Recursos de colección

Caltech Authors (142.336 recursos)

Repository of works by Caltech published authors.

Group = Infrared Processing and Analysis Center (IPAC)

Mostrando recursos 1 - 20 de 1.114

  1. (Sub)millimetre interferometric imaging of a sample of COSMOS/AzTEC submillimetre galaxies. IV. Physical properties derived from spectral energy distributions

    Miettinen, O.; Delvecchio, I.; Smolčić, V.; Novak, M.; Aravena, M.; Karim, A.; Murphy, E. J.; Schinnerer, E.; Capak, P.; Ilbert, O.; Intema, H. T.; Laigle, C.; McCracken, H. J.
    Context. Submillimetre galaxies (SMGs) in the early Universe are potential antecedents of the most massive galaxies we see in the present-day Universe. An important step towards quantifying this galactic evolutionary connection is to investigate the fundamental physical properties of SMGs, such as their stellar mass content (M⋆) and star formation rate (SFR). Aims. We attempt to characterise the physical nature of a 1.1 mm selected, flux-limited, and interferometrically followed up sample of SMGs in the COSMOS field. Methods. We used the latest release of the MAGPHYS code to fit the multiwavelength (UV to radio) spectral energy distributions (SEDs) of 16 of the...

  2. (Sub)millimetre interferometric imaging of a sample of COSMOS/AzTEC submillimetre galaxies. III. Environments

    Smolčić, V.; Miettinen, O.; Tomičić, N.; Zamorani, G.; Finoguenov, A.; Lemaux, B. C.; Aravena, M.; Capak, P.; Chiang, Y.-K.; Civano, F.; Delvecchio, I.; Ilbert, O.; Jurlin, N.; Karim, A.; Laigle, C.; Le Fèvre, O.; Marchesi, S.; McCracken, H. J.; Riechers, D. A.; Salvato, M.; Schinnerer, E.; Tasca, L.; Toft, S.
    We investigate the environment of 23 submillimetre galaxies (SMGs) drawn from a signal-to-noise (S/N)-limited sample of SMGs originally discovered in the James Clerk Maxwell Telescope (JCMT)/AzTEC 1.1 mm continuum survey of a Cosmic Evolution Survey (COSMOS) subfield and then followed up with the Submillimetre Array and Plateau de Bure Interferometer at 890 μm and 1.3 mm, respectively. These SMGs already have well-defined multiwavelength counterparts and redshifts. We also analyse the environments of four COSMOS SMGs spectroscopically confirmed to lie at redshifts z_(spec) > 4.5, and one at z_(spec) = 2.49 resulting in a total SMG sample size of 28. We...

  3. VIMOS Ultra-Deep Survey (VUDS): IGM transmission towards galaxies with 2.5 < z < 5.5 and the colour selection of high-redshift galaxies

    Thomas, R.; Capak, P.; Scoville, N.
    The observed UV rest-frame spectra of distant galaxies are the result of their intrinsic emission combined with absorption along the line of sight produced by the inter-galactic medium (IGM). Here we analyse the evolution of the mean IGM transmission Tr(Lyα) and its dispersion along the line of sight for 2127 galaxies with 2.5 < z < 5.5 in the VIMOS Ultra Deep Survey (VUDS). We fitted model spectra combined with a range of IGM transmission to the galaxy spectra using the spectral fitting algorithm GOSSIP+. We used these fits to derive the mean IGM transmission towards each galaxy for several...

  4. Four Sub-Saturns with Dissimilar Densities: Windows into Planetary Cores and Envelopes

    Petigura, Erik A.; Sinukoff, Evan; Lopez, Eric D.; Crossfield, Ian J. M.; Howard, Andrew W.; Brewer, John M.; Fulton, Benjamin J.; Isaacson, Howard T.; Ciardi, David R.; Howell, Steve B.; Everett, Mark E.; Horch, Elliott P.; Hirsch, Lea A.; Weiss, Lauren M.; Schlieder, Joshua E.
    We present results from a Keck/HIRES radial velocity campaign to study four sub-Saturn-sized planets, K2-27b, K2-32b, K2-39b, and K2-108b, with the goal of understanding their masses, orbits, and heavy-element enrichment. The planets have similar sizes (R_P = 4.5–5.5 R⊕), but have dissimilar masses (M_P = 16–60 M⊕), implying a diversity in their core and envelope masses. K2-32b is the least massive (M_P = 16.5 ± 2.7 M⊕) and orbits in close proximity to two sub-Neptunes near a 3:2:1 period commensurability. K2-27b and K2-39b are significantly more massive at M_P = 30.9 ± 4.6 M⊕ and M_P = 39.8 ± 4.4...

  5. Stellar and Planetary Parameters for K2's Late-type Dwarf Systems from C1 to C5

    Martinez, Arturo O.; Crossfield, Ian J. M.; Schlieder, Joshua E.; Dressing, Courtney D.; Obermeier, Christian; Livingston, John; Ciceri, Simona; Peacock, Sarah; Beichman, Charles A.; Lépine, Sébastien; Aller, Kimberly M.; Chance, Quadry A.; Petigura, Erik A.; Howard, Andrew W.; Werner, Michael W.
    The NASA K2 mission uses photometry to find planets transiting stars of various types. M dwarfs are of high interest since they host more short-period planets than any other type of main-sequence star and transiting planets around M dwarfs have deeper transits compared to other main-sequence stars. In this paper, we present stellar parameters from K and M dwarfs hosting transiting planet candidates discovered by our team. Using the SOFI spectrograph on the European Southern Observatory's New Technology Telescope, we obtained R ≈ 1000 J-, H-, and K-band (0.95–2.52 μm) spectra of 34 late-type K2 planet and candidate planet host...

  6. High-spatial-resolution, near-infrared observations of ARP 220

    Neugebauer, G.; Elias, J.; Matthews, K.; McGill, J.; Scoville, N.; Soifer, B. T.
    High-spatial-resolution slit scans of the nucleus of Arp 220 are presented along with near-infrared photometry of the nuclear region. A single nucleus is found coincident with the strongest radio peak. The core is resolved to be on the order of 1" (370 pc) in diameter. The photometry of the central region shows a minimum near 3.7 µm which is inconsistent with the near-infrared source being a "classical" nonthermal source, such as 3C 273, embedded in a dust cloud.

  7. The IRAS bright galaxy sample. II - The sample and luminosity function

    Soifer, B. T.; Sanders, D. B.; Madore, B. F.; Neugebauer, G.; Danielson, G. E.; Elias, J. H.; Lonsdale, Carol J.; Rice, W. L.
    A complete sample of 324 extragalactic objects with 60 μm flux densities greater than 5.4 Jy has been selected from the IRAS catalogs. Only one of these objects can be classified morphologically as a Seyfert nucleus; the others are all galaxies. The median distance of the galaxies in the sample is ~ 30 Mpc, and the median luminosity vL,(60 μm) is ~ 2 x 10^(10) L_☉ . This infrared selected sample is much more "infrared active" than optically selected galaxy samples. The range in far-infrared luminosities of the galaxies in the sample is 10^8 L_☉ -2 x 10^(12) L_☉ The...

  8. High spatial resolution continuum and Hɑ imaging of the high-redshift IRAS source FSC 10214+4724

    Soifer, B. T.; Neugebauer, G.; Matthews, K.; Lawrence, C.; Mazzarella, J.
    High spatial resolution images have been obtained of the high-redshift (z = 2.286) IRAS source FSC 10214+4724 at wavelengths corresponding to the optical continuum and Hɑ in the object's rest frame. The continuum shows two clumps separated by ~1" (~10 kpc) and aligned approximately north-south. The structure appears similar at rest wavelengths of 0.38, 0.64, and 0.67 μm. The continuum morphology suggests two separate concentrations of luminosity, likely the nuclei of interacting galaxies, although a large galaxy bifurcated by an immense dust lane cannot be ruled out. The southern component is predominantly extended in the east-west direction on a scale...

  9. Near-infrared observations of the Z about 2.3 IRAS source FSC 10214 + 4724

    Soifer, B. T.; Neugebauer, G.; Graham, J. R.; Matthews, K.; Mazzarella, J. M.; Lonsdale, C. J.; Rowan-Robinson, M.; Broadhurst, T.; Lawrence, A.; McMahon, R.
    Near-infrared imaging and spectroscopy of the extremely luminous IRAS source FSC 10214+4724 have been obtained using the Cassegrain infrared camera on the 200 inch (5.08 m) Hale Telescope. A low-resolution spectrumm (⋋/d⋋ ~ 100) in the 2.0-2.4 μm atmospheric window shows a very strong Hɑ line at the optically determined redshift z = 2.286. The observed rest-frame equivalent width of Hɑ is 0.07 ± 0.02 μm, consistent with the largest values found in quasars. The images show an unresolved source, while the near-infrared colors are somewhat redder than the mean colors of quasars observed at the same redshift. The reddening...

  10. Cosmic Web of Galaxies in the COSMOS Field: Public Catalog and Different Quenching for Centrals and Satellites

    Darvish, Behnam; Mobasher, Bahram; Martin, D. Christopher; Sobral, David; Scoville, Nick; Stroe, Andra; Hemmati, Shoubaneh; Kartaltepe, Jeyhan
    We use a mass complete (log(M/M⊙) ⩾ 9.6) sample of galaxies with accurate photometric redshifts in the COSMOS field to construct the density field and the cosmic web to z = 1.2. The comic web extraction relies on the density field Hessian matrix and breaks the density field into clusters, filaments, and the field. We provide the density field and cosmic web measures to the community. We show that at z ≾ 0.8, the median star formation rate (SFR) in the cosmic web gradually declines from the field to clusters and this decline is especially sharp for satellites (~1 dex...

  11. Infrared Imaging of GRB 970508

    Chary, R.; Neugebauer, G.; Morris, M.; Becklin, E. E.; Matthews, K.; Kulkarni, S. R.; Lowrance, P. J.; Zuckerman, B.; Mastrodemos, N.
    We have observed the field of the gamma-ray burst GRB 970508 at infrared wavelengths (2.2 μm) and have found a variable source coincident with the visible transient thought to be associated with the burst. The source was decaying in brightness with Ks magnitudes of 18.2±0.1, 18.8±0.1, and 19.0±0.3 mag on May 13.25, 16.25, and 20.21 UT, respectively. A 1 σ upper limit of K=21.3 mag was obtained for the brightness of the source on June 14.27 UT. The infrared light curve during this period is consistent with a ~t^(-1.2) power law, similar to the visible light curve. We do not...

  12. Near-Infrared Imaging of Ultraluminous IRAS Galaxies

    Surace, J.; Armus, L.; Graham, J.; Matthews, K.; Mazzarella, J.; Neugebauer, G.; Soifer, B. T.
    IRAS discovered a class of objects which emit most of their radiation at infrared wavelengths and which possess bolometric luminosities comparable to those of classical quasars. Due to their extreme power, and the fact that (1) they are nearly always in the late stages of a galactic merger, and (2) they have a space density in the local universe comparable to that of optically selected quasars (Soifer et al. 1986), it has been suggested that the ultraluminous infrared galaxies represent an early, dusty stage in the evolution of an interacting pair of gas rich spiral galaxies into an optically identifiable...

  13. Photodissociation Regions in Young PN

    Graham, James R.; Herbst, T. M.; Beckwith, S.; Matthews, K.; Neugebauer, G.; Serabyn, E.; Soifer, B. T.
    Infrared imaging of H2 and PAH emission in NGG 7027 and BD+30 3639 reveals the presence of photodissociation regions in the neutral gas surrounding these young planetary nebulae.

  14. High luminosity galaxies in the IRAS survey

    Sanders, D. B.; Soifer, B. T.; Neugebauer, G.
    The IRAS survey has demonstrated the existence of a previously unrecognized class of ultraluminous objects. These ultraluminous infrared galaxies represent the dominant population of extragalactic emitters at luminosities where the only other objects known are quasars. Observations suggest that these objects are all found in merging galaxies, and appear to be dust enshrouded quasars. We suggest that these IR loud quasars represent the formation stage of quasars, with the latter stages in the evolution of such systems being found in the UV excess quasars.

  15. Use of the Large Space Telescope for Infrared Observations

    Neugebauer, Gerry
    It is appropriate that a discussion of the infrared capabilities of the (L)ST follows one about the IRAS since the (L)ST bears much the same symbiotic relationship to IRAS as the 200-inch Hale Telescope does to the 48-inch telescope which performed the complete optical survey of the sky.

  16. Physical Properties of Sub-galactic Clumps at 0.5 ≤ Z ≤ 1.5 in the UVUDF

    Soto, Emmaris; de Mello, Duilia F.; Rafelski, Marc; Gardner, Jonathan P.; Teplitz, Harry I.; Koekemoer, Anton M.; Ravindranath, Swara; Grogin, Norman A.; Scarlata, Claudia; Kurczynski, Peter; Gawiser, Eric
    We present an investigation of clumpy galaxies in the Hubble Ultra Deep Field at 05 ≤ z ≤ 1.5 in the rest-frame far-ultraviolet (FUV) using Hubble Space Telescope Wide Field Camera 3 broadband imaging in F225W, F275W, and F336W. An analysis of 1404 galaxies yields 209 galaxies that host 403 kpc scale clumps. These host galaxies appear to be typical star-forming galaxies, with an average of 2 clumps per galaxy and reaching a maximum of 8 clumps. We measure the photometry of the clumps and determine the mass, age, and star formation rates (SFR) using the spectral energy distribution fitting...

  17. The Interstellar Medium in High-redshift Submillimeter Galaxies as Probed by Infrared Spectroscopy

    Wardlow, Julie L.; Cooray, Asantha; Osage, Willow; Bourne, Nathan; Clements, David; Dannerbauer, Helmut; Dunne, Loretta; Dye, Simon; Eales, Steve; Farrah, Duncan; Furlanetto, Cristina; Ibar, Edo; Ivison, Rob; Maddox, Steve; Michałowski, Michał J.; Riechers, Dominik; Rigopoulou, Dimitra; Scott, Douglas; Smith, Matthew W. L.; Wang, Lingyu; van der Werf, Paul; Valiante, Elisabetta; Valtchanov, Ivan; Verma, Aprajita
    Submillimeter galaxies (SMGs) at z ≿ 1 are luminous in the far-infrared, and have star formation rates, SFR, of hundreds to thousands of solar masses per year. However, it is unclear whether they are true analogs of local ULIRGs or whether the mode of their star formation is more similar to that in local disk galaxies. We target these questions by using Herschel-PACS to examine the conditions in the interstellar medium (ISM) in far-infrared luminous SMGs at z ~ 1–4. We present 70–160 μm photometry and spectroscopy of the [O IV]26 μm, [Fe II]26 μm, [S III]33 μm, [Si II]34...

  18. A High Space Density of Luminous Lyα Emitters at z ~ 6.5

    Bagley, Micaela B.; Scarlata, Claudia; Henry, Alaina; Rafelski, Marc; Malkan, Matthew; Teplitz, Harry; Dai, Y. Sophia; Baronchelli, Ivano; Colbert, James; Rutkowski, Michael; Mehta, Vihang; Dressler, Alan; McCarthy, Patrick; Bunker, Andrew; Atek, Hakim; Garel, Thibault; Martin, Crystal L.; Hathi, Nimish; Siana, Brian
    We present the results of a systematic search for Lyα emitters (LAEs) at 6 ≾ z ≾ 7.6 using the HST WFC3 Infrared Spectroscopic Parallel (WISP) Survey. Our total volume over this redshift range is ~ 8 x 10^5 Mpc^3, comparable to many of the narrowband surveys despite their larger area coverage. We find two LAEs at z = 6.38 and 6.44 with line luminosities of L_(Lyα) ~ 4.7 x 10^(43) erg s^(−1), putting them among the brightest LAEs discovered at these redshifts. Taking advantage of the broad spectral coverage of WISP, we are able to rule out almost all...

  19. Imaging of NGC 5907's stellar stream

    Laine, Seppo; Grillmair, Carl J.; Martínez-Delgado, David; Romanowsky, Aaron J.; Capak, Peter L.; Arendt, Richard G.; Ashby, Matthew L. N.; Davies, James E.; Majewski, Steven R.; GaBany, R. Jay
    We have obtained deep g, r, and i-band Subaru and ultra-deep 3.6 μm IRAC images of parts of the multiply-wrapped stellar stream around the nearby edge-on galaxy NGC 5907. We have fitted the surface brightness measurements of the stream with FSPS stellar population synthesis models to derive the metallicity and age of the brightest parts of the stream. The resulting relatively high metallicity ([Fe/H] = −0.3) is consistent with a major merger scenario but a satellite accretion event cannot be ruled out.

  20. High resolution WFPC2 imaging of IRAS 09104+4109

    Armus, L.; Soifer, B. T.; Neugebauer, G.
    With an infrared luminosity of L_(IR) = 6 x 10^(12) L_☉, IRAS 09104+4109 is one of the most luminous objects detected in the IRAS survey. First identified with a faint, R ~ 18 mag, galaxy at z = 0.442 by Kleinmann et al.(1988), IRAS 09104+4109 emits more than 99% of its bolometric luminosity longward of ⋋ ~ 1µm. Like most Ultraluminous Infrared Galaxies (ULIRGs), IRAS 09104+4109 has very strong emission lines. The nucleus exhibits a Seyfert type 2 spectrum, with strong, narrow lines over a wide range of ionization (Kleinmann et al.,1988; Soifer et al.,1996). Two-dimensional, ground-based spectrophotometry shows a "plume" of...

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