Browsing by Author "Tejos, Nicolas"

Now showing 1 - 4 of 4
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    A 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
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    A 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
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    Dissecting 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....
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    The 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, Nicolas
    We 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.