More Like this

1. DUVET: Spatially Resolved Observations of Star Formation Regulation via Galactic Outflows in a Starbursting Disk Galaxy

   https://doi.org/10.3847/1538-4357/aca1bd  

   Reichardt Chu, Bronwyn; Fisher, Deanne B.; Bolatto, Alberto D.; Chisholm, John; Fielding, Drummond; Berg, Danielle; Cameron, Alex J.; Glazebrook, Karl; Herrera-Camus, Rodrigo; Kacprzak, Glenn G.; et al (December 2022, The Astrophysical Journal)

   Abstract We compare 500 pc scale, resolved observations of ionized and molecular gas for thez∼ 0.02 starbursting disk galaxy IRAS08339+6517, using measurements from KCWI and NOEMA. We explore the relationship of the star-formation-driven ionized gas outflows with colocated galaxy properties. We find a roughly linear relationship between the outflow mass flux ( ${\dot{\mathrm{\Sigma }}}_{\mathrm{out}}$) and star formation rate surface density (Σ_SFR), ${\dot{\mathrm{\Sigma }}}_{\mathrm{out}}\propto {\mathrm{\Sigma }}_{\mathrm{SFR}}^{1.06\pm 0.10}$, and a strong correlation between ${\dot{\mathrm{\Sigma }}}_{\mathrm{out}}$and the gas depletion time, such that ${\dot{\mathrm{\Sigma }}}_{\mathrm{out}}\propto t_{\mathrm{dep}}^{-1.1\pm 0.06}$. Moreover, we find these outflows are so-calledbreakoutoutflows, according to the relationship between the gas fraction and disk kinematics. Assuming that ionized outflow mass scales with total outflow mass, our observations suggest that the regions of highest Σ_SFRin IRAS08 are removing more gas via the outflow than through the conversion of gas into stars. Our results are consistent with a picture in which the outflow limits the ability of a region of a disk to maintain short depletion times. Our results underline the need for resolved observations of outflows in more galaxies. 

   more » « less
2. What Does the Geometry of the Hβ BLR Depend On?

   https://doi.org/10.3847/1538-4357/accc84  

   Villafaña, Lizvette; Williams, Peter R.; Treu, Tommaso; Brewer, Brendon J.; Barth, Aaron J.; U, Vivian; Bennert, Vardha N.; Guo, Hengxiao; Bentz, Misty C.; Canalizo, Gabriela; et al (May 2023, The Astrophysical Journal)

   Abstract We combine our dynamical modeling black-hole mass measurements from the Lick AGN Monitoring Project 2016 sample with measured cross-correlation time lags and line widths to recover individual scale factors,f, used in traditional reverberation-mapping analyses. We extend our sample by including prior results from Code for AGN Reverberation and Modeling of Emission Lines (caramel) studies that have utilized our methods. Aiming to improve the precision of black-hole mass estimates, as well as uncover any regularities in the behavior of the broad-line region (BLR), we search for correlations betweenfand other AGN/BLR parameters. We find (i) evidence for a correlation between the virial coefficient ${\log }_{10}\left(f_{\mathrm{mean},\sigma }\right)$and black-hole mass, (ii) marginal evidence for a similar correlation between ${\log }_{10}\left(f_{\mathrm{rms},\sigma }\right)$and black-hole mass, (iii) marginal evidence for an anticorrelation of BLR disk thickness with ${\log }_{10}\left(f_{\mathrm{mean},\mathrm{FWHM}}\right)$and ${\log }_{10}\left(f_{\mathrm{rms},\mathrm{FWHM}}\right)$, and (iv) marginal evidence for an anticorrelation of inclination angle with ${\log }_{10}\left(f_{\mathrm{mean},\mathrm{FWHM}}\right)$, ${\log }_{10}\left(f_{\mathrm{rms},\sigma }\right)$, and ${\log }_{10}\left(f_{\mathrm{mean},\sigma }\right)$. Last, we find marginal evidence for a correlation between line-profile shape, when using the root-mean-square spectrum, ${\log }_{10}{\left(\mathrm{FWHM}/\sigma \right)}_{\mathrm{rms}}$, and the virial coefficient, ${\log }_{10}\left(f_{\mathrm{rms},\sigma }\right)$, and investigate how BLR properties might be related to line-profile shape usingcaramelmodels. 

   more » « less
3. In vivo estimation of anisotropic mechanical properties of the gastrocnemius during functional loading with MR elastography

   https://doi.org/10.1088/1361-6560/acb482  

   Smith, Daniel R; Caban-Rivera, Diego A; Williams, L Tyler; Van_Houten, Elijah_E W; Bayly, Phil V; Paulsen, Keith D; McGarry, Matthew_D J; Johnson, Curtis L (February 2023, Physics in Medicine & Biology)

   Abstract Objective.In vivoimaging assessments of skeletal muscle structure and function allow for longitudinal quantification of tissue health. Magnetic resonance elastography (MRE) non-invasively quantifies tissue mechanical properties, allowing for evaluation of skeletal muscle biomechanics in response to loading, creating a better understanding of muscle functional health.Approach. In this study, we analyze the anisotropic mechanical response of calf muscles using MRE with a transversely isotropic, nonlinear inversion algorithm (TI-NLI) to investigate the role of muscle fiber stiffening under load. We estimate anisotropic material parameters including fiber shear stiffness ( ${\mu }_1$), substrate shear stiffness ( ${\mu }_2$), shear anisotropy ( $\varphi$), and tensile anisotropy ( $\zeta$) of the gastrocnemius muscle in response to both passive and active tension.Main results. In passive tension, we found a significant increase in ${\mu }_1,$ $\varphi ,$and $\zeta$with increasing muscle length. While in active tension, we observed increasing ${\mu }_2$and decreasing $\varphi$and $\zeta$during active dorsiflexion and plantarflexion—indicating less anisotropy—with greater effects when the muscles act as agonist.Significance. The study demonstrates the ability of this anisotropic MRE method to capture the multifaceted mechanical response of skeletal muscle to tissue loading from muscle lengthening and contraction. 

   more » « less
4. Constraining Cosmological Parameters Using the Cluster Mass–Richness Relation

   https://doi.org/10.3847/1538-4357/ace773  

   Abdullah, Mohamed H.; Wilson, Gillian; Klypin, Anatoly; Ishiyama, Tomoaki (September 2023, The Astrophysical Journal)

   Abstract The cluster mass–richness relation (MRR) is an observationally efficient and potentially powerful cosmological tool for constraining the matter density Ω_mand the amplitude of fluctuationsσ₈using the cluster abundance technique. We derive the MRR relation usingGalWCat19, a publicly available galaxy cluster catalog we created from the Sloan Digital Sky Survey-DR13 spectroscopic data set. In the MRR, cluster mass scales with richness as $\log M_{200}=\alpha +\beta \log N_{200}$. We find that the MRR we derive is consistent with both the IllustrisTNG and mini-Uchuu cosmological numerical simulations, with a slope ofβ≈ 1. We use the MRR we derived to estimate cluster masses from theGalWCat19catalog, which we then use to set constraints on Ω_mandσ₈. Utilizing the all-member MRR, we obtain constraints of Ω_m= ${0.31}_{-0.03}^{+0.04}$andσ₈= ${0.82}_{-0.04}^{+0.05}$, and utilizing the red member MRR only, we obtain Ω_m= ${0.31}_{-0.03}^{+0.04}$andσ₈= ${0.81}_{-0.04}^{+0.05}$. Our constraints on Ω_mandσ₈are consistent and very competitive with the Planck 2018 results. 

   more » « less
5. KODIAQ-Z: Metals and Baryons in the Cool Intergalactic and Circumgalactic Gas at 2.2 ≲ z ≲ 3.6

   https://doi.org/10.3847/1538-4357/ac7400  

   Lehner, Nicolas; Kopenhafer, Claire; O’Meara, John M.; Howk, J. Christopher; Fumagalli, Michele; Prochaska, J. Xavier; Acharyya, Ayan; O’Shea, Brian W.; Peeples, Molly S.; Tumlinson, Jason; et al (September 2022, The Astrophysical Journal)

   Abstract We present the KODIAQ-Z survey aimed to characterize the cool, photoionized gas at 2.2 ≲z≲ 3.6 in 202 Hi-selected absorbers with 14.6 ≤ $\log N_{\mathrm{H}\mathrm{I}}$< 20 that probe the interface between galaxies and the intergalactic medium (IGM). We find that gas with $14.6\le \log N_{\mathrm{H}\mathrm{I}}<20$at 2.2 ≲z≲ 3.6 can be metal-rich (−1.6 ≲ [X/H] ≲ − 0.2) as seen in damped Lyαabsorbers (DLAs); it can also be very metal-poor ([X/H] < − 2.4) or even pristine ([X/H] < − 3.8), which is not observed in DLAs but is common in the IGM. For $16<\log N_{\mathrm{H}\mathrm{I}}<20$absorbers, the frequency of pristine absorbers is about 1%–10%, while for $14.6\le \log N_{\mathrm{H}\mathrm{I}}\le 16$absorbers it is 10%–20%, similar to the diffuse IGM. Supersolar gas is extremely rare (<1%) at these redshifts. The factor of several thousand spread from the lowest to highest metallicities and large metallicity variations (a factor of a few to >100) between absorbers separated by less than Δv< 500 km s⁻¹imply that the metals are poorly mixed in $14.6\le \log N_{\mathrm{H}\mathrm{I}}<20$gas. We show that these photoionized absorbers contribute to about 14% of the cosmic baryons and 45% of the cosmic metals at 2.2 ≲z≲ 3.6. We find that the mean metallicity increases withN_Hi, consistent with what is found inz< 1 gas. The metallicity of gas in this column density regime has increased by a factor ∼8 from 2.2 ≲z≲ 3.6 toz< 1, but the contribution of the $14.6\le \log N_{\mathrm{H}\mathrm{I}}<19$absorbers to the total metal budget of the universe atz< 1 is a quarter of that at 2.2 ≲z≲ 3.6. We show that FOGGIE cosmological zoom-in simulations have a similar evolution of [X/H] withN_Hi, which is not observed in lower-resolution simulations. In these simulations, very metal-poor absorbers with [X/H] < − 2.4 atz∼ 2–3 are tracers of inflows, while higher-metallicity absorbers are a mixture of inflows and outflows. 

   more » « less