Showing papers by "Tucker Jones published in 2020"
TL;DR: In this paper, the evolution of galaxy gas-phase metallicity over the range of 0-3.3 was investigated using the MOSDEF survey data, and it was shown that the low-mass power law slope of the mass-metallicity relation is remarkably invariant over time, such that the efficiency of metal removal increases toward lower O/H at fixed redshift.
Abstract: We investigate the evolution of galaxy gas-phase metallicity (O/H) over the range $z=0-3.3$ using samples of $\sim300$ galaxies at $z\sim2.3$ and $\sim150$ galaxies at $z\sim3.3$ from the MOSDEF survey. This analysis crucially utilizes different metallicity calibrations at $z\sim0$ and $z>1$ to account for evolving ISM conditions. We find significant correlations between O/H and stellar mass ($M_*$) at $z\sim2.3$ and $z\sim3.3$. The low-mass power law slope of the mass-metallicity relation is remarkably invariant over $z=0-3.3$, such that $\textrm{O/H}\propto M_*^{0.30}$ at all redshifts in this range. At fixed $M_*$, O/H decreases with increasing redshift as dlog(O/H)/d$z=-0.11\pm0.02$. We find no evidence that the fundamental metallicity relation between $M_*$, O/H, and star-formation rate (SFR) evolves out to $z\sim3.3$, with galaxies at $z\sim2.3-3.3$ having O/H within 0.04~dex of local galaxies matched in $M_*$ and SFR on average. We employ analytic chemical evolution models to place constraints on the mass and metal loading factors of galactic outflows. The efficiency of metal removal increases toward lower $M_*$ at fixed redshift, and toward higher redshift at fixed $M_*$. These models suggest that the slope of the mass-metallicity relation is set by the scaling of the metal loading factor of outflows with $M_*$, not by the change in gas fraction as a function of $M_*$. The evolution toward lower O/H at fixed $M_*$ with increasing redshift is driven by both higher gas fraction (leading to stronger dilution of ISM metals) and higher metal removal efficiency, with models suggesting that both effects contribute approximately equally to the observed evolution. These results suggest that the processes governing the smooth baryonic growth of galaxies via gas flows and star formation hold in the same form over at least the past 12~Gyr.
62 citations
TL;DR: In this article, Jones et al. estimate gas-phase oxygen abundances in five galaxies at z = 7.1-9.1 using the direct Te method and show that the typical abundances are 7.9 (∼0.2 times the solar value) and an evolution of 0.9 ± 0.5 dex in oxygen abundance at fixed stellar mass from z ≃ 8 to 0.2
Abstract: Author(s): Jones, T; Sanders, R; Roberts-Borsani, G; Ellis, RS; Laporte, N; Treu, T; Harikane, Y | Abstract: Physical properties of galaxies at z g 7 are of interest for understanding both the early phases of star formation and the process of cosmic reionization. Chemical abundance measurements offer valuable information on the integrated star formation history, and hence ionizing photon production, as well as the rapid gas accretion expected at such high redshifts. We use reported measurements of [O iii] 88 μm emission and star formation rate to estimate gas-phase oxygen abundances in five galaxies at z = 7.1-9.1 using the direct Te method. We find typical abundances = 7.9 (∼0.2 times the solar value) and an evolution of 0.9 ± 0.5 dex in oxygen abundance at fixed stellar mass from z ≃ 8 to 0. These results are compatible with theoretical predictions, albeit with large (conservative) uncertainties in both mass and metallicity. We assess both statistical and systematic uncertainties to identify promising means of improvement with the Atacama Large Millimeter/submillimeter Array (ALMA) and the James Webb Space Telescope (JWST). In particular we highlight [O iii] 52 μm as a valuable feature for robust metallicity measurements. Precision of 0.1-0.2 dex in Te-based O/H abundance can be reasonably achieved for galaxies at z ≈ 5-8 by combining [O iii] 52 μm with rest-frame optical strong lines. It will also be possible to probe gas mixing and mergers via resolved Te-based abundances on kiloparsec scales. With ALMA and JWST, direct metallicity measurements will thus be remarkably accessible in the reionization epoch.
37 citations
TL;DR: Wang et al. as discussed by the authors presented the largest sample of gas-phase metallicity radial gradients measured at sub-kpc resolution in star-forming galaxies in the redshift range of z ∈ [1.2, 2.3].
Abstract: Author(s): Wang, X; Jones, TA; Treu, T; Daddi, E; Brammer, GB; Sharon, K; Morishita, T; Abramson, LE; Colbert, JW; Henry, AL; Hopkins, PF; Malkan, MA; Schmidt, KB; Teplitz, HI; Vulcani, B | Abstract: We present the hitherto largest sample of gas-phase metallicity radial gradients measured at sub-kpc resolution in star-forming galaxies in the redshift range of z ∈ [1.2, 2.3]. These measurements are enabled by the synergy of slitless spectroscopy from the Hubble Space Telescope near-infrared channels and the lensing magnification from foreground galaxy clusters. Our sample consists of 76 galaxies with stellar mass ranging from 107 to 1010 M⊙, an instantaneous star formation rate in the range of [1, 100] M⊙ yr-1, and global metallicity [1/12 ,2] of solar. At a 2σ confidence level, 15/76 galaxies in our sample show negative radial gradients, whereas 7/76 show inverted gradients. Combining ours and all other metallicity gradients obtained at a similar resolution currently available in the literature, we measure a negative mass dependence of Δlog(O/H)/Δ r [dex kpc-1] = (-0.020 ± 0.007) + (-0.016 ± 0.008), with the intrinsic scatter being σ = 0.060 ± 0.006 over 4 orders of magnitude in stellar mass. Our result is consistent with strong feedback, not secular processes, being the primary governor of the chemostructural evolution of star-forming galaxies during the disk mass assembly at cosmic noon. We also find that the intrinsic scatter of metallicity gradients increases with decreasing stellar mass and increasing specific star formation rate. This increase in the intrinsic scatter is likely caused by the combined effect of cold-mode gas accretion and merger-induced starbursts, with the latter more predominant in the dwarf mass regime of M∗ ≤ 109 M⊙.
24 citations
TL;DR: In this paper, the spatial and kinematic distribution of MgII absorption in a star-forming galaxy at a resolution element of about 15 kpc$^2 was studied.
Abstract: Galaxy evolution is thought to be driven in large part by the flow of gas between galaxies and the circumgalactic medium (CGM), a halo of metal-enriched gas extending out to $\gtrsim100$ kpc from each galaxy. Studying the spatial structure of the CGM holds promise for understanding these gas flow mechanisms; however, the common method using background quasar sightlines provides minimal spatial information. Recent works have shown the utility of extended background sources such as giant gravitationally lensed arcs. Using background lensed arcs from the CSWA 38 lens system, we continuously probed, at a resolution element of about 15 kpc$^2$, the spatial and kinematic distribution of MgII absorption in a star-forming galaxy at $z=0.77$ (stellar mass $\approx 10^{9.7}$ M$_\odot$, star formation rate $\approx 10$ M$_\odot$ yr$^{-1}$) at impact parameters $D \simeq 5-30$ kpc. Our results present an anisotropic, optically thick medium whose absorption strength decreases with increasing impact parameter, in agreement with the statistics towards quasars and other gravitational arcs. Furthermore, we find generally low line-of-sight velocities in comparison to the relatively high velocity dispersion in the MgII gas (with typical $\sigma\approx 50$ km s$^{-1}$). While the galaxy itself exhibits a clear outflow (with MgII velocities up to $\sim 500$ km s$^{-1}$) in the down-the-barrel spectrum, the outflow component is sub-dominant and only weakly detected at larger impact parameters probed by the background arcs. Our results provide evidence of mainly dispersion-supported, metal-enriched gas recycling through the CGM.
11 citations
TL;DR: In this article, the authors used the T_e method to estimate gas-phase oxygen abundances in five galaxies at z = 7.1-9.1 using the direct T-e method.
Abstract: Physical properties of galaxies at z>7 are of interest for understanding both the early phases of star formation and the process of cosmic reionization. Chemical abundance measurements offer valuable information on the integrated star formation history, and hence ionizing photon production, as well as the rapid gas accretion expected at such high redshifts. We use reported measurements of [O III] 88$\mu$m emission and star formation rate to estimate gas-phase oxygen abundances in five galaxies at z=7.1-9.1 using the direct T_e method. We find typical abundances 12+log(O/H) = 7.9 ($\sim$0.2 times the solar value) and an evolution of 0.9$\pm$0.5 dex in oxygen abundance at fixed stellar mass from z$\simeq$8 to 0. These results are compatible with theoretical predictions, albeit with large (conservative) uncertainties in both mass and metallicity. We assess both statistical and systematic uncertainties to identify promising means of improvement with the Atacama Large Millimeter Array (ALMA) and the James Webb Space Telescope (JWST). In particular we highlight [O III] 52$\mu$m as a valuable feature for robust metallicity measurements. Precision of 0.1-0.2 dex in T_e-based O/H abundance can be reasonably achieved for galaxies at z$\approx$5-8 by combining [O III] 52$\mu$m with rest-frame optical strong lines. It will also be possible to probe gas mixing and mergers via resolved T_e-based abundances on kpc scales. With ALMA and JWST, direct metallicity measurements will thus be remarkably accessible in the reionization epoch.
8 citations
TL;DR: Pelliccia et al. as discussed by the authors found a correlation between the stellar/gas velocity dispersion (σ star, σ gas) and specific star formation rate (sSFR) for galaxies in the lowest mass bin (M ∗ ∼ 1010 M o˙).
Abstract: Author(s): Pelliccia, D; Mobasher, B; Darvish, B; Lemaux, BC; Lubin, LM; Hirtenstein, J; Shen, L; Wu, PF; El-Badry, K; Wetzel, A; Jones, T | Abstract: Recent zoom-in cosmological simulations have shown that stellar feedback can flatten the inner density profile of the dark matter halo in low-mass galaxies. A correlation between the stellar/gas velocity dispersion (σ star, σ gas) and the specific star formation rate (sSFR) is predicted as an observational test of the role of stellar feedback in re-shaping the dark matter density profile. In this work we test the validity of this prediction by studying a sample of star-forming galaxies at 0.6 l z l 1.0 from the LEGA-C survey, which provides high signal-to-noise measurements of stellar and gas kinematics. We find that a weak but significant correlation between σ star (and σ gas) and sSFR indeed exists for galaxies in the lowest mass bin (M ∗ ∼ 1010 M o˙). This correlation, albeit with a ∼35% scatter, holds for different tracers of star formation, and becomes stronger with redshift. This result generally agrees with the picture that at higher redshifts star formation rate was generally higher, and galaxies at M ∗ ≲ 1010 M o˙ have not yet settled into a disk. As a consequence, they have shallower gravitational potentials more easily perturbed by stellar feedback. The observed correlation between σ star (and σ gas) and sSFR supports the scenario predicted by cosmological simulations, in which feedback-driven outflows cause fluctuations in the gravitation potential that flatten the density profiles of low-mass galaxies.
5 citations
TL;DR: In this paper, a correlation between the stellar/gas velocity dispersion and specific star formation rate is predicted as an observational test of the role of stellar feedback in re-shaping the dark matter density profile.
Abstract: Recent zoom-in cosmological simulations have shown that stellar feedback can flatten the inner density profile of the dark matter halo in low-mass galaxies. A correlation between the stellar/gas velocity dispersion ($\sigma_{star}$, $\sigma_{gas}$) and the specific star formation rate (sSFR) is predicted as an observational test of the role of stellar feedback in re-shaping the dark matter density profile. In this work we test the validity of this prediction by studying a sample of star-forming galaxies at $0.6
1 citations