Browsing by Author "Toft, S."

Now showing 1 - 3 of 3
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    ALMA Lensing Cluster Survey: Hubble Space Telescope and Spitzer Photometry of 33 Lensed Fields Built with CHArGE
    (2022) Kokorev, V; Brammer, G.; Fujimoto, S.; Kohno, K.; Magdis, G. E.; Valentino, F.; Toft, S.; Oesch, P.; Davidzon, I; Bauer, F. E.; Coe, D.; Egami, E.; Oguri, M.; Ouchi, M.; Postman, M.; Richard, J.; Jolly, J-B; Knudsen, K. K.; Sun, F.; Weaver, J. R.; Ao, Y.; Baker, A. J.; Bradley, L.; Caputi, K., I; Dessauges-Zavadsky, M.; Espada, D.; Hatsukade, B.; Koekemoer, A. M.; Arancibia, A. M. Munoz; Shimasaku, K.; Umehata, H.; Wang, T.; Wang, W-H
    We present a set of multiwavelength mosaics and photometric catalogs in the Atacama Large Millimeter/submillimeter Array (ALMA) lensing cluster survey fields. The catalogs were built by the reprocessing of archival data from the Complete Hubble Archive for Galaxy Evolution compilation, taken by the Hubble Space Telescope (HST) in the Reionization Lensing Cluster Survey, Cluster Lensing And Supernova survey with Hubble, and Hubble Frontier Fields. Additionally, we have reconstructed the Spitzer Infrared Array Camera 3.6 and 4.5 mu m mosaics, by utilizing all the available archival IPAC Infrared Science Archive/Spitzer Heritage Archive exposures. To alleviate the effect of blending in such a crowded region, we have modeled the Spitzer photometry by convolving the HST detection image with the Spitzer point-spread function using the novel GOLFIR software. The final catalogs contain 218,000 sources, covering a combined area of 690 arcmin(2) , a factor of similar to 2 improvement over the currently existing photometry. A large number of detected sources is a result of reprocessing of all available and sometimes deeper exposures, in conjunction with a combined optical-near-IR detection strategy. These data will serve as an important tool in aiding the search of the submillimeter galaxies in future ALMA surveys, as well as follow-ups of the HST dark and high-z sources with JWST. Coupled with the available HST photometry, the addition of the 3.6 and 4.5 mu m bands will allow us to place a better constraint on the photometric redshifts and stellar masses of these objects, thus giving us an opportunity to identify high-redshift candidates for spectroscopic follow-ups and to answer the important questions regarding the Epoch of Reionization and formation of the first galaxies. The mosaics, photometric catalogs, and the best-fit physical properties are publicly available at https:// github.com/dawn-cph/alcs-clusters.
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    The Evolution of the IR Luminosity Function and Dust-obscured Star Formation over the Past 13 Billion Years
    (2021) Zavala, J. A.; Casey, C. M.; Manning, S. M.; Aravena, M.; Bethermin, M.; Caputi, K. I.; Clements, D. L.; Cunha, E. da; Drew, P.; Finkelstein, S. L.; Fujimoto, S.; Hayward, C.; Hodge, J.; Kartaltepe, J. S.; Knudsen, K.; Koekemoer, A. M.; Long, A. S.; Magdis, G. E.; Man, A. W. S.; Popping, G.; Sanders, D.; Scoville, N.; Sheth, K.; Staguhn, J.; Toft, S.; Treister, E.; Vieira, J. D.; Yun, M. S.
    We present the first results from the Mapping Obscuration to Reionization with ALMA (MORA) survey, the largest Atacama Large Millimeter/submillimeter Array (ALMA) blank-field contiguous survey to date (184 arcmin(2)) and the only at 2 mm to search for dusty star-forming galaxies (DSFGs). We use the 13 sources detected above 5 sigma to estimate the first ALMA galaxy number counts at this wavelength. These number counts are then combined with the state-of-the-art galaxy number counts at 1.2 and 3 mm and with a backward evolution model to place constraints on the evolution of the IR luminosity function and dust-obscured star formation in the past 13 billion years. Our results suggest a steep redshift evolution on the space density of DSFGs and confirm the flattening of the IR luminosity function at faint luminosities, with a slope of alpha(LF) = -0.42(-0.04)(+0.02). We conclude that the dust-obscured component, which peaks at z approximate to 2-2.5, has dominated the cosmic history of star formation for the past similar to 12 billion years, back to z similar to 4. At z = 5, the dust-obscured star formation is estimated to be similar to 35% of the total star formation rate density and decreases to 25%-20% at z = 6-7, implying a minor contribution of dusten-shrouded star formation in the first billion years of the universe. With the dust-obscured star formation history constrained up to the end of the epoch of reionization, our results provide a benchmark to test galaxy formation models, to study the galaxy mass assembly history, and to understand the dust and metal enrichment of the universe at early times.
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    The Gas and Stellar Content of a Metal-poor Galaxy at z=8.496 as Revealed by JWST and ALMA
    (2023) Heintz, K. E.; Gimenez-Arteaga, C.; Fujimoto, S.; Brammer, G.; Espada, D.; Gillman, S.; Gonzalez-Lopez, J.; Greve, T. R.; Harikane, Y.; Hatsukade, B.; Knudsen, K. K.; Koekemoer, A. M.; Kohno, K.; Kokorev, V.; Lee, M. M.; Magdis, G. E.; Nelson, E. J.; Rizzo, F.; Sanders, R. L.; Schaerer, D.; Shapley, A. E.; Strait, V. B.; Toft, S.; Valentino, F.; van der Wel, A.; Vijayan, A. P.; Watson, D.; Bauer, F. E.; Christiansen, C. R.; Wilson, S. N.
    We present a joint analysis of the galaxy S04590 at z = 8.496 based on NIRSpec, NIRCam, and NIRISS observations obtained as part of the Early Release Observations program of the James Webb Space Telescope (JWST) and the far-infrared [C ii] 158 mu m emission line detected by dedicated Atacama Large Millimeter/submillimeter Array (ALMA) observations. We determine the physical properties of S04590 from modeling of the spectral energy distribution (SED) and through the redshifted optical nebular emission lines detected with JWST/NIRSpec. The best-fit SED model reveals a low-mass (M-? = 10(7.2)-10(8) M-?) galaxy with a low oxygen abundance of derived from the strong nebular and auroral emission lines. Assuming that [C ii] effectively traces the interstellar medium, we estimate the total gas mass of the galaxy to be M-gas = (8.0 +/- 4.0) x 10(8) M-? based on the luminosity and spatial extent of [C ii]. This yields an exceptionally high gas fraction, f(gas) = M-gas/(M-gas + M-?) ? 90%, though one still consistent with the range expected for low metallicity. We further derive the metal mass of the galaxy based on the gas mass and gas-phase metallicity, which we find to be consistent with the expected metal production from Type II supernovae. Finally, we make the first constraints on the dust-to-gas (DTG) and dust-to-metal (DTM) ratios of galaxies in the epoch of reionization at z ? 6, showing overall low mass ratios of logDTG < -3.8 and logDTM < -0.5, though they are consistent with established scaling relations and in particular with those of the local metal-poor galaxy I Zwicky 18. Our analysis highlights the synergy between ALMA and JWST in characterizing the gas, metal, and stellar content of the first generation of galaxies.