Browsing by Author "Valentino, F."

Now showing 1 - 5 of 5
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    ALMA Lensing Cluster Survey: a strongly lensed multiply imaged dusty system at z ≥ 6
    (2021) Laporte, N.; Zitrin, A.; Ellis, R. S.; Fujimoto, S.; Brammer, G.; Richard, J.; Oguri, M.; Caminha, G. B.; Kohno, K.; Yoshimura, Y.; Ao, Y.; Bauer, F. E.; Caputi, K.; Egami, E.; Espada, D.; Gonzalez-Lopez, J.; Hatsukade, B.; Knudsen, K. K.; Lee, M. M.; Magdis, G.; Ouchi, M.; Valentino, F.; Wang, T.
    We report the discovery of an intrinsically faint, quintuply-imaged, dusty galaxy MACS0600-z6 at a redshift z = 6.07 viewed through the cluster MACSJ0600.1-2008 (z = 0.46). A similar or equal to 4 sigma dust detection is seen at 1.2mm as part of the ALMA Lensing Cluster Survey (ALCS), an on-going ALMA Large programme, and the redshift is secured via [C II] 158 mu m emission described in a companion paper. In addition, spectroscopic follow-up with GMOS/Gemini-North shows a break in the galaxy's spectrum, consistent with the Lyman break at that redshift. We use a detailed mass model of the cluster and infer a magnification mu greater than or similar to 30 for the most magnified image of this galaxy, which provides an unprecedented opportunity to probe the physical properties of a sub-luminous galaxy at the end of cosmic reionization. Based on the spectral energy distribution, we infer lensing-corrected stellar and dust masses of 2.9(-2.3)(+11.5) x 10(9) and 4.8(-3.4)(+4.5) x 10(6) M-circle dot, respectively, a star formation rate of 9.7(-6.6)(+22.0) M-circle dot yr(-1), an intrinsic size of 0.54(-0.14)(+0.26) kpc, and a luminosity-weighted age of 200 +/- 100 Myr. Strikingly, the dust production rate in this relatively young galaxy appears to be larger than that observed for equivalent, lower redshift sources. We discuss if this implies that early supernovae are more efficient dust producers and the consequences for using dust mass as a probe of earlier star formation.
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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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    GOODS-ALMA 2.0: Starbursts in the main sequence reveal compact star formation regulating galaxy evolution prequenching
    (2022) Gomez-Guijarro, C.; Elbaz, D.; Xiao, M.; Kokorev, V., I; Magdis, G. E.; Magnelli, B.; Daddi, E.; Valentino, F.; Sargent, M. T.; Dickinson, M.; Bethermin, M.; Franco, M.; Pope, A.; Kalita, B. S.; Ciesla, L.; Demarco, R.; Inami, H.; Rujopakarn, W.; Shu, X.; Wang, T.; Zhou, L.; Alexander, D. M.; Bournaud, F.; Chary, R.; Ferguson, H. C.; Finkelstein, S. L.; Giavalisco, M.; Iono, D.; Juneau, S.; Kartaltepe, J. S.; Lagache, G.; Le Floc'h, E.; Leiton, R.; Leroy, L.; Lin, L.; Motohara, K.; Mullaney, J.; Okumura, K.; Pannella, M.; Papovich, C.; Treister, E.
    Compact star formation appears to be generally common in dusty star-forming galaxies (SFGs). However, its role in the framework set by the scaling relations in galaxy evolution remains to be understood. In this work we follow up on the galaxy sample from the GOODS-ALMA 2.0 survey, an ALMA blind survey at 1.1 mm covering a continuous area of 72.42 arcmin(2) using two array configurations. We derived physical properties, such as star formation rates, gas fractions, depletion timescales, and dust temperatures for the galaxy sample built from the survey. There exists a subset of galaxies that exhibit starburst-like short depletion timescales, but they are located within the scatter of the so-called main sequence of SFGs. These are dubbed starbursts in the main sequence and display the most compact star formation and they are characterized by the shortest depletion timescales, lowest gas fractions, and highest dust temperatures of the galaxy sample, compared to typical SFGs at the same stellar mass and redshift. They are also very massive, accounting for similar to 60% of the most massive galaxies in the sample (log(M-*/M-circle dot) > 11.0). We find trends between the areas of the ongoing star formation regions and the derived physical properties for the sample, unveiling the role of compact star formation as a physical driver of these properties. Starbursts in the main sequence appear to be the extreme cases of these trends. We discuss possible scenarios of galaxy evolution to explain the results drawn from our galaxy sample. Our findings suggest that the star formation rate is sustained in SFGs by gas and star formation compression, keeping them within the main sequence even when their gas fractions are low and they are presumably on the way to quiescence.
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    The cold interstellar medium of a normal sub-L* galaxy at the end of reionization
    (2024) Valentino, F.; Fujimoto, S.; Gimenez-Arteaga, C.; Brammer, G.; Kohno, K.; Sun, F.; Kokorev, V.; Bauer, F. E.; Di Cesare, C.; Espada, D.; Lee, M.; Dessauges-Zavadsky, M.; Ao, Y.; Koekemoer, A. M.; Ouchi, M.; Wu, J. F.; Egami, E.; Jolly, J. -b.; Lagos, C. del P.; Magdis, G. E.; Schaerer, D.; Shimasaku, K.; Umehata, H.; Wang, W. -h.
    We present the results of a similar to 60-h multiband observational campaign with the Atacama Large Millimeter Array targeting a spectroscopically confirmed and lensed sub-L* galaxy at z = 6.07, first identified during the ALMA Lensing Cluster Survey (ALCS). We sampled the dust continuum emission from rest frame 90-370 mu m at six different frequencies and set constraining upper limits on the molecular gas line emission and content by targeting the CO (7 - 6) and [C I](P-3(2)-P-3(1)) transitions in two lensed images with mu greater than or similar to 20. Complementing these submillimeter observations with deep optical and near-IR photometry and spectroscopy with JWST, we find this galaxy to form stars at a rate of SFR similar to 7 M-circle dot yr(-1), similar to 50 - 70% of which is obscured by dust. This is consistent with what one would predict for a M-* similar to 7.5 x 10(8) M-circle dot object by extrapolating the relation between the fraction of the obscured star formation rate and stellar mass at z < 2.5 and with observations of IR-detected objects at 5 < z < 7. The light-weighted dust temperature of T-dust similar to 50 K is similar to that of more massive galaxies at similar redshifts, although with large uncertainties and with possible negative gradients. We measure a dust mass of M-dust similar to 1.5 x 10(6) M-circle dot and, by combining [C I], [C II], and a dynamical estimate, a gas mass of M-gas similar to 2 x 10(9) M-circle dot. Their ratio (delta(DGR)) is in good agreement with predictions from models and empirical relations in the literature. The dust-to-stellar mass fraction of f(dust) similar to 0.002 and the young stellar age (100 - 200 Myr) are consistent with efficient dust production via supernovae, as predicted by existing models and simulations of dust evolution. Also, the expected number density of galaxies with M-dust similar to 10(6) M-circle dot at z = 6 from a subset of these models is in agreement with the observational estimate that we set from the parent ALCS survey. The combination of gravitational lensing and deep multiwavelength observations allowed us to probe luminosity and mass regimes up to two orders of magnitude lower than what has been explored so far for field galaxies at similar redshifts. Our results serve as a benchmark for future observational endeavors of the high-redshift and faint sub-L* galaxy population that might have driven the reionization of the Universe.
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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.