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1. 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
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2. II. Apples to apples $A^2$: cluster selection functions for next-generation surveys

Author

Ascaso, Begoña, Mei, Simona, Bartlett, Jim G., and Benítez, Txitxo

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present the cluster selection function for three of the largest next-generation stage-IV surveys in the optical and infrared: Euclid-Optimistic, Euclid-Pessimistic and the Large Synoptic Survey Telescope (LSST). To simulate these surveys, we use the realistic mock catalogues introduced in the first paper of this series. We detected galaxy clusters using the Bayesian Cluster Finder (BCF) in the mock catalogues. We then modeled and calibrated the total cluster stellar mass observable-theoretical mass ($M^*_{\rm CL}-M_{\rm h}$) relation using a power law model, including a possible redshift evolution term. We find a moderate scatter of $\sigma_{M^*_{\rm CL} | M_{\rm h}}$ of 0.124, 0.135 and 0.136 $\rm dex$ for Euclid-Optimistic, Euclid-Pessimistic and LSST, respectively, comparable to other work over more limited ranges of redshift. Moreover, the three datasets are consistent with negligible evolution with redshift, in agreement with observational and simulation results in the literature. We find that Euclid-Optimistic will be able to detect clusters with $>80\%$ completeness and purity down to $8\times10^{13} h^{-1} M_{\odot}$ up to $z<1$. At higher redshifts, the same completeness and purity are obtained with the larger mass threshold of $2\times10^{14} h^{-1} M_{\odot}$ up to $z=2$. The Euclid-Pessimistic selection function has a similar shape with $\sim10\%$ higher mass limit. LSST shows $\sim 5\%$ higher mass limit than Euclid-Optimistic up to $z<0.7$ and increases afterwards, reaching values of $2\times10^{14} h^{-1} M_{\odot}$ at $z=1.4$. Similar selection functions with only $80\%$ completeness threshold have been also computed. The complementarity of these results with selection functions for surveys in other bands is discussed., Comment: 13 pages, 10 figures, accepted for publication in MNRAS

Published
2016
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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
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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
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5. I. Apples to apples $A^2$: realistic galaxy simulated catalogs and photometric redshift predictions for next-generation surveys

Author

Ascaso, Begoña, Mei, Simona, and Benítez, Narciso

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present new mock catalogues for two of the largest stage-IV next-generation surveys in the optical and infrared: LSST and Euclid, based on an N-body simulation+semi-analytical cone with a posterior modification with \texttt{PhotReal}. This technique modifies the original photometry by using an empirical library of spectral templates to make it more realistic. The reliability of the catalogues is confirmed by comparing the obtained color-magnitude relation, the luminosity and mass function and the angular correlation function with those of real data. Consistent comparisons between the expected photometric redshifts for different surveys are also provided. Very deep near infrared surveys such as Euclid will provide very good performance ($\Delta z/(1+z) \sim 0.025-0.053$) down to $H\sim24$ AB mag and up to $z\sim3$ depending on the optical observations available from the ground whereas extremely deep optical surveys such as LSST will obtain an overall lower photometric redshift resolution ($\Delta z/(1+z) \sim 0.045$) down to $i\sim27.5$ AB mag, being considerably improved ($\Delta z/(1+z) \sim 0.035$) if we restrict the sample down to i$\sim$24 AB mag. Those numbers can be substantially upgraded by selecting a subsample of galaxies with the best quality photometric redshifts. We finally discuss the impact that these surveys will have for the community in terms of photometric redshift legacy. This is the first of a series of papers where we set a framework for comparability between mock catalogues and observations with a particular focus on cluster surveys. The Euclid and LSST mocks are made publicly available in the following link: http://photmocks.obspm.fr/., Comment: accepted in MNRAS. Mocks available in the following link: http://photmocks.obspm.fr/

Published
2015
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6. Avoiding progenitor bias: The structural and mass evolution of Brightest Group and Cluster Galaxies in Hierarchical models since z~1

Author

Shankar, Francesco, Buchan, Stewart, Rettura, Alessandro, Bouillot, Vincent, Moreno, Jorge, Licitra, Rossella, Bernardi, Mariangela, Huertas-Company, Marc, Mei, Simona, Ascaso, Begoña, Sheth, Ravi, Delaye, Lauriane, and Raichoor, Anand

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

The mass and structural evolution of massive galaxies is one of the hottest topics in galaxy formation. This is because it may reveal invaluable insights into the still debated evolutionary processes governing the growth and assembly of spheroids. However, direct comparison between models and observations is usually prevented by the so-called "progenitor bias", i.e., new galaxies entering the observational selection at later epochs, thus eluding a precise study of how pre-existing galaxies actually evolve in size. To limit this effect, we here gather data on high-redshift brightest group and cluster galaxies, evolve their (mean) host halo masses down to z=0 along their main progenitors, and assign as their "descendants" local SDSS central galaxies matched in host halo mass. At face value, the comparison between high redshift and local data suggests a noticeable increase in stellar mass of a factor of >2 since z~1, and of >2.5 in mean effective radius. We then compare the inferred stellar mass and size growth with those predicted by hierarchical models for central galaxies, selected at high redshifts to closely match the halo and stellar mass bins as in the data. Only hierarchical models characterized by very limited satellite stellar stripping and parabolic orbits are capable of broadly reproducing the stellar mass and size increase of a factor ~2-4 observed in cluster galaxies since z ~1. The predicted, average (major) merger rate since z~1 is in good agreement with the latest observational estimates., Comment: 9 pages, 5 figures. ApJ, in press. Additional (minor) editing included in text and figure captions

Published
2015
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7. On the intermediate-redshift central stellar mass-halo mass relation, and implications for the evolution of the most massive galaxies since z~1

Author

Shankar, Francesco, Guo, Hong, Bouillot, Vincent, Rettura, Alessandro, Meert, Alan, Buchan, Stewart, Kravtsov, Andrey, Bernardi, Mariangela, Sheth, Ravi, Vikram, Vinu, Marchesini, Danilo, Behroozi, Peter, Zheng, Zheng, Maraston, Claudia, Ascaso, Begoña, Lemaux, Brian C., Capozzi, Diego, Huertas-Company, Marc, Gal, Roy R., Lubin, Lori M., Conselice, Christopher J., Carollo, Marcella, and Cattaneo, Andrea

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The stellar mass-halo mass relation is a key constraint in all semi-analytic, numerical, and semi-empirical models of galaxy formation and evolution. However, its exact shape and redshift dependence remain debated. Several recent works support a relation in the local Universe steeper than previously thought. Based on the comparisons with a variety of data on massive central galaxies, we show that this steepening holds up to z~1, for stellar masses Mstar>2e11 Msun. Specifically, we find significant evidence for a high-mass end slope of \beta>0.35-0.70, instead of the usual \beta~0.20-0.30 reported by a number of previous results. When including the independent constraints from the recent BOSS clustering measurements, the data, independent of any systematic errors in stellar masses, tend to favor a model with a very small scatter (< 0.15 dex) in stellar mass at fixed halo mass, in the redshift range z < 0.8 and for Mstar>3e11 Msun, suggesting a close connection between massive galaxies and host halos even at relatively recent epochs. We discuss the implications of our results with respect to the evolution of the most massive galaxies since z~1., Comment: 6 pages, 4 figures. ApJ Letters, accepted

Published
2014
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8. Optical Galaxy Clusters in the Deep Lens Survey

Author

Ascaso, Begoña, Wittman, David, and Dawson, William

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present the first sample of 882 optically selected galaxy clusters in the Deep Lens Survey (DLS), selected with the Bayesian Cluster Finder. We create mock DLS data to assess completeness and purity rates, and find that both are at least $70\%$ within 0.1$\le z \le$ 1.2 for clusters with $M_{200}\ge 1.2\times 10^{14}M_{\odot}$. We verified the integrity of the sample by performing several comparisons with other optical, weak lensing, X-ray and spectroscopic surveys which overlap the DLS footprint: the estimated redshifts are consistent with the spectroscopic redshifts of known clusters (for $z>0.25$ where saturation in the DLS is not an issue); our richness estimates in combination with a previously calibrated richness-mass relation yields individual cluster mass estimates consistent with available SHeLS dynamical mass estimates; synthetic mass maps made from the optical mass estimates are correlated ($>3\sigma$ significance) with the weak lensing mass maps; and the mass function thus derived is consistent with theoretical predictions for the CDM scenario. With the verified sample we investigated correlations between the brightest cluster galaxies (BCG) properties and the host cluster properties within a broader range in redshift (0.25 $\le z \le$ 0.8) and mass ($\ge2.4\times 10^{14}M_{\odot}$) than in previous work. We find that the slope of the BCG magnitude-redshift relation throughout this redshift range is consistent with that found at lower redshifts. This result supports an extrapolation to higher redshift of passive evolution of the BCG within the hierarchical scenario., Comment: Paper accepted for publication in MNRAS, Table 1 will be available online or under request

Published
2014
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9. The Violent Youth of Bright and Massive Cluster Galaxies and their Maturation over 7 Billion Years

Author

Ascaso, Begoña, Lemaux, Brian C., Lubin, Lori M., Gal, Roy R., Kocevski, Dale D., Rumbaugh, Nicholas, and Squires, Gordon

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

In this study we investigate the formation and evolution mechanisms of the brightest cluster galaxies (BCGs) over cosmic time. At high redshift ($z\sim0.9$), we selected BCGs and most massive cluster galaxies (MMCGs) from the Cl1604 supercluster and compared them to low-redshift ($z\sim0.1$) counterparts drawn from the MCXC meta-catalog, supplemented by SDSS imaging and spectroscopy. We observed striking differences in the morphological, color, spectral, and stellar mass properties of the BCGs/MMCGs in the two samples. High-redshift BCGs/MMCGs were, in many cases, star-forming, late-type galaxies, with blue broadband colors, properties largely absent amongst the low-redshift BCGs/MMCGs. The stellar mass of BCGs was found to increase by an average factor of $2.51\pm0.71$ from $z\sim0.9$ to $z\sim0.1$. Through this and other comparisons we conclude that a combination of major merging (mainly wet or mixed) and \emph{in situ} star formation are the main mechanisms which build stellar mass in BCGs/MMCGs. The stellar mass growth of the BCGs/MMCGs also appears to grow in lockstep with both the stellar baryonic and total mass of the cluster. Additionally, BCGs/MMCGs were found to grow in size, on average, a factor of $\sim3$, while their average S\'ersic index increased by $\sim$0.45 from $z\sim0.9$ to $z\sim0.1$, also supporting a scenario involving major merging, though some adiabatic expansion is required. These observational results are compared to both models and simulations to further explore the implications on processes which shape and evolve BCGs/MMCGs over the past $\sim$7 Gyr., Comment: Accepted for publication in MNRAS

Published
2013
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10. Witnessing galaxy clusters: from maturity to childhood

Author

Ascaso, Begoña

Subjects
Astrophysics - Cosmology and Extragalactic Astrophysics
Abstract

Galaxy clusters are the largest structures in Universe. They are very important as both cosmological probes and astrophysical laboratories. Several methods have been developed to detect galaxy clusters with different techniques (optical, X-rays, Weak Lensing and Sunyaev-Zeldovich effect) providing cluster samples with a well-characterized purity and completeness rates up to moderate redshift (z$<$1.2). These samples allow us to study the systematic of different methods and to obtain reliable mass estimations. On the contrary, high redshift clusters only started to be explored very recently with the advent of deep IR and X-ray data surveys, providing the first proto-clusters (z$>$1.5-2) ever detected. In this talk, I introduce these techniques and review some of the cluster samples obtained including particular striking cases. I discuss their relevance in terms of cosmological and galaxy evolution constraints and finally, I briefly refer to the cluster science predictions for the next generation surveys., Comment: Invited talk presented at the tenth scientific meeting of the Spanish Astronomical Society, held in Valencia, Spain, in July 2012. To appear in the proceedings of the SEA X

Published
2012

11. A Brightest Cluster Galaxy with an Extremely Large Flat Core

Author

Postman, Marc, Lauer, Tod R., Donahue, Megan, Graves, Genevieve, Coe, Dan, Moustakas, John, Koekemoer, Anton, Bradley, Larry, Ford, Holland C., Grillo, Claudio, Zitrin, Adi, Lemze, Doron, Broadhurst, Tom, Moustakas, Leonidas, Ascaso, Begona, Medezinski, Elinor, and Kelson, Daniel

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics - High Energy Astrophysical Phenomena
Abstract

Hubble Space Telescope images of the galaxy cluster Abell 2261, obtained as part of the Cluster Lensing And Supernova survey with Hubble, show that the brightest galaxy in the cluster, A2261-BCG, has the largest core yet detected in any galaxy. The cusp radius of A2261-BCG is 3.2 kpc, twice as big as the next largest core known, and ~3x bigger than those typically seen in the most luminous BCGs. The morphology of the core in A2261-BCG is also unusual, having a flat or even slightly-depressed interior surface brightness profile, rather than the typical shallow cusp. This implies that the galaxy has a core with constant or even centrally decreasing stellar density. Interpretation of the core as an end product of the "scouring" action of a binary supermassive black hole implies a total black hole mass ~1E+10 M_sun from the extrapolation of most relationships between core structure and black hole mass. The core falls 1-sigma above the cusp-radius versus galaxy luminosity relation. Its large size in real terms, and the extremely large black hole mass required to generate it, raise the possibility that the core has been enlarged by additional processes, such as the ejection of the black holes that originally generated the core. The flat central stellar density profile is consistent with this hypothesis. The core is also displaced by 0.7 kpc from the center of the surrounding envelope, consistent with a local dynamical perturbation of the core., Comment: 11 pages, 7 figures, accepted for publication in the Astrophysical Journal

Published
2012
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12. CLASH: Precise New Constraints on the Mass Profile of Abell 2261

Author

Coe, Dan, Umetsu, Keiichi, Zitrin, Adi, Donahue, Megan, Medezinski, Elinor, Postman, Marc, Carrasco, Mauricio, Anguita, Timo, Geller, Margaret J., Rines, Kenneth J., Diaferio, Antonaldo, Kurtz, Michael J., Bradley, Larry, Koekemoer, Anton, Zheng, Wei, Nonino, Mario, Molino, Alberto, Mahdavi, Andisheh, Lemze, Doron, Infante, Leopoldo, Ogaz, Sara, Melchior, Peter, Host, Ole, Ford, Holland, Grillo, Claudio, Rosati, Piero, Jiménez-Teja, Yolanda, Moustakas, John, Broadhurst, Tom, Ascaso, Begoña, Lahav, Ofer, Bartelmann, Matthias, Benítez, Narciso, Bouwens, Rychard, Graur, Or, Graves, Genevieve, Jha, Saurabh, Jouvel, Stephanie, Kelson, Daniel, Moustakas, Leonidas, Maoz, Dan, Meneghetti, Massimo, Merten, Julian, Riess, Adam, Rodney, Steve, and Seitz, Stella

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We precisely constrain the inner mass profile of Abell 2261 (z=0.225) for the first time and determine this cluster is not "over-concentrated" as found previously, implying a formation time in agreement with {\Lambda}CDM expectations. These results are based on strong lensing analyses of new 16-band HST imaging obtained as part of the Cluster Lensing and Supernova survey with Hubble (CLASH). Combining this with revised weak lensing analyses of Subaru wide field imaging with 5-band Subaru + KPNO photometry, we place tight new constraints on the halo virial mass M_vir = 2.2\pm0.2\times10^15 M\odot/h70 (within r \approx 3 Mpc/h70) and concentration c = 6.2 \pm 0.3 when assuming a spherical halo. This agrees broadly with average c(M,z) predictions from recent {\Lambda}CDM simulations which span 5 <~ <~ 8. Our most significant systematic uncertainty is halo elongation along the line of sight. To estimate this, we also derive a mass profile based on archival Chandra X-ray observations and find it to be ~35% lower than our lensing-derived profile at r2500 ~ 600 kpc. Agreement can be achieved by a halo elongated with a ~2:1 axis ratio along our line of sight. For this elongated halo model, we find M_vir = 1.7\pm0.2\times10^15 M\odot/h70 and c_vir = 4.6\pm0.2, placing rough lower limits on these values. The need for halo elongation can be partially obviated by non-thermal pressure support and, perhaps entirely, by systematic errors in the X-ray mass measurements. We estimate the effect of background structures based on MMT/Hectospec spectroscopic redshifts and find these tend to lower Mvir further by ~7% and increase cvir by ~5%., Comment: Submitted to the Astrophysical Journal. 19 pages, 14 figures

Published
2012
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13. Bayesian Cluster Finder: Clusters in the CFHTLS Archive Research Survey

Author

Ascaso, Begoña, Wittman, David M., and Benítez, Narciso

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The detection of galaxy clusters in present and future surveys enables measuring mass-to-light ratios, clustering properties, galaxy cluster abundances and therefore, constraining cosmological parameters. We present a new technique for detecting galaxy clusters, which is based on the Matched Filter Algorithm from a Bayesian point of view. The method is able to determine the position, redshift and richness of the cluster through the maximization of a filter depending on galaxy luminosity, density and photometric redshift combined with a galaxy cluster prior that accounts for color-magnitude relations and BCG-redshift relation. We tested the algorithm through realistic mock galaxy catalogs, revealing that the detections are 100% complete and 80% pure for clusters up to z $<$1.2 and richer than $\Lambda_{CL}>$20 (Abell Richness $\sim$0, M$\sim4\times10^{14} M_{\odot}$). The completeness and purity remains approximately the same if we do not include the prior information, implying that this method is able to detect galaxy cluster with and without a well defined red sequence. We applied the algorithm to the CFHTLS Archive Research Survey (CARS) data, recovering similar detections as previously published using the same or deeper data plus additional clusters which appear to be real., Comment: Accepted for publication in MNRAS; 17 pages, 38 figures

Published
2011
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14. Detecting Galaxy Clusters in the DLS and CARS: a Bayesian Cluster Finder

Author

Ascaso, Begoña, Wittman, David, Benítez, Narciso, and collaboration, the DLS

Subjects
Astrophysics - Cosmology and Extragalactic Astrophysics
Abstract

The detection of galaxy clusters in present and future surveys enables measuring mass-to-light ratios, clustering properties or galaxy cluster abundances and therefore, constraining cosmological parameters. We present a new technique for detecting galaxy clusters, which is based on the Matched Filter Algorithm from a Bayesian point of view. The method is able to determine the position, redshift and richness of the cluster through the maximization of a filter depending on galaxy luminosity, density and photometric redshift combined with a galaxy cluster prior. We tested the algorithm through realistic mock galaxy catalogs, revealing that the detections are 100% complete and 80% pure for clusters up to z <1.2 and richer than \Lambda > 25 (Abell Richness > 0). We applied the algorithm to the CFHTLS Archive Research Survey (CARS) data, recovering similar detections as previously published using the same data plus additional clusters that are very probably real. We also applied this algorithm to the Deep Lens Survey (DLS), obtaining the first sample of optical-selected galaxy in this survey. The sample is complete up to redshift 0.7 and we detect more than 780 cluster candidates up to redshift 1.2. We conclude by discussing the differences between previous weak lensing detections in this survey and optical detections in both samples., Comment: 6 pages, 1 figure, to appear in the proceedings of the conference "IX Scientific Meeting of the Spanish Astronomical Society" (Madrid, September 13-17, 2010)

Published
2010

15. New Multiply-Lensed Galaxies Identified in ACS/NIC3 Observations of Cl0024+1654 Using an Improved Mass Model

Author

Zitrin, Adi, Broadhurst, Tom, Umetsu, Keiichi, Coe, Dan, Benítez, Narciso, Ascaso, Begoña, Bradley, Larry, Ford, Holland, Jee, James, Medezinski, Elinor, Rephaeli, Yoel, and Zheng, Wei

Subjects
Astrophysics - Cosmology and Extragalactic Astrophysics
Abstract

We present an improved strong-lensing analysis of Cl0024+1654 ($z$=0.39) using deep HST/ACS/NIC3 images, based on 33 multiply-lensed images of 11 background galaxies. These are found with a model that assumes mass approximately traces light, with a low order expansion to allow for flexibility on large scales. The model is constrained initially by the well known 5-image system ($z$=1.675) and refined as new multiply-lensed systems are identified using the model. Photometric redshifts of these new systems are then used to constrain better the mass profile by adopting the standard cosmological relation between redshift and lensing distance. Our model requires only 6 free parameters to describe well all positional and redshift data. The resulting inner mass profile has a slope of $d\log M/d\log r\simeq -0.55$, consistent with new weak-lensing measurements where the data overlap, at $r\simeq200$ kpc/$h_{70}$. The combined profile is well fitted by a high concentration NFW mass profile, $C_{\rm vir}\sim 8.6\pm1.6$, similar to other well studied clusters, but larger than predicted with standard $\Lambda$CDM. A well defined radial critical curve is generated by the model and is clearly observed at $r \simeq 12\arcsec$, outlined by elongated images pointing towards the centre of mass. The relative fluxes of the multiply-lensed images are found to agree well with the modelled magnifications, providing an independent consistency check., Comment: 19 pages, 28 figures, published in MNRAS. A copy with high resolution figures can be found at: ftp://wise-ftp.tau.ac.il/pub/adiz/Cl0024+1654Paper/

Published
2009
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18. 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

19. High redshift galaxies in the ALHAMBRA survey? II. Strengthening the evidence of bright-end excess in UV luminosity functions at 2.5 ≤ z ≤ 4.5 by PDF analysis

Author

Generalitat Valenciana, Junta de Andalucía, Generalitat de Catalunya, Fundación Agencia Aragonesa para la Investigación y el Desarrollo, Fondo de Inversiones de Teruel, European Commission, Ministry of Science and Technology (Ethiopia), Ministerio de Economía y Competitividad (España), Viironen, K., López-Sanjuan, Carlos, Hernández-Monteagudo, Carlos, Chaves-Montero, Jonás, Ascaso, Begoña, Bonoli, Silvia, Cristóbal-Hornillos, David, Díaz-García, L. A., Fernández-Soto, Alberto, Márquez, Isabel, Masegosa, Josefa, Pović, Mirjana, Varela, Jesús, Cenarro, A. J., Aguerri, J.A.L., Alfaro, Emilio J., Aparicio Villegas, Teresa, Benítez, Narciso, Broadhurst, Tom, Cabrera-Caño, Jesús, Castander, Francisco J., Cepa, Jordi, Cerviño, Miguel, González Delgado, Rosa M., Husillos, César, Infante, Leopoldo, Martínez, Vicente J., Moles, Mariano, Molino, Alberto, Olmo, Ascensión del, Perea, Jaime, Prada, Francisco, Quintana, José María, Generalitat Valenciana, Junta de Andalucía, Generalitat de Catalunya, Fundación Agencia Aragonesa para la Investigación y el Desarrollo, Fondo de Inversiones de Teruel, European Commission, Ministry of Science and Technology (Ethiopia), Ministerio de Economía y Competitividad (España), Viironen, K., López-Sanjuan, Carlos, Hernández-Monteagudo, Carlos, Chaves-Montero, Jonás, Ascaso, Begoña, Bonoli, Silvia, Cristóbal-Hornillos, David, Díaz-García, L. A., Fernández-Soto, Alberto, Márquez, Isabel, Masegosa, Josefa, Pović, Mirjana, Varela, Jesús, Cenarro, A. J., Aguerri, J.A.L., Alfaro, Emilio J., Aparicio Villegas, Teresa, Benítez, Narciso, Broadhurst, Tom, Cabrera-Caño, Jesús, Castander, Francisco J., Cepa, Jordi, Cerviño, Miguel, González Delgado, Rosa M., Husillos, César, Infante, Leopoldo, Martínez, Vicente J., Moles, Mariano, Molino, Alberto, Olmo, Ascensión del, Perea, Jaime, Prada, Francisco, and Quintana, José María

Abstract

Context. Knowing the exact shape of the ultraviolet (UV) luminosity function (LF) of high-redshift galaxies is important to understand the star formation history of the early Universe. However, the uncertainties, especially at the faint and bright ends of the LFs, remain significant. Aims. In this paper, we study the UV LF of redshift z = 2:5 4.5 galaxies in 2.38 deg of ALHAMBRA data with I ≤ 24. Thanks to the large area covered by ALHAMBRA, we particularly constrain the bright end of the LF. We also calculate the cosmic variance and the corresponding bias values for our sample and derive their host dark matter halo masses. Methods.We have used a novel methodology based on redshift and magnitude probability distribution functions (PDFs). This methodology robustly takes into account the uncertainties due to redshift and magnitude errors, shot noise, and cosmic variance, and models the LF in two dimensions (z; M). Results. We find an excess of bright ∼M∗ galaxies as compared to the studies based on broad-band photometric data. However, our results agree well with the LF of the magnitude-selected spectroscopic VVDS data. We measure high bias values, b ∼ 8 10, that are compatible with the previous measurements considering the redshifts and magnitudes of our galaxies and further reinforce the real high-redshift nature of our bright galaxies. Conclusions. We call into question the shape of the LF at its bright end; is it a double power-law as suggested by the recent broadband photometric studies or rather a brighter Schechter function, as suggested by our multi-filter analysis and the spectroscopic VVDS data.© ESO 2018.

Published
2018

20. 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

21. 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

22. 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
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23. Galaxy clusters with the square kilometer array

Author

Ascaso, Begoña, Ascasíbar, Y., Diego, José María, Planelles, S., Ministero dell'Istruzione, dell'Università e della Ricerca, Università degli studi di Trieste, Istituto Nazionale di Astrofisica, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia e Innovación (España), European Commission, and Université de Paris

Subjects
Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics
Abstract

We review some science cases for galaxy clusters and the impact that the future SKA data will have in those analyses. We first describe how the search for galaxy clusters through radio-sources will be significantly improved through the detection of much fainter radiosources in a big volume. Secondly, we bring out the benefits of using very sensitive radio data to study the thermal and non-thermal component of clusters and disentangle the main processes happening in the physics of their plasma. Moreover, we discuss the possibility of using the high frequencies of the SKA to separate the thermal Sunyaev-Zeldovich (SZ) effect from the radio halo emission and use the former as a mass proxy for galaxy clusters. Finally, we investigate how the very high sensitivity and spatial resolution of SKA will result into a great improvement in the lensing treatment, underlining the lensing distribution of the 21-cm intensity from the reionization period. As a whole, SKA will become an impressive window covering a significant wider range in redshift to look at an unknown radio universe and set constraints on different mechanisms happening in clusters., This work has been supported by a grant funded by the “Consorzio per la Fisica di Trieste”. SP also acknowledges support by the PRIN-INAF09 project “Towards an Italian Network for Computational Cosmology”, by the PRIN-MIUR09 “Tracing the growth of structures in the Universe”, and by the PD51 INFN grant. Partial support is also provided by Spanish Ministerio de Ciencia e Innovación (AYA2010-21322-C03-02). JD acknowledges support from the Spanish Ministry of Economy and Competitiveness (MINECO) through grants AYA2010-21766-C03-02, AYA2012-30789, and the Consolider-Ingenio project CSD2010-00064 (EPI: Exploring the Physics of Inflation). YA is financially supported by the Spanish Ramón y Cajal programme (RyC-2011-09461) and grant AYA2013-47742-C4-3-P (MINECO), as well as the ‘Study of Emission-Line Galaxies with Integral-Field Spectroscopy’ (SELGIFS) exchange programme, funded by the EU through the IRSES scheme (FP7-PEOPLE-2013-IRSES-612701). BA acknowledges financial support for a postdoctoral fellowship from the Observatory of Paris.

Published
2015

24. I. MUFFIT: A multi-filter fitting code for stellar population diagnostics

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
Galaxies: high-redshift, Galaxies: evolution, Galaxies: photometry, Galaxies: formation, Galaxies: stellar content
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

25. 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

26. 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

27. 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

28. 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

29. Evolution of Balmer jump selected galaxies in the ALHAMBRA survey

Author

Ministerio de Economía y Competitividad (España), European Commission, Generalitat Valenciana, Fondo Nacional de Desarrollo Científico y Tecnológico (Chile), Comisión Nacional de Investigación Científica y Tecnológica (Chile), Troncoso Iribarren, P., Infante, Leopoldo, Cristóbal-Hornillos, David, Moles, Mariano, Fernández-Soto, Alberto, Martínez, Vicente J., Cerviño, Miguel, Alfaro, Emilio J., Ascaso, Begoña, Arnalte-Mur, P., Nieves-Seoane, L., Benítez, Narciso, Ministerio de Economía y Competitividad (España), European Commission, Generalitat Valenciana, Fondo Nacional de Desarrollo Científico y Tecnológico (Chile), Comisión Nacional de Investigación Científica y Tecnológica (Chile), Troncoso Iribarren, P., Infante, Leopoldo, Cristóbal-Hornillos, David, Moles, Mariano, Fernández-Soto, Alberto, Martínez, Vicente J., Cerviño, Miguel, Alfaro, Emilio J., Ascaso, Begoña, Arnalte-Mur, P., Nieves-Seoane, L., and Benítez, Narciso

Abstract

[Context]: Samples of star-forming galaxies at different redshifts have been traditionally selected via color techniques. The ALHAMBRA survey was designed to perform a uniform cosmic tomography of the Universe, and we here exploit it to trace the evolution of these galaxies. [Aims]: Our objective is to use the homogeneous optical coverage of the ALHAMBRA filter system to select samples of star-forming galaxies at different epochs of the Universe and study their properties. [Methods]: We present a new color-selection technique, based on the models of spectral evolution convolved with the ALHAMBRA bands and the redshifted position of the Balmer jump to select star-forming galaxies in the redshift range 0.5

Published
2016

30. 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

31. 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

32. 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

33. 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

34. 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

35. Galaxy clusters with the square kilometer array

Author

Ministero dell'Istruzione, dell'Università e della Ricerca, Università degli studi di Trieste, Istituto Nazionale di Astrofisica, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia e Innovación (España), European Commission, Université de Paris, Ascaso, Begoña, Ascasíbar, Y., Diego, José María, Planelles, S., Ministero dell'Istruzione, dell'Università e della Ricerca, Università degli studi di Trieste, Istituto Nazionale di Astrofisica, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia e Innovación (España), European Commission, Université de Paris, Ascaso, Begoña, Ascasíbar, Y., Diego, José María, and Planelles, S.

Abstract

We review some science cases for galaxy clusters and the impact that the future SKA data will have in those analyses. We first describe how the search for galaxy clusters through radio-sources will be significantly improved through the detection of much fainter radiosources in a big volume. Secondly, we bring out the benefits of using very sensitive radio data to study the thermal and non-thermal component of clusters and disentangle the main processes happening in the physics of their plasma. Moreover, we discuss the possibility of using the high frequencies of the SKA to separate the thermal Sunyaev-Zeldovich (SZ) effect from the radio halo emission and use the former as a mass proxy for galaxy clusters. Finally, we investigate how the very high sensitivity and spatial resolution of SKA will result into a great improvement in the lensing treatment, underlining the lensing distribution of the 21-cm intensity from the reionization period. As a whole, SKA will become an impressive window covering a significant wider range in redshift to look at an unknown radio universe and set constraints on different mechanisms happening in clusters.

Published
2015

36. IAA : Información y actualidad astronómica (39)

Author

Pérez Montero, Enrique, Villar Martín, Montserrat, López de Lacalle, Silbia, Cornet, Fernando, Ascaso, Begoña, Pérez Jiménez, Enrique, Alberdi, Antxón, Candini, Gian Paolo, and Abril, Miguel

Abstract

Sumario : La evolución química del universo.-- Supervientos galácticos.-- CIENCIA EN HISTORIAS. Williamina Patton Fleming. De criada a astrónoma.-- DECONSTRUCCIÓN Y otros ENSAYOS. El bosón de Higgs.-- EL “MOBY DICK” DE... Begoña Ascaso (IAA-CSIC).-- ACTUALIDAD.-- ENTRE BASTIDORES.-- SALA LIMPIA.-- CIENCIA: PILARES E INCERTIDUMBRES. Veinte años de cinturón transneptuniano.

Published
2013

37. IAA : Información y actualidad astronómica (35)

Author

Guerrero, Martín A., Gutiérrez, Pedro J., Villar Martín, Montserrat, Gutiérrez Vela, Yael, Laguillo Diego, Alejandra, Aguayo Díaz, Alberto, Prior, Marcos, Márquez, Isabel, García, Emilio José, Ascaso, Begoña, López de Lacalle, Silbia, Estupinyà, Pere, Abril, Miguel, and Barceló, Carlos

Abstract

Sumario : Nebulosas planetarias.-- ¿Solo 25 años de ciencia cometaria?.-- Leyendo entre líneas (I).-- DECONSTRUCCIÓN Y otros ENSAYOS. La física del Correcaminos.-- EL “MOBY DICK” DE... Isabel Márquez (IAA-CSIC).-- CIENCIA EN HISTORIAS. La ciencia es un fraude...desde siempre.-- ACTUALIDAD.-- ENTRE BASTIDORES.-- SALA LIMPIA.-- CIENCIA: PILARES E INCERTIDUMBRES. Agujeros negros.-- AGENDA/RECOMENDADOS.

Published
2011

38. AVOIDING PROGENITOR BIAS: THE STRUCTURAL AND MASS EVOLUTION OF BRIGHTEST GROUP AND CLUSTER GALAXIES IN HIERARCHICAL MODELS SINCEz≲ 1

Author

Shankar, Francesco, primary, Buchan, Stewart, additional, Rettura, Alessandro, additional, Bouillot, Vincent R., additional, Moreno, Jorge, additional, Licitra, Rossella, additional, Bernardi, Mariangela, additional, Huertas-Company, Marc, additional, Mei, Simona, additional, Ascaso, Begoña, additional, Sheth, Ravi, additional, Delaye, Lauriane, additional, and Raichoor, Anand, additional

Published
2015
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39. The ALHAMBRA survey: Evolution of galaxy clustering since z∼1

Author

Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Junta de Andalucía, Ministerio de Ciencia e Innovación (MICIN). España, Cabrera Caño, Jesús María, Alnarte Mur, P., Martínez, V. J., Norberg, P., Fernández Soto, A., Ascaso, Begoña, Merson, A. I., Castander, F. J., Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Junta de Andalucía, Ministerio de Ciencia e Innovación (MICIN). España, Cabrera Caño, Jesús María, Alnarte Mur, P., Martínez, V. J., Norberg, P., Fernández Soto, A., Ascaso, Begoña, Merson, A. I., and Castander, F. J.

Abstract

We study the clustering of galaxies as function of luminosity and redshift in the range 0.35< z < 1.25 using data from the Advanced Large Homogeneous Area Medium-Band Redshift Astronomical (ALHAMBRA) survey. The ALHAMBRA data used in this work cover 2.38 deg2 in seven independent fields, after applying a detailed angular selection mask, with accurate photometric redshifts,σz≲ 0.014(1 + z), down to IAB < 24. Given the depth of the survey, we select samples in B-band luminosity down to Lth ≃ 0.16L* at z=0.9. We measure the real-space clustering using the projected correlation function, accounting for photometric redshifts uncertainties. We infer the galaxy bias, and study its evolution with luminosity. We study the effect of sample variance, and confirm earlier results that the Cosmic Evolution Survey (COSMOS) and European Large Area ISO Survey North 1 (ELAIS-N1) fields are dominated by the presence of large structures. For the intermediate and bright samples, Lmed ≳ 0.6L*, we obtain a strong dependence of bias on luminosity, in agreement with previous results at similar redshift. We are able to extend this study to fainter luminosities, where we obtain an almost flat relation, similar to that observed at low redshift. Regarding the evolution of bias with redshift, our results suggest that the different galaxy populations studied reside in haloes covering a range in mass between log10[Mh( h-1M{bull's eye})] ≳ 11.5 for samples with Lmed = 0.3L* and log10[Mh( h-1M⊙)] ≳ 13.0 for samples with Lmed = 2L*, with typical occupation numbers in the range of 1-3 galaxies per halo.

Published
2014

40. ON THE INTERMEDIATE-REDSHIFT CENTRAL STELLAR MASS-HALO MASS RELATION, AND IMPLICATIONS FOR THE EVOLUTION OF THE MOST MASSIVE GALAXIES SINCE z ∼ 1

Author

Shankar, Francesco, primary, Guo, Hong, additional, Bouillot, Vincent, additional, Rettura, Alessandro, additional, Meert, Alan, additional, Buchan, Stewart, additional, Kravtsov, Andrey, additional, Bernardi, Mariangela, additional, Sheth, Ravi, additional, Vikram, Vinu, additional, Marchesini, Danilo, additional, Behroozi, Peter, additional, Zheng, Zheng, additional, Maraston, Claudia, additional, Ascaso, Begoña, additional, Lemaux, Brian C., additional, Capozzi, Diego, additional, Huertas-Company, Marc, additional, Gal, Roy R., additional, Lubin, Lori M., additional, Conselice, Christopher J., additional, Carollo, Marcella, additional, and Cattaneo, Andrea, additional

Published
2014
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41. The ALHAMBRA survey: Discovery of a faint QSO at z = 5.41

Author

Junta de Andalucía, Ministerio de Ciencia e Innovación (España), Generalitat Valenciana, Consejo Superior de Investigaciones Científicas (España), European Commission, Matute, Israel, Masegosa, Josefa, Márquez, Isabel, Fernández-Soto, Alberto, Husillos, César, Olmo, Ascensión del, Perea, Jaime, Pović, Mirjana, Ascaso, Begoña, Alfaro, Emilio J., Moles, Mariano, Aguerri, J.A.L., Aparicio Villegas, Teresa, Benítez, Narciso, Broadhurst, Tom, Cabrera-Caño, Jesús, Castander, Francisco J., Cepa, Jordi, Cerviño, Miguel, Cristóbal-Hornillos, David, Infante, Leopoldo, González Delgado, Rosa M., Martínez, Vicente J., Molino, Alberto, Prada, Francisco, Quintana, José María, Junta de Andalucía, Ministerio de Ciencia e Innovación (España), Generalitat Valenciana, Consejo Superior de Investigaciones Científicas (España), European Commission, Matute, Israel, Masegosa, Josefa, Márquez, Isabel, Fernández-Soto, Alberto, Husillos, César, Olmo, Ascensión del, Perea, Jaime, Pović, Mirjana, Ascaso, Begoña, Alfaro, Emilio J., Moles, Mariano, Aguerri, J.A.L., Aparicio Villegas, Teresa, Benítez, Narciso, Broadhurst, Tom, Cabrera-Caño, Jesús, Castander, Francisco J., Cepa, Jordi, Cerviño, Miguel, Cristóbal-Hornillos, David, Infante, Leopoldo, González Delgado, Rosa M., Martínez, Vicente J., Molino, Alberto, Prada, Francisco, and Quintana, José María

Abstract

[Aims]: We aim to illustrate the potentiality of the Advanced Large, Homogeneous Area, Medium-Band Redshift Astronomical (ALHAMBRA) survey to investigate the high-redshift universe through the detection of quasi stellar objects (QSOs) at redshifts higher than 5. [Methods]: We searched for QSOs candidates at high redshift by fitting an extensive library of spectral energy distributions-including active and non-active galaxy templates, as well as stars-to the photometric database of the ALHAMBRA survey (composed of 20 optical medium-band plus the 3 broad-band JHKs near-infrared filters). [Results]: Our selection over ≈1 square degree of ALHAMBRA data (∼1/4 of the total area covered by the survey), combined with GTC/OSIRIS spectroscopy, has yielded identification of an optically faint QSO at very high redshift (z = 5.41). The QSO has an absolute magnitude of ∼-24 at the 1450 Å continuum, a bolometric luminosity of ≈2 × 1046 erg s -1, and an estimated black hole mass of ≈108 M ⊙. This QSO adds itself to a reduced number of known UV faint sources at these redshifts. The preliminary derived space density is compatible with the most recent determinations of the high-z QSO luminosity functions. This new detection shows how ALHAMBRA, as well as forthcoming well-designed photometric surveys, can provide a wealth of information on the origin and early evolution of this kind of object. © 2013 ESO.

Published
2013

42. The ALHAMBRA survey: evolution of galaxy clustering since z∼1

Author

European Research Council, Royal Society (UK), Science and Technology Facilities Council (UK), Generalitat Valenciana, Junta de Andalucía, Ministerio de Ciencia e Innovación (España), Arnalte-Mur, P., Martínez, Vicente J., Norberg, Peder, Fernández-Soto, Alberto, Ascaso, Begoña, Merson, Alexander I., Aguerri, J.A.L., Castander, Francisco J., Hurtado-Gil, L., López-Sanjuan, Carlos, Molino, Alberto, Montero-Dorta, Antonio D., Stefanon, Mauro, Alfaro, Emilio J., Aparicio Villegas, Teresa, Benítez, Narciso, Broadhurst, Tom, Cabrera-Caño, Jesús, Cepa, Jordi, Cerviño, Miguel, Cristóbal-Hornillos, David, Olmo, Ascensión del, González Delgado, Rosa M., Husillos, César, Infante, Leopoldo, Márquez, Isabel, Masegosa, Josefa, Moles, Mariano, Perea, Jaime, Pović, Mirjana, Prada, Francisco, Quintana, José María, European Research Council, Royal Society (UK), Science and Technology Facilities Council (UK), Generalitat Valenciana, Junta de Andalucía, Ministerio de Ciencia e Innovación (España), Arnalte-Mur, P., Martínez, Vicente J., Norberg, Peder, Fernández-Soto, Alberto, Ascaso, Begoña, Merson, Alexander I., Aguerri, J.A.L., Castander, Francisco J., Hurtado-Gil, L., López-Sanjuan, Carlos, Molino, Alberto, Montero-Dorta, Antonio D., Stefanon, Mauro, Alfaro, Emilio J., Aparicio Villegas, Teresa, Benítez, Narciso, Broadhurst, Tom, Cabrera-Caño, Jesús, Cepa, Jordi, Cerviño, Miguel, Cristóbal-Hornillos, David, Olmo, Ascensión del, González Delgado, Rosa M., Husillos, César, Infante, Leopoldo, Márquez, Isabel, Masegosa, Josefa, Moles, Mariano, Perea, Jaime, Pović, Mirjana, Prada, Francisco, and Quintana, José María

Published
2013

43. The ALHAMBRA survey: reliable morphological catalogue of 22 051 early- and late-type galaxies

Author

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

Abstract

Advanced Large Homogeneous Area Medium Band Redshift Astronomical (ALHAMBRA) is photometric survey designed to trace the cosmic evolution and cosmic variance. It covers a large area of ~4 deg2 in eight fields, where seven fields overlap with other surveys, allowing us to have complementary data in other wavelengths. All observations were carried out in 20 continuous, medium band (30 nm width) optical and 3 near-infrared (JHK) bands, providing the precise measurements of photometric redshifts. In addition, morphological classification of galaxies is crucial for any kind of galaxy formation and cosmic evolution studies, providing the information about star formation histories, their environment and interactions, internal perturbations, etc. We present a morphological classification of >40 000 galaxies in the ALHAMBRA survey. We associate to every galaxy a probability to be early type using the automated Bayesian code GALSVM. Despite of the spatial resolution of theALHAMBRAimages (~1 arcsec), for 22 051 galaxies, we obtained the contamination by other type of less than 10 per cent. Of those, 1640 and 10 322 galaxies are classified as early-(down to redshifts ~0.5) and late-type (down to redshifts ~1.0), respectively, with magnitudes F613W ≤ 22.0. In addition, for magnitude range 22.0 < F613W ≤ 23.0, we classified other 10 089 late-type galaxies with redshifts ≤1.3.We show that the classified objects populate the expected regions in the colour-mass and colour-magnitude planes. The presented data set is especially attractive given the homogeneous multiwavelength coverage available in the ALHAMBRA fields, and is intended to be used in a variety of scientific applications. The low-contamination catalogue (<10 per cent) is made publicly available with this paper. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.

Published
2013

44. CLASH: PRECISE NEW CONSTRAINTS ON THE MASS PROFILE OF THE GALAXY CLUSTER A2261

Author

Coe, Dan, primary, Umetsu, Keiichi, additional, Zitrin, Adi, additional, Donahue, Megan, additional, Medezinski, Elinor, additional, Postman, Marc, additional, Carrasco, Mauricio, additional, Anguita, Timo, additional, Geller, Margaret J., additional, Rines, Kenneth J., additional, Diaferio, Antonaldo, additional, Kurtz, Michael J., additional, Bradley, Larry, additional, Koekemoer, Anton, additional, Zheng, Wei, additional, Nonino, Mario, additional, Molino, Alberto, additional, Mahdavi, Andisheh, additional, Lemze, Doron, additional, Infante, Leopoldo, additional, Ogaz, Sara, additional, Melchior, Peter, additional, Host, Ole, additional, Ford, Holland, additional, Grillo, Claudio, additional, Rosati, Piero, additional, Jiménez-Teja, Yolanda, additional, Moustakas, John, additional, Broadhurst, Tom, additional, Ascaso, Begoña, additional, Lahav, Ofer, additional, Bartelmann, Matthias, additional, Benítez, Narciso, additional, Bouwens, Rychard, additional, Graur, Or, additional, Graves, Genevieve, additional, Jha, Saurabh, additional, Jouvel, Stephanie, additional, Kelson, Daniel, additional, Moustakas, Leonidas, additional, Maoz, Dan, additional, Meneghetti, Massimo, additional, Merten, Julian, additional, Riess, Adam, additional, Rodney, Steve, additional, and Seitz, Stella, additional

Published
2012
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45. A BRIGHTEST CLUSTER GALAXY WITH AN EXTREMELY LARGE FLAT CORE

Author

Postman, Marc, primary, Lauer, Tod R., additional, Donahue, Megan, additional, Graves, Genevieve, additional, Coe, Dan, additional, Moustakas, John, additional, Koekemoer, Anton, additional, Bradley, Larry, additional, Ford, Holland C., additional, Grillo, Claudio, additional, Zitrin, Adi, additional, Lemze, Doron, additional, Broadhurst, Tom, additional, Moustakas, Leonidas, additional, Ascaso, Begoña, additional, Medezinski, Elinor, additional, and Kelson, Daniel, additional

Published
2012
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47. Bayesian Cluster Finder: Clusters in the CFHTLS Archive Research Survey

Author

Wittman, David, Ascaso, B., Benítez, Narciso, Benítez, N., Wittman, D., and Ascaso, Begoña

Subjects
Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

The detection of galaxy clusters in present and future surveys enables measuring mass-to-light ratios, clustering properties, galaxy cluster abundances and therefore, constraining cosmological parameters. We present a new technique for detecting galaxy clusters, which is based on the Matched Filter Algorithm from a Bayesian point of view. The method is able to determine the position, redshift and richness of the cluster through the maximization of a filter depending on galaxy luminosity, density and photometric redshift combined with a galaxy cluster prior that accounts for color-magnitude relations and BCG-redshift relation. We tested the algorithm through realistic mock galaxy catalogs, revealing that the detections are 100% complete and 80% pure for clusters up to z $$20 (Abell Richness $\sim$0, M$\sim4\times10^{14} M_{\odot}$). The completeness and purity remains approximately the same if we do not include the prior information, implying that this method is able to detect galaxy cluster with and without a well defined red sequence. We applied the algorithm to the CFHTLS Archive Research Survey (CARS) data, recovering similar detections as previously published using the same or deeper data plus additional clusters which appear to be real. Comment: Accepted for publication in MNRAS; 17 pages, 38 figures

48. Detecting Galaxy Clusters in the DLS and CARS: a Bayesian Cluster Finder

Author

Ascaso, Begoña, Wittman, David, Benítez, Narciso, and collaboration, the DLS

Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO), FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The detection of galaxy clusters in present and future surveys enables measuring mass-to-light ratios, clustering properties or galaxy cluster abundances and therefore, constraining cosmological parameters. We present a new technique for detecting galaxy clusters, which is based on the Matched Filter Algorithm from a Bayesian point of view. The method is able to determine the position, redshift and richness of the cluster through the maximization of a filter depending on galaxy luminosity, density and photometric redshift combined with a galaxy cluster prior. We tested the algorithm through realistic mock galaxy catalogs, revealing that the detections are 100% complete and 80% pure for clusters up to z 25 (Abell Richness > 0). We applied the algorithm to the CFHTLS Archive Research Survey (CARS) data, recovering similar detections as previously published using the same data plus additional clusters that are very probably real. We also applied this algorithm to the Deep Lens Survey (DLS), obtaining the first sample of optical-selected galaxy in this survey. The sample is complete up to redshift 0.7 and we detect more than 780 cluster candidates up to redshift 1.2. We conclude by discussing the differences between previous weak lensing detections in this survey and optical detections in both samples., 6 pages, 1 figure, to appear in the proceedings of the conference "IX Scientific Meeting of the Spanish Astronomical Society" (Madrid, September 13-17, 2010)

49. AVOIDING PROGENITOR BIAS: THE STRUCTURAL AND MASS EVOLUTION OF BRIGHTEST GROUP AND CLUSTER GALAXIES IN HIERARCHICAL MODELS SINCE z ≲ 1.

Author

Shankar, Francesco, Buchan, Stewart, Rettura, Alessandro, Bouillot, Vincent R., Moreno, Jorge, Licitra, Rossella, Bernardi, Mariangela, Huertas-Company, Marc, Mei, Simona, Ascaso, Begoña, Sheth, Ravi, Delaye, Lauriane, and Raichoor, Anand

Subjects
STELLAR mass, STELLAR evolution, GALAXY formation, STELLAR orbits, GALACTIC dynamics
Abstract

The mass and structural evolution of massive galaxies is one of the hottest topics in galaxy formation. This is because it may reveal invaluable insights into the still debated evolutionary processes governing the growth and assembly of spheroids. However, direct comparison between models and observations is usually prevented by the so-called progenitor bias, i.e., new galaxies entering the observational selection at later epochs, thus eluding a precise study of how pre-existing galaxies actually evolve in size. To limit this effect, we here gather data on high-redshift brightest group and cluster galaxies, evolve their (mean) host halo masses down to z = 0 along their main progenitors, and assign as their “descendants” local Sloan Digital Sky Survey central galaxies matched in host halo mass. At face value, the comparison between high redshift and local data suggests a noticeable increase in stellar mass of a factor of ≳ 2 since z ∼ 1, and of ≳ 2.5 in mean effective radius. We then compare the inferred stellar mass and size growth with those predicted by hierarchical models for central galaxies, selected at high redshifts to closely match the halo and stellar mass bins as in the data. Only hierarchical models characterized by very limited satellite stellar stripping and parabolic orbits are capable of broadly reproducing the stellar mass and size increase of a factor of ∼2-4 observed in cluster galaxies since z ∼ 1. The predicted, average (major) merger rate since z ∼ 1 is in good agreement with the latest observational estimates. [ABSTRACT FROM AUTHOR]

Published
2015
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