Recursos de colección

Caltech Authors (157.532 recursos)

Repository of works by Caltech published authors.

Group = COSMOS

Mostrando recursos 1 - 20 de 191

  1. Obscured active galactic nuclei triggered in compact star-forming galaxies

    Chang, Yu-Yen; Le Floc'h, Emeric; Juneau, Stéphanie; da Cunha, Elisabete; Salvato, Mara; Civano, Francesca; Marchesi, Stefano; Gabor, J. M.; Ilbert, Olivier; Laigle, Clotilde; McCracken, H. J.; Hsieh, Bau-Ching; Capak, Peter
    We present a structural study of 182 obscured active galactic nuclei (AGNs) at z ≤ 1.5, selected in the Cosmic Evolution Survey field from their extreme infrared to X-ray luminosity ratio and their negligible emission at optical wavelengths. We fit optical to far-infrared spectral energy distributions and analyse deep Hubble Space Telescope imaging to derive the physical and morphological properties of their host galaxies. We find that such galaxies are more compact than normal star-forming sources at similar redshift and stellar mass, and we show that it is not an observational bias related to the emission of the AGN. Based on...

  2. An ALMA survey of submillimetre galaxies in the COSMOS field: The extent of the radio-emitting region revealed by 3 GHz imaging with the Very Large Array

    Miettinen, O.; Capak, P. L.
    Context. The observed spatial scale of the radio continuum emission from star-forming galaxies can be used to investigate the spatial extent of active star formation, constrain the importance of cosmic-ray transport, and examine the effects of galaxy interactions. Aims. We determine the radio size distribution of a large sample of 152 submillimetre galaxies (SMGs) in the COSMOS field that were pre-selected at 1.1 mm, and later detected with the Atacama Large Millimetre/submillimetre Array (ALMA) in the observed-frame 1.3 mm dust continuum emission at a signal-to-noise ratio (S/N) of ≥5. Methods. We used the deep, subarcsecond-resolution (1σ = 2.3μJy beam^(-1); .̋ 75) centimetre...

  3. The VLA-COSMOS 3 GHz Large Project: Multiwavelength counterparts and the composition of the faint radio population

    Smolčić, V.; Delvecchio, I.; Zamorani, G.; Baran, N.; Novak, M.; Delhaize, J.; Schinnerer, E.; Berta, S.; Bondi, M.; Ciliegi, P.; Capak, P.; Civano, F.; Karim, A.; Le Fèvre, O.; Ilbert, O.; Laigle, C.; Marchesi, S.; McCracken, H. J.; Tasca, L.; Salvato, M.; Vardoulaki, E.
    We study the composition of the faint radio population selected from the Karl G. Jansky Very Large Array Cosmic Evolution Survey (VLA-COSMOS) 3 GHz Large Project, which is a radio continuum survey performed at 10 cm wavelength. The survey covers a 2.6 square degree area with a mean rms of ~ 2.3 μJy/beam, cataloging 10 830 sources above 5σ, and enclosing the full 2 square degree COSMOS field. By combining these radio data with optical, near-infrared (UltraVISTA), and mid-infrared (Spitzer/IRAC) data, as well as X-ray data (Chandra), we find counterparts to radio sources for ~93% of the total radio sample reaching...

  4. The VLA-COSMOS 3 GHz Large Project: Cosmic star formation history since z ~ 5

    Novak, M.; Smolčić, V.; Delhaize, J.; Delvecchio, I.; Zamorani, G.; Baran, N.; Bondi, M.; Capak, P.; Carilli, C. L.; Ciliegi, P.; Civano, F.; Ilbert, O.; Karim, A.; Laigle, C.; Le Fèvre, O.; Marchesi, S.; McCracken, H.; Miettinen, O.; Salvato, M.; Sargent, M.; Schinnerer, E.; Tasca, L.
    We make use of the deep Karl G. Jansky Very Large Array (VLA) COSMOS radio observations at 3 GHz to infer radio luminosity functions of star-forming galaxies up to redshifts of z ~ 5 based on approximately 6000 detections with reliable optical counterparts. This is currently the largest radio-selected sample available out to z ~ 5 across an area of 2 square degrees with a sensitivity of rms ≈ 2.3 μJy beam^(-1). By fixing the faint and bright end shape of the radio luminosity function to the local values, we find a strong redshift trend that can be fitted with...

  5. The VLA-COSMOS 3 GHz Large Project: The infrared-radio correlation of star-forming galaxies and AGN to z ≲ 6

    Delhaize, J.; Capak, P.
    We examine the behaviour of the infrared-radio correlation (IRRC) over the range 0

  6. The VLA-COSMOS 3 GHz Large Project: AGN and host-galaxy properties out to z  ≲  6

    Delvecchio, I.; Mooley, K.; Capak, P.
    We explore the multiwavelength properties of AGN host galaxies for different classes of radio-selected AGN out to z ≲ 6 via a multiwavelength analysis of about 7700 radio sources in the COSMOS field. The sources were selected with the Very Large Array (VLA) at 3 GHz (10 cm) within the VLA–COSMOS 3 GHz Large Project, and cross-matched with multiwavelength ancillary data. This is the largest sample of high-redshift (z ≲ 6) radio sources with exquisite photometric coverage and redshift measurements available. We constructed a sample of moderate-to-high radiative luminosity AGN (HLAGN) via spectral energy distribution decomposition combined with standard X-ray...

  7. The VLA-COSMOS 3 GHz Large Project: Continuum data and source catalog release

    Smolčić, V.; Mooley, K. P.; Bourke, S.; Baloković, M.; Hallinan, G.; Kulkarni, S. R.; Scoville, N. Z.; Capak, P.
    We present the VLA-COSMOS 3 GHz Large Project based on 384 h of observations with the Karl G. Jansky Very Large Array (VLA) at 3 GHz (10 cm) toward the two square degree Cosmic Evolution Survey (COSMOS) field. The final mosaic reaches a median rms of 2.3 μJy beam^(-1) over the two square degrees at an angular resolution of 0.75″. To fully account for the spectral shape and resolution variations across the broad (2 GHz) band, we image all data with a multiscale, multifrequency synthesis algorithm. We present a catalog of 10 830 radio sources down to 5σ, out of which...

  8. Dust Properties of C II Detected z ∼ 5.5 Galaxies: New HST/WFC3 Near-IR Observations

    Barisic, I.; Faisst, A. L.; Capak, P. L.; Pavesi, R.; Riechers, D. A.; Scoville, N. Z.; Cooke, K.; Kartaltepe, J. S.; Casey, C. M.; Smolčić, V.
    We examine the rest-frame ultraviolet (UV) properties of 10 [C II]λ158 μm-detected galaxies at z ~ 5.5 in COSMOS using new Hubble Space Telescope/Wide Field Camera 3 near-infrared imaging. Together with pre-existing 158 μm continuum and [C II] line measurements by the Atacama Large Millimeter/submillimeter Array, we study their dust attenuation properties on the IRX–β diagram, which connects the total dust emission (∝ IRX = log(L_(FIR)/L_(1600)) to the line-of-sight dust column (∝ β). We find systematically bluer UV continuum spectral slopes (β) compared to previous low-resolution ground-based measurements, which relieves some of the tension between models of dust attenuation and...

  9. The bright end of the galaxy luminosity function at z =7: before the onset of mass quenching?

    Bowler, R. A. A.; Dunlop, J. S.; McLure, R. J.; Rogers, A. B.; McCracken, H. J.; Milvang-Jensen, B.; Furusawa, H.; Fynbo, J. P. U.; Taniguchi, Y.; Afonso, J.; Bremer, M. N.; Le Fèvre, O.
    We present the results of a new search for bright star-forming galaxies at redshift z ≃ 7 within the UltraVISTA second data release (DR2) and UKIDSS (UKIRT Infrared Deep Sky Survey) UDS (Ultra Deep Survey) DR10 data, which together provide 1.65 deg^2 of near-infrared imaging with overlapping optical and Spitzer data. Using a full photometric redshift analysis, to identify high-redshift galaxies and reject contaminants, we have selected a sample of 34 luminous (−22.7

  10. The bright end of the galaxy luminosity function at z =7: before the onset of mass quenching?

    Bowler, R. A. A.; Dunlop, J. S.; McLure, R. J.; Rogers, A. B.; McCracken, H. J.; Milvang-Jensen, B.; Furusawa, H.; Fynbo, J. P. U.; Taniguchi, Y.; Afonso, J.; Bremer, M. N.; Le Fèvre, O.
    We present the results of a new search for bright star-forming galaxies at redshift z ≃ 7 within the UltraVISTA second data release (DR2) and UKIDSS (UKIRT Infrared Deep Sky Survey) UDS (Ultra Deep Survey) DR10 data, which together provide 1.65 deg^2 of near-infrared imaging with overlapping optical and Spitzer data. Using a full photometric redshift analysis, to identify high-redshift galaxies and reject contaminants, we have selected a sample of 34 luminous (−22.7

  11. Wide-Field InfrarRed Survey Telescope-Astrophysics Focused Telescope Assets WFIRST-AFTA 2015 Report

    Spergel, D.; Gehrels, N.; Baltay, C.; Bennett, D.; Breckinridge, J.; Donahue, M.; Dressler, A.; Gaudi, B. S.; Greene, T.; Guyon, O.; Hirata, C.; Kalirai, J.; Kasdin, N. J.; Macintosh, B.; Moos, W.; Perlmutter, S.; Postman, M.; Rauscher, B.; Rhodes, J.; Wang, Y.; Weinberg, D.; Benford, D.; Hudson, M.; Jeong, W. -S.; Mellier, Y.; Traub, W.; Yamada, T.; Capak, P.; Colbert, J.; Masters, D.; Penny, M.; Savransky, D.; Stern, D.; Zimmerman, N.; Barry, R.; Bartusek, L.; Carpenter, K.; Cheng, E.; Content, D.; Dekens, F.; Demers, R.; Grady, K.; Jackson, C.; Kuan, G.; Kruk, J.; Melton, M.; Nemati, B.; Parvin, B.; Poberezhskiy, I.; Peddie, C.; Ruffa, J.; Wallace, J. K.; Whipple, A.; Wollack, E.; Zhao, F.
    This report describes the 2014 study by the Science Definition Team (SDT) of the Wide-Field Infrared Survey Telescope (WFIRST) mission. It is a space observatory that will address the most compelling scientific problems in dark energy, exoplanets and general astrophysics using a 2.4-m telescope with a wide-field infrared instrument and an optical coronagraph. The Astro2010 Decadal Survey recommended a Wide Field Infrared Survey Telescope as its top priority for a new large space mission. As conceived by the decadal survey, WFIRST would carry out a dark energy science program, a microlensing program to determine the demographics of exoplanets, and a general observing...

  12. Wide-Field InfrarRed Survey Telescope-Astrophysics Focused Telescope Assets WFIRST-AFTA 2015 Report

    Spergel, D.; Gehrels, N.; Baltay, C.; Bennett, D.; Breckinridge, J.; Donahue, M.; Dressler, A.; Gaudi, B. S.; Greene, T.; Guyon, O.; Hirata, C.; Kalirai, J.; Kasdin, N. J.; Macintosh, B.; Moos, W.; Perlmutter, S.; Postman, M.; Rauscher, B.; Rhodes, J.; Wang, Y.; Weinberg, D.; Benford, D.; Hudson, M.; Jeong, W. -S.; Mellier, Y.; Traub, W.; Yamada, T.; Capak, P.; Colbert, J.; Masters, D.; Penny, M.; Savransky, D.; Stern, D.; Zimmerman, N.; Barry, R.; Bartusek, L.; Carpenter, K.; Cheng, E.; Content, D.; Dekens, F.; Demers, R.; Grady, K.; Jackson, C.; Kuan, G.; Kruk, J.; Melton, M.; Nemati, B.; Parvin, B.; Poberezhskiy, I.; Peddie, C.; Ruffa, J.; Wallace, J. K.; Whipple, A.; Wollack, E.; Zhao, F.
    This report describes the 2014 study by the Science Definition Team (SDT) of the Wide-Field Infrared Survey Telescope (WFIRST) mission. It is a space observatory that will address the most compelling scientific problems in dark energy, exoplanets and general astrophysics using a 2.4-m telescope with a wide-field infrared instrument and an optical coronagraph. The Astro2010 Decadal Survey recommended a Wide Field Infrared Survey Telescope as its top priority for a new large space mission. As conceived by the decadal survey, WFIRST would carry out a dark energy science program, a microlensing program to determine the demographics of exoplanets, and a general observing...

  13. The galaxy-halo connection from a joint lensing, clustering and abundance analysis in the CFHTLenS/VIPERS field

    Coupon, J.; Arnouts, S.; van Waerbeke, L.; Moutard, T.; Ilbert, O.; van Uitert, E.; Erben, T.; Garilli, B.; Guzzo, L.; Heymans, C.; Hildebrandt, H.; Hoekstra, H.; Kilbinger, M.; Kitching, T.; Mellier, Y.; Miller, L.; Scodeggio, M.; Bonnett, C.; Branchini, E.; Davidzon, I.; De Lucia, G.; Fritz, A.; Fu, L.; Hudelot, P.; Hudson, M. J.; Kuijken, K.; Leauthaud, A.; Le Fèvre, O.; McCracken, H. J.; Moscardini, L.; Rowe, B. T. P.; Schrabback, T.; Semboloni, E.; Velander, M.
    We present new constraints on the relationship between galaxies and their host dark matter haloes, measured from the location of the peak of the stellar-to-halo mass ratio (SHMR), up to the most massive galaxy clusters at redshift z ∼ 0.8 and over a volume of nearly 0.1 Gpc3. We use a unique combination of deep observations in the CFHTLenS/VIPERS field from the near-UV to the near-IR, supplemented by ∼60 000 secure spectroscopic redshifts, analysing galaxy clustering, galaxy–galaxy lensing and the stellar mass function. We interpret our measurements within the halo occupation distribution (HOD) framework, separating the contributions from central and satellite...

  14. The CHANDRA COSMOS Legacy Survey: Optical / IR Identifications

    Marchesi, S.; Civano, F.; Elvis, M.; Salvato, M.; Brusa, M.; Comastri, A.; Gilli, R.; Hasinger, G.; Lanzuisi, G.; Miyaji, T.; Treister, E.; Urry, C. M.; Vignali, C.; Zamorani, G.; Allevato, V.; Cappelluti, N.; Cardamone, C.; Finoguenov, A.; Griffiths, R. E.; Karim, A.; Laigle, C.; LaMassa, S. M.; Jahnke, K.; Ranalli, P.; Schawinski, K.; Schinnerer, E.; Silverman, J. D.; Smolcic, V.; Suh, H.; Trakhtenbrot, B.
    We present the catalog of optical and infrared counterparts of the Chandra COSMOS-Legacy Survey, a 4.6 Ms Chandra program on the 2.2 deg2 of the COSMOS field, combination of 56 new overlapping observations obtained in Cycle 14 with the previous C-COSMOS survey. In this Paper we report the i, K, and 3.6 μm identifications of the 2273 X-ray point sources detected in the new Cycle 14 observations. We use the likelihood ratio technique to derive the association of optical/infrared (IR) counterparts for 97% of the X-ray sources. We also update the information for the 1743 sources detected in C-COSMOS, using...

  15. The galaxy UV luminosity function at z≃ 2–4; new results on faint-end slope and the evolution of luminosity density

    Parsa, Shaghayegh; Dunlop, James S.; McLure, Ross J.; Mortlock, Alice
    We present a new, robust measurement of the evolving rest-frame ultraviolet (UV) galaxy luminosity function (LF) over the key redshift range from z ≃ 2 to z ≃ 4. Our results are based on the high dynamic range provided by combining the Hubble Ultra Deep Field (HUDF), CANDELS/GOODS-South, and UltraVISTA/COSMOS surveys. We utilize the unparalleled multifrequency photometry available in this survey ‘wedding cake’ to compile complete galaxy samples at z ≃ 2, 3, 4 via photometric redshifts (calibrated against the latest spectroscopy) rather than colour–colour selection, and to determine accurate rest-frame UV absolute magnitudes (M1500) from spectral energy distribution (SED)...

  16. z≳ 7 galaxies with red Spitzer/IRAC [3.6]-[4.5] colors in the full CANDELS data set: The brightest-known galaxies at z~ 7-9 and a probable spectroscopic confirmation at z = 7.48

    Roberts-Borsani, G. W.; Bouwens, R. J.; Oesch, P. A.; Labbe, I.; Smit, R.; Illingworth, G. D.; van Dokkum, P. G.; Holden, B.; Gonzalez, V.; Stefanon, M.; Holwerda, B.; Wilkins, S.
    We identify four unusually bright (H ${}_{160,{AB}}$ < 25.5) galaxies from Hubble Space Telescope (HST) and Spitzer CANDELS data with probable redshifts z ~ 7–9. These identifications include the brightest-known galaxies to date at z gsim 7.5. As Y-band observations are not available over the full CANDELS program to perform a standard Lyman-break selection of z > 7 galaxies, we employ an alternate strategy using deep Spitzer/IRAC data. We identify z ~ 7.1–9.1 galaxies by selecting z gsim 6 galaxies from the HST CANDELS data that show quite red IRAC [3.6]−[4.5] colors, indicating strong [O iii]+Hβ lines in the 4.5...

  17. The rest-frame optical (900nm) galaxy luminosity function at z~4-7: abundance matching points to limited evolution in the Mstar/Mhalo ratio at z>4

    Stefanon, Mauro; Bouwens, Rychard J.; Labbé, Ivo; Muzzin, Adam; Marchesini, Danilo; Oesch, Pascal; Gonzalez, Valentino
    We present the first determination of the galaxy luminosity function (LF) at z~4, 5, 6 and 7 in the rest-frame optical at lambda_rest~900 nm (z' band). The rest-frame optical light traces the content in low-mass evolved stars (~stellar mass - Mstar), minimizing potential measurement biases for Mstar. Moreover it is less affected by nebular line emission contamination and dust attenuation, is independent of stellar population models, and can be probed up to z~8 through Spitzer/IRAC. Our analysis leverages the unique full depth Spitzer/IRAC 3.6um-to-8.0um data over the CANDELS/GOODS-N, CANDELS/GOODS-S and COSMOS/UltraVISTA fields. We find that at absolute magnitudes M_z' fainter than >-23 mag, M_z' linearly correlates with M_UV,1600. At...

  18. Gas Fraction and depletion time of massive star-forming galaxies at z ∼ 3.2: No change in global star formation process out to z > 3

    Schinnerer, E.; Groves, B.; Sargent, M. T.; Karim, A.; Oesch, P. A.; Magnelli, B.; LeFevre, O.; Tasca, L.; Civano, F.; Cassata, P.; Smolčić, V.
    The observed evolution of the gas fraction and its associated depletion time in main-sequence (MS) galaxies provides insights on how star formation proceeds over cosmic time. We report ALMA detections of the rest-frame ~300 μm continuum observed at 240 GHz for 45 massive ($\langle \mathrm{log}({M}_{\star }({M}_{\odot }))\rangle =10.7$), normal star-forming ($\langle \mathrm{log}(\mathrm{sSFR}({\mathrm{yr}}^{-1}))\rangle =-8.6$), i.e., MS, galaxies at $z\approx 3.2$ in the COSMOS field. From an empirical calibration between cold neutral, i.e., molecular and atomic, gas mass ${M}_{\mathrm{gas}}$ and monochromatic (rest-frame) infrared luminosity, the gas mass for this sample is derived. Combined with stellar mass ${M}_{\star }$ and star formation rate...

  19. The COSMOS2015 galaxy stellar mass function: 13 billion years of stellar mass assembly in 10 snapshots

    Davidzon, I.; Ilbert, O.; Laigle, C.; Coupon, J.; McCracken, H. J.; Delvecchio, I.; Masters, D.; Capak, P. L.; Hsieh, B. C.; Tresse, L.; Le Fevre, O.; Bethermin, M.; Chang, Y. -Y.; Faisst, A. L.; Le Floc'h, E.; Steinhardt, C.; Toft, S.; Aussel, H.; Dubois, C.; Hasinger, G.; Salvato, M.; Sanders, D. B.; Scoville, N.; Silverman, J. D.
    We measure the stellar mass function (SMF) of galaxies in the COSMOS field up to $z\sim6$. We select them in the near-IR bands of the COSMOS2015 catalogue, which includes ultra-deep photometry from UltraVISTA-DR2, SPLASH, and Subaru/Hyper-SuprimeCam. At $z>2.5$ we use new precise photometric redshifts with error $\sigma_z=0.03(1+z)$ and an outlier fraction of $12\%$, estimated by means of the unique spectroscopic sample of COSMOS. The increased exposure time in the DR2, along with our panchromatic detection strategy, allow us to improve the stellar mass completeness at high $z$ with respect to previous UltraVISTA catalogues. We also identify passive galaxies through a robust colour-colour selection, extending their SMF estimate up to...

  20. The COSMOS2015 galaxy stellar mass function: Thirteen billion years of stellar mass assembly in ten snapshots

    Davidzon, I.; Ilbert, O.; Laigle, C.; Coupon, J.; McCracken, H. J.; Delvecchio, I.; Masters, D.; Capak, P.; Hsieh, B. C.; Le Fèvre, O.; Tresse, L.; Bethermin, M.; Chang, Y.-Y.; Faisst, A. L.; Le Floc'h, E.; Steinhardt, C.; Toft, S.; Aussel, H.; Dubois, C.; Hasinger, G.; Salvato, M.; Sanders, D. B.; Scoville, N.; Silverman, J. D.
    We measure the stellar mass function (SMF) and stellar mass density of galaxies in the COSMOS field up to z ~ 6. We select them in the near-IR bands of the COSMOS2015 catalogue, which includes ultra-deep photometry from UltraVISTA-DR2, SPLASH, and Subaru/Hyper Suprime-Cam. At z > 2.5 we use new precise photometric redshifts with error σ_z = 0.03(1 + z) and an outlier fraction of 12%, estimated by means of the unique spectroscopic sample of COSMOS (~100 000 spectroscopic measurements in total, more than one thousand having robust z_(spec)> 2.5). The increased exposure time in the DR2, along with our...

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