, Prada, Francisco, Quintana, José María, Generalitat Valenciana, Gobierno de Aragón, European Research Council, Fondo de Inversiones de Teruel, Ministerio de Economía y Competitividad (España), European Commission, Junta de Andalucía, and Consejo Superior de Investigaciones Científicas (España)

Subjects
high-redshift [Galaxies], Galaxies: distances and redshifts, Galaxies: statistics, statistics [Galaxies], Galaxies: high-redshift, distances and redshifts [Galaxies], Galaxies: evolution, evolution [Galaxies]
Abstract

Based on observations collected at the German-Spanish Astronomical Center, Calar Alto, jointly operated by the Max-Planck-Institut für Astronomie (MPIA) at Heidelberg and the Instituto de Astrofísica de Andalucía (CSIC).-- et al., [Context]: Most observational results on the high redshift restframe UV-bright galaxies are based on samples pinpointed using the so-called dropout technique or Ly-α selection. However, the availability of multifilter data now allows the dropout selections to be replaced by direct methods based on photometric redshifts. In this paper we present the methodology to select and study the population of high redshift galaxies in the ALHAMBRA survey data. [Aims]: Our aim is to develop a less biased methodology than the traditional dropout technique to study the high redshift galaxies in ALHAMBRA and other multifilter data. Thanks to the wide area ALHAMBRA covers, we especially aim at contributing to the study of the brightest, least frequent, high redshift galaxies. [Methods]: The methodology is based on redshift probability distribution functions (zPDFs). It is shown how a clean galaxy sample can be obtained by selecting the galaxies with high integrated probability of being within a given redshift interval. However, reaching both a complete and clean sample with this method is challenging. Hence, a method to derive statistical properties by summing the zPDFs of all the galaxies in the redshift bin of interest is introduced. [Results]: Using this methodology we derive the galaxy rest frame UV number counts in five redshift bins centred at z = 2.5,3.0,3.5,4.0, and 4.5, being complete up to the limiting magnitude at mUV(AB) = 24, where mUV refers to the first ALHAMBRA filter redwards of the Ly-α line. With the wide field ALHAMBRA data we especially contribute to the study of the brightest ends of these counts, accurately sampling the surface densities down to mUV(AB) = 21-22. [Conclusions]: We show that using the zPDFs it is easy to select a very clean sample of high redshift galaxies. We also show that it is better to do statistical analysis of the properties of galaxies using a probabilistic approach, which takes into account both the incompleteness and contamination issues in a natural way., K. Viironen acknowledges the Juan de la Cierva fellowship of the Spanish government. We acknowledge funding from the FITE (Fondos de Inversiones de Teruel) and support from the Spanish Ministry for Economy and Competitiveness and FEDER funds through grants AYA2012-30789, AYA2006-14056, AYA 2003-00128, AYA 2006-01325, AYA 2007-62190, AYA2010-15169, AYA2010-22111-C03-02 and AYA2013-48623-C2-2. We also acknowledge Junta de Andalucía through the grant TIC 114 and Generalitat Valenciana projects Prometeo 2009/064 and PROMETEOII/2014/060, and the financial support from the Aragón Government through the Research Group E103. I. Oteo acknowledges support from the European Research Council (ERC) in the form of Advanced Grant, cosmicism. A. J. Cenarro acknowledges the Ramón y Cajal fellowship of the Spanish government. M. Povic acknowledges financial support from JAE-Doc program of the Spanish National Research Council (CSIC), cofunded by the European Social Fund.

Published
2015

14. Stellar populations of galaxies in the ALHAMBRA survey up to z ~ 1

Author

Díaz-García, L. A., Cenarro, A.J., López-Sanjuan, C., Varela, Jesús, Viironen, Kerttu, Cristóbal-Hornillos, David, Moles, Mariano, Arnalte-Mur, P., Ascaso, Begoña, Cerviño, Miguel, González Delgado, Rosa M., Márquez, Isabel, Masegosa, Josefa, Molino, Alberto, Pović, Mirjana, Alfaro, Emilio J., Aparicio Villegas, Teresa, Benítez, Narciso, Broadhurst, T., Cabrera-Caño, Jesús, Castander, Francisco J., Cepa, Jordi, Fernández-Soto, Alberto, Husillos, César, Infante, Leopoldo, Aguerri, J.A.L., Martínez, Vicente J., Olmo, Ascensión del, Perea, Jaime, Prada, Francisco, Quintana, José María, Caja Rural de Teruel, European Commission, Gobierno de Aragón, Consejo Superior de Investigaciones Científicas (España), Junta de Andalucía, Ministerio de Economía y Competitividad (España), Generalitat Valenciana, Ministerio de Ciencia e Innovación (España), and Royal Astronomical Society

Subjects
high-redshift [Galaxies], photometry [Galaxies], stellar content [Galaxies], evolution [Galaxies], formation [Galaxies]
Abstract

Numerical methods and codes.-- et al. [Aims]: We present MUFFIT, a new generic code optimized to retrieve the main stellar population parameters of galaxies in photometric multi-filter surveys, and check its reliability and feasibility with real galaxy data from the ALHAMBRA survey. [Methods]: Making use of an error-weighted X2-test, we compare the multi-filter fluxes of galaxies with the synthetic photometry of mixtures of two single stellar populations at different redshifts and extinctions, to provide the most likely range of stellar population parameters (mainly ages and metallicities), extinctions, redshifts, and stellar masses. To improve the diagnostic reliability, MUFFIT identifies and removes from the analysis those bands that are significantly affected by emission lines. The final parameters and their uncertainties are derived by a Monte Carlo method, using the individual photometric uncertainties in each band. Finally, we discuss the accuracies, degeneracies, and reliability of MUFFIT using both simulated and real galaxies from ALHAMBRA, comparing with results from the literature. [Results]: MUFFIT is a precise and reliable code to derive stellar population parameters of galaxies in ALHAMBRA. Using the results from photometric-redshift codes as input, MUFFIT improves the photometric-redshift accuracy by ∼10-20%. MUFFIT also detects nebular emissions in galaxies, providing physical information about their strengths. The stellar masses derived from MUFFIT show excellent agreement with the COSMOS and SDSS values. In addition, the retrieved age-metallicity locus for a sample of z ≤ 0.22 early-type galaxies in ALHAMBRA at different stellar mass bins are in very good agreement with the ones from SDSS spectroscopic diagnostics. Moreover, a one-to-one comparison between the redshifts, ages, metallicities, and stellar masses derived spectroscopically for SDSS and by MUFFIT for ALHAMBRA reveals good qualitative agreements in all the parameters, hence reinforcing the strengths of multi-filter galaxy data and optimized analysis techniques, like MUFFIT, to conduct reliable stellar population studies. L.A.D.G. acknowledges support from the "Caja Rural de Teruel" for developing this research. A.J.C. is a Ramon y Cajal Fellow of the Spanish Ministry of Science and Innovation. This work has been supported by the "Programa Nacional de Astronomia y Astrofisica" of the Spanish Ministry of Economy and Competitiveness (MINECO) under grant AYA2012-30789, as well as by FEDER funds and the Government of Aragon, through the Research Group E103. L.A.D.G. also thanks the Mullard Space Science Laboratory (MSSL) and Royal Astronomical Society (RAS) for offering the opportunity to support and develop part of this research in collaboration with I.F. MINECO grants AYA2010-15081, AYA2010-15169, AYA2010-22111-C03-01, AYA2010-22111-C03-02, AYA2011-29517-C03-01, AYA2013-40611-P, AYA2013-42227-P, AYA2013-43188-P, AYA2013-48623-C2-1, AYA2013-48623-C2-2, and AYA2014-58861-C3-1 are also acknowledged, together with Generalitat Valenciana projects Prometeo 2009/064 and PROMETEOII/2014/060, and Junta de Andalucia grants TIC114, JA2828, and P10-FQM-6444. MP acknowledges financial support from the JAE-Doc programme of the Spanish National Research Council (CSIC), co-funded by the European Social Fund.

Published
2015

15. The alhambra survey: evolution of galaxy spectral segregation

Author

Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Ministerio de Economía y Competitividad (MINECO). España, Junta de Andalucía, Hurtado Gil, LL., Arnalte-Mur, P., Martinez, V. J., Fernández Soto, A., Stefanon, M., Ascaso, Begoña, López-Sanjuan, C., Márquez, I., Povic, M., Viironen, Kerttu, Cabrera Caño, Jesús María, Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Ministerio de Economía y Competitividad (MINECO). España, Junta de Andalucía, Hurtado Gil, LL., Arnalte-Mur, P., Martinez, V. J., Fernández Soto, A., Stefanon, M., Ascaso, Begoña, López-Sanjuan, C., Márquez, I., Povic, M., Viironen, Kerttu, and Cabrera Caño, Jesús María

Abstract

We study the clustering of galaxies as a function of spectral type and redshift in the range 0.35

Published
2016

16. The Alhambra survey: evolution of galaxy spectral segregation

Author

European Commission, Ministerio de Economía y Competitividad (España), Junta de Andalucía, Generalitat Valenciana, Generalitat de Catalunya, Hurtado-Gil, L., Arnalte-Mur, P., Martínez, Vicente J., Fernández-Soto, Alberto, Stefanon, Mauro, Ascaso, Begoña, López-Sanjuan, Carlos, Márquez, Isabel, Pović, Mirjana, Viironen, Kerttu, Aguerri, J.A.L., Alfaro, Emilio J., Aparicio Villegas, Teresa, Benítez, Narciso, Broadhurst, Tom, Cabrera-Caño, Jesús, Castander, Francisco J., Cepa, Jordi, Cerviño, Miguel, Cristóbal-Hornillos, David, González Delgado, Rosa M., Husillos, César, Infante, Leopoldo, Masegosa, Josefa, Moles, Mariano, Molino, Alberto, Olmo, Ascensión del, Paredes, Silvestre, Prada, Francisco, Quintana, José María, European Commission, Ministerio de Economía y Competitividad (España), Junta de Andalucía, Generalitat Valenciana, Generalitat de Catalunya, Hurtado-Gil, L., Arnalte-Mur, P., Martínez, Vicente J., Fernández-Soto, Alberto, Stefanon, Mauro, Ascaso, Begoña, López-Sanjuan, Carlos, Márquez, Isabel, Pović, Mirjana, Viironen, Kerttu, Aguerri, J.A.L., Alfaro, Emilio J., Aparicio Villegas, Teresa, Benítez, Narciso, Broadhurst, Tom, Cabrera-Caño, Jesús, Castander, Francisco J., Cepa, Jordi, Cerviño, Miguel, Cristóbal-Hornillos, David, González Delgado, Rosa M., Husillos, César, Infante, Leopoldo, Masegosa, Josefa, Moles, Mariano, Molino, Alberto, Olmo, Ascensión del, Paredes, Silvestre, Prada, Francisco, and Quintana, José María

Abstract

We study the clustering of galaxies as a function of spectral type and redshift in the range 0.35

Published
2016

17. Galaxy clusters and groups in the ALHAMBRA survey

Author

Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Ascaso, Begoña, Benitez, N., Fernandez-Soto, Alberto, Arnalte-Mur, P., López-Sanjuán, Carlos, Molino, Alberto, Schoenell, W., Jiménez-Teja, Yolanda, Merson, Alexander I., Huertas-Company, Marc, Díaz-García, Luis A., Martínez, Vicent J., Cenarro, Andres Javier, Dupke, Renato A., Márquez, I., Masegosa, J., Nieves-Seoane, L., Pović, Mirjana, Varela, Jesús, Viironen, Kerttu, Aguerri, José Alfonso López, Olmo, A. del, Moles, Mariano, Perea, Jaime D., Alfaro, Emilio J., Aparicio-Villegas, T., Broadhurst, Tom J., Cabrera Caño, Jesús María, Castander, Francisco Javier J., Cepa, Jordi P., Cerviño, Miguel, González Delgado, R. M., Cristóbal-Hornillos, David, Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Ascaso, Begoña, Benitez, N., Fernandez-Soto, Alberto, Arnalte-Mur, P., López-Sanjuán, Carlos, Molino, Alberto, Schoenell, W., Jiménez-Teja, Yolanda, Merson, Alexander I., Huertas-Company, Marc, Díaz-García, Luis A., Martínez, Vicent J., Cenarro, Andres Javier, Dupke, Renato A., Márquez, I., Masegosa, J., Nieves-Seoane, L., Pović, Mirjana, Varela, Jesús, Viironen, Kerttu, Aguerri, José Alfonso López, Olmo, A. del, Moles, Mariano, Perea, Jaime D., Alfaro, Emilio J., Aparicio-Villegas, T., Broadhurst, Tom J., Cabrera Caño, Jesús María, Castander, Francisco Javier J., Cepa, Jordi P., Cerviño, Miguel, González Delgado, R. M., and Cristóbal-Hornillos, David

Abstract

We present a catalogue of 348 galaxy clusters and groups with 0.2 < z < 1.2 selected in the 2.78 deg2 Advanced Large, Homogeneous Area Medium Band Redshift Astronomical (ALHAMBRA) survey. The high precision of our photometric redshifts, close to 1 per cent, and the wide spread of the seven ALHAMBRA pointings ensure that this catalogue has better mass sensitivity and is less affected by cosmic variance than comparable samples. The detection has been carried out with the Bayesian Cluster Finder, whose performance has been checked in ALHAMBRA-like light-cone mock catalogues. Great care has been taken to ensure that the observable properties of the mocks photometry accurately correspond to those of real catalogues. From our simulations, we expect to detect galaxy clusters and groups with both 70 per cent completeness and purity down to dark matter halo masses of Mh ~ 3 × 1013M* for z < 0.85. Cluster redshifts are expected to be recovered with ~0.6 per cent precision for z < 1. We also expect to measure cluster masses with σMh|MCL * ~ 0.25-0.35 precision down to ~ 3 × 1013M⊙, masses which are 50 per cent smaller than those reached by similar work. We have compared these detections with previous optical, spectroscopic and X-rays work, finding an excellent agreement with the rates reported from the simulations. We have also explored the overall properties of these detections such as the presence of a colour-magnitude relation, the evolution of the photometric blue fraction and the clustering of these sources in the different ALHAMBRA fields. Despite the small numbers, we observe tentative evidence that, for a fixed stellar mass, the environment is playing a crucial role at lower redshifts (z < 0.5). © 2015 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.

Published
2015

18. The impact from survey depth and resolution on the morphological classification of galaxies

Author

Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Ministerio de Economía y Competitividad (MINECO). España, Pović, Mirjana, Márquez, I., Masegosa, J., Perea, Jaime D., Olmo, A. del, Simpson, Chris J., Aguerri, José Alfonso López, Ascaso, Begoña, Jiménez-Teja, Yolanda, López-Sanjuán, Carlos, Molino, Alberto, Pérez García, Ana M., Viironen, Kerttu, Husillos, C., Cristóbal-Hornillos, David, Caldwell, Caroline E., Benítez, N., Alfaro, Emilio J., Aparicio-Villegas, T., Broadhurst, Tom J., Cabrera Caño, Jesús María, Castander, Francisco Javier J., Cepa, Jordi P., Cerviño, Miguel, Fernandez-Soto, Alberto, González Delgado, R. M., Infante, Leopoldo, Martínez, Vicent J., Moles, Mariano, Prada, Francisco, Quintana, José María, Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Ministerio de Economía y Competitividad (MINECO). España, Pović, Mirjana, Márquez, I., Masegosa, J., Perea, Jaime D., Olmo, A. del, Simpson, Chris J., Aguerri, José Alfonso López, Ascaso, Begoña, Jiménez-Teja, Yolanda, López-Sanjuán, Carlos, Molino, Alberto, Pérez García, Ana M., Viironen, Kerttu, Husillos, C., Cristóbal-Hornillos, David, Caldwell, Caroline E., Benítez, N., Alfaro, Emilio J., Aparicio-Villegas, T., Broadhurst, Tom J., Cabrera Caño, Jesús María, Castander, Francisco Javier J., Cepa, Jordi P., Cerviño, Miguel, Fernandez-Soto, Alberto, González Delgado, R. M., Infante, Leopoldo, Martínez, Vicent J., Moles, Mariano, Prada, Francisco, and Quintana, José María

Abstract

We consistently analyse for the first time the impact of survey depth and spatial resolution on the most used morphological parameters for classifying galaxies through non-parametric methods: Abraham and Conselice-Bershady concentration indices, Gini, M20moment of light, asymmetry, and smoothness. Three different non-local data sets are used, Advanced Large Homogeneous Area Medium Band Redshift Astronomical (ALHAMBRA) and Subaru/XMMNewton Deep Survey (SXDS, examples of deep ground-based surveys), and Cosmos Evolution Survey (COSMOS, deep space-based survey). We used a sample of 3000 local, visually classified galaxies, measuring their morphological parameters at their real redshifts (z ~ 0). Then we simulated them to match the redshift and magnitude distributions of galaxies in the non-local surveys. The comparisons of the two sets allow us to put constraints on the use of each parameter for morphological classification and evaluate the effectiveness of the commonly used morphological diagnostic diagrams. All analysed parameters suffer from biases related to spatial resolution and depth, the impact of the former being much stronger. When including asymmetry and smoothness in classification diagrams, the noise effects must be taken into account carefully, especially for ground-based surveys. M20 is significantly affected, changing both the shape and range of its distribution at all brightness levels. We suggest that diagnostic diagrams based on 2-3 parameters should be avoided when classifying galaxies in ground-based surveys, independently of their brightness; for COSMOS they should be avoided for galaxies fainter than F814 = 23.0. These results can be applied directly to surveys similar to ALHAMBRA, SXDS and COSMOS, and also can serve as an upper/lower limit for shallower/deeper ones.

Published
2015

19. The ALHAMBRA survey: accurate merger fractions derived by PDF analysis of photometrically close pairs

Author

Gobierno de Aragón, Generalitat Valenciana, Ministerio de Economía y Competitividad (España), Junta de Andalucía, European Commission, Fondo de Inversiones de Teruel, Ministerio de Ciencia e Innovación (España), Consejo Superior de Investigaciones Científicas (España), López-Sanjuan, Carlos, Cenarro, A. J., Varela, Jesús, Molino, Alberto, Benítez, Narciso, Arnalte-Mur, P., Ascaso, Begoña, Díaz-García, L. A., Fernández-Soto, Alberto, Jiménez-Teja, Y., Márquez, Isabel, Masegosa, Josefa, Moles, Mariano, Pović, Mirjana, Aguerri, J.A.L., Alfaro, Emilio J., Aparicio Villegas, Teresa, Broadhurst, Tom, Cabrera-Caño, Jesús, Castander, Francisco J., Cepa, Jordi, Cerviño, Miguel, Cristóbal-Hornillos, David, Olmo, Ascensión del, González Delgado, Rosa M., Husillos, César, Infante, Leopoldo, Martínez, Vicente J., Perea, Jaime, Prada, Francisco, Viironen, Kerttu, Quintana, José María, Gobierno de Aragón, Generalitat Valenciana, Ministerio de Economía y Competitividad (España), Junta de Andalucía, European Commission, Fondo de Inversiones de Teruel, Ministerio de Ciencia e Innovación (España), Consejo Superior de Investigaciones Científicas (España), López-Sanjuan, Carlos, Cenarro, A. J., Varela, Jesús, Molino, Alberto, Benítez, Narciso, Arnalte-Mur, P., Ascaso, Begoña, Díaz-García, L. A., Fernández-Soto, Alberto, Jiménez-Teja, Y., Márquez, Isabel, Masegosa, Josefa, Moles, Mariano, Pović, Mirjana, Aguerri, J.A.L., Alfaro, Emilio J., Aparicio Villegas, Teresa, Broadhurst, Tom, Cabrera-Caño, Jesús, Castander, Francisco J., Cepa, Jordi, Cerviño, Miguel, Cristóbal-Hornillos, David, Olmo, Ascensión del, González Delgado, Rosa M., Husillos, César, Infante, Leopoldo, Martínez, Vicente J., Perea, Jaime, Prada, Francisco, Viironen, Kerttu, and Quintana, José María

Abstract

[Aims]: Our goal is to develop and test a novel methodology to compute accurate close-pair fractions with photometric redshifts. [Methods]: We improved the currently used methodologies to estimate the merger fraction fm from photometric redshifts by (i) using the full probability distribution functions (PDFs) of the sources in redshift space; (ii) including the variation in the luminosity of the sources with z in both the sample selection and the luminosity ratio constrain; and (iii) splitting individual PDFs into red and blue spectral templates to reliably work with colour selections.We tested the performance of our new methodology with the PDFs provided by the ALHAMBRA photometric survey. [Results]: The merger fractions and rates from the ALHAMBRA survey agree excellently well with those from spectroscopic work for both the general population and red and blue galaxies. With the merger rate of bright (MB ≤ -20 - 1:1z) galaxies evolving as (1 + z)n, the power-law index n is higher for blue galaxies (n = 2:7 0:5) than for red galaxies (n = 1:3 0:4), confirming previous results. Integrating the merger rate over cosmic time, we find that the average number of mergers per galaxy since z = 1 is Nm red = 0:57 0:05 for red galaxies and Nm blue = 0:26 0:02 for blue galaxies. [Conclusions]: Our new methodology statistically exploits all the available information provided by photometric redshift codes and yields accurate measurements of the merger fraction by close pairs from using photometric redshifts alone. Current and future photometric surveys will benefit from this new methodology.

Published
2015

20. Stellar populations of galaxies in the ALHAMBRA survey up to z ~ 1

Author

Caja Rural de Teruel, European Commission, Gobierno de Aragón, Consejo Superior de Investigaciones Científicas (España), Junta de Andalucía, Ministerio de Economía y Competitividad (España), Generalitat Valenciana, Ministerio de Ciencia e Innovación (España), Royal Astronomical Society, Díaz-García, L. A., Cenarro, A. J., López-Sanjuan, Carlos, Varela, Jesús, Viironen, Kerttu, Cristóbal-Hornillos, David, Moles, Mariano, Arnalte-Mur, P., Ascaso, Begoña, Cerviño, Miguel, González Delgado, Rosa M., Márquez, Isabel, Masegosa, Josefa, Molino, Alberto, Pović, Mirjana, Alfaro, Emilio J., Aparicio Villegas, Teresa, Benítez, Narciso, Broadhurst, Tom, Cabrera-Caño, Jesús, Castander, Francisco J., Cepa, Jordi, Fernández-Soto, Alberto, Husillos, César, Infante, Leopoldo, Aguerri, J.A.L., Martínez, Vicente J., Olmo, Ascensión del, Perea, Jaime, Prada, Francisco, Quintana, José María, Caja Rural de Teruel, European Commission, Gobierno de Aragón, Consejo Superior de Investigaciones Científicas (España), Junta de Andalucía, Ministerio de Economía y Competitividad (España), Generalitat Valenciana, Ministerio de Ciencia e Innovación (España), Royal Astronomical Society, Díaz-García, L. A., Cenarro, A. J., López-Sanjuan, Carlos, Varela, Jesús, Viironen, Kerttu, Cristóbal-Hornillos, David, Moles, Mariano, Arnalte-Mur, P., Ascaso, Begoña, Cerviño, Miguel, González Delgado, Rosa M., Márquez, Isabel, Masegosa, Josefa, Molino, Alberto, Pović, Mirjana, Alfaro, Emilio J., Aparicio Villegas, Teresa, Benítez, Narciso, Broadhurst, Tom, Cabrera-Caño, Jesús, Castander, Francisco J., Cepa, Jordi, Fernández-Soto, Alberto, Husillos, César, Infante, Leopoldo, Aguerri, J.A.L., Martínez, Vicente J., Olmo, Ascensión del, Perea, Jaime, Prada, Francisco, and Quintana, José María

Abstract

[Aims]: We present MUFFIT, a new generic code optimized to retrieve the main stellar population parameters of galaxies in photometric multi-filter surveys, and check its reliability and feasibility with real galaxy data from the ALHAMBRA survey. [Methods]: Making use of an error-weighted X2-test, we compare the multi-filter fluxes of galaxies with the synthetic photometry of mixtures of two single stellar populations at different redshifts and extinctions, to provide the most likely range of stellar population parameters (mainly ages and metallicities), extinctions, redshifts, and stellar masses. To improve the diagnostic reliability, MUFFIT identifies and removes from the analysis those bands that are significantly affected by emission lines. The final parameters and their uncertainties are derived by a Monte Carlo method, using the individual photometric uncertainties in each band. Finally, we discuss the accuracies, degeneracies, and reliability of MUFFIT using both simulated and real galaxies from ALHAMBRA, comparing with results from the literature. [Results]: MUFFIT is a precise and reliable code to derive stellar population parameters of galaxies in ALHAMBRA. Using the results from photometric-redshift codes as input, MUFFIT improves the photometric-redshift accuracy by ∼10-20%. MUFFIT also detects nebular emissions in galaxies, providing physical information about their strengths. The stellar masses derived from MUFFIT show excellent agreement with the COSMOS and SDSS values. In addition, the retrieved age-metallicity locus for a sample of z ≤ 0.22 early-type galaxies in ALHAMBRA at different stellar mass bins are in very good agreement with the ones from SDSS spectroscopic diagnostics. Moreover, a one-to-one comparison between the redshifts, ages, metallicities, and stellar masses derived spectroscopically for SDSS and by MUFFIT for ALHAMBRA reveals good qualitative agreements in all the parameters, hence reinforcing the strengths of multi-filter galaxy dat

Published
2015

21. The impact from survey depth and resolution on the morphological classification of galaxies

Author

Consejo Superior de Investigaciones Científicas (España), European Commission, Junta de Andalucía, Ministerio de Economía y Competitividad (España), Pović, Mirjana, Márquez, Isabel, Masegosa, Josefa, Perea, Jaime, Olmo, Ascensión del, Aguerri, J.A.L., Ascaso, Begoña, Jiménez-Teja, Y., López-Sanjuan, Carlos, Molino, Alberto, Pérez-García, Ana M., Viironen, Kerttu, Husillos, César, Cristóbal-Hornillos, David, Benítez, Narciso, Alfaro, Emilio J., Aparicio Villegas, Teresa, Broadhurst, Tom, Cabrera-Caño, Jesús, Castander, Francisco J., Cepa, Jordi, Cerviño, Miguel, Fernández-Soto, Alberto, González Delgado, Rosa M., Infante, Leopoldo, Martínez, Vicente J., Moles, Mariano, Prada, Francisco, Quintana, José María, Consejo Superior de Investigaciones Científicas (España), European Commission, Junta de Andalucía, Ministerio de Economía y Competitividad (España), Pović, Mirjana, Márquez, Isabel, Masegosa, Josefa, Perea, Jaime, Olmo, Ascensión del, Aguerri, J.A.L., Ascaso, Begoña, Jiménez-Teja, Y., López-Sanjuan, Carlos, Molino, Alberto, Pérez-García, Ana M., Viironen, Kerttu, Husillos, César, Cristóbal-Hornillos, David, Benítez, Narciso, Alfaro, Emilio J., Aparicio Villegas, Teresa, Broadhurst, Tom, Cabrera-Caño, Jesús, Castander, Francisco J., Cepa, Jordi, Cerviño, Miguel, Fernández-Soto, Alberto, González Delgado, Rosa M., Infante, Leopoldo, Martínez, Vicente J., Moles, Mariano, Prada, Francisco, and Quintana, José María

Abstract

We consistently analyse for the first time the impact of survey depth and spatial resolution on the most used morphological parameters for classifying galaxies through non-parametric methods: Abraham and Conselice-Bershady concentration indices, Gini, M20moment of light, asymmetry, and smoothness. Three different non-local data sets are used, Advanced Large Homogeneous Area Medium Band Redshift Astronomical (ALHAMBRA) and Subaru/XMMNewton Deep Survey (SXDS, examples of deep ground-based surveys), and Cosmos Evolution Survey (COSMOS, deep space-based survey). We used a sample of 3000 local, visually classified galaxies, measuring their morphological parameters at their real redshifts (z ~ 0). Then we simulated them to match the redshift and magnitude distributions of galaxies in the non-local surveys. The comparisons of the two sets allow us to put constraints on the use of each parameter for morphological classification and evaluate the effectiveness of the commonly used morphological diagnostic diagrams. All analysed parameters suffer from biases related to spatial resolution and depth, the impact of the former being much stronger. When including asymmetry and smoothness in classification diagrams, the noise effects must be taken into account carefully, especially for ground-based surveys. M20 is significantly affected, changing both the shape and range of its distribution at all brightness levels. We suggest that diagnostic diagrams based on 2-3 parameters should be avoided when classifying galaxies in ground-based surveys, independently of their brightness; for COSMOS they should be avoided for galaxies fainter than F814 = 23.0. These results can be applied directly to surveys similar to ALHAMBRA, SXDS and COSMOS, and also can serve as an upper/lower limit for shallower/deeper ones.

Published
2015

22. Lyman break and ultraviolet-selected galaxies at z ∼ 1 - I. Stellar populations from the ALHAMBRA survey

Author

Ministerio de Economía y Competitividad (España), Alfred P. Sloan Foundation, National Science Foundation (US), Department of Energy (US), National Aeronautics and Space Administration (US), Japanese Government, Max Planck Society, Higher Education Funding Council for England, Junta de Andalucía, Oteo Gómez, Iván, Bongiovanni, Ángel, Cepa, Jordi, Pérez-García, Ana M., Ederoclite, Alessandro, Sánchez-Portal, Miguel, Pintos-Castro, Irene, Pérez-Martínez, Ricardo, Polednikova, Jana, Aguerri, J.A.L., Alfaro, Emilio J., Aparicio Villegas, Teresa, Benítez, Narciso, Broadhurst, Tom, Cabrera-Caño, Jesús, Castander, Francisco J., Cerviño, Miguel, Cristóbal-Hornillos, David, Fernández-Soto, Alberto, González Delgado, Rosa M., Husillos, César, Infante, Leopoldo, Martínez, Vicente J., Márquez, Isabel, Masegosa, Josefa, Matute, Israel, Moles, Mariano, Molino, Alberto, Olmo, Ascensión del, Perea, Jaime, Pović, Mirjana, Prada, Francisco, Quintana, José María, Viironen, Kerttu, Ministerio de Economía y Competitividad (España), Alfred P. Sloan Foundation, National Science Foundation (US), Department of Energy (US), National Aeronautics and Space Administration (US), Japanese Government, Max Planck Society, Higher Education Funding Council for England, Junta de Andalucía, Oteo Gómez, Iván, Bongiovanni, Ángel, Cepa, Jordi, Pérez-García, Ana M., Ederoclite, Alessandro, Sánchez-Portal, Miguel, Pintos-Castro, Irene, Pérez-Martínez, Ricardo, Polednikova, Jana, Aguerri, J.A.L., Alfaro, Emilio J., Aparicio Villegas, Teresa, Benítez, Narciso, Broadhurst, Tom, Cabrera-Caño, Jesús, Castander, Francisco J., Cerviño, Miguel, Cristóbal-Hornillos, David, Fernández-Soto, Alberto, González Delgado, Rosa M., Husillos, César, Infante, Leopoldo, Martínez, Vicente J., Márquez, Isabel, Masegosa, Josefa, Matute, Israel, Moles, Mariano, Molino, Alberto, Olmo, Ascensión del, Perea, Jaime, Pović, Mirjana, Prada, Francisco, Quintana, José María, and Viironen, Kerttu

Abstract

We take advantage of the exceptional photometric coverage provided by the combination of GALEX data in the ultraviolet (UV) and the ALHAMBRA survey in the optical and near-infrared to analyse the physical properties of a sample of 1225 GALEX-selected Lyman break galaxies (LBGs) at 0.8 ≲ z ≲ 1.2 that are located in the COSMOS field. This is the largest sample of LBGs studied in this redshift range to date. According to a spectral energy distribution (SED) fitting with synthetic stellar population templates, we find that LBGs at z ̃ 1 are mostly young galaxies with a median age of 341 Myr and have intermediate dust attenuation, (Es(B - V)) ̃ 0.20. Owing to the selection criterion, LBGs at z ̃ 1 are UV-bright galaxies and have a high dust-corrected total star formation rate (SFR), with a median value of 16.9M⊙ yr-1. Their median stellar mass is log (M*/M⊙) = 9.74. We find that the dustcorrected total SFR of LBGs increases with stellar mass and that the specific SFR is lower for more massive galaxies (downsizing scenario). Only 2 per cent of the galaxies selected through the Lyman break criterion have an active galactic nucleus nature. LBGs at z ̃ 1 are located mostly over the blue cloud of the colour-magnitude diagram of galaxies at their redshift, with only the oldest and/or the dustiest deviating towards the green valley and red sequence. Morphologically, 69 per cent of LBGs are disc-like galaxies, with the fractions of interacting, compact, or irregular systems being much lower, below 12 per cent. LBGs have a median effective radius of 2.5 kpc, and larger galaxies have a higher total SFR and stellar mass. Compared with their high-redshift analogues, we find evidence that LBGs at lower redshifts are larger, redder in the UV continuum, and have a major presence of older stellar populations in their SEDs. However, we do not find significant differences in the distributions of stellar mass or dust attenuation. ©2013 The Authors Published by Oxford University Press on be

Published
2013

24. The star formation rate density in the local universe using j-plus data

Author

Vilella Rojo, Gonzalo, López San Juan, Carlos, Viironen, Kerttu, UAM. Departamento de Física Teórica, López San Juan, Carlos (dir.), and Viironen, Kerttu (dir.)

Subjects
Galaxias - Tesis doctorales, Física, Estrellas - Formación - Tesis doctorales
Abstract

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física Teórica. Fecha de lectura: 21-06-2019, Esta tesis tiene embargado el acceso al texto completo hasta el 2020-12-21

Published
2019

Catalog

Books, media, physical & digital resources
See catalog results