Browsing by Author "Sharon, Keren"

Now showing 1 - 5 of 5
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    A 30 kpc Spatially Extended Clumpy and Asymmetric Galactic Outflow at z ∼ 1.7
    (2022) Shaban, Ahmed; Bordoloi, Rongmon; Chisholm, John; Sharma, Soniya; Sharon, Keren; Rigby, Jane R.; Gladders, Michael G.; Bayliss, Matthew B.; Barrientos, L. Felipe; Lopez, Sebastian; Tejos, Nicolas; Ledoux, Cedric; Florian, Michael K.
    We image the spatial extent of a cool galactic outflow with fine-structure Fe ii* emission and resonant Mg ii emission in a gravitationally lensed star-forming galaxy at z = 1.70347. The Fe ii* and Mg ii (continuum-subtracted) emissions span out to radial distances of similar to 14.33 and 26.5 kpc, respectively, with maximum spatial extents of similar to 21 kpc for Fe ii* emission and similar to 30 kpc for Mg ii emission. Mg ii emission is patchy and covers a total area of similar to 184 kpc(2), constraining the minimum area covered by the outflowing gas to be similar to 13% of the total area. Mg ii emission is asymmetric and shows similar to 21% more extended emission along the decl. direction. We constrain the covering fractions of the Fe ii* and Mg ii emission as a function of radial distance and characterize them with a power-law model. The Mg ii 2803 emission line shows two kinematically distinct emission components and may correspond to two distinct shells of outflowing gas with a velocity separation of Delta v similar to 400 km s(-1). By using multiple images with different magnifications of the galaxy in the image plane, we trace the Fe ii* and Mg ii emissions around three individual star-forming regions. In all cases, both the Fe ii* and Mg ii emissions are more spatially extended compared to the star-forming regions traced by the [O ii] emission. These findings provide robust constraints on the spatial extent of the outflowing gas and, combined with outflow velocity and column density measurements, will give stringent constraints on mass-outflow rates of the galaxy.
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    A variable active galactic nucleus at z=2.06 triply-imaged by the galaxy cluster MACS J0035.4-2015
    (2023) Furtak, Lukas J.; Mainali, Ramesh; Zitrin, Adi; Plat, Adele; Fujimoto, Seiji; Donahue, Megan; Nelson, Erica J.; Bauer, Franz E.; Uematsu, Ryosuke; Caminha, Gabriel B.; Andrade-Santos, Felipe; Bradley, Larry D.; Caputi, Karina, I; Charlot, Stephane; Chevallard, Jacopo; Coe, Dan; Curtis-Lake, Emma; Espada, Daniel; Frye, Brenda L.; Knudsen, Kirsten K.; Koekemoer, Anton M.; Kohno, Kotaro; Kokorev, Vasily; Laporte, Nicolas; Lee, Minju M.; Lemaux, Brian C.; Magdis, Georgios E.; Sharon, Keren; Stark, Daniel P.; Su, Yuanyuan; Suess, Katherine A.; Ueda, Yoshihiro; Umehata, Hideki; Vidal-Garcia, Alba; Wu, John F.
    We report the discovery of a triply imaged active galactic nucleus (AGN), lensed by the galaxy cluster MACS J0035.4-2015 (z(d) = 0.352). The object is detected in Hubble Space Telescope imaging taken for the RELICS program. It appears to have a quasi-stellar nucleus consistent with a point-source, with a de-magnified radius of r(e) less than or similar to 100 pc. The object is spectroscopically confirmed to be an AGN at z spec = 2.063 +/- 0.005 showing broad rest-frame UV emission lines, and detected in both X-ray observations with Chandra and in ALCS ALMA band 6 (1.2 mm) imaging. It has a relatively faint rest-frame UV luminosity for a quasar-like object, M (UV, 1450) = -19.7 +/- 0.2. The object adds to just a few quasars or other X-ray sources known to be multiply lensed by a galaxy cluster. Some diffuse emission from the host galaxy is faintly seen around the nucleus, and there is a faint object nearby sharing the same multiple-imaging symmetry and geometric redshift, possibly an interacting galaxy or a star-forming knot in the host. We present an accompanying lens model, calculate the magnifications and time delays, and infer the physical properties of the source. We find the rest-frame UV continuum and emission lines to be dominated by the AGN, and the optical emission to be dominated by the host galaxy of modest stellar mass M-* similar or equal to 10(9.2) M-circle dot. We also observe some variation in the AGN emission with time, which may suggest that the AGN used to be more active. This object adds a low-redshift counterpart to several relatively faint AGN recently uncovered at high redshifts with HST and JWST.
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    ALMA Resolves the Molecular Gas in a Young Low-metallicity Starburst Galaxy at z.=1.7
    (2017) González López, Jorge; Barrientos, Luis Felipe; Gladders, M. D.; Wuyts, Eva; Rigby, Jane; Sharon, Keren; Aravena, Manuel; Bayliss, Matthew B.; Ibar, Eduardo
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    Pilot-WINGS: An extended MUSE view of the structure of Abell 370
    (2022) Lagattuta, David J.; Richard, Johan; Bauer, Franz Erik; Cerny, Catherine; Claeyssens, Adelaide; Guaita, Lucia; Jauzac, Mathilde; Jeanneau, Alexandre; Koekemoer, Anton M.; Mahler, Guillaume; Prieto Lyon, Gonzalo; Acebron, Ana; Meneghetti, Massimo; Niemiec, Anna; Zitrin, Adi; Bianconi, Matteo; Connor, Thomas; Cen, Renyue; Edge, Alastair; Faisst, Andreas L.; Limousin, Marceau; Massey, Richard; Sereno, Mauro; Sharon, Keren; Weaver, John R.
    We investigate the strong-lensing cluster Abell 370 (A370) using a wide Integral Field Unit (IFU) spectroscopic mosaic from the Multi-Unit Spectroscopic Explorer (MUSE). IFU spectroscopy provides significant insight into the structure and mass content of galaxy clusters, yet IFU-based cluster studies focus almost exclusively on the central Einstein-radius region. Covering over 14 arcmin(2), the new MUSE mosaic extends significantly beyond the A370 Einstein radius, providing, for the first time, a detailed look at the cluster outskirts. Combining these data with wide-field, multi-band Hubble Space Telescope (HST) imaging from the BUFFALO project, we analyse the distribution of objects within the cluster and along the line of sight. Identifying 416 cluster galaxies, we use kinematics to trace the radial mass profile of the halo, providing a mass estimate independent from the lens model. We also measure radially averaged properties of the cluster members, tracking their evolution as a function of infall. Thanks to the high spatial resolution of our data, we identify six cluster members acting as galaxy-galaxy lenses, which constrain localized mass distributions beyond the Einstein radius. Finally, taking advantage of MUSE's 3D capabilities, we detect and analyse multiple spatially extended overdensities outside of the cluster that influence lensing-derived halo mass estimates. We stress that much of this work is only possible thanks to the robust, extended IFU coverage, highlighting its importance even in less optically dense cluster regions. Overall, this work showcases the power of combining HST + MUSE, and serves as the initial step towards a larger and wider program targeting several clusters.
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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.