Browsing by Author "Liu, Daizhong"

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  • Crimson Behemoth : A massive clumpy structure hosting a dusty AGN at z = 4.91
    (2024-12-01) Tanaka, Takumi S.; Silverman, John D.; Nakazato, Yurina; Onoue, Masafusa; Shimasaku, Kazuhiro; Fudamoto, Yoshinobu; Fujimoto, Seiji; Ding, Xuheng; Faisst, Andreas L.; Valentino, Francesco; Jin, Shuowen; Hayward, Christopher C.; Kokorev, Vasily; Ceverino, Daniel; Kalita, Boris S.; Casey, Caitlin M.; Liu, Zhaoxuan; Kaminsky, Aidan; Fei, Qinyue; Andika, Irham T.; Lambrides, Erini; Akins, Hollis B.; Kartaltepe, Jeyhan S.; Koekemoer, Anton M.; McCracken, Henry Joy; Rhodes, Jason; Robertson, Brant E.; Franco, Maximilien; Liu, Daizhong; Chartab, Nima; Gillman, Steven; Gozaliasl, Ghassem; Hirschmann, Michaela; Huertas-Company, Marc; Massey, Richard; Roy, Namrata; Sattari, Zahra; Shuntov, Marko; Sterling, Joseph; Toft, Sune; Trakhtenbrot, Benny; Yoshida, Naoki; Zavala, Jorge A.
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    The current paradigm for the co-evolution of galaxies and their supermassive black holes postulates that dust-obscured active galactic nuclei (AGNs) represent a transitional phase towards a more luminous and unobscured state. However, our understanding of dusty AGNs and their host galaxies at early cosmic times is inadequate due to observational limitations. Here, we present JWST observations of CID-931, an X-ray-detected AGN at a spectroscopic redshift of zspec = 4.91. Multiband NIRCam imaging from the COSMOS-Web program reveals an unresolved red core, similar to JWST-discovered dusty AGNs. Strikingly, the red core is surrounded by at least eight massive star-forming clumps spread over 1.6 ≈ 10 kpc, each of which has a stellar mass of 109–1010 M and a radius of ∼0.1–1 kpc. The whole system amounts to 1011 M in stellar mass, higher than typical star-forming galaxies at the same epoch. In this system, gas inflows and/or complex merger events may trigger clump formation and AGN activity, thus leading to the rapid formation of a massive galaxy hosting a supermassive black hole. Future followup observations will provide new insights into the evolution of the galaxy–black hole relationship during such transitional phases in the early universe.
  • The MBH-M∗ Relation up to z ∼ 2 through Decomposition of COSMOS-Web NIRCam Images
    (2025-02-01) Tanaka, Takumi S.; Silverman, John D.; Ding, Xuheng; Jahnke, Knud; Trakhtenbrot, Benny; Lambrides, Erini; Onoue, Masafusa; Andika, Irham Taufik; Bongiorno, Angela; Faisst, Andreas L.; Gillman, Steven; Hayward, Christopher C.; Hirschmann, Michaela; Koekemoer, Anton; Kokorev, Vasily; Liu, Zhaoxuan; Magdis, Georgios E.; Renzini, Alvio; Casey, Caitlin; Drakos, Nicole E.; Franco, Maximilien; Gozaliasl, Ghassem; Kartaltepe, Jeyhan; Liu, Daizhong; McCracken, Henry Joy; Rhodes, Jason; Robertson, Brant; Toft, Sune
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Our knowledge of relations between supermassive black holes and their host galaxies at z ≳ 1 is still limited, even though being actively sought out to z ∼ 6. Here, we use the high resolution and sensitivity of JWST to measure the host galaxy properties for 107 X-ray-selected type-I active galactic nuclei (AGNs) at 0.68 < z < 2.5 with rest-frame optical/near-infrared imaging from COSMOS-Web and PRIMER. Black hole masses ( log M BH / M ⊙ ∼ 6.9 − 9.6 ) are available from previous spectroscopic campaigns. We extract the host galaxy components from four NIRCam broadband images and the Hubble Space Telescope/Advanced Camera for Surveys F814W image by applying a 2D image decomposition technique. We detect the host galaxy for ∼90% of the sample after subtracting the unresolved AGN emission. With host photometry free of AGN emission, we determine the stellar mass of the host galaxies to be log M * / M ⊙ ∼ 9.5 − 11.6 through spectral energy distribution fitting and measure the evolution of the mass relation between SMBHs and their host galaxies. Considering selection biases and measurement uncertainties, we find that the MBH/M*ratio evolves as 1 + z 0.4 8 − 0.62 + 0.31 thus remains essentially constant or exhibits mild evolution up to z ∼ 2.5. We also see an amount of scatter ( σ μ = 0.3 0 − 0.13 + 0.14 ), similar to the local relation and consistent with low-z studies, and a noncausal cosmic assembly history where mergers contribute to the statistical averaging toward the local relation is still feasible. We highlight improvements to come with larger samples from JWST and, particularly, Euclid, which will exceed the statistical power of current wide and deep surveys.
  • A Near-infrared-faint, Far-infrared-luminous Dusty Galaxy at z ∼ 5 in COSMOS-Web
    (2023-10-10) McKinney, Jed; Manning, Sinclaire M.; Cooper, Olivia R.; Long, Arianna S.; Akins, Hollis; Casey, Caitlin M.; Faisst, Andreas L.; Franco, Maximilien; Hayward, Christopher C.; Lambrides, Erini; Magdis, Georgios; Whitaker, Katherine E.; Yun, Min; Champagne, Jaclyn B.; Drakos, Nicole E.; Gentile, Fabrizio; Gillman, Steven; Gozaliasl, Ghassem; Ilbert, Olivier; Jin, Shuowen; Koekemoer, Anton M.; Kokorev, Vasily; Liu, Daizhong; Rich, R. Michael; Robertson, Brant E.; Valentino, Francesco; Weaver, John R.; Zavala, Jorge A.; Allen, Natalie; Kartaltepe, Jeyhan S.; McCracken, Henry Joy; Paquereau, Louise; Rhodes, Jason; Shuntov, Marko; Toft, Sune
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    A growing number of far-infrared bright sources completely invisible in deep extragalactic optical surveys hint at an elusive population of z>4 dusty, star-forming galaxies. Cycle 1 JWST surveys are now detecting their rest-frame optical light, which provides key insight into their stellar properties and statistical constraints on the population as a whole. This work presents the JWST/NIRCam counterpart from the COSMOS-Web survey to a far-infrared SCUBA-2 and ALMA source, AzTECC71, which was previously undetected at wavelengths shorter than 850 microns. AzTECC71, amongst the reddest galaxies in COSMOS-Web with F277W - F444W~0.9, is undetected in NIRCam/F150W and F115W and fainter in F444W than other sub-millimeter galaxies identified in COSMOS-Web by 2-4 magnitudes. This is consistent with the system having both a lower stellar mass and higher redshift than the median dusty, star-forming galaxy. With deep ground- and space-based upper limits combined with detections in F277W, F444W and the far-IR including ALMA Band 6, we find a high probability (99%) that AzTECC71 is at z>4 with z_phot=5.7(+0.8,-0.7). This galaxy is massive (logM*/Msun~10.7) and IR-luminous (logLIR/Lsun~12.7), comparable to other optically-undetected but far-IR bright dusty, star-forming galaxies at z>4. This population of luminous, infrared galaxies at z>4 is largely unconstrained but comprises an important bridge between the most extreme dust-obscured galaxies and more typical high-redshift star-forming galaxies. If further far-IR-selected galaxies that drop out of the F150W filter in COSMOS-Web have redshifts z>4 like AzTECC71, then the volume density of such sources may be ~3-10x greater than previously estimated.
  • Not-so-little Red Dots : Two Massive and Dusty Starbursts at z ∼ 5-7 Pushing the Limits of Star Formation Discovered by JWST in the COSMOS-Web Survey
    (2024-09-01) Gentile, Fabrizio; Casey, Caitlin M.; Akins, Hollis B.; Franco, Maximilien; McKinney, Jed; Berman, Edward; Cooper, Olivia R.; Drakos, Nicole E.; Hirschmann, Michaela; Long, Arianna S.; Magdis, Georgios; Koekemoer, Anton M.; Kokorev, Vasily; Shuntov, Marko; Talia, Margherita; Allen, Natalie; Harish, Santosh; Ilbert, Olivier; McCracken, Henry Joy; Kartaltepe, Jeyhan S.; Liu, Daizhong; Paquereau, Louise; Rhodes, Jason; Rich, Michael R.; Robertson, Brant E.; Toft, Sune; Gozaliasl, Ghassem
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    We present the properties of two candidate massive (M ⋆ ∼ 1011 M ⊙) and dusty (A v > 2.5 mag) galaxies at z = 5-7 in the first 0.28 deg2 of the COSMOS-Web survey. One object is spectroscopically confirmed at z spec = 5.051, while the other has a robust z phot = 6.7 ± 0.3. Thanks to their extremely red colors (F277W-F444W ∼ 1.7 mag), these galaxies satisfy the nominal color selection for the widely studied “little red dot” (LRD) population with the exception of their spatially resolved morphologies. The morphology of our targets allows us to conclude that their red continuum is dominated by highly obscured stellar emission and not by reddened nuclear activity. Using a variety of spectral energy distribution fitting tools and star formation histories, we estimate the stellar masses to be log ( M ⋆ ) = 11.32 − 0.15 + 0.07 M ⊙ and log ( M ⋆ ) = 11.2 − 0.2 + 0.1 M ⊙ , respectively, with a red continuum emission dominated by a recent episode of star formation. We then compare their number density to the halo mass function to infer stellar baryon fractions of ϵ ⋆ ∼ 0.25 and ϵ ⋆ ∼ 0.5. Both are significantly higher than what is commonly observed in lower-z galaxies or more dust-obscured galaxies at similar redshifts. With very bright ultra-high-z Lyman-Break Galaxies and some non-AGN-dominated LRDs, such “extended” LRDs represent another population that may require very efficient star formation at early times.
  • SCUBADive. I. JWST+ALMA Analysis of 289 Submillimeter Galaxies in COSMOS-web
    (2025-02-01) McKinney, Jed; Casey, Caitlin M.; Long, Arianna S.; Cooper, Olivia R.; Manning, Sinclaire M.; Franco, Maximilien; Akins, Hollis; Lambrides, Erini; Gammon, Elaine; Silva, Camila; Gentile, Fabrizio; Zavala, Jorge A.; Amvrosiadis, Aristeidis; Andika, Irham; Brinch, Malte; Champagne, Jaclyn B.; Chartab, Nima; Drakos, Nicole E.; Faisst, Andreas L.; Fujimoto, Seiji; Gillman, Steven; Gozaliasl, Ghassem; Greve, Thomas R.; Harish, Santosh; Hayward, Christopher C.; Hirschmann, Michaela; Ilbert, Olivier; Kalita, Boris S.; Kartaltepe, Jeyhan S.; Koekemoer, Anton M.; Kokorev, Vasily; Liu, Daizhong; Magdis, Georgios; McCracken, Henry Joy; Rhodes, Jason; Robertson, Brant E.; Talia, Margherita; Valentino, Francesco; Vijayan, Aswin P.
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    JWST has enabled detecting and spatially resolving the heavily dust-attenuated stellar populations of submillimeter galaxies, revealing detail that was previously inaccessible. In this work, we construct a sample of 289 submillimeter galaxies with joint Atacama Large Millimeter/submillimeter Array (ALMA) and JWST constraints in the COSMOS field. Sources are originally selected using the SCUBA-2 instrument and have archival ALMA observations from various programs. Their JWST NIRCam imaging is from COSMOS-Web and PRIMER. We extract multiwavelength photometry in a manner that leverages the unprecedented near-infrared (NIR) spatial resolution of JWST, and we fit the data with spectral energy distribution models to derive photometric redshifts, stellar masses, star formation rates, and optical attenuation. The sample has an average 〈 z 〉 = 2 . 6 − 0.8 + 1.0 , 〈 A V 〉 = 2 . 5 − 1.0 + 1.5 , 〈 SFR 〉 = 30 0 − 200 + 400 M ⊙ yr − 1 , and 〈 log ( M * / M ⊙ ) 〉 = 11 . 1 − 0.5 + 0.3 . There are 81 (30%) galaxies that have no previous optical/NIR detections, including 75% of the z > 4 subsample (n = 28). The faintest observed NIR sources have the highest redshifts and largest AV = 4 ± 1. In a preliminary morphology analysis we find that ∼10% of the members of our sample exhibit spiral arms and 5% host stellar bars, with one candidate bar found at z > 3. Finally, we find that the clustering of JWST sources within 10″ of a submillimeter galaxy is a factor of 2 greater than what is expected based on either random clustering or the distribution of sources around any red galaxy irrespective of a submillimeter detection.
  • Uncovering a Massive z∼7.7 Galaxy Hosting a Heavily Obscured Radio-loud Active Galactic Nucleus Candidate in COSMOS-Web
    (2024-01-01) Lambrides, Erini; Chiaberge, Marco; Long, Arianna S.; Liu, Daizhong; Akins, Hollis B.; Ptak, Andrew F.; Andika, Irham Taufik; Capetti, Alessandro; Casey, Caitlin M.; Champagne, Jaclyn B.; Chworowsky, Katherine; Clarke, Tracy E.; Cooper, Olivia R.; Ding, Xuheng; Dong, Dillon Z.; Faisst, Andreas L.; Forman, Jordan Y.; Franco, Maximilien; Gillman, Steven; Gozaliasl, Ghassem; Hall, Kirsten R.; Harish, Santosh; Hayward, Christopher C.; Hirschmann, Michaela; Hutchison, Taylor A.; Jahnke, Knud; Jin, Shuowen; Kartaltepe, Jeyhan S.; Kleiner, Emma T.; Koekemoer, Anton M.; Kokorev, Vasily; Manning, Sinclaire M.; Martin, Crystal L.; McKinney, Jed; Norman, Colin; Nyland, Kristina; Onoue, Masafusa; Robertson, Brant E.; Shuntov, Marko; Silverman, John D.; Stiavelli, Massimo; Trakhtenbrot, Benny; Vardoulaki, Eleni; Zavala, Jorge A.; Allen, Natalie; Ilbert, Olivier; McCracken, Henry Joy; Paquereau, Louise; Rhodes, Jason; Toft, Sune
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    In this Letter, we report the discovery of the highest redshift, heavily obscured, radio-loud (RL) active galactic nucleus (AGN) candidate selected using JWST NIRCam/MIRI, mid-IR, submillimeter, and radio imaging in the COSMOS-Web field. Using multifrequency radio observations and mid-IR photometry, we identify a powerful, RL, growing supermassive black hole with significant spectral steepening of the radio spectral energy distribution (f1.28 GHz ∼ 2 mJy, q24 μm = −1.1, α1.28−3 GHz = − 1.2, Δα = − 0.4). In conjunction with ALMA, deep ground-based observations, ancillary space-based data, and the unprecedented resolution and sensitivity of JWST, we find no evidence of AGN contribution to the UV/optical/near-infrared (NIR) data and thus infer heavy amounts of obscuration (NH > 1023 cm−2). Using the wealth of deep UV to submillimeter photometric data, we report a singular solution photo-z of zphot = 7.7-+0.30.4 and estimate an extremely massive host galaxy (log M* = 11.92 0.5M) hosting a powerful, growing supermassive black hole (LBol = 4−12x × 1046 erg s−1). This source represents the farthest known obscured RL AGN candidate, and its level of obscuration aligns with the most representative but observationally scarce population of AGN at these epochs.
  • Unveiling the Distant Universe : Characterizing z ≥ 9 Galaxies in the First Epoch of COSMOS-Web
    (2024-09-01) Franco, Maximilien; Akins, Hollis B.; Casey, Caitlin M.; Finkelstein, Steven L.; Shuntov, Marko; Chworowsky, Katherine; Faisst, Andreas L.; Fujimoto, Seiji; Ilbert, Olivier; Koekemoer, Anton M.; Liu, Daizhong; Lovell, Christopher C.; Maraston, Claudia; McCracken, Henry Joy; McKinney, Jed; Robertson, Brant E.; Bagley, Micaela B.; Champagne, Jaclyn B.; Cooper, Olivia R.; Ding, Xuheng; Drakos, Nicole E.; Enia, Andrea; Gillman, Steven; Gozaliasl, Ghassem; Harish, Santosh; Hayward, Christopher C.; Hirschmann, Michaela; Jin, Shuowen; Kartaltepe, Jeyhan S.; Kokorev, Vasily; Laigle, Clotilde; Long, Arianna S.; Magdis, Georgios; Mahler, Guillaume; Martin, Crystal L.; Massey, Richard; Mobasher, Bahram; Paquereau, Louise; Renzini, Alvio; Rhodes, Jason; Rich, R. Michael; Sheth, Kartik; Silverman, John D.; Sparre, Martin; Talia, Margherita; Trakhtenbrot, Benny; Valentino, Francesco; Vijayan, Aswin P.; Wilkins, Stephen M.; Yang, Lilan; , COSMOS Team
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    We report the identification of 15 galaxy candidates at z ≥ 9 using the initial COSMOS-Web JWST observations over 77 arcmin2 through four Near Infrared Camera filters (F115W, F150W, F277W, and F444W) with an overlap with the Mid-Infrared Imager (F770W) of 8.7 arcmin2. We fit the sample using several publicly available spectral energy distribution (SED) fitting and photometric redshift codes and determine their redshifts between z = 9.3 and z = 10.9 (〈z〉 = 10.0), UV magnitudes between M UV = −21.2 and −19.5 (with 〈M UV〉 = −20.2), and rest-frame UV slopes (〈β〉 = −2.4). These galaxies are, on average, more luminous than most z ≥ 9 candidates discovered by JWST so far in the literature, while exhibiting similar blue colors in their rest-frame UV. The rest-frame UV slopes derived from SED fitting are blue (β ∼ [−2.0, −2.7]) without reaching extremely blue values as reported in other recent studies at these redshifts. The blue color is consistent with models that suggest the underlying stellar population is not yet fully enriched in metals like similarly luminous galaxies in the lower-redshift Universe. The derived stellar masses with 〈 log 10 ( M ⋆/M ⊙)〉 ≈ 8-9 are not in tension with the standard Lambda cold dark matter (ΛCDM) model, and our measurement of the volume density of such UV-luminous galaxies aligns well with previously measured values presented in the literature at z ∼ 9-10. Our sample of galaxies, although compact, is significantly resolved.