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Caltech Authors (170.931 recursos)

Repository of works by Caltech published authors.

Group = COSMOS

Mostrando recursos 1 - 20 de 336

  1. Hidden in Plain Sight: A Massive, Dusty Starburst in a Galaxy Protocluster at z = 5.7 in the COSMOS Field

    Pavesi, Riccardo; Riechers, Dominik A.; Sharon, Chelsea E.; Smolčić, Vernesa; Faisst, Andreas L.; Schinnerer, Eva; Carilli, Christopher L.; Capak, Peter L.; Scoville, Nick; Stacey, Gordon J.
    We report the serendipitous discovery of a dusty, starbursting galaxy at z = 5.667 (hereafter called CRLE) in close physical association with the "normal" main-sequence galaxy HZ10 at z = 5.654. CRLE was identified by detection of [C II], [N II], and CO(2–1) line emission, making it the highest-redshift, most luminous starburst in the COSMOS field. This massive, dusty galaxy appears to be forming stars at a rate of at least 1500 M⊙ yr^(−1) in a compact region only ~3 kpc in diameter. The dynamical and dust emission properties of CRLE suggest an ongoing merger driving the starburst, which is...

  2. Similar Scaling Relations for the Gas Content of Galaxies Across Environments to z ~ 3.5

    Darvish, Behnam; Scoville, Nick Z.; Martin, Christopher; Mobasher, Bahram; Díaz-Santos, Tanio; Shen, Lu
    We study the effects of the local environment on the molecular gas content of a large sample of log(M*/M⊙) ≳ 10 star-forming and starburst galaxies with specific star formation rates (sSFRs) on and above the main sequence (MS) to z ~ 3.5. ALMA observations of the dust continuum in the COSMOS field are used to estimate molecular gas masses at z ≈ 0.5–3.5. We also use a local universe sample from the ALFALFA H I survey after converting it into molecular masses. The molecular mass (M_(ISM)) scaling relation shows a dependence on z, M *, and sSFR relative to the...

  3. SILVERRUSH. V. Census of Lyα, [O III] λ5007, Hα, and [C II] 158 μm Line Emission with ~1000 LAEs at z = 4.9–7.0 Revealed with Subaru/HSC

    Harikane, Yuichi; Capak, Peter L.; Faisst, Andreas L.; Davidzon, Iary
    We investigate Lyα, [O III] λ5007, Hα, and [C II] 158 μm emission from 1124 galaxies at z = 4.9–7.0. Our sample is composed of 1092 Lyα emitters (LAEs) at z = 4.9, 5.7, 6.6, and 7.0 identified by Subaru/Hyper-Suprime-Cam (HSC) narrowband surveys covered by Spitzer Large Area Survey with Hyper-Suprime-Cam (SPLASH) and 34 galaxies at z = 5.148–7.508 with deep ALMA [C II] 158 μm data in the literature. Fluxes of strong rest-frame optical lines of [O III] and Hα (Hβ) are constrained by significant excesses found in the SPLASH 3.6 and 4.5 μm photometry. At z = 4.9,...

  4. The DEIMOS 10K Spectroscopic Survey Catalog of the COSMOS Field

    Hasinger, G.; Capak, P.; Salvato, M.; Barger, A. J.; Cowie, L. L.; Faisst, A.; Hemmati, S.; Kakazu, Y.; Kartaltepe, J.; Masters, D.; Mobasher, B.; Nayyeri, H.; Sanders, D. B.; Scoville, N. Z.; Suh, H.; Steinhardt, C.; Yang, Fengwei
    We present a catalog of 10,718 objects in the COSMOS field, observed through multi-slit spectroscopy with the Deep Imaging Multi-Object Spectrograph (DEIMOS) on the Keck II telescope in the wavelength range ~5500–9800 Å. The catalog contains 6617 objects with high-quality spectra (two or more spectral features), and 1798 objects with a single spectroscopic feature confirmed by the photometric redshift. For 2024 typically faint objects, we could not obtain reliable redshifts. The objects have been selected from a variety of input catalogs based on multi-wavelength observations in the field, and thus have a diverse selection function, which enables the study of...

  5. Simple hydrodynamical Simulations of the Circumnuclear Disk

    Coker, Robert F.; Christopher, Michol H.; Stolovy, Susan R.; Scoville, Nick Z.
    The “circumnuclear disk” (CND) is a dense, clumpy, asymmetric ring‐like feature centered on Sgr A*. The outer edge of the CND is not distinct but the disk extends for more than 7 pc; the distinct inner edge, at a radius of ≃1.5 pc, surrounds the “mini‐spiral” of the HII region, Sgr A West. We present simple 3D hydrodynamical models of the formation and evolution of the CND from multiple selfgravitating infalling clouds and compare the results with recent observations. We assume the clouds are initially Bonner‐Ebert spheres, in equilibrium with a hot confining inter‐cloud medium. We include the gravitational potential...

  6. Molecular outflow and feedback in the obscured quasar XID2028 revealed by ALMA

    Brusa, M.; Scoville, N. Z.
    We imaged, with ALMA and ARGOS/LUCI, the molecular gas and dust and stellar continuum in XID2028, which is an obscured quasi-stellar object (QSO) at z = 1.593, where the presence of a massive outflow in the ionised gas component traced by the [OIII]5007 emission has been resolved up to 10 kpc. This target represents a unique test case to study QSO feedback in action at the peak epoch of AGN-galaxy co-evolution. The QSO was detected in the CO(5 − 4) transition and in the 1.3 mm continuum at ~30 and ~20σ significance, respectively; both emissions are confined in the central...

  7. SPLASH-SXDF Multi-wavelength Photometric Catalog

    Mehta, Vihang; Scarlata, Claudia; Capak, Peter; Davidzon, Iary; Faisst, Andreas; Hsieh, Bau Ching; Ilbert, Olivier; Jarvis, Matt; Laigle, Clotilde; Phillips, John; Silverman, John; Strauss, Michael A.; Tanaka, Masayuki; Bowler, Rebecca; Coupon, Jean; Foucaud, Sébastien; Hemmati, Shoubaneh; Masters, Daniel; McCracken, Henry Joy; Mobasher, Bahram; Ouchi, Masami; Shibuya, Takatoshi; Wang, Wei-Hao
    We present a multi-wavelength catalog in the Subaru/XMM-Newton Deep Field (SXDF) as part of the Spitzer Large Area Survey with Hyper-Suprime-Cam (SPLASH). We include the newly acquired optical data from the Hyper-Suprime-Cam Subaru Strategic Program, accompanied by IRAC coverage from the SPLASH survey. All available optical and near-infrared data is homogenized and resampled on a common astrometric reference frame. Source detection is done using a multi-wavelength detection image including the u-band to recover the bluest objects. We measure multi-wavelength photometry and compute photometric redshifts as well as physical properties for ~1.17 million objects over ~4.2 deg^2, with ~800,000 objects in...

  8. Simple hydrodynamical Simulations of the Circumnuclear Disk

    Coker, Robert F.; Christopher, Michol H.; Stolovy, Susan R.; Scoville, Nick Z.
    [no abstract]

  9. Starburst to Quiescent from HST/ALMA: Stars and Dust Unveil Minor Mergers in Submillimeter Galaxies at z ~ 4.5

    Gómez-Guijarro, C.; Capak, P. L.
    Dust-enshrouded, starbursting, submillimeter galaxies (SMGs) at z ≥ 3 have been proposed as progenitors of z ≥ 2 compact quiescent galaxies (cQGs). To test this connection, we present a detailed spatially resolved study of the stars, dust, and stellar mass in a sample of six submillimeter-bright starburst galaxies at z ~ 4.5. The stellar UV emission probed by HST is extended and irregular and shows evidence of multiple components. Informed by HST, we deblend Spitzer/IRAC data at rest-frame optical, finding that the systems are undergoing minor mergers with a typical stellar mass ratio of 1:6.5. The FIR dust continuum emission...

  10. The ISM and Stellar Distributions Near Sgr A*

    Scoville, Nick; Stolovy, Susan R.; Christopher, Micol
    [no abstract]

  11. Empirical Modeling of the Redshift Evolution of the [N II]/Hα Ratio for Galaxy Redshift Surveys

    Faisst, Andreas L.; Masters, Daniel; Wang, Yun; Merson, Alexander; Capak, Peter; Malhotra, Sangeeta; Rhoads, James E.
    We present an empirical parameterization of the [N ii]/Hα flux ratio as a function of stellar mass and redshift valid at 0 < z < 2.7 and 8.5 < log(M/M_⊙) < 11.0. This description can (i) easily be applied to simulations for modeling [N ii]λ6584 line emission, (ii) deblend [N ii] and Hα in current low-resolution grism and narrow-band observations to derive intrinsic Hα fluxes, and (iii) reliably forecast the number counts of Hα emission-line galaxies for future surveys, such as those planned for Euclid and the Wide Field Infrared Survey Telescope (WFIRST). Our model combines the evolution of the...

  12. The stellar mass, star formation rate and dark matter halo properties of LAEs at z ∼ 2

    Kusakabe, Haruka; Shimasaku, Kazuhiro; Ouchi, Masami; Nakajima, Kimihiko; Goto, Ryosuke; Hashimoto, Takuya; Konno, Akira; Harikane, Yuichi; Silverman, John D.; Capak, Peter L.
    We present average stellar population properties and dark matter halo masses of z ∼ 2 Lyα emitters (LAEs) from spectral energy distribution fitting and clustering analysis, respectively, using ≃ 1250 objects (NB387 ≤ 25.5) in four separate fields of ≃ 1 deg^2 in total. With an average stellar mass of 10.2 ± 1.8 × 10^8 M⊙ and star formation rate of 3.4 ± 0.4 M⊙ yr^(−1), the LAEs lie on an extrapolation of the star-formation main sequence (MS) to low stellar mass. Their effective dark matter halo mass is estimated to be 4.0^(+5.1)_(−2.9)×10^(10) M⊙ with an effective bias of 1.22^(+0.16)_(−0.18, which is lower than that of z ∼...

  13. The Hyper Suprime-Cam SSP Survey: Overview and survey design

    Aihara, Hiroaki; Capak, P.
    Hyper Suprime-Cam (HSC) is a wide-field imaging camera on the prime focus of the 8.2-m Subaru telescope on the summit of Mauna Kea in Hawaii. A team of scientists from Japan, Taiwan, and Princeton University is using HSC to carry out a 300-night multi-band imaging survey of the high-latitude sky. The survey includes three layers: the Wide layer will cover 1400 deg^2 in five broad bands (grizy), with a 5 σ point-source depth of r ≈ 26. The Deep layer covers a total of 26 deg^2 in four fields, going roughly a magnitude fainter, while the UltraDeep layer goes almost a magnitude fainter...

  14. Global Properties of M31’s Stellar Halo from the SPLASH Survey. III. Measuring the Stellar Velocity Dispersion Profile

    Gilbert, Karoline M.; Tollerud, Erik J.; Beaton, Rachael L.; Guhathakurta, Puragra; Bullock, James S.; Chiba, Masashi; Kalirai, Jason S.; Kirby, Evan N.; Majewski, Steven R.; Tanaka, Mikito
    We present the velocity dispersion of red giant branch stars in M31's halo, derived by modeling the line-of-sight velocity distribution of over 5000 stars in 50 fields spread throughout M31's stellar halo. The data set was obtained as part of the Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo (SPLASH) Survey, and covers projected radii of 9 to 175 kpc from M31's center. All major structural components along the line of sight in both the Milky Way (MW) and M31 are incorporated in a Gaussian Mixture Model, including all previously identified M31 tidal debris features in the observed fields. The...

  15. Global Properties of M31’s Stellar Halo from the SPLASH Survey. III. Measuring the Stellar Velocity Dispersion Profile

    Gilbert, Karoline M.; Tollerud, Erik J.; Beaton, Rachael L.; Guhathakurta, Puragra; Bullock, James S.; Chiba, Masashi; Kalirai, Jason S.; Kirby, Evan N.; Majewski, Steven R.; Tanaka, Mikito
    We present the velocity dispersion of red giant branch stars in M31's halo, derived by modeling the line-of-sight velocity distribution of over 5000 stars in 50 fields spread throughout M31's stellar halo. The data set was obtained as part of the Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo (SPLASH) Survey, and covers projected radii of 9 to 175 kpc from M31's center. All major structural components along the line of sight in both the Milky Way (MW) and M31 are incorporated in a Gaussian Mixture Model, including all previously identified M31 tidal debris features in the observed fields. The...

  16. An Alternate Approach to Measure Specific Star Formation Rates at 2 < z < 7

    Davidzon, Iary; Ilbert, Olivier; Faisst, Andreas L.; Sparre, Martin; Capak, Peter L.
    We trace the specific star formation rate (sSFR) of massive star-forming galaxies (≳ (10)^(10) M_⊙) from z ~ 2 to 7. Our method is substantially different from previous analyses, as it does not rely on direct estimates of star formation rate, but on the differential evolution of the galaxy stellar mass function (SMF). We show the reliability of this approach by means of semianalytical and hydrodynamical cosmological simulations. We then apply it to real data, using the SMFs derived in the COSMOS and CANDELS fields. We find that the sSFR is proportional to (1+z)^(1.1 ± 0.2) at z > 2,...

  17. An ALMA survey of submillimeter galaxies in the COSMOS field: Multiwavelength counterparts and redshift distribution

    Brisbin, Drew; Capak, Peter
    We carried out targeted ALMA observations of 129 fields in the COSMOS region at 1.25 mm, detecting 152 galaxies at S/N ≥ 5with an average continuum RMS of 150 μJy. These fields represent a S/N-limited sample of AzTEC/ASTE sources with 1.1 mm S/N≥ 4 over an area of 0.72 square degrees. Given ALMA’s fine resolution and the exceptional spectroscopic and multiwavelength photometric data available in COSMOS, this survey allows us unprecedented power in identifying submillimeter galaxy counterparts and determining their redshifts through spectroscopic or photometric means. In addition to 30 sources with prior spectroscopic redshifts, we identified redshifts for 113...

  18. The faint radio sky: VLBA observations of the COSMOS field

    Herrera Ruiz, N.; Middelberg, E.; Deller, A.; Norris, R. P.; Best, P. N.; Brisken, W.; Schinnerer, E.; Smolčić, V.; Delvecchio, I.; Momjian, E.; Bomans, D.; Scoville, N. Z.; Carilli, C.
    Context. Quantifying the fraction of active galactic nuclei (AGN) in the faint radio population and understanding their relation with star-forming activity are fundamental to studies of galaxy evolution. Very long baseline interferometry (VLBI) observations are able to identify AGN above relatively low redshifts (z> 0.1) since they provide milli-arcsecond resolution. Aims. We have created an AGN catalogue from 2865 known radio sources observed in the Cosmic Evolution Survey (COSMOS) field, which has exceptional multi-wavelength coverage. With this catalogue we intend to study the faint radio sky with statistically relevant numbers and to analyse the AGN – host galaxy co-evolution, making...

  19. The faint radio sky: VLBA observations of the COSMOS field

    Herrera Ruiz, N.; Middelberg, E.; Deller, A.; Norris, R. P.; Best, P. N.; Brisken, W.; Schinnerer, E.; Smolčić, V.; Delvecchio, I.; Momjian, E.; Bomans, D.; Scoville, N. Z.; Carilli, C.
    Context. Quantifying the fraction of active galactic nuclei (AGN) in the faint radio population and understanding their relation with star-forming activity are fundamental to studies of galaxy evolution. Very long baseline interferometry (VLBI) observations are able to identify AGN above relatively low redshifts (z> 0.1) since they provide milli-arcsecond resolution. Aims. We have created an AGN catalogue from 2865 known radio sources observed in the Cosmic Evolution Survey (COSMOS) field, which has exceptional multi-wavelength coverage. With this catalogue we intend to study the faint radio sky with statistically relevant numbers and to analyse the AGN – host galaxy co-evolution, making...

  20. Scientific Synergy between LSST and Euclid

    Rhodes, Jason; Capak, Peter; Helou, George; Hemmati, Shoubaneh
    Euclid and the Large Synoptic Survey Telescope (LSST) are poised to dramatically change the astronomy landscape early in the next decade. The combination of high-cadence, deep, wide-field optical photometry from LSST with high-resolution, wide-field optical photometry, and near-infrared photometry and spectroscopy from Euclid will be powerful for addressing a wide range of astrophysical questions. We explore Euclid/LSST synergy, ignoring the political issues associated with data access to focus on the scientific, technical, and financial benefits of coordination. We focus primarily on dark energy cosmology, but also discuss galaxy evolution, transient objects, solar system science, and galaxy cluster studies. We concentrate...

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