Browsing by Author "Gonzalez-Lopez, Jorge"

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    ALMA Lensing Cluster Survey: ALMA-Herschel Joint Study of Lensed Dusty Star-forming Galaxies across z ≃ 0.5-6
    (2022) Sun, Fengwu; Egami, Eiichi; Fujimoto, Seiji; Rawle, Timothy; Bauer, Franz E.; Kohno, Kotaro; Smail, Ian; Perez-Gonzalez, Pablo G.; Ao, Yiping; Chapman, Scott C.; Combes, Francoise; Dessauges-Zavadsky, Miroslava; Espada, Daniel; Gonzalez-Lopez, Jorge; Koekemoer, Anton M.; Kokorev, Vasily; Lee, Minju M.; Morokuma-Matsui, Kana; Munoz Arancibia, Alejandra M.; Oguri, Masamune; Pello, Roser; Ueda, Yoshihiro; Uematsu, Ryosuke; Valentino, Francesco; van der Werf, Paul; Walth, Gregory L.; Zemcov, Michael; Zitrin, Adi
    We present an ALMA-Herschel joint analysis of sources detected by the ALMA Lensing Cluster Survey (ALCS) at 1.15 mm. Herschel/PACS and SPIRE data at 100-500 mu m are deblended for 180 ALMA sources in 33 lensing cluster fields that are detected either securely (141 sources; in our main sample) or tentatively at S/N >= 4 with cross-matched HST/Spitzer counterparts, down to a delensed 1.15 mm flux density of similar to 0.02 mJy. We performed far-infrared spectral energy distribution modeling and derived the physical properties of dusty star formation for 125 sources (109 independently) that are detected at >2 sigma in at least one Herschel band. A total of 27 secure ALCS sources are not detected in any Herschel bands, including 17 optical/near-IR-dark sources that likely reside at z = 4.2 +/- 1.2. The 16th, 50th, and 84th percentiles of the redshift distribution are 1.15, 2.08, and 3.59, respectively, for ALCS sources in the main sample, suggesting an increasing fraction of z similar or equal to 1 - 2 galaxies among fainter millimeter sources (f(1150) similar to 0.1 mJy). With a median lensing magnification factor of mu = 2.6(-0.8)(+2.6), ALCS sources in the main sample exhibit a median intrinsic star formation rate of 94(-54)(+84) M-circle dot yr(-1), lower than that of conventional submillimeter galaxies at similar redshifts by a factor of similar to 3. Our study suggests weak or no redshift evolution of dust temperature with L-IR < 10(12) L-circle dot galaxies within our sample at z similar or equal to 0 - 2. At L-IR > 10(12) L-circle dot, the dust temperatures show no evolution across z similar or equal to 1-4 while being lower than those in the local universe. For the highest-redshift source in our sample (z = 6.07), we can rule out an extreme dust temperature (>80 K) that was reported for MACS0416 Y1 at z = 8.31.
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    ALMA Lensing Cluster Survey: average dust, gas, and star-formation properties of cluster and field galaxies from stacking analysis
    (2023) Guerrero, Andrea; Nagar, Neil; Kohno, Kotaro; Fujimoto, Seiji; Kokorev, Vasily; Brammer, Gabriel; Jolly, Jean-Baptiste; Knudsen, Kirsten; Sun, Fengwu; Bauer, Franz E.; Caminha, Gabriel B.; Caputi, Karina; Neumann, Gerald; Orellana-Gonzalez, Gustavo; Cerulo, Pierluigi; Gonzalez-Lopez, Jorge; Laporte, Nicolas; Koekemoer, Anton M.; Ao, Yiping; Espada, Daniel; Arancibia, Alejandra M. Munoz
    We develop new tools for continuum and spectral stacking of Atacama Large Millimeter/submillimeter Array (ALMA) data, and apply these to the ALMA Lensing Cluster Survey. We derive average dust masses, gas masses, and star-formation rates (SFRs) from the stacked observed 260-GHz continuum of 3402 individually undetected star-forming galaxies, of which 1450 are cluster galaxies and 1952 field galaxies, over three redshift and stellar mass bins (over z = 0-1.6 and log M-*[M-circle dot] = 8-11.7), and derive the average molecular gas content by stacking the emission line spectra in a SFR-selected subsample. The average SFRs and specific SFRs of both cluster and field galaxies are lower than those expected for main-sequence (MS) star-forming galaxies, and only galaxies with stellar mass of log M-*[M-circle dot] = 9.35-10.6 show dust and gas fractions comparable with those in the MS. The ALMA-traced average 'highly obscured' SFRs are typically lower than the SFRs observed from optical to near-infrared spectral analysis. Cluster and field galaxies show similar trends in their contents of dust and gas, even when field galaxies were brighter in the stacked maps. From spectral stacking we find a potential CO (J = 4 -> 3) line emission (signal-to-noise ratio being similar to 4) when stacking cluster and field galaxies with the highest SFRs.
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    ALMA Lensing Cluster Survey: Bright [C ii] 158 μm Lines from a Multiply Imaged Sub-L* Galaxy at z=6.0719
    (2021) Fujimoto, Seiji; Oguri, Masamune; Brammer, Gabriel; Yoshimura, Yuki; Laporte, Nicolas; Gonzalez-Lopez, Jorge; Caminha, Gabriel B.; Kohno, Kotaro; Zitrin, Adi; Richard, Johan; Ouchi, Masami; Bauer, Franz E.; Smail, Ian; Hatsukade, Bunyo; Ono, Yoshiaki; Kokorev, Vasily; Umehata, Hideki; Schaerer, Daniel; Knudsen, Kirsten; Sun, Fengwu; Magdis, Georgios; Valentino, Francesco; Ao, Yiping; Toft, Sune; Dessauges-Zavadsky, Miroslava; Shimasaku, Kazuhiro; Caputi, Karina; Kusakabe, Haruka; Morokuma-Matsui, Kana; Shotaro, Kikuchihara; Egami, Eiichi; Lee, Minju M.; Rawle, Timothy; Espada, Daniel
    We present bright [C ii] 158 mu m line detections from a strongly magnified and multiply imaged (mu similar to 20-160) sub-L* (MUV=-19.75-0.44+0.55) Lyman-break galaxy (LBG) at z = 6.0719 +/- 0.0004, drawn from the ALMA Lensing Cluster Survey (ALCS). Emission lines are identified at 268.7 GHz at >= 8 sigma exactly at the positions of two multiple images of the LBG, behind the massive galaxy cluster RXCJ0600-2007. Our lens models, updated with the latest spectroscopy from VLT/MUSE, indicate that a sub region of the LBG crosses the caustic, and is lensed into a long (similar to 6 '') arc with a local magnification of mu similar to 160, for which the [C ii] line is also significantly detected. The source plane reconstruction resolves the interstellar medium (ISM) structure, showing that the [C ii] line is co-spatial with the rest-frame UV continuum at a scale of similar to 300 pc. The [C ii] line properties suggest that the LBG is a rotation-dominated system, whose velocity gradient explains a slight difference in redshifts between the whole LBG and its sub-region. The star formation rate (SFR)-L-[CII] relations, for whole and sub-regions of the LBG, are consistent with those of local galaxies. We evaluate the lower limit of the faint-end of the [C ii] luminosity function at z = 6, finding it to be consistent with predictions from semi-analytical models and from the local SFR-L-[CII] relation with a SFR function at z = 6. These results imply that the local SFR-L-[CII] relation is universal for a wide range of scales, including the spatially resolved ISM, the whole region of the galaxy, and the cosmic scale, even in the epoch of reionization.
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    First Detection of Molecular Gas in the Giant Low Surface Brightness Galaxy Malin 1
    (2024) Galaz, Gaspar; Gonzalez-Lopez, Jorge; Guzman, Viviana; Messias, Hugo; Junais, Samuel; Boissier, Samuel; Epinat, Benoit; Weilbacher, Peter M.; Puzia, Thomas; Johnston, Evelyn J.; Amram, Philippe; Frayer, David; Blana, Matias; Howk, J. Christopher; Berg, Michelle; Bustos-Espinoza, Roy; Munoz-Mateos, Juan Carlos; Cortes, Paulo; Garcia-Appadoo, Diego; Joachimi, Katerine
    After over three decades of unsuccessful attempts, we report the first detection of molecular gas emission in Malin 1, the largest spiral galaxy observed to date, and one of the most iconic giant low surface brightness galaxies. Using Atacama Large Millimeter/submillimeter Array, we detect significant 12CO (J = 1-0) emission in the galaxy's central region and tentatively identify CO emission across three regions on the disk. These observations allow for a better estimate of the H2 mass and molecular gas mass surface density, both of which are remarkably low given the galaxy's scale. By integrating data on its H i mass, we derive a very low molecular-to-atomic gas mass ratio. Overall, our results highlight the minimal presence of molecular gas in Malin 1, contrasting sharply with its extensive, homogeneous atomic gas reservoir. For the first time, we position Malin 1 on the Kennicutt-Schmidt diagram, where it falls below the main sequence for normal spirals, consistent with previous upper limits but now with more accurate figures. These findings are crucial for constraining our understanding of star formation processes in environments characterized by extremely low molecular gas densities and for refining models of galaxy formation, thereby improving predictions concerning the formation, evolution, and distribution of these giant, elusive galaxies.
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    JWST and ALMA Multiple-line Study in and around a Galaxy at z=8.496: Optical to Far-Infrared Line Ratios and the Onset of an Outflow Promoting Ionizing Photon Escape
    (2024) Fujimoto, Seiji; Ouchi, Masami; Nakajima, Kimihiko; Harikane, Yuichi; Isobe, Yuki; Brammer, Gabriel; Oguri, Masamune; Gimenez-Arteaga, Clara; Heintz, Kasper E.; Kokorev, Vasily; Bauer, Franz E.; Ferrara, Andrea; Kojima, Takashi; Lagos, Claudia del P.; Laura, Sommovigo; Schaerer, Daniel; Shimasaku, Kazuhiro; Hatsukade, Bunyo; Kohno, Kotaro; Sun, Fengwu; Valentino, Francesco; Watson, Darach; Fudamoto, Yoshinobu; Inoue, Akio K.; Gonzalez-Lopez, Jorge; Koekemoer, Anton M.; Knudsen, Kirsten; Lee, Minju M.; Magdis, Georgios E.; Richard, Johan; Strait, Victoria B.; Sugahara, Yuma; Tamura, Yoichi; Toft, Sune; Umehata, Hideki; Walth, Gregory
    We present Atacama Large Millimeter/submillimeter Array (ALMA) deep spectroscopy for a lensed galaxy at z(spec) = 8.496 with log(M-star/M-circle dot) similar to 7.8 whose optical nebular lines and stellar continuum are detected by JWST/NIRSpec and NIRCam Early Release Observations in the field of SMACS J0723.3-7327. Our ALMA spectrum shows [O III] 88 mu m and [C II] 158 mu m line detections at 4.0 sigma and 4.5 sigma, respectively. The redshift and position of the [O III] line coincide with those of the JWST source, while the [C II] line is blueshifted by 90 km s(-1) with a spatial offset of 0.'' 5 (approximate to 0.5 kpc in the source plane) from the centroid of the JWST source. The NIRCam F444W image, including [O III] lambda 5007 and H beta line emission, spatially extends beyond the stellar components by a factor of >8. This indicates that the z = 8.5 galaxy has already experienced strong outflows as traced by extended [O III] lambda 5007 and offset [C II] emission, which would promote ionizing photon escape and facilitate reionization. With careful slit-loss corrections and the removal of emission spatially outside the galaxy, we evaluate the [O III] 88 mu m/lambda 5007 line ratio, and derive the electron density n (e) by photoionization modeling to be 220(-130)(+230) cm(-3), which is comparable with those of z similar to 2-3 galaxies. We estimate an [O III] 88 mu m/[C II] 158 mu m line ratio in the galaxy of >4, as high as those of known z similar to 6-9 galaxies. This high [O III] 88 mu m/[C II] 158 mu m line ratio is generally explained by the high n(e) as well as the low metallicity (Z(gas)/Z(circle dot)=0.04(-0.02)(+0.02)), high ionization parameter (log U > -2.27), and low carbon-to-oxygen abundance ratio (log(C/O) = [-0.52: -0.24]) obtained from the JWST/NIRSpec data; further [C II] follow-up observations will constrain the covering fraction of photodissociation regions.
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    Measuring the Average Molecular Gas Content of Star-forming Galaxies at z=3-4
    (2021) Boogaard, Leindert A.; Bouwens, Rychard J.; Riechers, Dominik; van der Werf, Paul; Bacon, Roland; Matthee, Jorryt; Stefanon, Mauro; Feltre, Anna; Maseda, Michael; Inami, Hanae; Aravena, Manuel; Brinchmann, Jarle; Carilli, Chris; Contini, Thierry; Decarli, Roberto; Gonzalez-Lopez, Jorge; Nanayakkara, Themiya; Walter, Fabian
    We study the molecular gas content of 24 star-forming galaxies at z = 3-4, with a median stellar mass of 10(9.1) M-circle dot, from the MUSE Hubble Ultra Deep Field (HUDF) Survey. Selected by their Ly alpha lambda 1216 emission and H (F160W)-band magnitude, the galaxies show an average < EWLy alpha 0 > approximate to 20 angstrom, below the typical selection threshold for Ly alpha emitters (EWLy alpha 0 > 25 angstrom), and a rest-frame UV spectrum similar to Lyman-break galaxies. We use rest-frame optical spectroscopy from KMOS and MOSFIRE, and the UV features observed with MUSE, to determine the systemic redshifts, which are offset from Ly alpha by = 346 km s(-1), with a 100 to 600 km s(-1) range. Stacking (CO)-C-12 J = 4 -> 3 and [C I]P-3(1) -> P-3(0) (and higher-J CO lines) from the ALMA Spectroscopic Survey of the HUDF, we determine 3 sigma upper limits on the line luminosities of 4.0 x 10(8) K km s(-1)pc(2) and 5.6 x 10(8) K km s(-1)pc(2), respectively (for a 300 km s(-1) line width). Stacking the 1.2 mm and 3 mm dust-continuum flux densities, we find a 3 sigma upper limits of 9 mu Jy and 1.2 mu Jy, respectively. The inferred gas fractions, under the assumption of a "Galactic" CO-to-H-2 conversion factor and gas-to-dust ratio, are in tension with previously determined scaling relations. This implies a substantially higher alpha(CO) >= 10 and delta(GDR) >= 1200, consistent with the subsolar metallicity estimated for these galaxies (12 + log(O/H) approximate to 7.8 +/- 0.2). The low metallicity of z >= 3 star-forming galaxies may thus make it very challenging to unveil their cold gas through CO or dust emission, warranting further exploration of alternative tracers, such as [C II].
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    New Spectroscopic Confirmations of Lyα Emitters at Z ∼ 7 from the LAGER Survey
    (2022) Harish, Santosh; Wold, Isak G. B.; Malhotra, Sangeeta; Rhoads, James E.; Hu, Weida; Wang, Junxian; Zheng, Zhen-ya; Barrientos, L. Felipe; Gonzalez-Lopez, Jorge; Perez, Lucia A.; Khostovan, Ali Ahmad; Infante, Leopoldo; Jiang, Chunyan; Moya-Sierralta, Cristobal; Pharo, John; Valdes, Francisco; Yang, Huan
    We report spectroscopic confirmations of 15 Ly alpha galaxies at z similar to 7, implying a spectroscopic confirmation rate of similar to 80% on candidates selected from the Ly alpha Galaxies in the Epoch of Reionization (LAGER), which is the largest (24 deg(2)) survey aimed at finding Ly alpha emitters (LAEs) at z similar to 7 and uses deep narrowband imaging from the Dark Energy Camera at CTIO. LAEs at high redshifts are sensitive probes of cosmic reionization, and narrowband imaging is a robust and effective method for selecting a large number of LAEs. In this work, we present results from the spectroscopic follow-up of LAE candidates in two LAGER fields, COSMOS and WIDE-12, using observations from Keck/LRIS. We report the successful detection of Ly alpha emission in 15 candidates. Three of these in COSMOS have matching confirmations from a previous spectroscopic follow-up and are part of the overdense region, LAGER-z7OD1. Two other candidates that were not detected with LRIS have prior spectroscopic confirmations from Magellan. Including these, we obtain a spectroscopic confirmation success rate of similar to 80% for LAGER LAE candidates. Thorough checks were performed to reject the possibility of these detections being foreground emission resulting with a probability of, at most, one contaminant. We do not detect any other UV nebular lines in our LRIS spectra, apart from Ly alpha. We estimate a 2 sigma upper limit for the ratio of N v/Ly alpha, f (NV)/f (Ly alpha ) less than or similar to 0.27. Including confirmations from this work, a total of 33 LAE sources from LAGER are now spectroscopically confirmed. LAGER has more than doubled the sample of spectroscopically confirmed LAE sources at z similar to 7.
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    Revealing the Nature of a Lyα Halo in a Strongly Lensed Interacting System at z=2.92
    (2022) Solimano, Manuel; Gonzalez-Lopez, Jorge; Aravena, Manuel; Johnston, Evelyn J.; Moya-Sierralta, Cristobal; Barrientos, Luis F.; Baylis, Matthew B.; Gladders, Michael; Infante, Leopoldo; Ledoux, Cedric; Lopez, Sebastian; Poudel, Suraj; Rigby, Jane R.; Sharon, Keren; Tejos, Nicolas
    Spatially extended halos of H i Ly alpha emission are now ubiquitously found around high-redshift star-forming galaxies. But our understanding of the nature and powering mechanisms of these halos is still hampered by the complex radiative transfer effects of the Ly alpha line and limited angular resolution. In this paper, we present resolved Multi Unit Spectroscopic Explorer (MUSE) observations of SGAS J122651.3+215220, a strongly lensed pair of L* galaxies at z = 2.92 embedded in a Ly alpha halo of L (Ly alpha ) = (6.2 +/- 1.3) x 10(42) erg s(-1). Globally, the system shows a line profile that is markedly asymmetric and redshifted, but its width and peak shift vary significantly across the halo. By fitting the spatially binned Ly alpha spectra with a collection of radiative transfer galactic wind models, we infer a mean outflow expansion velocity of approximate to 211 km s(-1), with higher values preferentially found on both sides of the system's major axis. The velocity of the outflow is validated with the blueshift of low-ionization metal absorption lines in the spectra of the central galaxies. We also identify a faint (M (1500) approximate to -16.7) companion detected in both Ly alpha and the continuum, whose properties are in agreement with a predicted population of satellite galaxies that contribute to the extended Ly alpha emission. Finally, we briefly discuss the impact of the interaction between the central galaxies on the properties of the halo and the possibility of in situ fluorescent Ly alpha production.
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    The ALMA-CRISTAL Survey: Spatially Resolved Star Formation Activity and Dust Content in 4 < z < 6 Star-forming Galaxies
    (2024) Li, Juno; Da Cunha, Elisabete; Gonzalez-Lopez, Jorge; Aravena, Manuel; De Looze, Ilse; Schreiber, N. M. Foerster; Herrera-Camus, Rodrigo; Spilker, Justin; Tadaki, Ken-ichi; Barcos-Munoz, Loreto; Battisti, Andrew J.; Birkin, Jack E.; Bowler, Rebecca A. A.; Davies, Rebecca; Diaz-Santos, Tanio; Ferrara, Andrea; Fisher, Deanne B.; Hodge, Jacqueline; Ikeda, Ryota; Killi, Meghana; Lee, Lilian; Liu, Daizhong; Lutz, Dieter; Mitsuhashi, Ikki; Naab, Thorsten; Posses, Ana; Relano, Monica; Solimano, Manuel; Uebler, Hannah; van der Giessen, Stefan Anthony; Villanueva, Vicente
    Using a combination of Hubble Space Telescope (HST), JWST, and Atacama Large Millimeter/submillimeter Array (ALMA) data, we perform spatially resolved spectral energy distributions (SED) fitting of fourteen 4 < z < 6 ultraviolet (UV)-selected main-sequence galaxies targeted by the ALMA Large Program [C ii] Resolved ISM in Star-forming Galaxies. We consistently model the emission from stars and dust in similar to 0.5-1 kpc spatial bins to obtain maps of their physical properties. We find no offsets between the stellar masses (M-*) and star formation rates (SFRs) derived from their global emission and those from adding up the values in our spatial bins, suggesting there is no bias of outshining by young stars on the derived global properties. We show that ALMA observations are important to derive robust parameter maps because they reduce the uncertainties in L-dust (hence, A(V) and SFR). Using these maps, we explore the resolved star-forming main sequence for z similar to 5 galaxies, finding that this relation persists in typical star-forming galaxies in the early Universe. We find less obscured star formation where the M-* (and SFR) surface densities are highest, typically in the central regions, contrary to the global relation between these parameters. We speculate this could be caused by feedback driving gas and dust out of these regions. However, more observations of IR luminosities with ALMA are needed to verify this. Finally, we test empirical SFR prescriptions based on the UV+IR and [C ii] line luminosity, finding they work well at the scales probed (approximately kiloparsec). Our work demonstrates the usefulness of joint HST-, JWST-, and ALMA-resolved SED modeling analyses at high redshift.
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    The Identification of a Dusty Multiarm Spiral Galaxy at z =3.06 with JWST and ALMA
    (2023) Wu, Yunjing; Cai, Zheng; Sun, Fengwu; Bian, Fuyan; Lin, Xiaojing; Li, Zihao; Li, Mingyu; Bauer, Franz E.; Egami, Eiichi; Fan, Xiaohui; Gonzalez-Lopez, Jorge; Li, Jianan; Wang, Feige; Yang, Jinyi; Zhang, Shiwu; Zou, Siwei
    Spiral arms serve crucial purposes in star formation and galaxy evolution. In this paper, we report the identification of "A2744-DSG-z3," a dusty, multiarm spiral galaxy at z = 3.059 using the James Webb Space Telescope (JWST) NIRISS imaging and grism spectroscopy. A2744-DSG-z3 was discovered as a gravitationally lensed submillimeter galaxy with the Atacama Large Millimeter/submillimeter Array (ALMA). This is the most distant stellar spiral structure seen thus far, consistent with cosmological simulations that suggest z approximate to 3 as the epoch when spirals emerge. Thanks to the gravitational lensing and excellent spatial resolution of JWST, the spiral arms are resolved with a spatial resolution of approximate to 290 pc. Based on spectral energy distribution fitting, the spiral galaxy has a delensed star formation rate of 85 +/- 30 M (circle dot) yr(-1), and a stellar mass of approximate to 10(10.6) M (circle dot), indicating that A2744-DSG-z3 is a main-sequence galaxy. After fitting the spiral arms, we find a stellar effective radius (R (e,star)) of 5.0 +/- 1.5 kpc. Combining with ALMA measurements, we find that the effective radii ratio between dust and stars is approximate to 0.4, similar to those of massive star-forming galaxies (SFGs) at z similar to 2, indicating a compact dusty core in A2744-DSG-z3. Moreover, this galaxy appears to be living in a group environment: including A2744-DSG-z3, at least three galaxies at z = 3.05-3.06 are spectroscopically confirmed by JWST/NIRISS and ALMA, residing within a lensing-corrected projected scale of approximate to 70 kpc. This, along with the asymmetric brightness profile, further suggests that the spiral arms may be triggered by minor-merger events at z greater than or similar to 3.