Browsing by Author "Tejos, Nicolas"
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- ItemA 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.
- ItemA clumpy and anisotropic galaxy halo at redshift 1 from gravitational-arc tomography(2018) Lopez, Sebastian; Tejos, Nicolas; Ledoux, Cedric; Felipe Barrientos, L.; Sharon, Keren; Rigby, Jane R.; Gladders, Michael D.; Bayliss, Matthew B.; Pessa, Ismael
- ItemA VLT/MUSE galaxy survey towards QSO Q1410: looking for awhim traced by blas in inter-cluster filaments(2018) Pessa, Ismael; Tejos, Nicolas; Felipe Barrientos, L.; Werk, Jessica; Bielby, Richard; Padilla, Nelson; Morris, Simon L.; Prochaska, J. Xavier; Lopez, Sebastian; Hummels, Cameron
- ItemDissecting a 30 kpc galactic outflow at z 1.7(2023) Shaban, Ahmed; Bordoloi, Rongmon; Chisholm, John; Rigby, Jane R.; Sharma, Soniya; Sharon, Keren; Tejos, Nicolas; Bayliss, Matthew B.; Barrientos, Luis Felipe; López, Sebastian; Ledoux, Cédric; Gladders, Michael G.; Florian, Michael K.We present the spatially resolved measurements of a cool galactic outflow in the gravitationally lensed galaxy RCS0327 at z ≈ 1.703 using VLT/MUSE IFU observations. We probe the cool outflowing gas, traced by blueshifted Mg II and Fe II absorption lines, in 15 distinct regions of the same galaxy in its image-plane. Different physical regions, 5 to 7 kpc apart within the galaxy, drive the outflows at different velocities (Vout ~ -161 to -240 km s-1), and mass outflow rates ($\dot{M}_{out} \sim$ 183 to 527 M⊙ yr-1). The outflow velocities from different regions of the same galaxy vary by 80 km s-1, which is comparable to the variation seen in a large sample of star-burst galaxies in the local Universe. Using multiply lensed images of RCS0327, we probe the same star-forming region at different spatial scales (0.5 kpc2 -- 25 kpc2), we find that outflow velocities vary between ~ -120 to -242 km s-1, and the mass outflow rates vary between ~ 37 to 254 M⊙ yr-1. The outflow momentum flux in this galaxy is ≥ 100% of the momentum flux provided by star-formation in individual regions, and outflow energy flux is ≈ 10% of the total energy flux provided by star-formation. These estimates suggest that the outflow in RCS0327 is energy driven. This work shows the importance of small scale variations of outflow properties due to the variations of local stellar properties of the host galaxy in the context of galaxy evolution....
- ItemRevealing 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, NicolasSpatially 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.
- ItemThe COS-Halos Survey: Metallicities in the Low-redshift Circumgalactic Medium(IOP PUBLISHING LTD, 2017) Prochaska, J. Xavier; Werk, Jessica K.; Worseck, Gabor; Tripp, Todd M.; Tumlinson, Jason; Burchett, Joseph N.; Fox, Andrew J.; Fumagalli, Michele; Lehner, Nicolas; Peeples, Molly S.; Tejos, NicolasWe analyze new far-ultraviolet spectra of 13 quasars from the z similar to 0.2 COS-Halos survey that cover the H I Lyman limit of 14 circumgalactic medium (CGM) systems. These data yield precise estimates or more constraining limits than previous COS-Halos measurements on the H I column densities N-H (I). We then apply a Monte-Carlo Markov chain approach on 32 systems from COS-Halos to estimate the metallicity of the cool (T similar to 10(4) K) CGM gas that gives rise to low-ionization state metal lines, under the assumption of photoionization equilibrium with the extragalactic UV background. The principle results are: (1) the CGM of field L* galaxies exhibits a declining H I surface density with impact parameter R-perpendicular to (at >99.5% confidence), (2) the transmission of ionizing radiation through CGM gas alone is 70 +/- 7%; (3) the metallicity distribution function of the cool CGM is unimodal with a median of 10(-0.51) Z(circle dot) and a 95% interval approximate to 1/50 Z(circle dot) to > 3 Z(circle dot); the incidence of metal=poor(< 1/100 Z) gas is low, implying any such gas discovered along quasar sightlines is typically unrelated to L* galaxies; (4) we find an unexpected increase in gas metallicity with declining N-H (I) (at >99.9% confidence) and, therefore, also with increasing R-perpendicular to; the high metallicity at large radii implies early enrichment; and (5) a non-parametric estimate of the cool CGM gas mass is M-CGM (cool) = (9.2 +/- 4.3) x 10(10) M-circle dot, cool 10, which together with new mass estimates for the hot CGM may resolve the galactic missing baryons problem. Future analyses of halo gas should focus on the underlying astrophysics governing the CGM, rather than processes that simply expel the medium from the halo.