Browsing by Author "Caputi, Karina I."

Now showing 1 - 4 of 4
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    Extensive Lensing Survey of Optical and Near-infrared Dark Objects (El Sonido): HST H-faint Galaxies behind 101 Lensing Clusters
    (2021) Sun, Fengwu; Egami, Eiichi; Perez-Gonzalez, Pablo G.; Smail, Ian; Caputi, Karina I.; Bauer, Franz E.; Rawle, Timothy D.; Fujimoto, Seiji; Kohno, Kotaro; Dudzeviciute, Ugne; Atek, Hakim; Bianconi, Matteo; Chapman, Scott C.; Combes, Francoise; Jauzac, Mathilde; Jolly, Jean-Baptiste; Koekemoer, Anton M.; Magdis, Georgios E.; Rodighiero, Giulia; Rujopakarn, Wiphu; Schaerer, Daniel; Steinhardt, Charles L.; Van der Werf, Paul; Walth, Gregory L.; Weaver, John R.
    We present a Spitzer/IRAC survey of H-faint (H-160 greater than or similar to 26.4, < 5 sigma) sources in 101 lensing cluster fields. Across a CANDELS/Wide-like survey area of similar to 648 arcmin(2) (effectively similar to 221 arcmin(2) in the source plane), we have securely discovered 53 sources in the IRAC Channel-2 band (CH2, 4.5 mu m; median CH2 = 22.46 +/- 0.11 AB mag) that lack robust HST/WFC3-IR F160W counterparts. The most remarkable source in our sample, namely ES-009 in the field of Abell 2813, is the brightest H-faint galaxy at 4.5 mu m known so far (CH2 = 20.48 +/- 0.03 AB mag). We show that the H-faint sources in our sample are massive (median M-star = 10 10.3 +/- 0.3 M-circle dot, star-forming (median star formation rate =1001 M-circle dot yr(-1)), and dust-obscured (A(v) = 2.6 +/- 0.3) galaxies around a median photometric redshift of z = 3.9 +/- 0.4. The stellar continua of 14 H-faint galaxies can be resolved in the CH2 band, suggesting a median circularized effective radius (R-e,R-circ; lensing corrected) of 1.9 +/- 0.2 kpc and <1.5 kpc for the resolved and whole samples, respectively. This is consistent with the sizes of massive unobscured galaxies at z similar to 4, indicating that H-faint galaxies represent the dusty tail of the distribution of a wider galaxy population. Comparing with the ALMA dust continuum sizes of similar galaxies reported previously, we conclude that the heavy dust obscuration in H-faint galaxies is related to the compactness of both stellar and dust continua (R-e,R-circ similar to 1 kpc). These H-faint galaxies make up 161 3 % of the galaxies in the stellar-mass range of 10(10) - 10(11.2) M-circle dot at z = 3 similar to 5, contributing to 8(-4)(+8)% of the cosmic star formation rate density in this epoch and likely tracing the early phase of massive galaxy formation.
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    JWST Insight into a Lensed HST-dark Galaxy and Its Quiescent Companion at z=2.58
    (2023) Kokorev, Vasily; Jin, Shuowen; Magdis, Georgios E.; Caputi, Karina I.; Valentino, Francesco; Dayal, Pratika; Trebitsch, Maxime; Brammer, Gabriel; Fujimoto, Seiji; Bauer, Franz; Iani, Edoardo; Kohno, Kotaro; Sese, David Blanquez; Gomez-Guijarro, Carlos; Rinaldi, Pierluigi; Navarro-Carrera, Rafael
    Using the novel James Webb Space Telescope (JWST)/NIRCam observations in the A2744 field, we present a first spatially resolved overview of a Hubble Space Telescope (HST)-dark galaxy, spectroscopically confirmed at z = 2.58 with magnification mu approximate to 1.9. While being largely invisible at similar to 1 mu m with NIRCam, except for sparse clumpy substructures, the object is well detected and resolved in the long-wavelength bands with a spiral shape clearly visible in F277W. By combining ancillary Atacama Large Millimeter/submillimeter Array (ALMA) and Herschel data, we infer that this object is an edge-on dusty spiral with an intrinsic stellar mass log (M (*)/M (circle dot)) similar to 11.3 and a dust-obscured star formation rate similar to 300 M (circle dot) yr(-1). A massive quiescent galaxy (log (M (*)/M (circle dot)) similar to 10.8) with tidal features lies 2.'' 0 away (r similar to 9 kpc), at a consistent redshift as inferred by JWST photometry, indicating a potential major merger. The dusty spiral lies on the main sequence of star formation, and shows high dust attenuation in the optical (3 < A ( V ) < 4.5). In the far-infrared, its integrated dust spectral energy distribution is optically thick up to lambda (0) similar to 500 mu m, further supporting the extremely dusty nature. Spatially resolved analysis of the HST-dark galaxy reveals a largely uniform A ( V ) similar to 4 area spanning similar to 57 kpc(2), which spatially matches to the ALMA 1 mm continuum emission. Accounting for the surface brightness dimming and the depths of current JWST surveys, unlensed analogs of the HST-dark galaxy at z > 4 would be only detectable in F356W and F444W in an UNCOVER-like survey, and become totally JWST-dark at z similar to 6. This suggests that detecting highly attenuated galaxies in the Epoch of Reionization might be a challenging task for JWST.
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    Mapping Obscuration to Reionization with ALMA (MORA): 2 mm Efficiently Selects the Highest-redshift Obscured Galaxies
    (2021) Casey, Caitlin M.; Zavala, Jorge A.; Manning, Sinclaire M.; Aravena, Manuel; Béthermin, Matthieu; Caputi, Karina I.; Champagne, Jaclyn B.; Clements, David L.; Drew, Patrick; Finkelstein, Steven L.; Fujimoto, Seiji; Hayward, Christopher C.; Dekel, Anton M.; Kokorev, Vasily; Lagos, Claudia del P.; Long, Arianna S.; Magdis, Georgios E.; Man, Allison W. S.; Mitsuhashi, Ikki; Popping, Gergö; Spilker, Justin; Staguhn, Johannes; Talia, Margherita; Toft, Sune; Treister, Ezequiel; Weaver, John R.; Yun, Min
    We present the characteristics of 2 mm selected sources from the largest Atacama Large Millimeter/submillimeter Array (ALMA) blank-field contiguous survey conducted to date, the Mapping Obscuration to Reionization with ALMA (MORA) survey covering 184 arcmin(2) at 2 mm. Twelve of 13 detections above 5 sigma are attributed to emission from galaxies, 11 of which are dominated by cold dust emission. These sources have a median redshift of < Z(2) (mm)> = 3.6(-0.3)(+0.4) primarily based on optical/near-infrared photometric redshifts with some spectroscopic redshifts, with 77% +/- 11% of sources at z > 3 and 38% +/- 12% of sources at z > 4. This implies that 2 mm selection is an efficient method for identifying the highest-redshift dusty star-forming galaxies (DSFGs). Lower-redshift DSFGs (z < 3) are far more numerous than those at z > 3 yet are likely to drop out at 2 mm. MORA shows that DSFGs with star formation rates in excess of 300 M-circle dot yr(-1) and a relative rarity of similar to 10(-5) Mpc(-3) contribute similar to 30% to the integrated star formation rate density at 3 < z < 6. The volume density of 2 mm selected DSFGs is consistent with predictions from some cosmological simulations and is similar to the volume density of their hypothesized descendants: massive, quiescent galaxies at z > 2. Analysis of MORA sources' spectral energy distributions hint at steeper empirically measured dust emissivity indices than reported in typical literature studies, with = 2.2(-0.4)(+0.5). The MORA survey represents an important step in taking census of obscured star formation in the universe's first few billion years, but larger area 2 mm surveys are needed to more fully characterize this rare population and push to the detection of the universe's first dusty galaxies.
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    Physical Characterization of an Unlensed, Dusty Star-forming Galaxy at z = 5.85
    (2019) Casey, Caitlin M.; Zavala, Jorge A.; Aravena, Manuel; Bethermin, M.; Caputi, Karina I.; Champagne, Jaclyn B.; Clements, David L.; Cunha, Elisabete da; Drew, Patrick; Treister, Ezequiel