Gothenburg, Sweden (20-24 June 2022)
- Molecular gas properties set by local environment but SF proceeds fast
- (Utomo+ 2018) Observed SF efficiency per free-fall time is pretty close to theoretical expectations, 1%(?) (Krumholz+ 2012); however, it varies, and there are observed distributions
- Using FIR clump counts to estimate the SFR of the entire MW (~1.74
$\pm$ 0.66 M$_\odot$/yr; Elia+ in prep) - Decreased SFR between 2-4 kpc with a global maximum in the central but a local maximum at 5 kpc
- 50% (90/99%) of all SFR occurs within 6 (9/13) kpc
- Planck results (XXV paper) suggest that MCs are subcritical (i.e. magnetic pressure < gravity)
- (Soler+ 2013; Soler & Hennebelle 2017) In the strong B-field case, gas structures run parallel to the field at low column density (N) and perp at high N. The transition is somehow related to the transition to gravitational instability
- (Pattle+ 2022) Feedback effects: protostellar outflows affect the B-field, basically erasing the initial conditions to SF, which is even further changed by stellar feedback (i.e. HII regions)
- (Pattle+ 2019) B-fields are parallel with the pillars in M16 (aka Pillars of Creation)
- (Pattle+ 2021) M82: B-fields in winds are polodial and outside are torodial or aligned with the spiral arms
- Grain alignment is important and carbon grains aren't typically aligned with the general ISM
- PROMISE survey at 8 microns across 40 degrees in the MW plane at a resolution of 2" (~0.1 pc)
- Covers about 10k clouds/clumps in DR1
- (Barnes+ 2021) Investigated about a dozen regions over a large range (core fragments, cores, clumps, and clouds), looking at
- Mass-radius relation for fragmentation (similar to high mass SF simulations)
- Dynamics: thermal pressure and virial parameters as functions of mass and radius, respectively
- Analysis of how core properties are inherited from their host MCs, e.g. more massive and turbulent clouds result in more cores
- SILCC-ZOOM simulations: zoom-in MHD simulations of galactic plane simulations (CRs, feedback, shielding with TreeCol)
- (Ganguly+ 2022) Computes dendrograms to identify sheets, filaments, clouds. Finds that the virial parameters scatter around unity at low surface densities but converge to one at higher values.
- B-fields are energetically important in the atomic phase but not so much in the molecular
Smith: How galactic environment alters molecular clouds & star formation using the CLOUDFACTORY simulations
- Cloud Factory AREPO simulations: zoom-in simulations from a global disk simulation
- Clouds formed in high feedback environments are less suspectible to feedback-induced fragmentation
- Compared against observations (Hacar+ 2022) of all collapsed structures in the MW and showed agreement
- (Tress+ 2021) Similar simulation suite but in a M51-like galaxy/halo. Similar to the MW except in the center
Jeffreson: Molecular clouds in diverse dynamical environments: Early-type galaxies vs. Milky Way-like discs
- AREPO simulations of isolated disk galaxies (with usual star formation and feedback algorithms used with AREPO/Heidelberg)
- Investigates cloud properties (turbulent pressure, virial parameters, etc) w.r.t. environments
- (Liu+ 2021; Eqn A3) Virial analysis with a split between self- and external gravity sources. Important to include gravitational potential from external sources (i.e. disk, larger structures) to accurately determine the gravitational instability.
Frost: Linking the multiplicity and formation of massive stars to their influence at galactic scales
- (Frost+ 2022ab) Effects of mass transfer, mergers and magnetic fields on massive star formation
- Circumstellar (disk) material can be affected by multiplicity (Price+ 2018; Oliva+ 2020)
- (Rosen+ 2019) Fragmentation happens at different scales depending on the cloud properties, i.e. virial parameter
- Finds accretion shocks at the centrifugal barrier for the first time for a high mass object -- 650 M$\odot$ clump, 120 M$\odot$ envelope, and expected 50 M$_\odot$ star
- Early hot core phase: shocks (outflow, accretion) may contribute to the chemical enrichment, in addition to the radiative heating
- Refs: Csengeri+ (2018, 2019, in prep); Bouscasse+ (2022)
Bonfand: A rich population of young high-mass proto-stars unveiled by complex organic molecules from ALMA-IMF
- ALMA-IMF (Motte+ 2022): targeting 15 of the most extreme nearby massive clumps, ranging from young to evolved systems
- They find that 90% of cores over 60 M$_\odot$ are hot and could say something about the timing of massive SF
- See Offner+ (2014) review to see how the core mass function transform into the IMF
- Hot cores with radii around 2000 AU don't fragment (much)
- Using Zhang & Tan model (series of papers, starting in 2018) to model massive SF to interpret SOFIA observations
- sedcreator: python toolkit to fit SEDs from the Zhang & Tan models
- (Fedriani+ 2019) Kinematics and dynamics of a protostellar jet out to ~0.1pc
- (Karnath+ 2020) Observations of the youngest cores (< 6000 years) -- heating from compression not feedback
- (Hartmann+ 2016) Low-mass protostellar accretion flows are controlled by B-fields, but high-mass accretion flows are still debated
- (Mendigutia+ 2020; Vioque+ 2022) Transition from magnetosopheric to disk accretion flows going from low- to high-mass SF
- Break in power law at the transition when looking at accretion rate versus core mass.
- Also using ML to identify new Herbig stars
- (Kueffmeier+ 2018, 2019, 2020) Cloud simulations and zoom-in simulations of individual stars
- Polarization at >250 microns traces B-field structure down to the disk scale (but not inside the disk)
- Question of merger model (conveyor-belt formation) versus monolithic model
- (Wright & Parker 2019) Suite of N-body simulations of star clusters to investigate mass segregation (Spitzer acceleration)
- Cool collapse of a stellar system results in violent relaxation that accelerates Spitzer acceleration
- Spatial autocorrelation tests are a statistical tool to quantify the spatial correlation (clustering) of similar objects in 2D space
- Arnold, Wright, & Parker (2022) used Moran's I statistic on the stellar projected speeds
- They found that the hierarchical collapse has a much higher signal compared to basically zero signal in the monolithic collapse
- STARFORGE simulations. Adding physics progressively: gravity + turbulence; ideal MHD; Thermo; protostellar jets; radiation heating; stellar winds and SNe
- Protostellar jets moved the IMF peak from 1 solar mass to ~0.1 solar mass
- However jets can't quench SF. Need radiation and SN feedback to expel gas from the cloud
- IMF is insensitive to variations in surface density, virial parameter, cloud mass, ISRF, and metallicity.
- IMF slope is sensitive to magnetization, metallicity, as well as driving and IC
Nony: Understanding the origin of the IMF from the mass distribution of cores: prestellar vs protostellar CMFs
- Using ALMA-IMF to identify several dozen protostellar cores and outflows (Nony+ 2020, in prep)
- Local minimum in the core mass around 2 solar masses
- Prestellar CMF slope is consistent with Salpeter:
$-1.46 \pm 0.17$ - Protostellar CMF is "top-heavy", i.e. an excess of high-mass cores
- Suggests an evolution in time (Pouteau+ 2022)
Gonzalez: On the origin of massive stars: discs and outflows in the early phases of massive star formation
- Suite of simulations: RT (FLD and M1) and MHD (ideal and non-ideal :: ambipolar diffusion) with RAMSES-RT
- (Commercon+ 2022) Amipolar diffusion (AD) results in small and thin disks compared with ideal MHD.
- Thermal pressure dominates magnetic pressure
- The B-field is polodoial (AD) instead of torodial (ideal MHD)
- Turbulent-dominated results in multipicity, and magnetic dominated results in an isolated massive star
- (Mignon-Risse+ 2021ab) Mass ratios between 1.1-1.6 with separations of several hundreds of AU
- Found that the collapse is hierarchical and not monolithic
- Dustribution: latent variable Gaussian processes; variational inference, inducing points, GPU acceleration
- Also using Astrodendro
- Dharmawardena+ (2022) looks at the tomography of Orion, California, and Vela nebulae
- Larson mass-radius relationship does not change much if one considers a sphere or take the true cloud extent, but increases the scatter
- Now using Gaia DR3 to map extinctions
- (Della Bruna+ 2022ab) Impact of pre-SN (winds, radiation pressure, thermal pressure) on local galaxies from a study of young stellar clusters (YSCs)
- In shocked regions, [OIII] is brighter than H$\alpha$ in M83. 4700 HII regions. 532 regions contain YSCs (< 10 Myr). 27-68 Wolf-Rayet stars. 150 regions have SNRs.
- M83 is on the high-end on the SFR-Mstar relation
- Investigating direct pressure and ionizing radiation pressure as a function of radius to determine whether the HII regions are expanding or not
- (Dobbs+ 2022) Zoom-in simulations of MW-like galaxy (Pettitt+ 2015). 2-levels: MW to kpc-scales, then kpc- to pc-scales.
- Includes photoionizing feedback and SNe (Bending+ 2020, 2022). Star formation on the cluster-scale but not individual stars
- Clusters undergo mergers and splits. More massive clusters are usually the result of mergers, and lower mass ones the result of splits
- (Crocker+ 2021) Cosmic rays (CRs) can be constrained with gamma-ray luminosities of star-forming galaxies (SFGs)
- Gyration radius is around ~AU scale, but that scale is dominated by neutral species, not ions
- (Sampson+ 2022) Local CR motion is streaming along field lines, but they bend/move (diffusion-like)
- They can model it as "super-diffusion," i.e. a scale-dependent diffusion coefficient
- (Roth+ 2021) GRUNTS model makes high-energy mock spectra from their models
Chevance: Pre-supernova feedback mechanisms drive destruction of molecular clouds in nearby disc galaxies
- (Kruijssen & Longmore 2014; Kruijssen+ 2018, 2019) Determined an analytical description of star formation and feedback based on an aperature size
- Can measure timescales of formation and feedback, length scales, and SF efficiency
- (Chevance+ 2022; Kim+ in prep) Variations in feedback (i.e. cloud destruction) timescales (2-4 Myr) across galaxies
Panopoulou: 3D mapping the magnetized ISM: unveiling interplay between feedback & magnetism in the Solar vicinity
- Local bubble (~400 pc diameter; Zucker+ 2022) affects the B-field morphology
- (Panopoulou+ 2021) Uses star polarization maps to determine that the B-field drapes over the bubble wall
- Feedback on larger scales hasn't (yet) erased B-field coherency
- B-field is preferentially aligned with a Radcliffe wave
Koda: Abundant Molecular Cloud Cores w/ Photo-Dissociated Envelopes Discovered in the XUV Disk of M83 w/ ALMA
- Detected 23 clouds with 800 to 20,000 solar masses in XUV disk, i.e. photo-dissociated envelopes
- Used multi-wavelength (21cm, CO, UV, H-alpha) observations to study these clouds
- Bridge low- and high-z universe, which can justifies the use of mid-J CO lines to trace ISM masses
- (Sarkar+ 2021ab) Using PLUTO simulations to study SNRs.
- During the cooling phase, the radiation can be very bright, as much as an O-star for ~20 kyr.
- The radiation can actually ionize the nearby gas and change the observational properties
- New approach for subgrid models: fitting to observations (also see Chevance talk)
- (Keller+ 2022b) Built a self-similar star formation and feedback model that includes early feedback (i.e. radiation and winds) in addition to SNe
- Gives a distribution of timescales and specific momentum input
- Makes a qualitative difference in isolated disk galaxy simulations, especially in SF clustering (decreased with early feedback) by disrupting clouds
- Also results in a thinner gas disk
- (Cosentino+ 2018, 2020) Using SiO (ALMA) emission to detect shock interactions
- Focusing on a region that's between an SNR (W44) and star-forming region
- (Ustamujic+ 2020; Cosentino+ 2022) SiO emission study of a molecular cloud being impacted by a SNR
- Momentum transfer per area: 700 M$_\odot$ km s$^{-1}$ pc$^{-2}$
- Molecular material may carry away up to 40% of the momentum injected by SNRs
Orr: Clustered Supernova Feedback in Local & High-redshift Galaxies: Trade-off Between Turbulence & Outflows
- Is there some sort of "variable" feedback? Motivated by the fact that outflows are driven out of galaxies and SF is clustered
- (Orr+ 2022ab) Superbubble model that's applied to some local patch in a disk galaxy
- Four cases: powered break out; powered stall; coasting break out; coasting fragmentation
- Determined in galactic rotation versus gas fraction phase space
- Clustered SF and thus SNe is likely to drive outflows
- Model evolves with redshift with more outflows at high-z
- (Kruijssen+ 2019) E-MOSAICS has been quite successful, but it doesn't include a cold ISM, which is crucial to get a realistic cluster population
- Using an empirically-motivated (EMP) feedback model (see Chevance and Keller talks) recovers better agreement with observations
- EMP sims produce bigger and thinner disks, but the stellar masses aren't much different but more consistent with observations
- EMP regulates SF by disrupting clouds, not by driving outflows
- (Reina-Campos+ 2022) EMP models produce a realistic cluster mass function at z=2-4 explains GC formation in a non-exotic manner
Wang: Feedback and Global Evolution of the ISM from Spiral Arms to Inter-arm Regions in Nearby Face-on Galaxies
- (Wang+ 2021?) Using X-rays to trace feedback affected gases and its interplay with the ISM/CGM
- Strong anti-correlation between X-ray emission and polarized non-thermal radio fraction
$\rightarrow$ B-field is relatively weak in diffuse hot plasma and is strongly turbulent
- (Tacconi+ 2020 review) At halo masses above
$10^{12} M_\odot$ , star formation is quenched
- (Tacconi+ 2020) What causes the SFR peak at z = 1-2? Depletion times decrease over the galaxy main sequence. No dependence on stellar mass.
- Molecular gas fractions increase dramatically at
$(1+z)^{2.5}$ to z ~ 2.5 - (in prep) Searching for signatures of gas infall / transport at z ~ 2 through ALMA CO (1.3 kpc resolution). Bulge formation?
Wetzel: Resolving the ISM and stellar populations in the FIRE cosmological simulations of Milky Way-mass galaxies
- FIRE-2 model (Hopkins+ 2018) in MW-mass galaxies
- (Benincasa+ 2020) Investigated cloud mass functions and lifetimes (most die within 15 Myr). Variations with virial parameter
- (Kim+ 2018; Ma+ 2020; Sameie+ 2022) Proto-GC formation from (1) galaxy and cloud mergers and (2) feedback-driven compression
- (Rodriguez+ 2022; Grudic+ 2022) Using post-processing to evolve these proto-GCs to the present-day
- Cloud SFRs are uncertain because the measurements in simulations depend on the time and method. Using ionizing photons is especially a bad method (Grudic+ 2022).
- The MW has a SF efficiency per free-fall time of 0.6%
- Solution to solve that SF is "slow" is to recognize that
- Molecular clouds are unbound
- Use a metallicity correction of
$\alpha_{\rm CO}$ - Include a dependence of SF efficiency on virial parameter
- (Chen+ 2018; Burkhart 2018) Density PDFs have a long shallow high-density tail as strutures collapse, resulting in a piecewise log-normal + power-law distribution
- (Appel+ 2022) Outflow feedback and B-fields are critical for low SF efficiencies. Simulations without these processes cannot model SF accurately.
- Gas cycling through feedback keeps the SF efficiency low
- CATS: Catalog for Astrophysical Turbulence Simulations
- UCLCHEM: gas-grain chemical code for astrochemical modeling
- Including LTE, RT, constraining physical parameters and observational quantities
- Holdship & Viti (2022)
- Chemulator: solves the radiative transfer and chemical model with a neural network
- Density (HCN, CS), CR ionization (C2H, H3O+), and shocks (HNCO, SiO) are all important to determine molecular ratios and species fractions, however molecular ratios can be degenerate.
- (Bolatto+ 2013, 2021) Cold outflows are ubiquitous in nearby starbursts
- Removes a significant amount of gas. Most of the gas doesn't make it past 1-2 kpc but still disrupts SF
- (Walter+ 2017; Martini+ 2018) However some gas is accelerated to very high velocities and is lost from the galaxy
- (Leroy+ 2018; Levy+ 2012, 2022,; Emig+ 2020) Very young super star clusters are common in these cold outflows
Petkova: The role of the Galactic potential in shaping the structure and kinematics of the CMZ cloud "the Brick"
- (Henshaw+ 2022) Survey of galactic molecular masses, showing that the MW CMZ (inner ~100 pc) is typical
- (Kruijssen, Petkova+ 2019) Simulations of clouds traveling along an orbit toward the galactic center, using an empirically based gravitational potential
- (Petkova+ submitted; 2104.9558) Simulated "the Brick" cloud, which is one of the most massive and optically thick clouds in the CMZ
- Their mock observables (rotation, measures of turbulence) are remarkably similar to the real object (Federrath+ 2016)
- Strong shear within the cloud could be driving rotational and solenoidal turbulence
- Additional small-scale structure requires more physics (B-fields?)
- (Tanaka & Tan 2017, 2018) Investigated massive SF in single clouds, finding that more mass is photo-ionized and less SF as metallicity decreases. MHD outflows dominate at solar metallicity.
- (Tanaka & Omukai 2014) Found stronger cooling in metal-poor clouds (weaker than solar and extremely metal-poor), resulting in more fragmentation
- New ALMA survey MAGOS of protostars in the LMC/SMC to investigate SF at lower metallcities
- (Chon+ 2022) GADGET simulations with Omukai cooling model at various metallicities of a Bonnor-Ebert sphere with transonic turbulence
- Sink particle formation at
$2 \times 10^{16}$ cm$^{-3}$ with an accretion radius of 1 AU - 1950 M$_\odot$, 10 pc, 200 K cloud
- Sink particle formation at
- After 150 M$_\odot$ stars form (efficiency ~ 8%),
- [Z/H] = -1: Filamentary fragmentation instead of disk fragmentation
- [Z/H] = -2 - -4: Vigorgous fragmentation
- [Z/H] < -4: Stable disk and more massive star formation
- They find that the IMF gradually changes from top-heavy to "Salpeter" with increasing metallicity
- The massive component slowly disappears from the bimodal distribution. See Chon+ (2022) for a fit for the high-mass component.
- (Fontani+ 2022ab) IRAM survey of 35 star-forming cores between 12-24 kpc from the Galactic center
- Comparing molecular species and their abundances with nearby SF regions
- They find that the organic molecule formation efficiency doesn't depend on galactic radius
- Has implications on the "Galactic Habitable Zone" that needs enough metallicity to form planets and organic species and few "catastrophic" events
- (Buchhave+ 2012; Maliuk & Budaj 2020) Terrestrial planets prescence is independent of metallicity
- Using RADEX (Finn+ 2021) to determine the properties (mainly temperature) of the largest and brightest SF region in SMC
- Using ALMA CO observations have a resolution of 0.7 pc as the main observational constraint
- Upcoming JWST observations of NGC 346 with NIRCam, NIRSpec, and MIRI this month
- Goals: Characterize SEDs of >1k YSOs; determine physical conditions
- Dwarf galaxies with
$< 0.1 Z_\odot$ aren't necessarily primordial but could resemble them, such as line ratios - How do XMDs retain their metal-poor gas?
- Outflows could preferentially expel metal-rich ejecta, but they're not detected
- Inflows could feed these galaxies additional metal-poor gas from which stars form
- Ref: Monkiewicz (2022, in prep)
- (Monkiewicz & Carleton, in prep) Using TNG100-1 to search for similar XMD galaxies in the above galaxy
- Found tens of them in the simulation that have similar metallicity and luminosities
- More isolated than normal dwarfs
- Using UV absorption lines to determine the outflow properties
- CII line shows that the cool gas is expanding
- Strong evolution in the centroids and absorption EWs with time
- The wind accelerate and gets thicker
- Wind flow/structure grows by a few kpc in ~10 Myr
- The 1st moment (mean velocity) increases linearly, but the outer edge is increasingly accelerated
- Exceeds the escape velocity, probably contributing to the CGM
- Acceleration efficiency of mechanical energy of ~1%
- "Atari" disk (AncienT Accreted stellaR populatIon)
-
$h_R$ = 2.48 kpc,$h_Z$ = 1.68, 154 km/s (lags the thick disk) rotational velocity, metal-poor (cut at [Fe/H] = -0.7) - 333, 34, 5 have [Fe/H] < -2, -3, -4
- Selected stars in action space
-
- Similar to the "rich-alpha-disk" and "Wukong", "Nyx" structures in action space
- Metal-poorness indicates that it's been accreted
- Most of the EMP Atari stars aren't carbon-enhanced
- Studying ultra-faint dwarfs (UFDs;
$M_V < -7.7$ ; M/L = 100-1000;$\log_{10} (M_\star/M_\odot) = 2-5$ ) with an HST Treasury program with 164(?) dwarfs - (Kallivayalil+ 2018) Satellites of satellites, focusing on LMC analog in a simulation
- (Sacchi+ 2021) SFHs of UFDs
- Most form 90% of their stars before reionization
- Magellanic satellites have more recent SF than ones that aren't associated with the LMC
- Luminosity-size plane is a good space to understand the formation of UFDs and constrain feedback models
Malhan: The Global Dynamical Atlas of Milky Way mergers: constraints from globular clusters, streams & dwarfs
- (Malhan+ 2022) Used Gaia EDR3 to identify 257 objects in action space, consisting of 170 GCs, 46 satellite galaxies, and 41 stellar streams
- Searching for mergers within these groups. Found 6 mergers at
$>2\sigma$ -- 5 of which were previously known- New merger, named Pontus
- Previously known LMS-1 "Wukong": most metal-poor merger in the MW
- Contains 3 of the most metal-poor streams around [Fe/H] = -3
- Posits that ~10% metal-poor "halo" GCs are associated with DM halos
- 11/19 have no evidence for DM halos
- 6/19 are flat or falling velocity profiles
- M54 was originally thought to be a GC alone but was later to have a LSB galaxy around it
- DM halo of mass ~few
$\times 10^8 M_\odot$ with a <50 pc core (or no core)
- DM halo of mass ~few
Lahen: Star formation in extreme, low metallicity environments – luminosities, star clusters and multiple populations
- (Lahen+ 2020ab) Dwarf galaxy simulations in the GRIFFIN suite (GADGET)
- 4
$M_\odot$ gas particles, 0.1 (63) pc softening for (DM) gas - Feedback from individual stars, sampled from an IMF
- Non-equilibrium cooling
- Target halo:
$M_{\rm vir} = 2 \times 10^{10} M_\odot$ , 0.1 Z$_\odot$ - Finding some proto-GCs in their simulation
- 4
- (Lahen+ 2022) Studies the star cluster mass function in the same simulation, along with mock observations during its evolution
- (Lahen+ in prep) Investigating multiple populations within GC
- Using BoOST stellar tracks (Szecsi+ 2022) to follow wind enrichment
- Including pair-instability SN
- (Greener+ 2021, 2022) Looking at cumulative metallicity functions of nearby galaxies in MANGA, binned by stellar mass
- MW is typical with galaxies of comparable stellar masses
- Also testing models with closed box chemical evolution
- (Zhou+ 2022ab) Semi-analytic spectral fitting with a simple model of SF
- Uses stellar population to determine SED, along with the emission lines as a constraint (gives SFR and gas-phase metallicity)
- Second paper distinguishes between the bulge and disk and includes a delay between Type II and Ia SNe
- Molecular and dust formation depends on the abudnacen structure within the progenitor star
- PMid-IR is the key to decipher the envelope
- The radiation field and SN environment interaction will alter the dust progenitor
- Metal-poor DLAs at z=2-3 are consistent with MW halo stars in oxygen vs iron space, even below [Fe/H] = -3
- DLA at z=3 has [Fe/H] = -3.25 and [O/Fe] = +0.65
- 3-$\sigma$ distinct in [O/Fe] from very metal-poor stars
- Determined that less than 20 CCSNe with 2e51 erg explosions enriched this cloud
- (Welch+ 2019) Stellar masses are constrained between
$10^3$ and$10^4$ M$_\odot$
- (Welsh+ in prep) [Fe/H] = -3.7 upper limit of the Cooke+ (2017) most metal-poor DLA with new Keck dataset
Hopkins: From Micro to Macro: Connecting Dust, CRs, & Individual Stars & Black Holes to Cloud & Galaxy Scales
- Cosmic Rays
- (Ji+ 2019; Butsky+ 2020) Investigated how cosmic rays affect the CGM, supporting cold gas that would otherwise fall back onto the galaxy
- (Chan+ 2018; Su+ 2018, 2021) Investigated how
$\kappa_\parallel$ affects SFRs of MW-like galaxies
- Dust
- (Squire & Hopkins 2017; Moseley+ 2018, 2022) Resonant drag (clustering) instabilities when considering the dust equation of motion
- (Hopkins, Rosen+ 2021) Dusty outflow simulations (RT+Dust+MHD+Lorentz force)
- (Steinwandel+ 2021) Application to cool star / AGN dusty outflows
- FIRE-3 has updated their prescriptions and included AGN feedback
- (Agertz+ 2021; Renaud+ 2021ab) Zoom-in cosmological simulations of MW-like galaxies with RAMSES
- The low [$\alpha$/Fe] sequence at low [Fe/H] is a signature of an outer disk forming rapidly at early times (8-10 Gyr ago)
- At low resolution (500 pc vs 20 pc), you overmix the metals and lose the bimodality in [$\alpha$/Fe] - [Fe/H] space
- (Agertz+ in prep) Including genetic ICs (i.e. Pontzen+ 2019)
- Varying last major merger between 1:10 to 1:2
- The disk size grows with decreasing merger mass ratio
- More metallicity bimodality in simulations with smaller mergers
Bellstedt: The cosmic star formation history by galaxy components from simultaneous spatial and spectral fitting
- (Bellstedt+ 2020) Fits SEDs from UV to sub-mm and cosmic SFRs to obtain galaxy properties with ProSpect (Robotham+ 2020)
- New code ProFuse to combine source finding, 2D decomposition, and SED fitting
- (Robotham+ 2022) Linking the mass-size relationship to the stellar population properties
- (Bellstedt+ in prep) Latest work suggest that bulges are older than classical elliptical galaxies
- (Fensch & Bournaud 2021) Inspected how (isolated) disk galaxies fragment depending on their mass-loading factor (outflow rate / SFR) and gas fraction
- Why are z ~ 2 galaxies so gas-rich (50%)?
- Perhaps feedback isn't that efficient at driving outflows but does regulate SF
- (Fensch+ in prep) Zoom-in isolated galaxy simulations to focus on star-forming regions (a la SILCC)
- Currently only isothermal hydro of a gas-rich disk
- (Concas+ 2017, 2019, 2022) Using the KLEVER survey to search for galactic outflows at z = 1-2 in ~200 (lensed and unlensed) galaxies
- Also stacks spectra in stellar mass bins to inspect emission line strengths to determine outflow properties
- Difficult to decompose the disk and outflow
- (Concas+ 2022) New decomposition method that's physically motivated
- Calculates a stack of rotating disk models and fits to stacked emission line
- Residual is assumed to be the outflow
- No clear outflows in dwarf galaxies with
$\log(M_\star/M_\odot) = 8-9.6$ - Outflows increase with AGN fraction
- Mass loading factors are very similar to the local observed derived ones that are ~0.1, whereas TNG50 has values around 10
- (Fontanot+ 2018) Exploring variable IMFs at both the high- and low-mass ends in semi-analytic models of galaxy formation to explain the chemical, dynamics, and spectral observations
- If the IMF is indeed variable, then the inferred galaxy properties will be different than expected
- (Graham & Sahu 2022) Using 145 SMBHs to determine relations (e.g. spheroid or stellar mass versus BH mass)
- Split their data based on morphology, which have slightly different slopes
- Jumps between relations caused by dry mergers of S0 galaxies to create an elliptical
- (Sahu+ 2022) Relation between BH mass and spheroid internal density and many different relationships between properties (see paper)
- (Whitler+ 2022) Stellar ages of z=7-8 galaxies show that SF starts well before z=10
- (Stefanon+ 2022) Stacked z=7-8 galaxies to show that most have young ages (10-100 Myr), however it's possible that they outshine older populations (Tang+ 2022)
- (Hashimoto+ 2018; Laporte+ 2021) Balmer break gives a good measure of age (200-300 Myr) of z=7-9 galaxies, showing that SF goes back to at least z=20
- Rotating disk galaxy at z~9: 120 km/s rotation, ~$1 (2) \times 10^9 M_\odot$ in gas (stars), 500 pc diameter
- (Ferrara+ 2022; Sommovigo+ 2022) Dust temperature within high-z galaxies and how it increases with redshift (
$T_{\rm dust}$ ~ 50 K at z=5) - (Dayal+ 2022) High dust-to-gas ratio (> 0.03) and dust mass is independent of stellar mass
- The amount of dust found is required to fit the UV luminosity function
- (Qin+ 2021) The fluctuations in ionization can explain the different QSO sightlines, including the z~5.7 (160 Mpc) GP trough found in Becker+ (2017)
- (Nikolic+ in prep) Predicts that the escape fraction is indepedent of halo mass with a mean 5
$\pm$ 3%
(Apologies to the last set of talks as I was distracted by my own talk!)
This is great to have - thanks for making your notes publicly available!