Trident: A Universal Tool for Generating Synthetic Absorption Spectra from Astrophysical Simulations

Hummels, Cameron B.; Smith, Britton D.; Silvia, Devin W.

doi:10.3847/1538-4357/aa7e2d

Cited by 89 publications

(82 citation statements)

References 87 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In particular, observations find an abundance of OVI in the CGM of galaxies of a range of masses, only well matched in simulations at high galaxy masses above 10 10.5 M [149]. Other simulations post-process their outputs with Trident [150] to produce mock absorption line profiles and compare them with quasar absorption line observations. The predicted CGM column densities and covering fractions of ions such as OVI depend on the models of star formation and stellar feedback (see Fig.…”

Section: Simulating Line Absorption From the Cgmmentioning

confidence: 95%

Challenges and Techniques for Simulating Line Emission

et al. 2018

View full text Add to dashboard Cite

Modeling emission lines from the millimeter to the UV and producing synthetic spectra is crucial for a good understanding of observations, yet it is an art filled with hazards. This is the proceedings of "Walking the Line", a 3-day conference held in 2018 that brought together scientists working on different aspects of emission line simulations, in order to share knowledge and discuss the methodology. Emission lines across the spectrum from the millimeter to the UV were discussed, with most of the focus on the interstellar medium, but also some topics on the circumgalactic medium. The most important quality of a useful model is a good synergy with observations and experiments. Challenges in simulating line emission are identified, some of which are already being worked upon, and others that must be addressed in the future for models to agree with observations. Recent advances in several areas aiming at achieving that synergy are summarized here, from micro-physical to galactic and circum-galactic scale.2 of 29 us to characterize the mass, composition, and chemical state of the ISM, as well as to trace galaxy properties such as star formation rate (SFR), metallicity and dynamics. For example, the emission from major cooling lines, such as Hα or [C II], is sensitive to the physical conditions (densities, radiation field) and dynamics of the ISM. In addition, emission lines work on all physical scales, from galaxy dynamics and inflows to turbulent and collapse motions in star-forming clouds and cores. By systematically comparing spectral-line signatures of different physical models, one can correctly identify the physical processes occurring in these regions. Furthermore, the emission from ionized interstellar gas contains particularly valuable information about the nature of the ionizing radiation sources in a galaxy. In fact, prominent optical emission lines are routinely used to estimate whether ionization is dominated by young massive stars (tracing SFR), an AGN or evolved, post-asymptotic giant branch (post-AGB) stars. Three of the most widely used line-ratio diagnostic "BPT" diagrams 1 , relate the [OIII]/Hβ ratio to the [NII]/Hα, [SII]/Hα and [OI]/Hα ratios. These diagrams have proven useful in identifying the nature of the ionizing radiation in large samples of galaxies in the local Universe [2,3]. Complementary to line emission are the observations of absorption lines of the circumgalactic medium (CGM), which can give key information on the history of the feedback, in terms of chemical, ionization, and thermodynamical state of the outflowing/inflowing gas, that regulates the star formation process. Gas kinematics, from both emission and absorption, give information about large scale gas flows. Thus galactic outflows, from active galactic nuclei (AGN) and starbursts, can be combined with CGM absorption line observations, to study the star formation history, AGN activity history, and feedback processes that regulate both the evolution of the galaxy and its environment.Looking back on the past three decades, t...

show abstract

Section: Simulating Line Absorption From the Cgmmentioning

confidence: 95%

Challenges and Techniques for Simulating Line Emission

et al. 2018

View full text Add to dashboard Cite

show abstract

“…We now explore the possible physical conditions of the Ne viii-traced material by employing collisional-and photoionization models across phase space to estimate total masses and characteristic lengths for the absorbing medium. For all calculations, we use a high-resolution grid 2 of Cloudy (Ferland et al 2013) ionization models provided by the Trident team (Hummels et al 2017) assuming Z = Z and the extragalactic UV background of Haardt & Madau (2012) at z = 0.7; the ion fractions from this grid are shown in the upper left panel of Figure 5. Varying metallicity has a minor impact on the equilibrium ionization balance of individual ions that we employ here.…”

Section: The Physical Conditions Of Ne Viii-traced Gasmentioning

confidence: 99%

The COS Absorption Survey of Baryon Harbors (CASBaH): Warm–Hot Circumgalactic Gas Reservoirs Traced by Ne viii Absorption

Burchett

Tripp²,

Prochaska

et al. 2019

ApJL

View full text Add to dashboard Cite

We survey the highly ionized circumgalactic media (CGM) of 29 blindly selected galaxies at 0.49 < z gal < 1.44 based on high-S/N ultraviolet spectra of z 1 QSOs and the galaxy database from the COS Absorption Survey of Baryon Harbors (CASBaH). We detect the Ne VIII doublet in nine of the galaxies, and for gas with N (Ne viii) > 10 13.3 cm −2 (> 10 13.5 cm −2 ), we derive a Ne viii covering fraction f c = 75 +15 −25 % (44 +22 −20 %) within impact parameter ρ ≤ 200 kpc of M * = 10 9.5−11.5 M galaxies and f c = 70 +16−22 % (f c = 42 +20 −17 %) within ρ ≤ 1.5 virial radii. We estimate the mass in Ne viii-traced gas to be M gas (Ne viii) ≥ 10 9.5 M (Z/Z ) −1 , or 6-20% of the expected baryonic mass if the Ne viii absorbers have solar metallicity. Ionizing Ne vii to Ne viii requires 207 eV, and photons with this energy are scarce in the CGM. However, for the median halo mass and redshift of our sample, the virial temperature is close to the peak temperature for the Ne viii ion, and the Ne viii-bearing gas

show abstract

“…Our intent is to provide a proof-of-concept level of analysis while sampling various regions throughout the cluster, as would be probed in an actual absorption-line spectroscopic survey using sightlines piercing galaxy clusters. Using Trident (Hummels et al 2017, discussed in §2.2), we extracted sixteen sightlines through the RomulusC cluster; the sightline locations are indicated in Figure 8. The sightlines were chosen to pass through ambient ICM regions far away from infalling galaxies, the immediate CGM of cluster galaxies, and detritus stripped as galaxies fall into the cluster.…”

Section: The Physical Conditions Of Cool and Warm Gas In The Icm Frommentioning

confidence: 99%

Ultraviolet signatures of the multiphase intracluster and circumgalactic media in the romulusc simulation

Butsky

Burchett

Nagai

et al. 2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Quasar absorption-line studies in the ultraviolet (UV) can uniquely probe the nature of the multiphase cool-warm (10 4 < T < 10 6 K) gas in and around galaxy clusters, promising to provide unprecedented insights into 1) interactions between the circumgalactic medium (CGM) associated with infalling galaxies and the hot (T > 10 6 K) X-ray emitting intracluster medium (ICM), 2) the stripping of metal-rich gas from the CGM, and 3) a multiphase structure of the ICM with a wide range of temperatures and metallicities. In this work, we present results from a high-resolution simulation of a ∼ 10 14 M galaxy cluster to study the physical properties and observable signatures of this cool-warm gas in galaxy clusters. We show that the ICM becomes increasingly multiphased at large radii, with the cool-warm gas becoming dominant in cluster outskirts. The diffuse cool-warm gas also exhibits a wider range of metallicity than the hot X-ray emitting gas. We make predictions for the covering fractions of key absorptionline tracers, both in the ICM and in the CGM of cluster galaxies, typically observed with the Cosmic Origins Spectrograph aboard the Hubble Space Telescope (HST). We further extract synthetic spectra to demonstrate the feasibility of detecting and characterizing the thermal, kinematic, and chemical composition of the cool-warm gas using H i, O vi, and C iv lines, and we predict an enhanced population of broad Lyα absorbers tracing the warm gas. Lastly, we discuss future prospects of probing the multiphase structure of the ICM beyond HST.

show abstract

Trident: A Universal Tool for Generating Synthetic Absorption Spectra from Astrophysical Simulations

Cited by 89 publications

References 87 publications

Challenges and Techniques for Simulating Line Emission

Challenges and Techniques for Simulating Line Emission

The COS Absorption Survey of Baryon Harbors (CASBaH): Warm–Hot Circumgalactic Gas Reservoirs Traced by Ne viii Absorption

Ultraviolet signatures of the multiphase intracluster and circumgalactic media in the romulusc simulation

Contact Info

Product

Resources

About