Search

Your search keyword '"Kneib, J."' showing total 2,007 results
Start Over "Kneib, J."
2,007 results on '"Kneib, J."'

401. The zCOSMOS-Bright survey: the clustering of early and late galaxy morphological types since z≃ 1

Author

de la Torre, S., Le Fèvre, O., Porciani, C., Guzzo, L., Meneux, B., Abbas, U., Tasca, L., Carollo, C. M., Contini, T., Kneib, J.-P, Lilly, S. J., Mainieri, V., Renzini, A., Scodeggio, M., Zamorani, G., Bardelli, S., Bolzonella, M., Bongiorno, A., Caputi, K., Coppa, G., Cucciati, O., de Ravel, L., Franzetti, P., Garilli, B., Halliday, C., Iovino, A., Kampczyk, P., Knobel, C., Koekemoer, A. M., Kovač, K., Lamareille, F., Le Borgne, J.-F, Le Brun, V., Maier, C., Mignoli, M., Pelló, R., Peng, Y., Perez-Montero, E., Ricciardelli, E., Silverman, J., Tanaka, M., Tresse, L., Vergani, D., Zucca, E., Bottini, D., Cappi, A., Cassata, P., Cimatti, A., Leauthaud, A., Maccagni, D., Marinoni, C., McCracken, H. J., Memeo, P., Oesch, P., Pozzetti, L., Scaramella, R., de la Torre, S., Le Fèvre, O., Porciani, C., Guzzo, L., Meneux, B., Abbas, U., Tasca, L., Carollo, C. M., Contini, T., Kneib, J.-P, Lilly, S. J., Mainieri, V., Renzini, A., Scodeggio, M., Zamorani, G., Bardelli, S., Bolzonella, M., Bongiorno, A., Caputi, K., Coppa, G., Cucciati, O., de Ravel, L., Franzetti, P., Garilli, B., Halliday, C., Iovino, A., Kampczyk, P., Knobel, C., Koekemoer, A. M., Kovač, K., Lamareille, F., Le Borgne, J.-F, Le Brun, V., Maier, C., Mignoli, M., Pelló, R., Peng, Y., Perez-Montero, E., Ricciardelli, E., Silverman, J., Tanaka, M., Tresse, L., Vergani, D., Zucca, E., Bottini, D., Cappi, A., Cassata, P., Cimatti, A., Leauthaud, A., Maccagni, D., Marinoni, C., McCracken, H. J., Memeo, P., Oesch, P., Pozzetti, L., and Scaramella, R.

Abstract

We measure the spatial clustering of galaxies as a function of their morphological type at z≃ 0.8, for the first time in a deep redshift survey with full morphological information. This is obtained by combining high-resolution Hubble Space Telescope imaging and Very Large Telescope spectroscopy for about 8500 galaxies to with accurate spectroscopic redshifts from the zCOSMOS-Bright redshift survey. At this epoch, early-type galaxies already show a significantly stronger clustering than late-type galaxies on all probed scales. A comparison to the Sloan Digital Sky Survey Data at z≃ 0.1 shows that the relative clustering strength between early and late morphological classes tends to increase with cosmic time at small separations, while on large scales it shows no significant evolution since z≃ 0.8. This suggests that most early-type galaxies had already formed in intermediate and dense environments at this epoch. Our results are consistent with a picture in which the relative clustering of different morphological types between z≃ 1 and 0 reflects the evolving role of environment in the morphological transformation of galaxies, on top of a global evolution driven by mass

Published
2017

402. Bars in early- and late-type discs in COSMOS

Author

Cameron, E., Carollo, C. M., Oesch, P., Aller, M. C., Bschorr, T., Cerulo, P., Aussel, H., Capak, P., Le Floc'h, E., Ilbert, O., Kneib, J.-P, Koekemoer, A., Leauthaud, A., Lilly, S. J., Massey, R., McCracken, H. J., Rhodes, J., Salvato, M., Sanders, D. B., Scoville, N., Sheth, K., Taniguchi, Y., Thompson, D., Cameron, E., Carollo, C. M., Oesch, P., Aller, M. C., Bschorr, T., Cerulo, P., Aussel, H., Capak, P., Le Floc'h, E., Ilbert, O., Kneib, J.-P, Koekemoer, A., Leauthaud, A., Lilly, S. J., Massey, R., McCracken, H. J., Rhodes, J., Salvato, M., Sanders, D. B., Scoville, N., Sheth, K., Taniguchi, Y., and Thompson, D.

Abstract

We investigate the (large-scale) bar fraction in a mass-complete sample of M > 1010.5 M⊙ disc galaxies at 0.2 < z < 0.6 in the Cosmological Evolution Survey (COSMOS) field. The fraction of barred discs strongly depends on mass, disc morphology and specific star formation rate (SSFR). At intermediate stellar mass (1010.5 < M < 1011 M⊙) the bar fraction in early-type discs is much higher, at all redshifts, by a factor of ∼2, than that in late-type discs. This trend is reversed at higher stellar mass (M > 1011 M⊙), where the fraction of bars in early-type discs becomes significantly lower, at all redshifts, than that in late-type discs. The bar fractions for galaxies with low and high SSFRs closely follow those of the morphologically selected early- and late-type populations, respectively. This indicates a close correspondence between morphology and SSFR in disc galaxies at these earlier epochs. Interestingly, the total bar fraction in 1010.5 < M < 1011 M⊙ discs is built up by a factor of ∼2 over the redshift interval explored, while for M > 1011 M⊙ discs it remains roughly constant. This indicates that, already by z∼ 0.6, spectral and morphological transformations in the most massive disc galaxies have largely converged to the familiar Hubble sequence that we observe in the local Universe, while for intermediate-mass discs this convergence is ongoing until at least z∼ 0.2. Moreover, these results highlight the importance of employing mass-limited samples for quantifying the evolution of barred galaxies. Finally, the evolution of the barred galaxy populations investigated does not depend on the large-scale environmental density (at least, on the scales which can be probed with the available photometric redshifts)

Published
2017

403. Investigating the relationship between AGN activity and stellar mass in zCOSMOS galaxies at 0

Author

Vitale, M, Mignoli, M, Cimatti, A, Lilly, S, Carollo, C, Contini, T, Kneib, J, Fevre, O, Mainieri, V, Renzini, A, Scodeggio, M, Zamorani, G, Bardelli, S, Barnes, L, Bolzonella, M, Bongiorno, A, Bordoloi, R, Bschorr, T, Cappi, A, Caputi, K, Coppa, G, Cucciati, O, Torre, S, Ravel, L, and Franzetti, P

Abstract

We investigate the link between AGN activity, star-formation and stellar mass of the host galaxy at 010.2 threshold. Moreover, the stellar populations of AGN hosts are found to be older with respect to star-forming and composites galaxies. This could be due to the the tendency of AGN to reside in massive hosts. The dependence of the AGN classification on the stellar mass is in agreement with what has been already found in previous studies. It is consistent with, together with the evidence of older stellar populations inhabiting the AGN-like galaxies, the downsizing scenario. In particular, our evidence points to an evolutionary scenario where the AGN-feedback is capable of quenching the star formation in the most massive galaxies. Therefore, the AGN-feedback is the best candidate for initiating the passive evolutionary phase of galaxies.

Published
2016

404. Understanding the shape of the galaxy two-point correlation function at z~1 in the COSMOS field

Author

Torre, S, Guzzo, L, Kovac, K, Porciani, C, Abbas, U, Meneux, B, Carollo, C, Contini, T, Kneib, J, Fevre, O, Lilly, S, Mainieri, V, Renzini, A, Sanders, D, Scodeggio, M, Scoville, N, Zamorani, G, Bardelli, S, Bolzonella, M, Bongiorno, A, Caputi, K, Coppa, G, Cucciati, O, Ravel, L, and Franzetti, P

Abstract

We investigate how the shape of the galaxy two-point correlation function as measured in the zCOSMOS survey depends on local environment, quantified in terms of the density contrast on scales of 5 Mpc/h. We show that the flat shape previously observed at redshifts between z=0.6 and z=1 can be explained by this volume being simply 10% over-abundant in high-density environments, with respect to a Universal density probability distribution function. When galaxies corresponding to the top 10% tail of the distribution are excluded, the measured w_p(r_p) steepens and becomes indistinguishable from LCDM predictions on all scales. This is the same effect recognised by Abbas and Sheth in the SDSS data at z~0 and explained as a natural consequence of halo-environment correlations in a hierarchical scenario. Galaxies living in high-density regions trace dark matter halos with typically higher masses, which are more correlated. If the density probability distribution function of the sample is particularly rich in high-density regions because of the variance introduced by its finite size, this produces a distorted two-point correlation function. We argue that this is the dominant effect responsible for the observed "peculiar" clustering in the COSMOS field.

Published
2016
Full Text
View/download PDF

405. New constraints on the co-moving star formation rate in the redshift interval 6

Author

Ellis, R, Stark, D, Richard, J, Bunker, A, Egami, E, and Kneib, J

Abstract

Recent progress in measuring the optical depth of neutral hydrogen in distant quasars and that of electron scattering of microwave background photons suggests that most of the sources responsible for cosmic re-ionisation probably lie in the redshift interval 6 to 10. We present two new observational results which, together, provide valuable constraints on the contribution from star-forming sources in this redshift interval. First, using a large sample of v-band dropouts with unconfused Spitzer-IRAC detections, we determine the integrated stellar mass density at z = 5. This provides a valuable integral constraint on past star formation. It seems difficult to reconcile the observed stellar mass at z = 5 with the low abundance of luminous i-z- and J-band dropouts in deep Hubble Space Telescope data. Accordingly, we explore whether less luminous star-forming sources in the redshift interval 6 to 10 might be the dominant cause of cosmic re-ionization. In the second component of our research, we report on the results of two surveys for weak Lyman emitters and z- and J-band dropouts highly-magnified by foreground lensing clusters. Although some promising z = 89 candidates are found, it seems unlikely that low luminosity sources in this redshift interval can dominate cosmic reionization. If our work is substantiated by more extensive and precise surveys, the bulk of the re-ionizing photons may come from yet earlier sources lying at redshifts z>10. © 2007 International Astronomical Union.

Published
2016

406. Wide field spectrograph concepts for the European extremely large telescope - art. no. 62692G

Author

Moretto, G, Bacon, R, Cuby, J-G, Hammer, F, Amram, P, Blais-Ouellette, S, Blanc, P-E, Devriendt, J, Epinat, B, Fusco, T, Jagourel, P, Hernandez, O, Kneib, J-P, Montilla, I, Neichel, B, Pecontal, E, Prieto, E, and Puech, M

Abstract

We report on the science case high level specifications for a wide field spectrograph instrument for an Extremely Large Telescope (ELT) and present possible concepts. Preliminary designs are presented which resort to different instrument concepts: monolithic integral field (IFU), multi-IFU, and a smart tunable filter. This work is part of the activities performed in the work package 'Instrumentation' of the 'ELT Design Study', a programme supported by the European Community, Framework Programme 6.

Published
2016

407. Proto-groups at 1.8

Author

Diener, C, Lilly, S, Knobel, C, Zamorani, G, Lemson, G, Kampczyk, P, Scoville, N, Carollo, C, Contini, T, Kneib, J, Fevre, O, Mainieri, V, Renzini, A, Scodeggio, M, Bardelli, S, Bolzonella, M, Bongiorno, A, Caputi, K, Cucciati, O, Torre, S, Ravel, L, Franzetti, P, Garilli, B, Iovino, A, and Kovač, K

Abstract

We identify 42 candidate groups lying between 1.8

Published
2016

408. The COSMOS Density Field: A Reconstruction Using Both Weak Lensing and Galaxy Distributions

Author

Amara, A, Lilly, S, Kovac, K, Rhodes, J, Massey, R, Zamorani, G, Carollo, C, Contini, T, Kneib, J, Fevre, O, Mainieri, V, Renzini, A, Scodeggio, M, Bardelli, S, Bolzonella, M, Bongiorno, A, Caputi, K, Cucciati, O, Torre, S, Ravel, L, Franzetti, P, Garilli, B, Iovino, A, Kampczyk, P, and Knobel, C

Abstract

The COSMOS field has been the subject of a wide range of observations, with a number of studies focusing on reconstructing the 3D dark matter density field. Typically, these studies have focused on one given method or tracer. In this paper, we reconstruct the distribution of mass in the COSMOS field out to a redshift z=1 by combining Hubble Space Telescope weak lensing measurements with zCOSMOS spectroscopic measurements of galaxy clustering. The distribution of galaxies traces the distribution of mass with high resolution (particularly in redshift, which is not possible with lensing), and the lensing data empirically calibrates the mass normalisation (bypassing the need for theoretical models). Two steps are needed to convert a galaxy survey into a density field. The first step is to create a smooth field from the galaxy positions, which is a point field. We investigate four possible methods for this: (i) Gaussian smoothing, (ii) convolution with truncated isothermal sphere, (iii) fifth nearest neighbour smoothing and (iv) a muliti-scale entropy method. The second step is to rescale this density field using a bias prescription. We calculate the optimal bias scaling for each method by comparing predictions from the smoothed density field with the measured weak lensing data, on a galaxy-by-galaxy basis. In general, we find scale-independent bias for all the smoothing schemes, to a precision of 10%. For the nearest neighbour smoothing case, we find the bias to be 2.51\pm 0.25. We also find evidence for a strongly evolving bias, increasing by a factor of ~3.5 between redshifts 0

Published
2016
Full Text
View/download PDF

409. X-ray Groups of Galaxies at 0.5

Author

Tanaka, M, Finoguenov, A, Lilly, S, Bolzonella, M, Carollo, C, Contini, T, Iovino, A, Kneib, J, Lamareille, F, Fevre, O, Mainieri, V, Presotto, V, Renzini, A, Scodeggio, M, Silverman, J, Zamorani, G, Bardelli, S, Bongiorno, A, Caputi, K, Cucciati, O, Torre, S, Ravel, L, Franzetti, P, Garilli, B, and Kampczyk, P

Abstract

We present a photometric and spectroscopic study of galaxies at 0.5

Published
2016

410. Mass assembly in quiescent and star-forming galaxies since z similar or equal to 4 from UltraVISTA

Author

Ilbert, O., McCracken, H. J., Le Fevre, O., Capak, P., Dunlop, J., Karim, A., Renzini, M. A., Caputi, K., Boissier, S., Arnouts, S., Aussel, H., Comparat, J., Guo, Q., Hudelot, P., Kartaltepe, J., Kneib, J. P., Krogager, J. K., Le Floc'h, E., Lilly, S., Mellier, Y., Milvang-Jensen, B., Moutard, T., Onodera, M., Richard, J., Salvato, M., Sanders, D. B., Scoville, N., Silverman, J. D., Taniguchi, Y., Tasca, L., Thomas, R., Toft, S., Tresse, L., Vergani, D., Wolk, M., Zirm, A., Ilbert, O., McCracken, H. J., Le Fevre, O., Capak, P., Dunlop, J., Karim, A., Renzini, M. A., Caputi, K., Boissier, S., Arnouts, S., Aussel, H., Comparat, J., Guo, Q., Hudelot, P., Kartaltepe, J., Kneib, J. P., Krogager, J. K., Le Floc'h, E., Lilly, S., Mellier, Y., Milvang-Jensen, B., Moutard, T., Onodera, M., Richard, J., Salvato, M., Sanders, D. B., Scoville, N., Silverman, J. D., Taniguchi, Y., Tasca, L., Thomas, R., Toft, S., Tresse, L., Vergani, D., Wolk, M., and Zirm, A.

Published
2013

411. Molecular gas properties of a lensed star-forming galaxy at z ~ 3.6: a case study

Author

Dessauges-Zavadsky, M., primary, Zamojski, M., additional, Rujopakarn, W., additional, Richard, J., additional, Sklias, P., additional, Schaerer, D., additional, Combes, F., additional, Ebeling, H., additional, Rawle, T. D., additional, Egami, E., additional, Boone, F., additional, Clément, B., additional, Kneib, J.-P., additional, Nyland, K., additional, and Walth, G., additional

Published
2017
Full Text
View/download PDF

413. The SDSS-IV extended Baryon Oscillation Spectroscopic Survey: final emission line galaxy target selection

Author

Raichoor, A., primary, Comparat, J., additional, Delubac, T., additional, Kneib, J.-P., additional, Yèche, Ch, additional, Dawson, K. S., additional, Percival, W. J., additional, Dey, A., additional, Lang, D., additional, Schlegel, D. J., additional, Gorgoni, C., additional, Bautista, J., additional, Brownstein, J. R., additional, Mariappan, V., additional, Seo, H.-J., additional, Tinker, J. L., additional, Ross, A. J., additional, Wang, Y., additional, Zhao, G.-B., additional, Moustakas, J., additional, Palanque-Delabrouille, N., additional, Jullo, E., additional, Newmann, J. A., additional, Prada, F., additional, and Zhu, G. B., additional

Published
2017
Full Text
View/download PDF

414. VICS82: The VISTA–CFHT Stripe 82 Near-infrared Survey

Author

Geach, J. E., primary, Lin, Y.-T., additional, Makler, M., additional, Kneib, J.-P., additional, Ross, N. P., additional, Wang, W.-H., additional, Hsieh, B.-C., additional, Leauthaud, A., additional, Bundy, K., additional, McCracken, H. J., additional, Comparat, J., additional, Caminha, G. B., additional, Hudelot, P., additional, Lin, L., additional, Waerbeke, L. Van, additional, Pereira, M. E. S., additional, and Mast, D., additional

Published
2017
Full Text
View/download PDF

415. Photometric redshifts and clustering of emission line galaxies selected jointly by DES and eBOSS

Author

Jouvel, S., primary, Delubac, T., additional, Comparat, J., additional, Camacho, H., additional, Carnero, A., additional, Abdalla, F. B., additional, Kneib, J.-P., additional, Merson, A., additional, Lima, M., additional, Sobreira, F., additional, da Costa, Luiz, additional, Prada, F., additional, Zhu, G. B., additional, Benoit-Levy, A., additional, Macora, A. De La, additional, Kuropatkin, N., additional, Lin, H., additional, Abbott, T. M. C., additional, Allam, S., additional, Banerji, M., additional, Bertin, E., additional, Brooks, D., additional, Capozzi, D., additional, Kind, M. Carrasco, additional, Carretero, J., additional, Castander, F. J., additional, Cunha, C. E., additional, Desai, S., additional, Doel, P., additional, Eifler, T. F., additional, Estrada, J., additional, Neto, A. Fausti, additional, Flaugher, B., additional, Fosalba, P., additional, Frieman, J., additional, Gaztanaga, E., additional, Gerdes, D. W., additional, Gruen, D., additional, Gruendl, R. A., additional, Gutierrez, G., additional, Honscheid, K., additional, James, D. J., additional, Kuehn, K., additional, Lahav, O., additional, Li, T. S., additional, Maia, M. A. G., additional, March, M., additional, Marshall, J. L., additional, Miquel, R., additional, Ogando, R., additional, Percival, W. J., additional, Plazas, A. A., additional, Reil, K., additional, Romer, A. K., additional, Roodman, A., additional, Rykoff, E. S., additional, Sako, M., additional, Sanchez, E., additional, Santiago, B., additional, Scarpine, V., additional, Sevilla-Noarbe, I., additional, Soares-Santos, M., additional, Suchyta, E., additional, Tarle, G., additional, Thaler, J., additional, Thomas, D., additional, Walker, A., additional, Zhang, Y., additional, and Brownstein, J., additional

Published
2017
Full Text
View/download PDF

416. CODEX weak lensing: concentration of galaxy clusters at z ∼ 0.5

Author

Cibirka, N., primary, Cypriano, E. S., additional, Brimioulle, F., additional, Gruen, D., additional, Erben, T., additional, van Waerbeke, L., additional, Miller, L., additional, Finoguenov, A., additional, Kirkpatrick, C., additional, Henry, J. Patrick, additional, Rykoff, E., additional, Rozo, E., additional, Dupke, R., additional, Kneib, J.-P., additional, Shan, H., additional, and Spinelli, P., additional

Published
2017
Full Text
View/download PDF

419. Strong lensing by a node of the cosmic web The core of MACS J0717.5+3745 at z=0.55

Author

Limousin, Marceau Karim Emile, Ebeling, H., Richard, J., Swinbank, A.M., Smith, G.P., Jauzac, M., Rodionov, S., Ma, C.-J, Smail, I., Edge, A.C., Jullo, E., Kneib, J.-P, Limousin, Marceau Karim Emile, Ebeling, H., Richard, J., Swinbank, A.M., Smith, G.P., Jauzac, M., Rodionov, S., Ma, C.-J, Smail, I., Edge, A.C., Jullo, E., and Kneib, J.-P

Published
2012

420. Evolution of the observed Ly-alpha luminosity function from z = 6.5 to z = 7.7: evidence for the epoch of reionization ?

Author

Clément, B., Cuby, J.-G., Courbin, F., Fontana, A., Freudling, W., Fynbo, Johan Peter Uldall, Gallego, J., Hibon, P., Kneib, J.-P., Le Févre, O., Lidman, C., McMahon, R., Milvang-Jensen, Bo, Clément, B., Cuby, J.-G., Courbin, F., Fontana, A., Freudling, W., Fynbo, Johan Peter Uldall, Gallego, J., Hibon, P., Kneib, J.-P., Le Févre, O., Lidman, C., McMahon, R., and Milvang-Jensen, Bo

Published
2012

421. Extreme emission-line galaxies out to z similar to 1 in zCOSMOS I. Sample and characterization of global properties

Author

Amorin, R., Perez-Montero, F., Contini, T., Vilchez, J. M., Bolzonella, M., Tasca, L. A. M., Lamareille, F., Zamorani, G., Maier, C., Carollo, C. M., Kneib, J. -P., Le Fevre, O., Lilly, S., Mainieri, V., Renzinis, A., Scodeggio, M., Bardelli, S., Bongiorno, A., Caputi, K., Cucciati, O., de la Torre, S., de Ravel, L., Franzetti, P., Garilli, B., Iovino, A., Kampczyk, P., Knobel, C., Kovac, K., Le Borgne, J. -F., Le Brun, V., Mignoli, M., Pello, R., Peng, Y., Presotto, V., Ricciardelli, E., Silverman, J. D., Tanaka, M., Tresse, L., Vergani, D., Zucca, E., and Kapteyn Astronomical Institute

Subjects
ACTIVE GALACTIC NUCLEI, galaxies: irregular galaxies: star formation, ULTRA DEEP FIELD, METAL-POOR GALAXIES, galaxies: fundamental parameters, galaxies: starburst, Astrophysics::Cosmology and Extragalactic Astrophysics, LYMAN BREAK GALAXIES, LY-ALPHA EMITTERS, LUMINOSITY-METALLICITY RELATION, COMPACT DWARF GALAXIES, STAR-FORMING GALAXIES, Astrophysics::Solar and Stellar Astrophysics, DIGITAL SKY SURVEY, galaxies: abundances, Astrophysics::Earth and Planetary Astrophysics, GREEN PEA GALAXIES, galaxies: evolution, Astrophysics::Galaxy Astrophysics
Abstract

Context. The study of large and representative samples of low-metallicity star-forming galaxies at different cosmic epochs is of great interest to the detailed understanding of the assembly history and evolution of low-mass galaxies. Aims. We present a thorough characterization of a large sample of 183 extreme emission-line galaxies (EELGs) at redshift 0.11 Methods. We use multiwavelength COSMOS photometry, HST-ACS I-band imaging, and optical zCOSMOS spectroscopy to derive the main global properties of star-forming EELGs, such as sizes, stellar masses, star formation rates (SFR), and reliable oxygen abundances using both "direct" and "strong-line" methods. Results. The EELGs are extremely compact (r(50) similar to 1.3 kpc), low-mass (M-* similar to 10(7)-10(10) M-circle dot) galaxies forming stars at unusually high specific star formation rates (sSFR equivalent to SFR/M-star up to 10(-7) yr(-1)) compared to main sequence star-forming galaxies of the same stellar mass and redshift. At rest-frame UV wavelengths, the EELGs are luminous and show high surface brightness and include strong Ly alpha emitters, as revealed by GALEX spectroscopy. We show that zCOSMOS EELGs are high-ionization, low-metallicity systems, with median 12+log(O/H) = 8.16 +/- 0.21 (0.2 Z(circle dot)) including a handful of extremely metal-deficient ( Conclusions. The zCOSMOS EELGs are galaxies caught in a transient and probably early period of their evolution, where they are efficiently building up a significant fraction of their present-day stellar mass in an ongoing, galaxy-wide starburst. Therefore, the EELGs constitute an ideal benchmark for comparison studies between low- and high-redshift low-mass star-forming galaxies.

Published
2015

422. Molecular gas content in strongly lensed z similar to 1.5-3 star-forming galaxies with low infrared luminosities

Author

Dessauges-Zavadsky, M., Zamojski, M., Schaerer, D., Combes, F., Egami, E., Swinbank, A. M., Richard, J., Sklias, P., Rawle, T. D., Rex, M., Kneib, J-P., Boone, F., Blain, A., Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève = University of Geneva (UNIGE), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Collège de France - Chaire Galaxies et cosmologie, Collège de France (CdF (institution)), Steward Observatory, University of Arizona, Department of Physics, Durham University, Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Herschel Science Centre, Agence Spatiale Européenne = European Space Agency (ESA), Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Services communs OMP (UMS 831), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), AUTRES, Department of Physics and Astronomy [Leicester], University of Leicester, Université de Genève (UNIGE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Chaire Galaxies et cosmologie, École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), European Space Agency (ESA), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), and Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES)

Subjects
galaxies: high-redshift, cosmology: observations, gravitational lensing: strong, Astrophysics::Cosmology and Extragalactic Astrophysics, galaxies: evolution, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics, ISM: molecules
Abstract

International audience; To extend the molecular gas measurements to more typical star-forming galaxies (SFGs) with star formation rates SFR \textless 40 M-circle dot yr(-1) and stellar masses M-* \textless 2.5 x 10(10) M-circle dot at z similar to 1.5-3, we have observed CO emission with the IRAM Plateau de Bure Interferometer and the IRAM 30 m telescope for five strongly lensed galaxies, selected from the Herschel Lensing Survey. These observations are combined with a compilation of CO measurements from the literature. From this, we infer the CO luminosity correction factors r(2,1) = 0.81 +/- 0.20 and r(3,1) = 0.57 +/- 0.15 for the J = 2 and J = 3 CO transitions, respectively, valid for SFGs at z \textgreater 1. The combined sample of CO-detected SFGs at z \textgreater 1 shows a large spread in star formation efficiency (SFE) with a dispersion of 0.33 dex, such that the SFE extends well beyond the low values of local spirals and overlaps the distribution of z \textgreater 1 submm galaxies. We find that the spread in SFE (or equivalently in molecular gas depletion timescale) is due to the variations of several physical parameters, primarily the specific star formation rate, and also stellar mass and redshift. The dependence of SFE on the offset from the main sequence and the compactness of the starburst is less clear. The possible increase of the molecular gas depletion timescale with stellar mass, now revealed by low M-* SFGs at z \textgreater 1 and also observed at z = 0, contrasts with the generally acknowledged constant molecular gas depletion timescale and refutes the linearity of the Kennicutt-Schmidt relation. A net rise of the molecular gas fraction (f(gas)) is observed from z similar to 0.2 to z similar to 1.2, followed by a very mild increase toward higher redshifts, as found in earlier studies. At each redshift the molecular gas fraction shows a large dispersion, mainly due to the dependence of f(gas) on stellar mass, producing a gradient of increasing f(gas) with decreasing M-*. We provide the first measurement of the molecular gas fraction of z \textgreater 1 SFGs at the low-M-* end between 10(9.4) \textless M-*/M-circle dot \textless 10(9.9), reaching a mean af(gas)o = 0.69 +/- 0.18, which shows a clear f(gas) upturn at these lower stellar masses. Finally, we find evidence for a nonuniversal dust-to-gas ratio among high-redshift SFGs, high-redshift submm galaxies, local spirals, and local ultraluminous IR galaxies with near-solar metallicities, as inferred from a homogeneous analysis of their rest-frame 850 mu m luminosity per unit gas mass. The SFGs with z \textgreater 1 show a trend for a lower L-nu(850 mu m)/M-gas mean by 0.33 dex compared to the other galaxy populations.

Published
2015
Full Text
View/download PDF

423. The Red Radio Ring: a gravitationally lensed hyperluminous infrared radio galaxy at z=2.553 discovered through citizen science

Author

Geach, J. E., More, A., Verma, A., Marshall, P. J., Jackson, N., Belles, P. -E., Beswick, R., Baeten, E., Chavez, M., Cornen, C., Cox, B. E., Erben, T., Erickson, N. J., Garrington, S., Harrison, P. A., Harrington, K., Hughes, D. H., Ivison, R. J., Jordan, C., Lin, Y. -T., Leauthaud, A., Lintott, C., Lynn, S., Kapadia, A., Kneib, J. -P., Macmillan, C., Makler, M., Miller, G., Montana, A., Mujica, R., Muxlow, T., Narayanan, G., Briain, D. O, O'Brien, T., Oguri, M., Paget, E., Parrish, M., Ross, N. P., Rozo, E., Rusu, E., Rykoff, E. S., Sanchez-Arguelles, D., Simpson, R., Snyder, C., Schloerb, F. P., Tecza, M., Van Waerbeke, L., Wilcox, J., Viero, M., Wilson, G. W., Yun, M. S., and Zeballos, M.

Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics of Galaxies (astro-ph.GA), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We report the discovery of a gravitationally lensed hyperluminous infrared galaxy (L_IR~10^13 L_sun) with strong radio emission (L_1.4GHz~10^25 W/Hz) at z=2.553. The source was identified in the citizen science project SpaceWarps through the visual inspection of tens of thousands of iJKs colour composite images of Luminous Red Galaxies (LRGs), groups and clusters of galaxies and quasars. Appearing as a partial Einstein ring (r_e~3") around an LRG at z=0.2, the galaxy is extremely bright in the sub-millimetre for a cosmological source, with the thermal dust emission approaching 1 Jy at peak. The redshift of the lensed galaxy is determined through the detection of the CO(3-2) molecular emission line with the Large Millimetre Telescope's Redshift Search Receiver and through [OIII] and H-alpha line detections in the near-infrared from Subaru/IRCS. We have resolved the radio emission with high resolution (300-400 mas) eMERLIN L-band and JVLA C-band imaging. These observations are used in combination with the near-infrared imaging to construct a lens model, which indicates a lensing magnification of ~10x. The source reconstruction appears to support a radio morphology comprised of a compact (, 9 pages, 7 figures, published in MNRAS

Published
2015

424. Galaxies in X-ray groups. I: Robust membership assignment and the impact of group environments on quenching

Author

George, M R, Leauthaud, A, Bundy, K, Finoguenov, A, Tinker, J, Lin, Y T, Mei, S, Kneib, J-P, Aussel, H, Behroozi, P S, Busha, M T, Capak, P, Coccato, L, Covone, G, Faure, C, Fiorenza, S L, Ilbert, O, Le Floc'h, E, Koekemoer, A M, Tanaka, M, Wechsler, R H, Wolk, M, George, M R, Leauthaud, A, Bundy, K, Finoguenov, A, Tinker, J, Lin, Y T, Mei, S, Kneib, J-P, Aussel, H, Behroozi, P S, Busha, M T, Capak, P, Coccato, L, Covone, G, Faure, C, Fiorenza, S L, Ilbert, O, Le Floc'h, E, Koekemoer, A M, Tanaka, M, Wechsler, R H, and Wolk, M

Abstract

Understanding the mechanisms that lead dense environments to host galaxies with redder colors, more spheroidal morphologies, and lower star formation rates than field populations remains an important problem. As most candidate processes ultimately depend on host halo mass, accurate characterizations of the local environment, ideally tied to halo mass estimates and spanning a range in halo mass and redshift, are needed. In this work, we present and test a rigorous, probabilistic method for assigning galaxies to groups based on precise photometric redshifts and X-ray-selected groups drawn from the COSMOS field. The groups have masses in the range 1013 <~ M 200c/M ☉ <~ 1014 and span redshifts 0 < z < 1. We characterize our selection algorithm via tests on spectroscopic subsamples, including new data obtained at the Very Large Telescope, and by applying our method to detailed mock catalogs. We find that our group member galaxy sample has a purity of 84% and completeness of 92% within 0.5{R_{200c}}. We measure the impact of uncertainties in redshifts and group centering on the quality of the member selection with simulations based on current data as well as future imaging and spectroscopic surveys. As a first application of our new group member catalog which will be made publicly available, we show that member galaxies exhibit a higher quenched fraction compared to the field at fixed stellar mass out to z ~ 1, indicating a significant relationship between star formation and environment at group scales. We also address the suggestion that dusty star-forming galaxies in such groups may impact the high-l power spectrum of the cosmic microwave background and find that such a population cannot explain the low power seen in recent Sunyaev-Zel'dovich measurements.

Published
2011

430. The COSMOS Density Field: A Reconstruction Using Both Weak Lensing and Galaxy Distributions

Author

Amara, A., Lilly, S., Kovac, K., Rhodes, J., Massey, R., Zamorani, G., Carollo, C. M., Contini, T., Kneib, J-P, Le Fevre, O., Mainieri, V., Renzini, A., Scodeggio, M., Bardelli, S., Bolzonella, M., Bongiorno, A., Caputi, K., Cucciati, O., Torre, S., Ravel, L., Franzetti, P., Garilli, B., Iovino, A., Kampczyk, P., Knobel, C., Lamareille, F., Le Borgne, J-F, Le Brun, V., Maier, C., Mignoli, M., Pello, R., Peng, Y., Perez Montero, E., Presotto, V., Silverman, J., Tanaka, M., Tasca, L., Tresse, L., Vergani, D., Zucca, E., BARNES, L., Bordoloi, R., Cappi, A., Cimatti, Alessandro, Coppa, G., Koekoemoer, A., Lopez-Sanjuan, C., McCracken, H. J., Moresco, M., Nair, P., Pozzetti, L., Welikala, N., Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Amara A., Lilly S., Kovač K., Rhodes J., Massey R., Zamorani G., Carollo C. M., Contini T., Kneib J.-P., Le Fevre O., Mainieri V., Renzini A., Scodeggio M., Bardelli S., Bolzonella M., Bongiorno A., Caputi K., Cucciati O., de la Torre S., de Ravel L., Franzetti P., Garilli B., Iovino A., Kampczyk P., Knobel C., Lamareille F., Le Borgne J.-F., Le Brun V., Maier C., Mignoli M., Pello R., Peng Y., Montero E. Perez, Presotto V., Silverman J., Tanaka M., Tasca L., Tresse L., Vergani D., Zucca E., Barnes L., Bordoloi R., Cappi A., Cimatti A., Coppa G., Koekoemoer A., López-Sanjuan C., McCracken H. J., Moresco M., Nair P., Pozzetti L., Welikala N., Astronomy, and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)

Subjects
SAMPLE, Cosmology and Nongalactic Astrophysics (astro-ph.CO), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], DEEP, DATA RELEASE, FOS: Physical sciences, HUBBLE-SPACE-TELESCOPE, Astrophysics::Cosmology and Extragalactic Astrophysics, dark matter, ADVANCED CAMERA, Large-scale structure of Universe, LARGE-SCALE STRUCTURE, DARK-MATTER, Dark matter, DIGITAL SKY SURVEY, dark matter, large-scale structure of Universe, large-scale structure of Universe, CLUSTERS, ZCOSMOS GALAXIES, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The COSMOS field has been the subject of a wide range of observations, with a number of studies focusing on reconstructing the 3D dark matter density field. Typically, these studies have focused on one given method or tracer. In this paper, we reconstruct the distribution of mass in the COSMOS field out to a redshift z=1 by combining Hubble Space Telescope weak lensing measurements with zCOSMOS spectroscopic measurements of galaxy clustering. The distribution of galaxies traces the distribution of mass with high resolution (particularly in redshift, which is not possible with lensing), and the lensing data empirically calibrates the mass normalisation (bypassing the need for theoretical models). Two steps are needed to convert a galaxy survey into a density field. The first step is to create a smooth field from the galaxy positions, which is a point field. We investigate four possible methods for this: (i) Gaussian smoothing, (ii) convolution with truncated isothermal sphere, (iii) fifth nearest neighbour smoothing and (iv) a muliti-scale entropy method. The second step is to rescale this density field using a bias prescription. We calculate the optimal bias scaling for each method by comparing predictions from the smoothed density field with the measured weak lensing data, on a galaxy-by-galaxy basis. In general, we find scale-independent bias for all the smoothing schemes, to a precision of 10%. For the nearest neighbour smoothing case, we find the bias to be 2.51\pm 0.25. We also find evidence for a strongly evolving bias, increasing by a factor of ~3.5 between redshifts 0, Comment: Accepted by MNRAS. 12 pages with 6 Figures

Published
2012
Full Text
View/download PDF

431. [C II] emission in z ~ 6 strongly lensed, star-forming galaxies

Author

Knudsen, K., Richard, J., Kneib, J., Jauzac, M., Clement, B., Drouart, Guillaume, Egami, E., Lindroos, L., Knudsen, K., Richard, J., Kneib, J., Jauzac, M., Clement, B., Drouart, Guillaume, Egami, E., and Lindroos, L.

Abstract

The far-infrared fine-structure line [C ii] at 1900.5 GHz is known to be one of the brightest cooling lines in local galaxies, and therefore it has been suggested to be an efficient tracer for star formation in very high redshift galaxies. However, recent results for galaxies at z > 6 have yielded numerous non-detections in star-forming galaxies, except for quasars and submillimetre galaxies. We report the results of ALMA observations of two lensed, star-forming galaxies at z = 6.029 and z = 6.703. The galaxy A383-5.1 (star formation rate [SFR] of 3.2 M☉ yr−1 and magnification of μ = 11.4 ± 1.9) shows a line detection with L[CII]=8.9×106 L L☉, making it the lowest L[CII] detection at z > 6. For MS0451-H (SFR = 0.4 M☉ yr−1 and μ = 100 ± 20) we provide an upper limit of L[CII]<3×105 L☉, which is 1 dex below the local SFR–L[CII] relations. The results are consistent with predictions for low-metallicity galaxies at z > 6; however, other effects could also play a role in terms of decreasing L[CII]. The detection of A383-5.1 is encouraging and suggests that detections are possible, but much fainter than initially predicted.

Published
2016

432. High-redshift supernova rates measured with the gravitational telescope A 1689

Author

Petrushevska, Tanja, Amanullah, Rahman, Goobar, Ariel, Fabbro, S., Johansson, J., Kjellsson, Tor, Lidman, C., Paech, K., Richard, J., Dahle, H., Ferretti, Raphael, Kneib, J. P., Limousin, M., Nordin, J., Stanishev, V., Petrushevska, Tanja, Amanullah, Rahman, Goobar, Ariel, Fabbro, S., Johansson, J., Kjellsson, Tor, Lidman, C., Paech, K., Richard, J., Dahle, H., Ferretti, Raphael, Kneib, J. P., Limousin, M., Nordin, J., and Stanishev, V.

Abstract

Aims. We present a ground-based, near-infrared search for lensed supernovae behind the massive cluster Abell 1689 at z = 0.18, which is one of the most powerful gravitational telescopes that nature provides. Methods. Our survey was based on multi-epoch J-band observations with the HAWK-I instrument on VLT, with supporting optical data from the Nordic Optical Telescope. Results. Our search resulted in the discovery of five photometrically classified, core-collapse supernovae with high redshifts of 0.671 < z < 1.703 and magnifications in the range Delta m = -0.31 to -1.58 mag, as calculated from lensing models in the literature. Owing to the power of the lensing cluster, the survey had the sensitivity to detect supernovae up to very high redshifts, z similar to 3, albeit for a limited region of space. We present a study of the core-collapse supernova rates for 0.4 < z < 2.9, and find good agreement with previous estimates and predictions from star formation history. During our survey, we also discovered two Type Ia supernovae in A 1689 cluster members, which allowed us to determine the cluster Ia rate to be 0.14(-0.09)(+0.19) SNuB h(2) (SNuB 10(-12) SNe L-circle dot,B(-1) yr(-1)), where the error bars indicate 1 sigma confidence intervals, statistical and systematic, respectively. The cluster rate normalized by the stellar mass is 0.10(-0.06)(+0.13) +/- 0.02 in SNuM h(2) (SNuM = 10(-12) SNe M-1 yr(-1)). Furthermore, we explore the optimal future survey for improving the core-collapse supernova rate measurements at z greater than or similar to 2 using gravitational telescopes, and for detections with multiply lensed images, and we find that the planned WFIRST space mission has excellent prospects. Conclusions. Massive clusters can be used as gravitational telescopes to significantly expand the survey range of supernova searches, with important implications for the study of the high-z transient Universe.

Published
2016
Full Text
View/download PDF

433. Molecular gas properties of a lensed star-forming galaxy at z~3.6: a case study

Author

Dessauges-Zavadsky, M., Zamojski, M., Rujopakarn, W., Richard, J., Sklias, P., Schaerer, D., Combes, F., Ebeling, H., Rawle, T. D., Egami, E., Boone, F., Clément, B., Kneib, J. -P., Nyland, K., Walth, G., Dessauges-Zavadsky, M., Zamojski, M., Rujopakarn, W., Richard, J., Sklias, P., Schaerer, D., Combes, F., Ebeling, H., Rawle, T. D., Egami, E., Boone, F., Clément, B., Kneib, J. -P., Nyland, K., and Walth, G.

Abstract

We report on the galaxy MACSJ0032-arc at z=3.6314 discovered during the Herschel Lensing snapshot Survey of massive galaxy clusters, and strongly lensed by the cluster MACSJ0032.1+1808. The successful detections of its rest-frame UV, optical, FIR, millimeter, and radio continua, and of its CO emission enable us to characterize, for the first time at such a high redshift, the stellar, dust, and molecular gas properties of a compact star-forming galaxy with a size smaller than 2.5 kpc, a fairly low stellar mass of 4.8x10^9 Msun, and a moderate IR luminosity of 4.8x10^11 Lsun. We find that the bulk of the molecular gas mass and star formation seems to be spatially decoupled from the rest-frame UV emission. About 90% of the total star formation rate is undetected at rest-frame UV wavelengths because of severe obscuration by dust, but is seen through the thermal FIR dust emission and the radio synchrotron radiation. The observed CO(4-3) and CO(6-5) lines demonstrate that high-J transitions, at least up to J=6, remain excited in this galaxy, whose CO spectral line energy distribution resembles that of high-redshift submm galaxies, even though the IR luminosity of MACSJ0032-arc is ten times lower. This high CO excitation is possibly due to the compactness of the galaxy. We find evidence that this high CO excitation has to be considered in the balance when estimating the CO-to-H2 conversion factor. The inferred depletion time of the molecular gas in MACSJ0032-arc supports the decrease in the gas depletion timescale of galaxies with redshift, although to a lesser degree than predicted by galaxy evolution models. Instead, the measured molecular gas fraction as high as 60-79% in MACSJ0032-arc favors the continued increase in the gas fraction of galaxies with redshift as expected, despite the plateau observed between z~1.5 and z~2.5., Comment: 18 pages, 11 figures, 2 tables. Revised version accepted for publication in A&A

Published
2016
Full Text
View/download PDF

434. CODEX Weak Lensing: Concentration of Galaxy Clusters at z ~ 0.5

Author

Cibirka, N., Cypriano, E. S., Brimioulle, F., Gruen, D., Erben, T., van Waerbeke, L., Miller, L., Finoguenov, A., Kirkpatrick, C., Henry, J. Patrick, Rykoff, E., Rozo, E., Dupke, R., Kneib, J-P., Shan, H., Spinelli, P., Cibirka, N., Cypriano, E. S., Brimioulle, F., Gruen, D., Erben, T., van Waerbeke, L., Miller, L., Finoguenov, A., Kirkpatrick, C., Henry, J. Patrick, Rykoff, E., Rozo, E., Dupke, R., Kneib, J-P., Shan, H., and Spinelli, P.

Abstract

We present a stacked weak lensing analysis of 27 richness selected galaxy clusters at $0.40 \leqslant z \leqslant 0.62$ in the CODEX survey. The fields were observed in 5 bands with the CFHT. We measure the stacked surface mass density profile with a $14\sigma$ significance in the radial range $0.1 < R\ Mpc\ h^{-1} < 2.5$. The profile is well described by the halo model, with the main halo term following an NFW profile and including the off-centring effect. We select the background sample using a conservative colour-magnitude method to reduce the potential systematic errors and contamination by cluster member galaxies. We perform a Bayesian analysis for the stacked profile and constrain the best-fit NFW parameters $M_{200c} = 6.6^{+1.0}_{-0.8} \times 10^{14} h^{-1} M_{\odot}$ and $c_{200c} = 3.7^{+0.7}_{-0.6}$. The off-centring effect was modelled based on previous observational results found for redMaPPer SDSS clusters. Our constraints on $M_{200c}$ and $c_{200c}$ allow us to investigate the consistency with numerical predictions and select a concentration-mass relation to describe the high richness CODEX sample. Comparing our best-fit values for $M_{200c}$ and $c_{200c}$ with other observational surveys at different redshifts, we find no evidence for evolution in the concentration-mass relation, though it could be mitigated by particular selection functions. Similar to previous studies investigating the X-ray luminosity-mass relation, our data suggests a lower evolution than expected from self-similarity., Comment: 28 pages, 17 figures, submitted to MNRAS

Published
2016
Full Text
View/download PDF

435. ASTErIsM - Application of topometric clustering algorithms in automatic galaxy detection and classification

Author

Tramacere, A., Paraficz, D., Dubath, P., Kneib, J. -P., Courbin, F., Tramacere, A., Paraficz, D., Dubath, P., Kneib, J. -P., and Courbin, F.

Abstract

We present a study on galaxy detection and shape classification using topometric clustering algorithms. We first use the DBSCAN algorithm to extract, from CCD frames, groups of adjacent pixels with significant fluxes and we then apply the DENCLUE algorithm to separate the contributions of overlapping sources. The DENCLUE separation is based on the localization of pattern of local maxima, through an iterative algorithm which associates each pixel to the closest local maximum. Our main classification goal is to take apart elliptical from spiral galaxies. We introduce new sets of features derived from the computation of geometrical invariant moments of the pixel group shape and from the statistics of the spatial distribution of the DENCLUE local maxima patterns. Ellipticals are characterized by a single group of local maxima, related to the galaxy core, while spiral galaxies have additional ones related to segments of spiral arms. We use two different supervised ensemble classification algorithms, Random Forest, and Gradient Boosting. Using a sample of ~ 24000 galaxies taken from the Galaxy Zoo 2 main sample with spectroscopic redshifts, and we test our classification against the Galaxy Zoo 2 catalog. We find that features extracted from our pipeline give on average an accuracy of ~ 93%, when testing on a test set with a size of 20% of our full data set, with features deriving from the angular distribution of density attractor ranking at the top of the discrimination power., Comment: 20 pages, 13 Figures, 8 Tables, Accepted for publication in the Monthly Notices of the Royal Astronomical Society

Published
2016
Full Text
View/download PDF

436. The SDSS-IV eBOSS: emission line galaxy catalogues at z=0.8 and study of systematic errors in the angular clustering

Author

Delubac, T., Raichoor, A., Comparat, J., Jouvel, S., Kneib, J. -P., Yèche, C., Zou, H., Brownstein, J. R., Abdalla, F. B., Dawson, K., Jullo, E., Myers, A. D., Newman, J. A., Percival, W. J., Prada, F., Ross, A. J., Schneider, D. P., Zhou, X., Zhou, Z., Zhu, G., Delubac, T., Raichoor, A., Comparat, J., Jouvel, S., Kneib, J. -P., Yèche, C., Zou, H., Brownstein, J. R., Abdalla, F. B., Dawson, K., Jullo, E., Myers, A. D., Newman, J. A., Percival, W. J., Prada, F., Ross, A. J., Schneider, D. P., Zhou, X., Zhou, Z., and Zhu, G.

Abstract

We present two wide-field catalogs of photometrically-selected emission line galaxies (ELGs) at z=0.8 covering about 2800 deg^2 over the south galactic cap. The catalogs were obtained using a Fisher discriminant technique described in a companion paper. The two catalogs differ by the imaging used to define the Fisher discriminant: the first catalog includes imaging from the Sloan Digital Sky Survey and the Wide-Field Infrared Survey Explorer, the second also includes information from the South Galactic Cap U-band Sky Survey (SCUSS). Containing respectively 560,045 and 615,601 objects, they represent the largest ELG catalogs available today and were designed for the ELG programme of the extended Baryon Oscillation Spectroscopic Survey (eBOSS). We study potential sources of systematic variation in the angular distribution of the selected ELGs due to fluctuations of the observational parameters. We model the influence of the observational parameters using a multivariate regression and implement a weighting scheme that allows effective removal of all of the systematic errors induced by the observational parameters. We show that fluctuations in the imaging zero-points of the photometric bands have minor impact on the angular distribution of objects in our catalogs. We compute the angular clustering of both catalogs and show that our weighting procedure effectively removes spurious clustering on large scales. We fit a model to the small scale angular clustering, showing that the selections have similar biases of 1.35/D_a(z) and 1.28/D_a(z). Both catalogs are publicly available., Comment: Accepted for publication in MNRAS. 16 pages, 12 figures

Published
2016
Full Text
View/download PDF

437. The Extraordinary Amount of Substructure in the Hubble Frontier Fields Cluster Abell 2744

Author

Jauzac, M., Eckert, D., Schwinn, J., Harvey, D., Baugh, C. M., Robertson, A., Bose, S., Massey, R., Owers, M., Ebeling, H., Shan, H. Y., Jullo, E., Kneib, J. -P., Richard, J., Atek, H., Clément, B., Egami, E., Israel, H., Knowles, K., Limousin, M., Natarajan, P., Rexroth, M., Taylor, P., Tchernin, C., Jauzac, M., Eckert, D., Schwinn, J., Harvey, D., Baugh, C. M., Robertson, A., Bose, S., Massey, R., Owers, M., Ebeling, H., Shan, H. Y., Jullo, E., Kneib, J. -P., Richard, J., Atek, H., Clément, B., Egami, E., Israel, H., Knowles, K., Limousin, M., Natarajan, P., Rexroth, M., Taylor, P., and Tchernin, C.

Abstract

We present a joint optical/X-ray analysis of the massive galaxy cluster Abell 2744 (z=0.308). Our strong- and weak-lensing analysis within the central region of the cluster, i.e., at R<1Mpc from the brightest cluster galaxy, reveals eight substructures, including the main core. All of these dark-matter halos are detected with a significance of at least 5sigma and feature masses ranging from 0.5 to 1.4x10^{14}Msun within R<150kpc. Merten et al. (2011) and Medezinski et al. (2016) substructures are also detected by us. We measure a slightly higher mass for the main core component than reported previously and attribute the discrepancy to the inclusion of our tightly constrained strong-lensing mass model built on Hubble Frontier Fields data. X-ray data obtained by XMM-Newton reveal four remnant cores, one of them a new detection, and three shocks. Unlike Merten et al. (2011), we find all cores to have both dark and luminous counterparts. A comparison with clusters of similar mass in the MXXL simulations yields no objects with as many massive substructures as observed in Abell 2744, confirming that Abell 2744 is an extreme system. We stress that these properties still do not constitute a challenge to $\Lambda$CDM, as caveats apply to both the simulation and the observations: for instance, the projected mass measurements from gravitational lensing and the limited resolution of the sub-haloes finders. We discuss implications of Abell 2744 for the plausibility of different dark-matter candidates and, finally, measure a new upper limit on the self-interaction cross-section of dark matter of sigma_{DM}<1.28cm2/g(68\% CL), in good agreement with previous results from Harvey et al. (2015)., Comment: Submitted to MNRAS -- 19 pages, 8 figures, 6 tables

Published
2016
Full Text
View/download PDF

438. The PCA Lens-Finder: application to CFHTLS

Author

Paraficz, D., Courbin, F., Tramacere, A., Joseph, R., Metcalf, R. B., Kneib, J. -P., Dubath, P., Droz, D., Filleul, F., Ringeisen, D., Schäfer, C., Paraficz, D., Courbin, F., Tramacere, A., Joseph, R., Metcalf, R. B., Kneib, J. -P., Dubath, P., Droz, D., Filleul, F., Ringeisen, D., and Schäfer, C.

Abstract

We present the results of a new search for galaxy-scale strong lensing systems in CFHTLS Wide. Our lens-finding technique involves a preselection of potential lens galaxies, applying simple cuts in size and magnitude. We then perform a Principal Component Analysis of the galaxy images, ensuring a clean removal of the light profile. Lensed features are searched for in the residual images using the clustering topometric algorithm DBSCAN. We find 1098 lens candidates that we inspect visually, leading to a cleaned sample of 109 new lens candidates. Using realistic image simulations we estimate the completeness of our sample and show that it is independent of source surface brightness, Einstein ring size (image separation) or lens redshift. We compare the properties of our sample to previous lens searches in CFHTLS. Including the present search, the total number of lenses found in CFHTLS amounts to 678, which corresponds to ~4 lenses per square degree down to i=24.8. This is equivalent to ~ 60.000 lenses in total in a survey as wide as Euclid, but at the CFHTLS resolution and depth., Comment: 21 pages, 12 figures, accepted for publication on A&A

Published
2016
Full Text
View/download PDF

439. Strong Lensing In The Inner Halo Of Galaxy Clusters

Author

Saez, C., Campusano, L. E., Cypriano, E. S., Sodré, L., Kneib, J. -P., Saez, C., Campusano, L. E., Cypriano, E. S., Sodré, L., and Kneib, J. -P.

Abstract

We present an axially symmetric formula to calculate the probability of finding gravitational arcs in galaxy clusters, being induced by their massive dark matter haloes, as a function of clusters redshifts and virial masses. The formula includes the ellipticity of the clusters dark matter potential by using a pseudo-elliptical approximation. The probabilities are calculated and compared for two dark-matter halo profiles, the Navarro, Frenk and White (NFW) and the Non-Singular-Isothermal-Sphere (NSIS). We demonstrate the power of our formulation through a Kolmogorov-Smirnov (KS) test on the strong lensing statistics of an X-ray bright sample of low redshift Abell clusters. This KS test allows to establish limits on the values of the concentration parameter for the NFW profile ($c_\Delta$) and the core radius for the NSIS profile (\rc), which are related to the lowest cluster redshift ($z_{\rm cut}$) where strong arcs can be observed. For NFW dark matter profiles, we infer cluster haloes with concentrations that are consistent to those predicted by $\Lambda$CDM simulations. As for NSIS dark matter profiles, we find only upper limits for the clusters core radii and thus do not rule out a purely SIS model. For alternative mass profiles, our formulation provides constraints through $z_{\rm cut}$ on the parameters that control the concentration of mass in the inner region of the clusters haloes. We find that $z_{\rm cut}$ is expected to lie in the 0.0--0.2 redshift, highlighting the need to include very low-$z$ clusters in samples to study the clusters mass profiles., Comment: 15 pages, 14 figures, MNRAS accepted

Published
2016
Full Text
View/download PDF

440. The DESI Experiment Part II: Instrument Design

Author

DESI Collaboration, Desi, C, Aghamousa, A, Aguilar, J, Ahlen, S, Alam, S, Allen, L, Allende Prieto, C, Annis, J, Bailey, S, Balland, C, Ballester, O, Baltay, C, Beaufore, L, Bebek, C, Beers, T, Bell, E, Bernal, J, Besuner, R, Beutler, F, Blake, Chris, B, Hannes, Blomqvist, M, Blum, R, Bolton, A, Briceno, C, Brooks, D, Brownstein, J, Buckley-Geer, E, Burden, A, Burtin, E, Busca, N, Cahn, R, Cai, Y, Cardiel-Sas, L, Carlberg, R, Carton, P, Casas, R, Castander, F, Cervantes-Cota, J, Claybaugh, T, Close, M, Coker, C, Cole, S, Comparat, J, Cooper, A, Cousinou, M, Crocce, M, Cuby, J, Cunningham, D, Davis, T, Dawson, K, de la Macorra, A, De Vicente, J, Delubac, T, Derwent, M, Dey, A, Dhungana, G, Ding, Z, Doel, P, Duan, Y, Ealet, A, Edelstein, J, Eftekharzadeh, S, Eisenstein, D, Elliott, A, Escoffier, S, Evatt, M, Fagrelius, P, Fan, X, Fanning, K, Farahi, A, Farihi, J, Favole, G, Feng, Y, Fernandez, E, Findlay, J, Finkbeiner, D, Fitzpatrick, M, Flaugher, B, Flender, S, Font-Ribera, A, Forero-Romero, J, Fosalba, P, Frenk, C, Fumagalli, M, Gaensicke, B, Gallo, G, Garcia-Bellido, J, Gaztanaga, E, Pietro Gentile Fusillo, N, Gerard, T, Gershkovich, I, Giannantonio, T, Gillet, D, Gonzalez-de-Rivera, G, Gonzalez-Perez, V, Gott, S, Graur, O, Gutierrez, G, Guy, J, Habib, S, Heetderks, H, Heetderks, I, Heitmann, K, Hellwing, W, Herrera, D, Ho, S, Holland, S, Honscheid, K, Huff, E, Hutchinson, T, Huterer, D, Hwang, H, Illa Laguna, J, Ishikawa, Y, Jacobs, D, Jeffrey, N, Jelinsky, P, Jennings, E, Jiang, L, Jimenez, J, Johnson, J, Joyce, R, Jullo, E, Juneau, S, Kama, S, Karcher, A, Karkar, S, Kehoe, R, Kennamer, N, Kent, S, Kilbinger, M, Kim, A, Kirkby, D, Kisner, T, Kitanidis, E, Kneib, J, Koposov, S, Kovacs, E, Koyama, K, Kremin, A, Kron, R, Kronig, L, Kueter-Young, A, Lacey, C, Lafever, R, Lahav, O, Lambert, A, Lampton, M, Landriau, M, Lang, D, Lauer, T, Le Goff, J, Le Guillou, L, Le Van Suu, A, Lee, J, Lee, S, Leitner, D, Lesser, M, Levi, M, L'Huillier, B, Li, B, Liang, M, Lin, H, Linder, E, Loebman, S, Lukić, Z, Ma, J, Maccrann, N, Magneville, C, Makarem, L, Manera, M, Manser, C, Marshall, R, Martini, P, Massey, R, Matheson, T, Mccauley, J, Mcdonald, P, Mcgreer, I, Meisner, A, Metcalfe, N, Miller, T, Miquel, R, Moustakas, J, Myers, A, Naik, M, Newman, J, Nichol, R, Nicola, A, Nicolati da Costa, L, Nie, J, Niz, G, Norberg, P, Nord, B, Norman, D, Nugent, P, O'Brien, T, Oh, M, Olsen, K, Padilla, C, Padmanabhan, H, Padmanabhan, N, Palanque-Delabrouille, N, Palmese, A, Pappalardo, D, Pâris, I, Park, C, Patej, A, Peacock, J, Peiris, H, Peng, X, Percival, W, Perruchot, S, Pieri, M, Pogge, R, Pollack, J, Poppett, C, Prada, F, Prakash, A, Probst, R, Rabinowitz, D, Raichoor, A, Ree, C, Refregier, A, Regal, X, Reid, B, Reil, K, Rezaie, M, Rockosi, C, Roe, N, Ronayette, S, Roodman, A, Ross, A, Ross, N, Rossi, G, Rozo, E, Ruhlmann-Kleider, V, Rykoff, E, Sabiu, C, Samushia, L, Sanchez, E, Sanchez, J, Schlegel, D, Schneider, M, Schubnell, M, Secroun, A, Seljak, U, Seo, H, Serrano, S, Shafieloo, A, Shan, H, Sharples, R, Sholl, M, Shourt, W, Silber, J, Silva, D, Sirk, M, Slosar, A, Smith, A, Smoot, G, Som, D, Song, Y, Sprayberry, D, Staten, R, Stefanik, A, Tarle, G, Sien Tie, S, Tinker, J, Tojeiro, R, Valdes, F, Valenzuela, O, Valluri, M, Vargas-Magana, M, Verde, L, Walker, A, Wang, J, Wang, Y, Weaver, B, Weaverdyck, C, Wechsler, R, Weinberg, D, White, M, Yang, Q, Yeche, C, Zhang, T, Zhao, G, Zheng, Y, Zhou, X, Zhou, Z, Zhu, Y, Zou, H, Zu, Y, DESI Collaboration, Aghamousa, Amir, Aguilar, Jessica, Ahlen, Steve, Alam, Shadab, Allen, Lori E., Allende Prieto, Carlos, Annis, James, Bailey, Stephen, Balland, Christophe, Ballester, Otger, Baltay, Charles, Beaufore, Lucas, Bebek, Chris, Beers, Timothy C., Bell, Eric F., Bernal, José Luis, Besuner, Robert, Beutler, Florian, Chris Bleuler, Blomqvist, Michael, Blum, Robert, Bolton, Adam S., Briceno, Cesar, Brooks, David, Brownstein, Joel R., Buckley-Geer, Elizabeth, Burden, Angela, Burtin, Etienne, Busca, Nicolas G., Cahn, Robert N., Cai, Yan-Chuan, Cardiel-Sas, Laia, Carlberg, Raymond G., Carton, Pierre-Henri, Casas, Ricard, Castander, Francisco J., Cervantes-Cota, Jorge L., Claybaugh, Todd M., Close, Madeline, Coker, Carl T., Cole, Shaun, Comparat, Johan, Cooper, Andrew P., Cousinou, M. -C., Crocce, Martin, Cuby, Jean-Gabriel, Cunningham, Daniel P., Davis, Tamara M., Dawson, Kyle S., de la Macorra, Axel, De Vicente, Juan, Delubac, Timothée, Derwent, Mark, Dey, Arjun, Dhungana, Govinda, Ding, Zhejie, Doel, Peter, Duan, Yutong T., Ealet, Anne, Edelstein, Jerry, Eftekharzadeh, Sarah, Eisenstein, Daniel J., Elliott, Ann, Escoffier, Stéphanie, Evatt, Matthew, Fagrelius, Parker, Fan, Xiaohui, Fanning, Kevin, Farahi, Arya, Farihi, Jay, Favole, Ginevra, Feng, Yu, Fernandez, Enrique, Findlay, Joseph R., Finkbeiner, Douglas P., Fitzpatrick, Michael J., Flaugher, Brenna, Flender, Samuel, Font-Ribera, Andreu, Forero-Romero, Jaime E., Fosalba, Pablo, Frenk, Carlos S., Fumagalli, Michele, Gaensicke, Boris T., Gallo, Giuseppe, Garcia-Bellido, Juan, Gaztanaga, Enrique, Pietro Gentile Fusillo, Nicola, Gerard, Terry, Gershkovich, Irena, Giannantonio, Tommaso, Gillet, Denis, Gonzalez-de-Rivera, Guillermo, Gonzalez-Perez, Violeta, Gott, Shelby, Graur, Or, Gutierrez, Gaston, Guy, Julien, Habib, Salman, Heetderks, Henry, Heetderks, Ian, Heitmann, Katrin, Hellwing, Wojciech A., Herrera, David A., Ho, Shirley, Holland, Stephen, Honscheid, Klaus, Huff, Eric, Hutchinson, Timothy A., Huterer, Dragan, Hwang, Ho Seong, Illa Laguna, Joseph Maria, Ishikawa, Yuzo, Jacobs, Dianna, Jeffrey, Niall, Jelinsky, Patrick, Jennings, Elise, Jiang, Linhua, Jimenez, Jorge, Johnson, Jennifer, Joyce, Richard, Jullo, Eric, Juneau, Stéphanie, Kama, Sami, Karcher, Armin, Karkar, Sonia, Kehoe, Robert, Kennamer, Noble, Kent, Stephen, Kilbinger, Martin, Kim, Alex G., Kirkby, David, Kisner, Theodore, Kitanidis, Ellie, Kneib, Jean-Paul, Koposov, Sergey, Kovacs, Eve, Koyama, Kazuya, Kremin, Anthony, Kron, Richard, Kronig, Luzius, Kueter-Young, Andrea, Lacey, Cedric G., Lafever, Robin, Lahav, Ofer, Lambert, Andrew, Lampton, Michael, Landriau, Martin, Lang, Dustin, Lauer, Tod R., Le Goff, Jean-Marc, Le Guillou, Laurent, Le Van Suu, Auguste, Lee, Jae Hyeon, Lee, Su-Jeong, Leitner, Daniela, Lesser, Michael, Levi, Michael E., L'Huillier, Benjamin, Li, Baojiu, Liang, Ming, Lin, Huan, Linder, Eric, Loebman, Sarah R., Lukić, Zarija, Ma, Jun, MacCrann, Niall, Magneville, Christophe, Makarem, Laleh, Manera, Marc, Manser, Christopher J., Marshall, Robert, Martini, Paul, Massey, Richard, Matheson, Thomas, McCauley, Jeremy, McDonald, Patrick, McGreer, Ian D., Meisner, Aaron, Metcalfe, Nigel, Miller, Timothy N., Miquel, Ramon, Moustakas, John, Myers, Adam, Naik, Milind, Newman, Jeffrey A., Nichol, Robert C., Nicola, Andrina, Nicolati da Costa, Luiz, Nie, Jundan, Niz, Gustavo, Norberg, Peder, Nord, Brian, Norman, Dara, Nugent, Peter, O'Brien, Thomas, Oh, Minji, Olsen, Knut A. G., Padilla, Cristobal, Padmanabhan, Hamsa, Padmanabhan, Nikhil, Palanque-Delabrouille, Nathalie, Palmese, Antonella, Pappalardo, Daniel, Pâris, Isabelle, Park, Changbom, Patej, Anna, Peacock, John A., Peiris, Hiranya V., Peng, Xiyan, Percival, Will J., Perruchot, Sandrine, Pieri, Matthew M., Pogge, Richard, Pollack, Jennifer E., Poppett, Claire, Prada, Francisco, Prakash, Abhishek, Probst, Ronald G., Rabinowitz, David, Raichoor, Anand, Ree, Chang Hee, Refregier, Alexandre, Regal, Xavier, Reid, Beth, Reil, Kevin, Rezaie, Mehdi, Rockosi, Constance M., Roe, Natalie, Ronayette, Samuel, Roodman, Aaron, Ross, Ashley J., Ross, Nicholas P., Rossi, Graziano, Rozo, Eduardo, Ruhlmann-Kleider, Vanina, Rykoff, Eli S., Sabiu, Cristiano, Samushia, Lado, Sanchez, Eusebio, Sanchez, Javier, Schlegel, David J., Schneider, Michael, Schubnell, Michael, Secroun, Aurélia, Seljak, Uros, Seo, Hee-Jong, Serrano, Santiago, Shafieloo, Arman, Shan, Huanyuan, Sharples, Ray, Sholl, Michael J., Shourt, William V., Silber, Joseph H., Silva, David R., Sirk, Martin M., Slosar, Anze, Smith, Alex, Smoot, George F., Som, Debopam, Song, Yong-Seon, Sprayberry, David, Staten, Ryan, Stefanik, Andy, Tarle, Gregory, Sien Tie, Suk, Tinker, Jeremy L., Tojeiro, Rita, Valdes, Francisco, Valenzuela, Octavio, Valluri, Monica, Vargas-Magana, Mariana, Verde, Licia, Walker, Alistair R., Wang, Jiali, Wang, Yuting, Weaver, Benjamin A., Weaverdyck, Curtis, Wechsler, Risa H., Weinberg, David H., White, Martin, Yang, Qian, Yeche, Christophe, Zhang, Tianmeng, Zhao, Gong-Bo, Zheng, Yi, Zhou, Xu, Zhou, Zhimin, Zhu, Yaling, Zou, Hu, Zu, Ying, DESI Collaboration, Desi, C, Aghamousa, A, Aguilar, J, Ahlen, S, Alam, S, Allen, L, Allende Prieto, C, Annis, J, Bailey, S, Balland, C, Ballester, O, Baltay, C, Beaufore, L, Bebek, C, Beers, T, Bell, E, Bernal, J, Besuner, R, Beutler, F, Blake, Chris, B, Hannes, Blomqvist, M, Blum, R, Bolton, A, Briceno, C, Brooks, D, Brownstein, J, Buckley-Geer, E, Burden, A, Burtin, E, Busca, N, Cahn, R, Cai, Y, Cardiel-Sas, L, Carlberg, R, Carton, P, Casas, R, Castander, F, Cervantes-Cota, J, Claybaugh, T, Close, M, Coker, C, Cole, S, Comparat, J, Cooper, A, Cousinou, M, Crocce, M, Cuby, J, Cunningham, D, Davis, T, Dawson, K, de la Macorra, A, De Vicente, J, Delubac, T, Derwent, M, Dey, A, Dhungana, G, Ding, Z, Doel, P, Duan, Y, Ealet, A, Edelstein, J, Eftekharzadeh, S, Eisenstein, D, Elliott, A, Escoffier, S, Evatt, M, Fagrelius, P, Fan, X, Fanning, K, Farahi, A, Farihi, J, Favole, G, Feng, Y, Fernandez, E, Findlay, J, Finkbeiner, D, Fitzpatrick, M, Flaugher, B, Flender, S, Font-Ribera, A, Forero-Romero, J, Fosalba, P, Frenk, C, Fumagalli, M, Gaensicke, B, Gallo, G, Garcia-Bellido, J, Gaztanaga, E, Pietro Gentile Fusillo, N, Gerard, T, Gershkovich, I, Giannantonio, T, Gillet, D, Gonzalez-de-Rivera, G, Gonzalez-Perez, V, Gott, S, Graur, O, Gutierrez, G, Guy, J, Habib, S, Heetderks, H, Heetderks, I, Heitmann, K, Hellwing, W, Herrera, D, Ho, S, Holland, S, Honscheid, K, Huff, E, Hutchinson, T, Huterer, D, Hwang, H, Illa Laguna, J, Ishikawa, Y, Jacobs, D, Jeffrey, N, Jelinsky, P, Jennings, E, Jiang, L, Jimenez, J, Johnson, J, Joyce, R, Jullo, E, Juneau, S, Kama, S, Karcher, A, Karkar, S, Kehoe, R, Kennamer, N, Kent, S, Kilbinger, M, Kim, A, Kirkby, D, Kisner, T, Kitanidis, E, Kneib, J, Koposov, S, Kovacs, E, Koyama, K, Kremin, A, Kron, R, Kronig, L, Kueter-Young, A, Lacey, C, Lafever, R, Lahav, O, Lambert, A, Lampton, M, Landriau, M, Lang, D, Lauer, T, Le Goff, J, Le Guillou, L, Le Van Suu, A, Lee, J, Lee, S, Leitner, D, Lesser, M, Levi, M, L'Huillier, B, Li, B, Liang, M, Lin, H, Linder, E, Loebman, S, Lukić, Z, Ma, J, Maccrann, N, Magneville, C, Makarem, L, Manera, M, Manser, C, Marshall, R, Martini, P, Massey, R, Matheson, T, Mccauley, J, Mcdonald, P, Mcgreer, I, Meisner, A, Metcalfe, N, Miller, T, Miquel, R, Moustakas, J, Myers, A, Naik, M, Newman, J, Nichol, R, Nicola, A, Nicolati da Costa, L, Nie, J, Niz, G, Norberg, P, Nord, B, Norman, D, Nugent, P, O'Brien, T, Oh, M, Olsen, K, Padilla, C, Padmanabhan, H, Padmanabhan, N, Palanque-Delabrouille, N, Palmese, A, Pappalardo, D, Pâris, I, Park, C, Patej, A, Peacock, J, Peiris, H, Peng, X, Percival, W, Perruchot, S, Pieri, M, Pogge, R, Pollack, J, Poppett, C, Prada, F, Prakash, A, Probst, R, Rabinowitz, D, Raichoor, A, Ree, C, Refregier, A, Regal, X, Reid, B, Reil, K, Rezaie, M, Rockosi, C, Roe, N, Ronayette, S, Roodman, A, Ross, A, Ross, N, Rossi, G, Rozo, E, Ruhlmann-Kleider, V, Rykoff, E, Sabiu, C, Samushia, L, Sanchez, E, Sanchez, J, Schlegel, D, Schneider, M, Schubnell, M, Secroun, A, Seljak, U, Seo, H, Serrano, S, Shafieloo, A, Shan, H, Sharples, R, Sholl, M, Shourt, W, Silber, J, Silva, D, Sirk, M, Slosar, A, Smith, A, Smoot, G, Som, D, Song, Y, Sprayberry, D, Staten, R, Stefanik, A, Tarle, G, Sien Tie, S, Tinker, J, Tojeiro, R, Valdes, F, Valenzuela, O, Valluri, M, Vargas-Magana, M, Verde, L, Walker, A, Wang, J, Wang, Y, Weaver, B, Weaverdyck, C, Wechsler, R, Weinberg, D, White, M, Yang, Q, Yeche, C, Zhang, T, Zhao, G, Zheng, Y, Zhou, X, Zhou, Z, Zhu, Y, Zou, H, Zu, Y, DESI Collaboration, Aghamousa, Amir, Aguilar, Jessica, Ahlen, Steve, Alam, Shadab, Allen, Lori E., Allende Prieto, Carlos, Annis, James, Bailey, Stephen, Balland, Christophe, Ballester, Otger, Baltay, Charles, Beaufore, Lucas, Bebek, Chris, Beers, Timothy C., Bell, Eric F., Bernal, José Luis, Besuner, Robert, Beutler, Florian, Chris Bleuler, Blomqvist, Michael, Blum, Robert, Bolton, Adam S., Briceno, Cesar, Brooks, David, Brownstein, Joel R., Buckley-Geer, Elizabeth, Burden, Angela, Burtin, Etienne, Busca, Nicolas G., Cahn, Robert N., Cai, Yan-Chuan, Cardiel-Sas, Laia, Carlberg, Raymond G., Carton, Pierre-Henri, Casas, Ricard, Castander, Francisco J., Cervantes-Cota, Jorge L., Claybaugh, Todd M., Close, Madeline, Coker, Carl T., Cole, Shaun, Comparat, Johan, Cooper, Andrew P., Cousinou, M. -C., Crocce, Martin, Cuby, Jean-Gabriel, Cunningham, Daniel P., Davis, Tamara M., Dawson, Kyle S., de la Macorra, Axel, De Vicente, Juan, Delubac, Timothée, Derwent, Mark, Dey, Arjun, Dhungana, Govinda, Ding, Zhejie, Doel, Peter, Duan, Yutong T., Ealet, Anne, Edelstein, Jerry, Eftekharzadeh, Sarah, Eisenstein, Daniel J., Elliott, Ann, Escoffier, Stéphanie, Evatt, Matthew, Fagrelius, Parker, Fan, Xiaohui, Fanning, Kevin, Farahi, Arya, Farihi, Jay, Favole, Ginevra, Feng, Yu, Fernandez, Enrique, Findlay, Joseph R., Finkbeiner, Douglas P., Fitzpatrick, Michael J., Flaugher, Brenna, Flender, Samuel, Font-Ribera, Andreu, Forero-Romero, Jaime E., Fosalba, Pablo, Frenk, Carlos S., Fumagalli, Michele, Gaensicke, Boris T., Gallo, Giuseppe, Garcia-Bellido, Juan, Gaztanaga, Enrique, Pietro Gentile Fusillo, Nicola, Gerard, Terry, Gershkovich, Irena, Giannantonio, Tommaso, Gillet, Denis, Gonzalez-de-Rivera, Guillermo, Gonzalez-Perez, Violeta, Gott, Shelby, Graur, Or, Gutierrez, Gaston, Guy, Julien, Habib, Salman, Heetderks, Henry, Heetderks, Ian, Heitmann, Katrin, Hellwing, Wojciech A., Herrera, David A., Ho, Shirley, Holland, Stephen, Honscheid, Klaus, Huff, Eric, Hutchinson, Timothy A., Huterer, Dragan, Hwang, Ho Seong, Illa Laguna, Joseph Maria, Ishikawa, Yuzo, Jacobs, Dianna, Jeffrey, Niall, Jelinsky, Patrick, Jennings, Elise, Jiang, Linhua, Jimenez, Jorge, Johnson, Jennifer, Joyce, Richard, Jullo, Eric, Juneau, Stéphanie, Kama, Sami, Karcher, Armin, Karkar, Sonia, Kehoe, Robert, Kennamer, Noble, Kent, Stephen, Kilbinger, Martin, Kim, Alex G., Kirkby, David, Kisner, Theodore, Kitanidis, Ellie, Kneib, Jean-Paul, Koposov, Sergey, Kovacs, Eve, Koyama, Kazuya, Kremin, Anthony, Kron, Richard, Kronig, Luzius, Kueter-Young, Andrea, Lacey, Cedric G., Lafever, Robin, Lahav, Ofer, Lambert, Andrew, Lampton, Michael, Landriau, Martin, Lang, Dustin, Lauer, Tod R., Le Goff, Jean-Marc, Le Guillou, Laurent, Le Van Suu, Auguste, Lee, Jae Hyeon, Lee, Su-Jeong, Leitner, Daniela, Lesser, Michael, Levi, Michael E., L'Huillier, Benjamin, Li, Baojiu, Liang, Ming, Lin, Huan, Linder, Eric, Loebman, Sarah R., Lukić, Zarija, Ma, Jun, MacCrann, Niall, Magneville, Christophe, Makarem, Laleh, Manera, Marc, Manser, Christopher J., Marshall, Robert, Martini, Paul, Massey, Richard, Matheson, Thomas, McCauley, Jeremy, McDonald, Patrick, McGreer, Ian D., Meisner, Aaron, Metcalfe, Nigel, Miller, Timothy N., Miquel, Ramon, Moustakas, John, Myers, Adam, Naik, Milind, Newman, Jeffrey A., Nichol, Robert C., Nicola, Andrina, Nicolati da Costa, Luiz, Nie, Jundan, Niz, Gustavo, Norberg, Peder, Nord, Brian, Norman, Dara, Nugent, Peter, O'Brien, Thomas, Oh, Minji, Olsen, Knut A. G., Padilla, Cristobal, Padmanabhan, Hamsa, Padmanabhan, Nikhil, Palanque-Delabrouille, Nathalie, Palmese, Antonella, Pappalardo, Daniel, Pâris, Isabelle, Park, Changbom, Patej, Anna, Peacock, John A., Peiris, Hiranya V., Peng, Xiyan, Percival, Will J., Perruchot, Sandrine, Pieri, Matthew M., Pogge, Richard, Pollack, Jennifer E., Poppett, Claire, Prada, Francisco, Prakash, Abhishek, Probst, Ronald G., Rabinowitz, David, Raichoor, Anand, Ree, Chang Hee, Refregier, Alexandre, Regal, Xavier, Reid, Beth, Reil, Kevin, Rezaie, Mehdi, Rockosi, Constance M., Roe, Natalie, Ronayette, Samuel, Roodman, Aaron, Ross, Ashley J., Ross, Nicholas P., Rossi, Graziano, Rozo, Eduardo, Ruhlmann-Kleider, Vanina, Rykoff, Eli S., Sabiu, Cristiano, Samushia, Lado, Sanchez, Eusebio, Sanchez, Javier, Schlegel, David J., Schneider, Michael, Schubnell, Michael, Secroun, Aurélia, Seljak, Uros, Seo, Hee-Jong, Serrano, Santiago, Shafieloo, Arman, Shan, Huanyuan, Sharples, Ray, Sholl, Michael J., Shourt, William V., Silber, Joseph H., Silva, David R., Sirk, Martin M., Slosar, Anze, Smith, Alex, Smoot, George F., Som, Debopam, Song, Yong-Seon, Sprayberry, David, Staten, Ryan, Stefanik, Andy, Tarle, Gregory, Sien Tie, Suk, Tinker, Jeremy L., Tojeiro, Rita, Valdes, Francisco, Valenzuela, Octavio, Valluri, Monica, Vargas-Magana, Mariana, Verde, Licia, Walker, Alistair R., Wang, Jiali, Wang, Yuting, Weaver, Benjamin A., Weaverdyck, Curtis, Wechsler, Risa H., Weinberg, David H., White, Martin, Yang, Qian, Yeche, Christophe, Zhang, Tianmeng, Zhao, Gong-Bo, Zheng, Yi, Zhou, Xu, Zhou, Zhimin, Zhu, Yaling, Zou, Hu, and Zu, Ying

Abstract

DESI (Dark Energy Spectropic Instrument) is a Stage IV ground-based dark energy experiment that will study baryon acoustic oscillations and the growth of structure through redshift-space distortions with a wide-area galaxy and quasar redshift survey. The DESI instrument is a robotically-actuated, fiber-fed spectrograph capable of taking up to 5,000 simultaneous spectra over a wavelength range from 360 nm to 980 nm. The fibers feed ten three-arm spectrographs with resolution $R= lambda/Deltalambda$ between 2000 and 5500, depending on wavelength. The DESI instrument will be used to conduct a five-year survey designed to cover 14,000 deg$^2$. This powerful instrument will be installed at prime focus on the 4-m Mayall telescope in Kitt Peak, Arizona, along with a new optical corrector, which will provide a three-degree diameter field of view. The DESI collaboration will also deliver a spectroscopic pipeline and data management system to reduce and archive all data for eventual public use.

Published
2016

441. A shock front at the radio relic of Abell 2744

Author

Eckert, D., Jauzac, M., Vazza, F., Owers, M., Kneib, J., Tchernin, C., Intema, Hubertus, Knowles, K., Eckert, D., Jauzac, M., Vazza, F., Owers, M., Kneib, J., Tchernin, C., Intema, Hubertus, and Knowles, K.

Abstract

Radio relics are Mpc-scale diffuse radio sources at the peripheries of galaxy clusters which are thought to trace outgoing merger shocks. We present XMM-Newton and Suzaku observations of the galaxy cluster Abell 2744 (z = 0.306), which reveal the presence of a shock front 1.5 Mpc east of the cluster core. The surface-brightness jump coincides with the position of a known radio relic. Although the surface-brightness jump indicates a weak shock with a Mach number M=1.7-0.3+0.5, the plasma in the post-shock region has been heated to a very high temperature (~13 keV) by the passage of the shock wave. The low-acceleration efficiency expected from such a weak shock suggests that mildly relativistic electrons have been re-accelerated by the passage of the shock front.

Published
2016

443. Precision photometric redshift calibration for galaxy–galaxy weak lensing

Author

Mandelbaum, R, Seljak, U, Hirata, C M, Bardelli, S, Bolzonella, M, Bongiorno, A, Carollo, M, Contini, T, Cunha, C E, Garilli, B, Iovino, A, Kampczyk, K, Kneib, J P, Knobel, C, Koo, D C, Lamareille, F, Le Fèvre, O, Leborgne, J F, Lilly, S J, Maier, C, Mainieri, V, Mignoli, M, Newman, J A, Oesch, P A, Perez-Montero, E, Ricciardelli, E, Scodeggio, M, Silverman, J, Tasca, L, Mandelbaum, R, Seljak, U, Hirata, C M, Bardelli, S, Bolzonella, M, Bongiorno, A, Carollo, M, Contini, T, Cunha, C E, Garilli, B, Iovino, A, Kampczyk, K, Kneib, J P, Knobel, C, Koo, D C, Lamareille, F, Le Fèvre, O, Leborgne, J F, Lilly, S J, Maier, C, Mainieri, V, Mignoli, M, Newman, J A, Oesch, P A, Perez-Montero, E, Ricciardelli, E, Scodeggio, M, Silverman, J, and Tasca, L

Abstract

Accurate photometric redshifts are among the key requirements for precision weak lensing measurements. Both the large size of the Sloan Digital Sky Survey (SDSS) and the existence of large spectroscopic redshift samples that are flux-limited beyond its depth have made it the optimal data source for developing methods to properly calibrate photometric redshifts for lensing. Here, we focus on galaxy-galaxy lensing in a survey with spectroscopic lens redshifts, as in the SDSS. We develop statistics that quantify the effect of source redshift errors on the lensing calibration and on the weighting scheme, and show how they can be used in the presence of redshift failure and sampling variance. We then demonstrate their use with 2838 source galaxies with spectroscopy from DEEP2 and zCOSMOS, evaluating several public photometric redshift algorithms, in two cases including a full p(z) for each object, and find lensing calibration biases as low as <1 per cent (due to fortuitous cancellation of two types of bias) or as high as 20 per cent for methods in active use (despite the small mean photoz bias of these algorithms). Our work demonstrates that lensing-specific statistics must be used to reliably calibrate the lensing signal, due to asymmetric effects of (frequently non-Gaussian) photoz errors. We also demonstrate that large-scale structure (LSS) can strongly impact the photoz calibration and its error estimation, due to a correlation between the LSS and the photoz errors, and argue that at least two independent degree-scale spectroscopic samples are needed to suppress its effects. Given the size of our spectroscopic sample, we can reduce the galaxy-galaxy lensing calibration error well below current SDSS statistical errors.

Published
2008

444. The Nonlinear Biasing of the zCOSMOS Galaxies up to z ~ 1 from the 10k Sample

Author

Kova, #269, Porciani C., Lilly S. J., Marinoni C., Guzzo L., Zamorani G., Iovino A., Oesch P., Bolzonella M., Peng Y., Meneux B., Zucca E., Bardelli S., Carollo C. M., Contini T., Kneib J. P., Le Fèvre O., Mainieri V., Renzini A., Scodeggio M., Bongiorno A., Caputi K., Coppa G., de la Torre S., de Ravel L., Finoguenov A., Franzetti P., Garilli B., Kampczyk P., Knobel C., Lamareille F., Le Borgne J. F., Le Brun V., Maier C., Mignoli M., Pello R., Perez Montero E., Pozzetti L., Ricciardelli E., Silverman J. D., Tanaka M., Tasca L. A. M., Tresse L., Vergani D., Abbas U., Bottini D., Cappi A., Cassata P., Fumana M., Koekemoer A. M., Leauthaud A., Maccagni D., McCracken H. J., Memeo P., Scaramella R., Scoville N. Z., CUCCIATI, OLGA, CIMATTI, ANDREA, Kova&#269, K., Porciani C., Lilly S. J., Marinoni C., Guzzo L., Cucciati O., Zamorani G., Iovino A., Oesch P., Bolzonella M., Peng Y., Meneux B., Zucca E., Bardelli S., Carollo C. M., Contini T., Kneib J.-P., Le Fèvre O., Mainieri V., Renzini A., Scodeggio M., Bongiorno A., Caputi K., Coppa G., de la Torre S., de Ravel L., Finoguenov A., Franzetti P., Garilli B., Kampczyk P., Knobel C., Lamareille F., Le Borgne J.-F., Le Brun V., Maier C., Mignoli M., Pello R., Perez-Montero E., Pozzetti L., Ricciardelli E., Silverman J. D., Tanaka M., Tasca L. A. M., Tresse L., Vergani D., Abbas U., Bottini D., Cappi A., Cassata P., Cimatti A., Fumana M., Koekemoer A. M., Leauthaud A., Maccagni D., McCracken H. J., Memeo P., Scaramella R., and Scoville N. Z.

Subjects
Physics, cosmology: observation, Field (physics), 010308 nuclear & particles physics, Dark matter, Astronomy and Astrophysics, Biasing, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Redshift, Galaxy, Luminosity, Space and Planetary Science, cosmology: observations, 0103 physical sciences, Halo effect, galaxies: evolution, galaxies: statistics, 010303 astronomy & astrophysics, Smoothing, Astrophysics::Galaxy Astrophysics
Abstract

We use the zCOSMOS galaxy overdensity field to study the biasing of galaxies in the COSMOS field. By comparing the probability distribution function of the galaxy density contrast δ g to the lognormal approximation of the mass density contrast δ, we obtain the mean biasing function b(δ, z, R) between the galaxy and matter overdensity fields and its second moments \hat{b} and \tilde{b}. Over the redshift interval 0.4 < z < 1 the conditional mean function langδ g |δrang = b(δ, z, R)δ is of a characteristic shape, requiring nonlinear biasing in the most overdense and underdense regions. Taking into account the uncertainties due to cosmic variance, we do not detect any significant evolution in the langδ g |δrang function, but we do detect a significant redshift evolution in the linear biasing parameter \hat{b} from 1.23 ± 0.11 at z ~ 0.55 to 1.62 ± 0.14 at z ~ 0.75, for a luminosity-complete sample of MB < -20 - z galaxies. The \hat{b} parameter does not change significantly with smoothing scale between 8 and 12 h -1 Mpc, but increases systematically with luminosity (at 2σ-3σ significance between the MB < -20.5 - z and MB < -20 - z samples). The nonlinearity parameter \tilde{b}/ \hat{b} is offset from unity by at most 2%, with an uncertainty of the same order. The \tilde{b}/\hat{b} parameter does not show any significant redshift evolution, dependence on the smoothing scale or on the luminosity. By matching the linear bias of galaxies to the halo bias, we infer that the MB < -20 - z galaxies reside in dark matter halos with a characteristic mass of about (2.6 - 5.6) × 1012 M sun with a small dependence on the adopted bias-mass relation. Our detailed error analysis and comparison with previous studies lead us to conclude that cosmic variance is the main contributor to the differences in the linear bias measured from different surveys. While our results support the general picture of biased galaxy formation up to z ~ 1, the fine-tuning of the galaxy formation models is still limited by the restrictions of the current spectroscopic surveys at these redshifts.

Published
2011

445. The zCOSMOS-Bright survey: the clustering of early and late galaxy morphological types since z≃ 1

Author

de la Torre S., Le Fèvre O., Porciani C., Guzzo L., Meneux B., Abbas U., Tasca L., Carollo C. M., Contini T., Kneib J. P., Lilly S. J., Mainieri V., Renzini A., Scodeggio M., Zamorani G., Bardelli S., Bolzonella M., Bongiorno A., Caputi K., Coppa G., de Ravel L., Franzetti P., Garilli B., Halliday C., Iovino A., Kampczyk P., Knobel C., Koekemoer A. M., Kova, #269, Lamareille F., Le Borgne J. F., Le Brun V., Maier C., Mignoli M., Pelló R., Peng Y., Perez Montero E., Ricciardelli E., Silverman J., Tanaka M., Tresse L., Vergani D., Zucca E., Bottini D., Cappi A., Cassata P., Leauthaud A., Maccagni D., Marinoni C., McCracken H. J., Memeo P., Oesch P., Pozzetti L., Scaramella R., CUCCIATI, OLGA, CIMATTI, ANDREA, de la Torre S., Le Fèvre O., Porciani C., Guzzo L., Meneux B., Abbas U., Tasca L., Carollo C. M., Contini T., Kneib J.-P., Lilly S. J., Mainieri V., Renzini A., Scodeggio M., Zamorani G., Bardelli S., Bolzonella M., Bongiorno A., Caputi K., Coppa G., Cucciati O., de Ravel L., Franzetti P., Garilli B., Halliday C., Iovino A., Kampczyk P., Knobel C., Koekemoer A. M., Kova&#269, K., Lamareille F., Le Borgne J.-F., Le Brun V., Maier C., Mignoli M., Pelló R., Peng Y., Perez-Montero E., Ricciardelli E., Silverman J., Tanaka M., Tresse L., Vergani D., Zucca E., Bottini D., Cappi A., Cassata P., Cimatti A., Leauthaud A., Maccagni D., Marinoni C., McCracken H. J., Memeo P., Oesch P., Pozzetti L., and Scaramella R.

Subjects
cosmology: observation, galaxies: high-redshift, galaxies: statistic, Astrophysics::Cosmology and Extragalactic Astrophysics, large-scale structure of Universe, galaxies: evolution, Astrophysics::Galaxy Astrophysics
Abstract

We measure the spatial clustering of galaxies as a function of their morphological type at z≃ 0.8, for the first time in a deep redshift survey with full morphological information. This is obtained by combining high-resolution Hubble Space Telescope imaging and Very Large Telescope spectroscopy for about 8500 galaxies to ? with accurate spectroscopic redshifts from the zCOSMOS-Bright redshift survey. At this epoch, early-type galaxies already show a significantly stronger clustering than late-type galaxies on all probed scales. A comparison to the Sloan Digital Sky Survey Data at z≃ 0.1 shows that the relative clustering strength between early and late morphological classes tends to increase with cosmic time at small separations, while on large scales it shows no significant evolution since z≃ 0.8. This suggests that most early-type galaxies had already formed in intermediate and dense environments at this epoch. Our results are consistent with a picture in which the relative clustering of different morphological types between z≃ 1 and 0 reflects the evolving role of environment in the morphological transformation of galaxies, on top of a global evolution driven by mass.

Published
2011

446. The evolution of quiescent galaxies at high redshifts (z≥ 1.4)

Author

Domínguez Sánchez H., Gruppioni C., Ilbert O., Pozzetti L., McCracken H., Capak P., Le Floch E., Salvato M., Zamorani G., Carollo C. M., Contini T., Kneib J. P., Le Fèvre O., Lilly S. J., Mainieri V., Renzini A., Scodeggio M., Bardelli S., Bolzonella M., Bongiorno A., Caputi K., Coppa G., de la Torre S., de Ravel L., Franzetti P., Garilli B., Iovino A., Kampczyk P., Knobel C., Kova, #269, Lamareille F., Le Borgne J. F., Le Brun V., Maier C., Mignoli M., Pelló R., Peng Y., Perez Montero E., Ricciardelli E., Silverman J. D., Tanaka M., Tasca L. A. M., Tresse L., Vergani D., Zucca E., POZZI, FRANCESCA, CIMATTI, ANDREA, CUCCIATI, OLGA, Domínguez Sánchez H., Pozzi F., Gruppioni C., Cimatti A., Ilbert O., Pozzetti L., McCracken H., Capak P., Le Floch E., Salvato M., Zamorani G., Carollo C. M., Contini T., Kneib J.-P., Le Fèvre O., Lilly S. J., Mainieri V., Renzini A., Scodeggio M., Bardelli S., Bolzonella M., Bongiorno A., Caputi K., Coppa G., Cucciati O., de la Torre S., de Ravel L., Franzetti P., Garilli B., Iovino A., Kampczyk P., Knobel C., Kova&#269, K., Lamareille F., Le Borgne J.-F., Le Brun V., Maier C., Mignoli M., Pelló R., Peng Y., Perez-Montero E., Ricciardelli E., Silverman J. D., Tanaka M., Tasca L. A. M., Tresse L., Vergani D., and Zucca E.

Subjects
galaxies: high-redshift, galaxies: star formation, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, galaxies: evolution, Astrophysics::Galaxy Astrophysics
Abstract

The goal of this work is to study the evolution of high-redshift (z≥ 1.4) quiescent galaxies over an effective area of ˜1.7 deg2 in the COSMOS field. Galaxies have been divided according to their star formation activity and the evolution of the different populations, in particular of the quiescent galaxies, has been investigated in detail. We have studied an IRAC (mag 3.6 μm < 22.0) selected sample of ˜18 000 galaxies at z≥ 1.4 in the COSMOS field with multiwavelength coverage extending from the U band to the Spitzer 24 μm one. We have derived accurate photometric redshifts (?) through a SED-fitting procedure. Other important physical parameters [masses, ages and star formation rates (SFR)] of the galaxies have been obtained using Maraston models. We have divided our sample into actively star-forming, intermediate and quiescent galaxies depending on their specific star formation rate (SSFR = SFR/M). We have computed the galaxy stellar mass function (GSMF) of the total sample and the different populations at z= 1.4-3.0. We have studied the properties of high-redshift quiescent galaxies finding that they are old (1-4 Gyr), massive (˜ 1010.65 M⊙), weakly star-forming stellar populations with low dust extinction [E(B-V) ≤ 0.15] and small e-folding time-scales (τ˜ 0.1-0.3 Gyr). We observe a significant evolution of the quiescent stellar mass function from 2.5 < z < 3.0 to 1.4 < z < 1.6, increasing by ˜1 dex in this redshift interval. We find that z˜ 1.5 is an epoch of transition of the GSMF: while the GSMF at z≳ 1.5 is dominated by the star-forming galaxies at all stellar masses, at z≲ 1.5 the contribution to the total GSMF of the quiescent galaxies is significant and becomes higher than that of the star-forming population for M≥ 1010.75 M⊙. The fraction of star-forming galaxies decreases from 60-20 per cent from z˜ 2.5-3.0 to 1.4-1.6 for M˜ 1011.0 M⊙, while the quiescent population increases from 10-50 per cent at the same redshift and mass intervals. We compare the fraction of quiescent galaxies derived with that predicted by theoretical models and find that the Kitzbichler & White model, implemented on the Millennium Simulation, is the one that better reproduces the shape of the data. Finally, we calculate the stellar mass density of the star-forming and quiescent populations as a function of redshift and find that there is already a significant number of quiescent galaxies at z > 2.5 (logρ[M⊙ Mpc-3]˜ 6), meaning that efficient star formation had to take place before that time.

Published
2011

447. An increase in the faint red galaxy population in massive clusters since z ∼ 0.5

Author

Stott, J. P., Smail, I., Edge, A. C., Ebeling, H., Smith, G. P., Kneib, J. P., Pimbblet, K. A., Stott, J. P., Smail, I., Edge, A. C., Ebeling, H., Smith, G. P., Kneib, J. P., and Pimbblet, K. A.

Abstract

We compare the luminosity functions for red galaxies lying on the rest-frame (U - V) color-magnitude sequence in a homogeneous sample of 10 X-ray-luminous clusters from the MACS survey at z ∼ 0.5 to a similarly selected X-ray cluster sample at z ∼ 0.1. We exploit deep Hubble Space Telescope ACS imaging in the F555 W and F814W passbands of the central 1.2 Mpc diameter regions of the distant clusters to measure precise colors for the galaxies in these regions and statistically correct for contamination by field galaxies using observations of blank fields. We apply an identical analysis to ground-based photometry of the z ∼ 0.1 sample. This comparison demonstrates that the number of faint, Mv ∼ -19, red galaxies relative to the bright population seen in the central regions of massive clusters has roughly doubled over the 4 Gyr between z ~ 0.5 and z ∼ 0.1. We quantify this difference by measuring the dwarf-giant ratio on the red sequence, which increases by a factor of at least 2.2 ± 0.4 since z ∼ 0.5. This is consistent with the idea that many faint, blue, star-forming galaxies in high-density environments are transforming onto the red sequence in the last half of the Hubble time.

Published
2007

448. Truncation of galaxy dark matter halos in high density environments

Author

Limousin, M., Kneib, J. P., Bardeau, S., Natarajan, P., Czoske, O., Smail, I., Ebeling, H., Smith, G. P., Limousin, M., Kneib, J. P., Bardeau, S., Natarajan, P., Czoske, O., Smail, I., Ebeling, H., and Smith, G. P.

Abstract

Udgivelsesdato: 3 Jan.

Published
2007

450. The bimodality of the 10k zCOSMOS-bright galaxies up to z ~ 1: a new statistical and portable classification based on the optical galaxy properties

Author

Coppa G., Mignoli M., Zamorani G., Bardelli S., Lilly S. J., Bolzonella M., Scodeggio M., Vergani D., Nair P., Pozzetti L., Zucca E., Carollo C. M., Contini T., Le Fèvre O., Renzini A., Mainieri V., Bongiorno A., Caputi K. I., de la Torre S., de Ravel L., Franzetti P., Garilli B., Memeo P., Iovino A., Kampczyk P., Kneib J. P., Knobel C., Koekemoer A. M., Kova, #269, Lamareille F., Le Borgne J. F., Le Brun V., Maier C., Pellò R., Peng Y., Perez Montero E., Ricciardelli E., Scarlata C., Silverman J. D., Tanaka M., Tasca L., Tresse L., Abbas U., Bottini D., Capak P., Cappi A., Cassata P., Fumana M., Guzzo L., Leauthaud A., Maccagni D., Marinoni C., Meneux B., Oesch P., Porciani C., Scaramella R., Scoville N., CIMATTI, ANDREA, CUCCIATI, OLGA, Coppa G., Mignoli M., Zamorani G., Bardelli S., Lilly S. J., Bolzonella M., Scodeggio M., Vergani D., Nair P., Pozzetti L., Cimatti A., Zucca E., Carollo C. M., Contini T., Le Fèvre O., Renzini A., Mainieri V., Bongiorno A., Caputi K. I., Cucciati O., de la Torre S., de Ravel L., Franzetti P., Garilli B., Memeo P., Iovino A., Kampczyk P., Kneib J.-P., Knobel C., Koekemoer A. M., Kova&#269, K., Lamareille F., Le Borgne J.-F., Le Brun V., Maier C., Pellò R., Peng Y., Perez-Montero E., Ricciardelli E., Scarlata C., Silverman J. D., Tanaka M., Tasca L., Tresse L., Abbas U., Bottini D., Capak P., Cappi A., Cassata P., Fumana M., Guzzo L., Leauthaud A., Maccagni D., Marinoni C., Meneux B., Oesch P., Porciani C., Scaramella R., Scoville N., Institute for Astronomy [Zürich], Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), INAF - Osservatorio Astronomico di Bologna (OABO), University of Chicago, Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), European Southern Observatory (ESO), College of Computing (GATECH), Georgia Institute of Technology [Atlanta], AUTRES, Dipartimento di Fisica, Università degli Studi di Milano-Bicocca [Milano] (UNIMIB)-Università degli Studi di Milano [Milano] (UNIMI), Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Département Informatique pour les Systèmes Coopératifs Ouverts et Décentralisés (ISCOD-ENSMSE), École des Mines de Saint-Étienne (Mines Saint-Étienne MSE), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Henri Fayol, Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Hunan Normal University, Spitzer Science Center, California Institute of Technology (CALTECH), Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre de Physique Théorique - UMR 6207 (CPT), Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN)-Université de Provence - Aix-Marseille 1-Université de la Méditerranée - Aix-Marseille 2, Astronomy, Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Milano-Bicocca = University of Milano-Bicocca (UNIMIB)-Università degli Studi di Milano = University of Milan (UNIMI), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Hunan Normal University (HNU), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), and Université de la Méditerranée - Aix-Marseille 2-Université de Provence - Aix-Marseille 1-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO), FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, STAR-FORMATION, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], MORPHOLOGICAL CLASSIFICATION, 0103 physical sciences, Range (statistics), PHOTOMETRIC REDSHIFTS, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, Galaxies: evolution, Galaxies: fundamental parameters, Galaxies: general, Astronomy and Astrophysics, Space and Planetary Science, DIGITAL-SKY-SURVEY, 010308 nuclear & particles physics, FORMATION HISTORIES, HUBBLE DEEP FIELD, Order (ring theory), galaxies: fundamental parameters, ENVIRONMENTAL DEPENDENCE, Redshift survey, galaxies: general, Redshift, Galaxy, Bimodality, LUMINOSITY FUNCTION, SPECTROSCOPIC SAMPLE, STELLAR MASS FUNCTION, Cube, galaxies: evolution, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

Our goal is to develop a new and reliable statistical method to classify galaxies from large surveys. We probe the reliability of the method by comparing it with a three-dimensional classification cube, using the same set of spectral, photometric and morphological parameters.We applied two different methods of classification to a sample of galaxies extracted from the zCOSMOS redshift survey, in the redshift range 0.5 < z < 1.3. The first method is the combination of three independent classification schemes, while the second method exploits an entirely new approach based on statistical analyses like Principal Component Analysis (PCA) and Unsupervised Fuzzy Partition (UFP) clustering method. The PCA+UFP method has been applied also to a lower redshift sample (z < 0.5), exploiting the same set of data but the spectral ones, replaced by the equivalent width of H$��$. The comparison between the two methods shows fairly good agreement on the definition on the two main clusters, the early-type and the late-type galaxies ones. Our PCA-UFP method of classification is robust, flexible and capable of identifying the two main populations of galaxies as well as the intermediate population. The intermediate galaxy population shows many of the properties of the green valley galaxies, and constitutes a more coherent and homogeneous population. The fairly large redshift range of the studied sample allows us to behold the downsizing effect: galaxies with masses of the order of $3\cdot 10^{10}$ Msun mainly are found in transition from the late type to the early type group at $z>0.5$, while galaxies with lower masses - of the order of $10^{10}$ Msun - are in transition at later epochs; galaxies with $M 5\cdot 10^{10}$ Msun) mostly completed their transition before $z\sim 1$., 16 pages, 14 figures, accepted for publication in A&A

Published
2010
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results