Astrophysics and Astronomy Commons^™

Measurements Of Charged-Particle Multiplicity Dependence Of Higher-Order Net-Proton Cumulants In 𝑝+𝑝 Collisions At √𝑠 = 200 Gev From Star At Rhic, Star Collaboration

Physics and Astronomy Faculty Publications

We report on the charged-particle multiplicity dependence of net-proton cumulant ratios up to sixth order from√𝑠 = 200 GeV 𝑝+𝑝 collisions at the Relativistic Heavy Ion Collider (RHIC). The measured ratios 𝐶4 ∕𝐶2, 𝐶5 ∕𝐶1, and 𝐶6 ∕𝐶2 decrease with increased charged-particle multiplicity and rapidity acceptance. Neither the Skellam baselines nor PYTHIA8 calculations account for the observed multiplicity dependence. In addition, the ratios 𝐶5 ∕𝐶1 and 𝐶6 ∕𝐶2 approach negative values in the highest-multiplicity events, which implies that thermalized QCD matter may be formed in 𝑝+𝑝 collisions.

Measurements Of The 𝑍0 ∕𝛾∗ Cross Section And Transverse Single Spin Asymmetry In 510 Gev 𝑝+𝑝 Collisions, The Star Collaboration

Physics and Astronomy Faculty Publications

The differential cross section for 𝑍0 production, measured as a function of the boson’s transverse momentum (𝑝T), provides important constraints on the evolution of the transverse momentum dependent parton distribution functions (TMDs). The transverse single spin asymmetry (TSSA) of the 𝑍0 is sensitive to one of the polarized TMDs, the Sivers function, which is predicted to have the opposite sign in 𝑝 + 𝑝 → 𝑊 ∕𝑍 + 𝑋 from that which enters in semi-inclusive deep inelastic scattering. In this Letter, the STAR Collaboration reports the first measurement of the 𝑍0 ∕𝛾∗ differential cross section as a function of its …

Measurement Of Flow Coefficients In High-Multiplicity P + Au, D + Au, And 3 He + Au Collisions At √S Nn = 200 Gev, Star Collaboration

Physics and Astronomy Faculty Publications

Flow coefficients (v2 and v3 ) are measured in high-multiplicity p + Au, d + Au, and 3 He + Au collisions at a center-of-mass energy of √s NN = 200 GeV using the STAR detector. The measurements utilize two-particle correlations with a pseudorapidity requirement of |η| < 0.9 and a pair gap of |Δη| > 1.0. The primary focus is on analysis methods, particularly the subtraction of nonflow contributions. Four established nonflow subtraction methods are applied to determine vn, validated using the HIJING event generator. vn values are compared across the three collision systems at similar multiplicities; this comparison cancels the final-state effects and isolates the …

Reaction Plane Correlated Triangular Flow In Au+Au Collisions At √S Nn = 3 Gev, Star Collaboration

Physics and Astronomy Faculty Publications

We measure triangular flow relative to the reaction plane at 3 GeV center-of-mass energy in Au+Au collisions at the BNL Relativistic Heavy Ion Collider. A significant v3 signal for protons is observed, which increases for higher rapidity, higher transverse momentum, and more peripheral collisions. The triangular flow is essentially rapidity-odd with a slope at midrapidity, dv3/dy|(y=0), opposite in sign compared to the slope for directed flow. No significant v3 signal is observed for charged pions and kaons. Comparisons with models suggest that a mean field potential is required to describe these results, and that the triangular shape of the participant …

Results On Elastic Cross Sections In Proton–Proton Collisions At √𝑠 = 510 Gev With The Star Detector At Rhic, The Star Collaboration

Physics and Astronomy Faculty Publications

We report results on an elastic cross section measurement in proton–proton collisions at a center-of-mass energy√𝑠 = 510 GeV, obtained with the Roman Pot setup of the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The elastic differential cross section is measured in the four-momentum transfer squared range 0.23 ≤ −𝑡 ≤ 0.67 GeV2. This is the only measurement of the proton-proton elastic cross section in this 𝑡 range for collision energies above the Intersecting Storage Rings (ISR) and below the Large Hadron Collider (LHC) colliders. We find that a constant slope 𝐵 does not fit the data in …

Upper Limit On The Chiral Magnetic Effect In Isobar Collisions At The Relativistic Heavy-Ion Collider, Star Collaboration

Physics and Astronomy Faculty Publications

The chiral magnetic effect (CME) is a phenomenon that arises from the QCD anomaly in the presence of an external magnetic field. The experimental search for its evidence has been one of the key goals of the physics program of the Relativistic Heavy-Ion Collider. The STAR Collaboration has previously presented the results of a blind analysis of isobar collisions (96 44 Ru + 96 44 Ru, 96 40 Zr + 96 40 Zr) in the search for the CME. The isobar ratio (Y ) of CME-sensitive observable, charge separation scaled by elliptic anisotropy, is close to but systematically larger than …

Production Of Protons And Light Nuclei In Au+Au Collisions At √S Nn = 3 Gev With The Star Detector, Star Collaboration

Physics and Astronomy Faculty Publications

We report the systematic measurement of protons and light nuclei production in Au+Au collisions at √s NN = 3 GeV by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The transverse momentum (pT ) spectra of protons (p), deuterons (d), tritons (t), 3 He, and 4 He have been measured from midrapidity to target rapidity for different collision centralities. We present the rapidity and centrality dependence of particle yields (dN/dy), average transverse momentum (〈pT 〉), yield ratios (d/p, t/p, 3 He /p, 4 He /p), as well as the coalescence parameters (B2 , B3 ). The 4π yields …

Performance Optimization For A Scintillating Glass Electromagnetic Calorimeter At The Eic, J. Crafts, Renee H. Fatemi, T. Horn, D. Kalinkin

Physics and Astronomy Faculty Publications

The successful realization of the EIC scientific program requires the design and construction of high-performance particle detectors. Recent developments in the field of scientific computing and increased availability of high performance computing resources have made it possible to perform optimization of multi-parameter designs, even when the latter require longer computational times (for example simulations of particle interactions with matter). Procedures involving machine-assisted techniques used to inform the design decision have seen a considerable growth in popularity among the EIC detector community. Having already been realized for tracking and RICH PID detectors, it has a potential application in calorimetry designs. A …

Advanced Thermoluminescence Spectroscopy As A Research Tool For Semiconductor And Photonic Materials: A Review And Perspective, Farida Selim

Physics and Astronomy Faculty Publications

Thermoluminescence (TL) or thermally stimulated luminescence (TSL) spectroscopy is based on liberating charge carriers from traps in the bandgap by providing enough thermal energy to overcome the potential barrier of the traps. It provides a powerful tool to measure the positions of the localized states/traps in the bandgap. Despite that, its applications in semiconductors are very limited. Herein, the basics of TL spectroscopy and the recent advances in the technique with focus on cryogenic thermally stimulated photoemission spectroscopy (C-TSPS) which extends TL measurements to cryogenic regime and allows the detection of very low concentrations of shallow and deep localized states …

Jwst/Nirspec Measurements Of The Relationships Between Nebular Emission-Line Ratios And Stellar Mass At Z ∼ 3–6, Alice E. Shapley, Naveen Reddy, Ryan L. Sanders, Michael W. Topping, Gabriel B. Brammer

Physics and Astronomy Faculty Publications

We analyze the rest-optical emission-line ratios of star-forming galaxies at 2.7 ≤ z < 6.5 drawn from the Cosmic Evolution Early Release Science (CEERS) Survey and their relationships with stellar mass (M _*). Our analysis includes both line ratios based on the [N ii] λ6583 feature ([N ii] λ6583/Hα, ([O iii] λ5007/Hβ)/([N ii] λ6583/Hα) (O3N2), and [N ii] λ6583/[O ii] λ3727) and those featuring α-elements ([O iii] λ5007/Hβ, [O iii] λ5007/[O ii] λ3727 (O₃₂), ([O iii] λλ4959, 5007 + [O ii] λ3727)/Hβ (R₂₃), and [Ne iii] λ3869/[O ii] λ3727). Given the typical flux levels of [N ii] λ6583 and [Ne iii] λ3869, which are undetected in the majority of individual CEERS galaxies at 2.7 …

Higher-Order Cumulants And Correlation Functions Of Proton Multiplicity Distributions In √Snn = 3 Gev Au+Au Collisions At The Rhic Star Experiment, The Star Collaboration

Physics and Astronomy Faculty Publications

We report a measurement of cumulants and correlation functions of event-by-event proton multiplicity distributions from fixed-target Au+Au collisions at √sNN = 3 GeV measured by the STAR experiment. Protons are identified within the rapidity (y) and transverse momentum (pT ) region −0.9 < y < 0 and 0.4 < pT < 2.0 GeV/c in the center-of-mass frame. A systematic analysis of the proton cumulants and correlation functions up to sixth order as well as the corresponding ratios as a function of the collision centrality, pT , and y are presented. The effect of pileup and initial volume fluctuations on these observables and the respective corrections are discussed in detail. The results are compared to calculations from the hadronic transport UrQMD model as well as a hydrodynamic model. In the most central 5% collisions, the value of proton cumulant ratio C4/C2 is negative, drastically different from the values observed in Au+Au collisions at higher energies. Compared to model calculations including lattice QCD, a hadronic transport model, and a hydrodynamic model, the strong suppression in the ratio of C4/C2 at 3 GeV Au+Au collisions indicates an energy regime dominated by hadronic interactions.

Azimuthal Anisotropy Measurement Of (Multi)Strange Hadrons In Au+Au Collisions At √S Nn = 54.4 Gev, Star Collaboration

Physics and Astronomy Faculty Publications

Azimuthal anisotropy of produced particles is one of the most important observables used to access the collective properties of the expanding medium created in relativistic heavy-ion collisions. In this paper, we present second (v2) and third (v3) order azimuthal anisotropies of KS0, φ, Λ, Ξ, and ω at midrapidity (|y|< 1) in Au+Au collisions at sNN=54.4 GeV measured by the STAR detector. The v2 and v3 are measured as a function of transverse momentum and centrality. Their energy dependence is also studied. v3 is found to be more sensitive to the change in the center-of-mass energy than v2. Scaling by constituent quark number is found to hold for v2 within 10%. This observation could be evidence for the development of partonic collectivity in 54.4 GeV Au+Au collisions. Differences in v2 and v3 between baryons and antibaryons are presented, and ratios of v3/v23/2 are studied and motivated by hydrodynamical calculations. The ratio of v2 of φ mesons to that of antiprotons [v2(φ)/v2(p¯)] shows centrality dependence at low transverse momentum, presumably resulting from the larger effects from hadronic interactions on antiproton v2.

Gauging The Mass Of Metals In The Gas Phase Of Galaxies From The Local Universe To The Epoch Of Reionization, K. E. Heintz, Alice E. Shapley, Ryan L. Sanders, M. Killi, D. Watson, G. Magdis, F. Valentino, M. Ginolfi, D. Narayanan, T. R. Greve, J. P. U. Fynbo, D. Vizgan, S. N. Wilson

Physics and Astronomy Faculty Publications

The chemical enrichment of dust and metals are vital processes in constraining the star formation history of the universe. These are important ingredients in the formation and evolution of galaxies overall. Previously, the dust masses of high-redshift star-forming galaxies have been determined through their far-infrared continuum, however, equivalent, and potentially simpler, approaches to determining the metal masses have yet to be explored at z ≳ 2. Here, we present a new method of inferring the metal mass in the interstellar medium (ISM) of galaxies out to z 8, using the far-infrared [C II]- 158† μm emission line as a proxy. …

Jwst/Nirspec Balmer-Line Measurements Of Star Formation And Dust Attenuation At Z ∼ 3–6, Alice E. Shapley, Ryan L. Sanders, Naveen Reddy, Michael W. Topping, Gabriel B. Brammer

Physics and Astronomy Faculty Publications

We present an analysis of the star formation rates (SFRs) and dust attenuation properties of star-forming galaxies at 2.7 ≤ z < 6.5 drawn from the Cosmic Evolution Early Release Science Survey. Our analysis is based on JWST/NIRSpec Micro-Shutter Assembly R ∼ 1000 spectroscopic observations covering approximately 1-5 μm. Our primary rest-frame optical spectroscopic measurements are Hα/Hβ Balmer decrements, which we use as an indicator of nebular dust attenuation. In turn, we use Balmer decrements to obtain dust-corrected Hα-based SFRs (i.e., SFR(Hα)). We construct the relationship between SFR(Hα) and stellar mass (M _*) in three bins of redshift (2.7 ≤ z < 4.0, 4.0 ≤ z < 5.0, and 5.0 ≤ z < 6.5), which represents the first time the star-forming main sequence has been traced at these redshifts using direct spectroscopic measurements of Balmer emission as a proxy for SFR. In tracing the relationship between SFR(Hα) and M _* back to such early times (z > 3), it is essential to use a conversion factor between Hα and SFR that accounts for the subsolar metallicity prevalent among distant galaxies. We also use measured Balmer decrements to investigate the relationship between dust attenuation and stellar mass out to z ∼ 6. The lack of significant redshift evolution in attenuation at fixed stellar mass, previously confirmed using Balmer decrements out …

Azimuthal Anisotropy Measurement Of (Multi)Strange Hadrons In Au+Au Collisions At √𝑠𝑁⁢𝑁=54.4 Gev, Star Collaboration

Physics and Astronomy Faculty Publications

Azimuthal anisotropy of produced particles is one of the most important observables used to access the collective properties of the expanding medium created in relativistic heavy-ion collisions. In this paper, we present second (v2) and third (v3) order azimuthal anisotropies of KS0, φ, Λ, Ξ, and ω at midrapidity (|y|< 1) in Au+Au collisions at sNN=54.4 GeV measured by the STAR detector. The v2 and v3 are measured as a function of transverse momentum and centrality. Their energy dependence is also studied. v3 is found to be more sensitive to the change in the center-of-mass energy than v2. Scaling by constituent quark number is found to hold for v2 within 10%. This observation could be evidence for the development of partonic collectivity in 54.4 GeV Au+Au collisions. Differences in v2 and v3 between baryons and antibaryons are presented, and ratios of v3/v23/2 are studied and motivated by hydrodynamical calculations. The ratio of v2 of φ mesons to that of antiprotons [v2(φ)/v2(p¯)] shows centrality dependence at low transverse momentum, presumably resulting from the larger effects from hadronic interactions on antiproton v2.

Beam Energy Dependence Of Fifth- And Sixth-Order Net-Proton Number Fluctuations In Au + Au Collisions At Rhic, Star Collaboration

Physics and Astronomy Faculty Publications

We report the beam energy and collision centrality dependence of fifth and sixth order cumulants (C5, C6) and factorial cumulants (κ5, κ6) of net-proton and proton number distributions, from center-of-mass energy (sNN) 3 GeV to 200 GeV Au+Au collisions at RHIC. Cumulant ratios of net-proton (taken as proxy for net-baryon) distributions generally follow the hierarchy expected from QCD thermodynamics, except for the case of collisions at 3 GeV. The measured values of C6/C2 for 0%-40% centrality collisions show progressively negative trend with decreasing energy, while it is positive for the lowest energy studied. These observed negative signs are consistent with …

Measurement Of Sequential ϒ Suppression In Au + Au Collisions At √Snn = 200 Gev With The Star Experiment, Star Collaboration

Physics and Astronomy Faculty Publications

We report on measurements of sequential ϒ suppression in Au+Au collisions at sNN=200 GeV with the STAR detector at the Relativistic Heavy Ion Collider (RHIC) through both the dielectron and dimuon decay channels. In the 0%-60% centrality class, the nuclear modification factors (RAA), which quantify the level of yield suppression in heavy-ion collisions compared to p+p collisions, for ϒ(1S) and ϒ(2S) are 0.40±0.03(stat)±0.03(sys)±0.09(norm) and 0.26±0.08(stat)±0.02(sys)±0.06(norm), respectively, while the upper limit of the ϒ(3S) RAA is 0.17 at a 95% confidence level. This provides experimental evidence that the ϒ(3S) is significantly more suppressed than the ϒ(1S) at RHIC. The level of …

Measurementus Magnetic Moment To 0.20 Ppm Of The Positive Muon Anomalo, The Muon G − 2 Collaboration

Physics and Astronomy Faculty Publications

We present a new measurement of the positive muon magnetic anomaly, aμ(gμ-2)/2, from the Fermilab Muon g-2 Experiment using data collected in 2019 and 2020. We have analyzed more than 4 times the number of positrons from muon decay than in our previous result from 2018 data. The systematic error is reduced by more than a factor of 2 due to better running conditions, a more stable beam, and improved knowledge of the magnetic field weighted by the muon distribution, p′, and of the anomalous precession frequency corrected for beam dynamics effects, ωa. From the ratio ωa/p′, together with precisely …

Ai-Assisted Optimization Of The Ecce Tracking System At The Electron Ion Collider, C. Fanelli, Z. Papandreou, K. Suresh

Physics and Astronomy Faculty Publications

The Electron-Ion Collider (EIC) is a cutting-edge accelerator facility that will study the nature of the ‘‘glue’’ that binds the building blocks of the visible matter in the universe. The proposed experiment will be realized at Brookhaven National Laboratory in approximately 10 years from now, with detector design and R&D currently ongoing. Notably, EIC is one of the first large-scale facilities to leverage Artificial Intelligence (AI) already starting from the design and R&D phases. The EIC Comprehensive Chromodynamics Experiment (ECCE) is a consortium that proposed a detector design based on a 1.5 T solenoid. The EIC detector proposal review concluded …

Scientific Computing Plan For The Ecce Detector At The Electron Ion Collider, J. C. Bernauer, C. T. Dean, C. Fanelli, J. Huang, K. Kauder, D. Lawrence, J. D. Osborn

Physics and Astronomy Faculty Publications

The Electron Ion Collider (EIC) is the next generation of precision QCD facility to be built at Brookhaven National Laboratory in conjunction with Thomas Jefferson National Laboratory. There are a significant number of software and computing challenges that need to be overcome at the EIC. During the EIC detector proposal development period, the ECCE consortium began identifying and addressing these challenges in the process of producing a complete detector proposal based upon detailed detector and physics simulations. In this document, the software and computing efforts to produce this proposal are discussed; furthermore, the computing and software model and resources required …

Paschen-Line Constraints On Dust Attenuation And Star Formation At Z ∼ 1–3 With Jwst/ Nirspec, Naveen Reddy, Michael W. Topping, Ryan L. Sanders, Alice E. Shapley, Gabriel B. Brammer

Physics and Astronomy Faculty Publications

We use medium-resolution JWST/NIRSpec observations from the Cosmic Evolution Early Release Science Survey to place the first constraints on dust attenuation and star formation based on Paschen lines for a sizable sample of 63 galaxies at redshifts z = 1.0-3.1. Our analysis indicates strong correlations between the Balmer decrement, Hα/Hβ, and line ratios that include Paschen lines (i.e., Paα/Hβ, Paβ/Hβ, and the Paschen decrement, Paα/Paβ), suggesting that the former is sensitive to the overall dust obscuration toward H ii regions in high-redshift galaxies. The line ratios are used to derive nebular reddening, E(B − V)_neb, and star formation …

The Gas And Stellar Content Of A Metal-Poor Galaxy At Z = 8.496 As Revealed By Jwst And Alma, K. E. Heintz, C. Giménez-Arteaga, S. Fujimoto, Gabriel B. Brammer, D. Espada, S. Gillman, J. González-López, T. R. Greve, Yuichi Harikane, B. Hatsukade, K. K. Knudsen, Anton M. Koekemoer, K. Kohno, V. Kokorev, M. M. Lee, Georgios E. Magdis, E. J. Nelson, F. Rizzo, Ryan L. Sanders, D. Schaerer, Alice E. Shapley, V. B. Strait, S. Toft, F. Valentino, A. Van Der Wel, A. P. Vijayan, D. Watson, F. E. Bauer, Amber Christiansen, C. R. Christiansen, S. N. Wilson

Physics and Astronomy Faculty Publications

We present a joint analysis of the galaxy S04590 at z = 8.496 based on NIRSpec, NIRCam, and NIRISS observations obtained as part of the Early Release Observations program of the James Webb Space Telescope (JWST) and the far-infrared [C ii] 158 μm emission line detected by dedicated Atacama Large Millimeter/submillimeter Array (ALMA) observations. We determine the physical properties of S04590 from modeling of the spectral energy distribution (SED) and through the redshifted optical nebular emission lines detected with JWST/NIRSpec. The best-fit SED model reveals a low-mass (M _⋆ = 10^7.2-10⁸ M _⊙) galaxy with a …

A Jwst/Nirspec Exploration Of The Connection Between Ionization Parameter, Electron Density, And Star-Formation-Rate Surface Density In Z = 2.7–6.3 Galaxies, Naveen Reddy, Michael W. Topping, Ryan L. Sanders, Alice E. Shapley, Gabriel B. Brammer

Physics and Astronomy Faculty Publications

We examine the factors responsible for the variation in the ionization parameter (U) of high-redshift star-forming galaxies based on medium-resolution JWST/NIRSpec observations obtained by the Cosmic Evolution Early Release Science survey. The sample consists of 48 galaxies with redshifts zspec = 2.7−6.3, which are largely representative of typical galaxies at these redshifts. The [S II] λλ6718, 6733 doublet is used to estimate electron densities (n e), and dust-corrected Hα luminosities are used to compute ionizing photon rates (Q). Using composite spectra of galaxies in bins of [O III] λλ4960, 5008/[O II] λλ3727, 3730 (O32) as a proxy for U, we …

An Updated Dust-To-Star Geometry: Dust Attenuation Does Not Depend On Inclination In 1.3 <= Z <= 2.6 Star-Forming Galaxies From Mosdef, Brian Lorenz, Mariska Kriek, Alice E. Shapley, Naveen Reddy, Ryan L. Sanders, Guillermo Barro, Alison L. Coil, Bahram Mobasher, Sedona H. Price, Jordan N. Runco, Irene Shivaei, Brian Siana, Daniel R. Weisz

Physics and Astronomy Faculty Publications

We investigate dust attenuation and its dependence on viewing angle for 308 star-forming galaxies at 1.3 < = z < = 2.6 from the MOSFIRE Deep Evolution Field survey. We divide galaxies with a detected Hα emission line and coverage of Hβ into eight groups by stellar mass, star formation rate (SFR), and inclination (i.e., axis ratio), and we then stack their spectra. From each stack, we measure the Balmer decrement and gas-phase metallicity, and then we compute the median AV and UV continuum spectral slope (β). First, we find that none of the dust properties (Balmer decrement, AV , or β) varies with the axis ratio. Second, both stellar and nebular attenuation increase with increasing galaxy mass, showing little residual dependence on SFR or metallicity. Third, nebular emission is more attenuated than stellar emission, and this difference grows even larger at higher galaxy masses and SFRs. Based on these results, we propose a three-component dust model in which attenuation predominantly occurs in star-forming regions and large, dusty star-forming clumps, with minimal attenuation in the diffuse ISM. In this model, nebular attenuation primarily originates in clumps, while stellar attenuation is dominated by star-forming regions. Clumps become larger and more common with increasing galaxy mass, creating the above mass trends. Finally, we argue that a fixed metal yield naturally leads to mass regulating dust attenuation. Infall of low-metallicity gas increases the SFR and lowers the metallicity, but leaves the dust column density mostly unchanged. We quantify this idea using the Kennicutt–Schmidt and fundamental metallicity relations, showing that galaxy mass is indeed the primary driver of dust attenuation.

A Preview Of Jwst Metallicity Studies At Cosmic Noon: The First Detection Of Auroral [O Ii] Emission At High Redshift, Ryan L. Sanders, Alice E. Shapley, Leonardo Clarke, Michael W. Topping, Naveen Reddy, Mariska Kriek, Tucker Jones, Daniel P. Stark, Mengtao Tang

Physics and Astronomy Faculty Publications

We present ultradeep Keck/MOSFIRE rest-optical spectra of two star-forming galaxies at z = 2.18 in the COSMOS field with bright emission lines, representing more than 20 hr of total integration. The fidelity of these spectra enabled the detection of more than 20 unique emission lines for each galaxy, including the first detection of the auroral [O II]λλ7322, 7332 lines at high redshift. We use these measurements to calculate the electron temperature in the low-ionization O+ zone of the ionized interstellar medium and derive abundance ratios of O/H, N/H, and N/O using the direct method. The N/O and α/Fe abundance patterns …

Early Results From Glass–Jwst. Xxi. Rapid Asembly Of A Galaxy At Z = 6.23 Revealed By Its C/O Abundance, Tucker Jones, Ryan L. Sanders, Yuguang Chen, Xin Wang, Takahiro Morishita, Guido Roberts-Borsani, Tommaso Treu, Alan Dressler, Emiliano Merlin, Diego Paris, Paola Santini, Pietro Bergamini, A. Henry, Erin Huntzinger, Themiya Nanayakkara, Kristan Boyett, Marusa Bradac, Gabriel B. Brammer, Antonello Calabró, Karl Glazebrook, Kathryn Grasha, Sara Mascia, Laura Pentericci, Michele Trenti, Benedetta Vulcani

Physics and Astronomy Faculty Publications

The abundance of carbon relative to oxygen (C/O) is a promising probe of star formation history in the early universe, as the ratio changes with time due to production of these elements by different nucleosynthesis pathways. We present a measurement of log ( C / O ) = − 1.01 ± 0.12 (stat) ±0.15 (sys) in a z = 6.23 galaxy observed as part of the GLASS-JWST Early Release Science Program. Notably, we achieve good precision thanks to the detection of the rest-frame ultraviolet O iii], C iii], and C iv emission lines delivered by JWST/NIRSpec. The C/O abundance is …

Co Emission, Molecular Gas, And Metallicity In Main-Sequence Star-Forming Galaxies At Z ∼ 2.3, Ryan L. Sanders, Alice E. Shapley, Tucker Jones, Irene Shivaei, Gergö Popping, Naveen Reddy, Romeel Davé, Sedona H. Price, Bahram Mobasher, Mariska Kriek, Alison L. Coil, Brian Siana

Physics and Astronomy Faculty Publications

We present observations of CO(3−2) in 13 main-sequence z = 2.0-2.5 star-forming galaxies at log ( M * / M ⊙ ) = 10.2 - 10.6 that span a wide range in metallicity (O/H) based on rest-optical spectroscopy. We find that L CO ( 3 − 2 ) ′ /SFR decreases with decreasing metallicity, implying that the CO luminosity per unit gas mass is lower in low-metallicity galaxies at z ∼ 2. We constrain the CO-to-H₂ conversion factor (α _CO) and find that α _CO inversely correlates with metallicity at z ∼ 2. We derive molecular gas masses …

The Art Of Measuring Physical Parameters In Galaxies: A Critical Assessment Of Spectral Energy Distribution Fitting Techniques, Camilla Pacifici, Kartheik G. Iyer, Bahram Mobasher, Elisabete Da Cunha, Viviana Acquaviva, Denis Burgarella, Gabriela Calistro Rivera, Adam C. Carnall, Yu-Yen Chang, Nima Chartab, Kevin C. Cooke, Ciaran Fairhurst, Jeyhan Kartaltepe, Joel Leja, Katarzyna Małek, Brett Salmon, Marianna Torelli, Alba Vidal-García, Médéric Boquien, Gabriel B. Brammer, Michael J. I. Brown, Peter L. Capak, Jacopo Chevallard, Chiara Circosta, Darren Croton, Iary Davidzon, Mark Dickinson, Kenneth J. Duncan, Sandra M. Faber, Harry C. Ferguson, Adriano Fontana, Yicheng Guo, Boris Haeussler, Shoubaneh Hemmati, Marziye Jafariyazani, Susan A. Kassin, Rebecca L. Larson, Bomee Lee, Kameswara Bharadwaj Mantha, Francesca Marchi, Hooshang Nayyeri, Jeffrey A. Newman, Viraj Pandya, Janine Pforr, Naveen Reddy, Ryan L. Sanders, Ekta Shah, Abtin Shahidi, Matthew L. Stevans, Dian Puspita Triani, Krystal D. Tyler, Brittany N. Vanderhoof, Alexander De La Vega, Weichen Wang, Madalyn E. Weston

Physics and Astronomy Faculty Publications

The study of galaxy evolution hinges on our ability to interpret multiwavelength galaxy observations in terms of their physical properties. To do this, we rely on spectral energy distribution (SED) models, which allow us to infer physical parameters from spectrophotometric data. In recent years, thanks to wide and deep multiwave band galaxy surveys, the volume of high-quality data have significantly increased. Alongside the increased data, algorithms performing SED fitting have improved, including better modeling prescriptions, newer templates, and more extensive sampling in wavelength space. We present a comprehensive analysis of different SED-fitting codes including their methods and output with the …

The Dust-To-Gas Mass Ratio Of Luminous Galaxies As A Function Of Their Metallicity At Cosmic Noon, Gergö Popping, Irene Shivaei, Ryan L. Sanders, Tucker Jones, Alexandra Pope, Naveen Reddy, Alice E. Shapley, Alison L. Coil, Mariska Kriek

Physics and Astronomy Faculty Publications

Aims. We aim to quantify the relation between the dust-to-gas mass ratio (DTG) and gas-phase metallicity of z = 2.1-2.5 luminous galaxies and contrast this high-redshift relation against analogous constraints at z = 0.

Methods. We present a sample of ten star-forming main-sequence galaxies in the redshift range 2.1 < z < 2.5 with rest-optical emission-line information available from the MOSDEF survey and with ALMA 1.2 millimetre and CO J = 3-2 follow-up observations. The galaxies have stellar masses ranging from 1010.3 to 1010.6 M? and cover a range in star-formation rate from 35 to 145 M? yr-1. We calculated the gas-phase oxygen abundance of these galaxies from rest-optical nebular emission lines (8.4 < 12+log (O=H) < 8.8, corresponding to 0.5..1.25 Z?). We estimated the dust and H2 masses of the galaxies (using a metallicity-dependent CO-to-H2 conversion factor) from the 1.2mm and CO J = 3..2 observations, respectively, from which we estimated a DTG.

Results. We find that the galaxies in this sample follow the trends already observed between CO line luminosity and dust-continuum luminosity from z = 0 to z = 3, extending such trends to fainter galaxies at 2.1 < z < 2.5 than observed to date. We find no second-order metallicity dependence in the CO - dust-continuum luminosity relation for the galaxies presented in this work. The DTGs of main-sequence galaxies at 2.1 < z < 2.5 are consistent with an increase in the DTG with gas-phase metallicity. The metallicity dependence of the DTG is driven by the metallicity dependence of the CO-to-H2 conversion factor. Galaxies at z = 2.1-2.5 are furthermore consistent with the DTG-metallicity relation found at z = 0 (i.e. with no significant evolution), providing relevant constraints for galaxy formation models. These results furthermore imply that the metallicity of galaxies should be taken into account when estimating cold-gas masses from dust-continuum emission, which is especially relevant when studying metal-poor low-mass or high-redshift galaxies.

Resolved Velocity Profiles Of Galactic Winds At Cosmic Noon, Keerthi Vasan G. C., Tucker Jones, Ryan L. Sanders, Richard S. Ellis, Daniel P. Stark, Glenn G. Kacprzak, Tania M. Barone, Kim-Vy H. Tran, Karl Glazebrook, Colin Jacobs

Physics and Astronomy Faculty Publications

We study the kinematics of the interstellar medium (ISM) viewed “down the barrel” in 20 gravitationally lensed galaxies during cosmic noon (z = 1.5-3.5). We use moderate-resolution spectra (R ∼ 4000) from Keck’s Echellette Spectrograph and Imager and Magellan/MagE to spectrally resolve the ISM absorption in these galaxies into ∼10 independent elements and use double Gaussian fits to quantify the velocity structure of the gas. We find that the bulk motion of gas in this galaxy sample is outflowing, with average velocity centroid v cent = − 141 km s⁻¹ (±111 km s⁻¹ scatter) measured with respect to …