NYC -- 20-23 May 2024
- (in prep) z = 6-15 Galaxy LFs and cosmic SFR from new spec-z observations. There is tension with models with constant SF efficiency models at z>10.
- Different galaxy formation physics at early times: High SFE, top-heavy IMF, radiation driven outflows, bursty SF, cosmology, AGN?
- (Cameron+ 2023) Nebular continuum dominated galaxies may occur with a top-heavy IMF
- (in prep) 70% of bright galaxies are clumpy at z_spec ~ 7. Recent starbursts from mergers?
- However, these galaxies, especially at z>10, are very compact, e.g. GN-z11, GHZ2 (Tacchella+ 2023, Ono+ 2023).
- (Harikane+ 2023b) Many AGN at z>4 with broad H-alpha and narrow [OIII] from 185 galaxies. 70% show extended morphologies, similar to Seyferts. M_BH in the range 10^6 - 10^8 Msun.
- Freebad-free starbursts at SFE~1
- At z~10, this occurs in halos with >10^10.5 Msun. Observable by JWST.
- SMBHs with MBH/Mstar ratios could be caused by heavy seeds with migration to the center within 500 Myr
- (Feathers+ 2024) SAM for Pop III to Pop II transition within 3 Mpc wide cells for use in large-scale simulations. Takes hours of compute for each cell. Input: JLW, vbc, history of JLW. Output: Pop II and Pop III SFRs
- Using this as a model to train a NN
- (Feathers+ in prep) Use the NN as a emulator in a large-scale model. Compared to an integral calculation, there are enhanced spatial fluctuations due to varying merger trees
- ALPINE and REBELS has given us the first database of dusty galaxies at high-z that can be used to constrain dust properties in early galaxies
- (Sommovigo+ 2022) Estimating dust masses wrt stellar mass. They have a non-parameteric SFH model that gives a flat Md/Mstar relation. Compared to a constant SFH, it gives higher stellar masses, which is more inline with observations.
- Massive galaxies appear to be significantly dust-obscured (>50%) already at z=7
- Blue UV slopes doesn't necessarily mean that they dust-poor/free. Prefers an outflow explanation, not geometry.
Lily Whitler - Implications for early star formation and ionized bubble growth from the JADES UV luminosity function at z~9-15
- (in prep) Find candidates with photo-z > 14. Two examples had M_UV = -20.3 and -18.5. Slow evolution in the bright galaxy population at least out to z~14.
- Bright galaxy excess when compared to FIRE-2, FLARES, and UniverseMachine.
- Faint galaxies also have some excess when compared to a constant SFE model.
- (Di Cesare+ 2023) dustyGadget simulations of the first galaxies, including Pop III SF.
- (Venditti+ 2024a) Indirect probes of Pop III from PISNe, which are short and rare
- (Venditti+ 2024b) Searching for HeII 1640. Current survey may not have enough sensitivity and/or big enough field of view.
- (in prep) Detailed Pop III synthetic spectra with dust absorption
Seiji Fujimoto - Early Galaxy Assembly Probed by IFU Trio of JWST+ALMA+MUSE: From Young Star Clusters to Dynamical Interplay at z=6
- (Fujimoto+ 2024a) Targeting a lensed (mu=30) z~6 sub-L* galaxy. Brightest [CII] spec-z > 6 galaxy but still a low-mass main-sequence galaxy (Mstar ~ 10^9 Msun)
- 15 individual SF regions each with an effective radius of 10-60 pc, which are resolved only with lensing. Without it, the galaxy would appear and confused as a smooth disk.
- The numerous clumps can be modeled within a smooth rotating disk with sigma ~ 20 km/s and V/sigma ~ 3. Very low Toomre-Q ~ 0.2
- (Sharda+ this week) Rad MHD Pop III simulations. Showing less fragmentation than MHD or RHD simulations. Simulated one example but will extend it to a larger sample.
- (D'Odorico+ 2023) XQR-30 survey. 30 z~6 QSOs with high SNR to probe IGM/CGM metal enrichment.
- (D'Odorico+ 2022) Studied the evolution of number density of metal absorbers, where some ions can probe the change in ionization state in addition to the metal enrichment
- (Saccardi+ 2023) CEMP-no absorbers at z~3.5. Searched in Lyman-limit and sub-DLA systems that are more promising than DLAs because they can be less affected by SF. Found 14 very metal-poor (VMP) systems. Abundances consistent with faint SNe as observed from local VMP stars.
- (Sodini+ 2024) Comparing absorber abundances with Pop III SN yields in O, Si, Fe, and C. There are three in their sample that suggest that Pop III SNe contributed ~30% to their metals.
- (D'Odorico+ 2023) Extragalactic white paper for future cases on ELT
Allison Strom - Studying Metal-poor Stellar Populations in High-redshift Galaxies with JWST and Keck
- (Goetberg+ 2019; student? in prep) High-ionization emission lines from early massive stars are important to explain observations
- (Strom+ 2023; Choe+ 2024) OI 8448 line is strong from HII regions and is present in some (most?) high-z galaxies
- High-z galaxies are significantly alpha-enhanced, even at moderate O/H or Fe/H.
- (Skuladottir+ 2024a) Sculptor experienced significant enrichment from high-energy Pop III SNe.
- Sculptor and MW halo have very similar abundance patterns. However, the data has shown that the halo isn't constructed by the disruption of Sculptor-like dwarfs -- only ~5% contribute to the halo.
- (Xing+ 2023) Abundance pattern in MP star that is consistent with PISN
- (Koutsourido+ 2024) Constraining Pop III IMF with abundance patterns from a handful (single?) of stars. However in a follow-up paper, they found that the C and Al lines is not in agreement with Pop III enrichment, invalidating their previous result (Skuladottir+ 2024b)
Devesh Nandal - Deciphering the chemical footprint of massive and supermassive Pop III stars in the early Universe
- (Nandal+ 2023a) As the star accrete and/or pulsates, the mixing and structure will be dramatically affected, thus the yields will change as well
- (Nandal+ 2024a) Stellar evolution models from Regan+ (2020)
- One case study has 8900 Msun and then studies the mass loss and metal enrichment from it, considering metal transport through the convective zones.
- (Nandal+ 2024b) Metal enrichment from fast rotating Pop III stars. There's a new object (GS3043?) at z=5.5 with a very high N/O ratio that can only be explained by rotating supermassive stars.
Xihan Ji - The exotic nebular emission in GN-z11: Evidence of peculiar chemical enrichment in the most distant AGN REMOTE
- (Ji+ 2024) Higher gas temperatures -> weaker Balmer jump. The FeII emission complex in AGN between 2200-3600 A looks like a continuum, which occurs when Lbol/Ledd and column density are high (Ferland+ 2009; Sarkar+ 2020).
Kohei Inayoshi - The Age of Discovery with JWST: Excavating the First Massive Black Holes and First Galaxies
- (Li, Inayoshi+ 2024) Early BH - Galaxy coevolution -> Overmassive MBHs when compared to low-z. Is this intrinsic? If yes, the BH growth may be larger or heavy seeds. If not, there could be a large intrinsic scatter or there are selection biases.
- (Toyouchi+ 2023) Mass function of seed BHs, combining both light seeds in minihalos and heavy seeds in overdense regions
- (Inayoshi+ 2022b) Mock spectra for rapidly growing seed BHs. Strong H-alpha lines (EW > 1300A) and OI lines (EW > 10A) from Ly-beta fluorescence
- (Nakajima & Maiolino 2022) Early galaxy vs growing seed BH diagnostics with H-beta and HeII, but there are some uncertainties associated (e.g. AGN disk versus winds) with the method
Anna de Graaff - RUBIES: a complete census of the rare, extreme and red early Universe with JWST/NIRSpec
- (in prep) Heterogeneous population of red sources. Dusty SF, Massive quiescent, z=8 star forming, AGN.
- (Wang+ 2024) Stellar masses are still uncertain by 1 dex. Broad Balmer lines (AGN) and Balmer breaks (evolved stellar system) within sample.
- (Eilers+ 2023) Finds some examples with redshift clustering (up to 200x) around bright QSOs, but one was shown without any clustering.
- Using the QSO-galaxy cross-correlation, they constrained the host halo masses between 10^12 and 10^12.5.
- (Topping+ 2022; Cullen+ 2024) UV slope
$\beta < -2.6$ implies there's little to no dust attenuation, which are detected in a JWST sample with 121 galaxies between M_UV = -17.5 -> -21.5 between z=9-12. - The slope evolves from a mean of -2.17 at z=9.5 to -2.59 at z=11.5. There is a lot of scatter. See discussion in Cullen+ (2024) for redshift selection effects and/or measurement biases.
- (Chernerysnska+ 2024) 10-100x excess of bright galaxies
- Euclid press release on Thursday, May 23
- (Chernerysnska+ in prep) The low-mass MZR continues as a power-law, e.g. 0.01-0.1 Zsun at 10^6 - 10^7 Msun in stars.
- Upcoming survey GLIMPSE will probe galaxies between M_UV = -12 -> -15 in lensed fields
Rebecca Larson - CEERS Spectroscopic Characterization of Galaxies and AGN in the Heart of Reionization
- (Marques-Chaves+ 2023) Proto-GC? High N/O ratios.
- (Carniani+ in prep) Narrow and broad [OIII] components, broad H-beta line. Is this caused by outflows?
- (Yung+ 2024) With a top-heavy IMF, the UV galaxy LF is boosted by 2-10x, which could alleviate tension with JWST observations and simulations.
- (Umeda+ 2023) Constraining reionization history with Lya damping wings. There is strong absorption, which could suggest lower escape fractions (<0.2) to reduce the ionizing photon luminosity now implied from the new JWST excess of bright galaxies
- (Chworowsky+ 2024) Excess of bright high-z galaxies in CEERS
- (Cole+ 2024) CEERS determination of SFR-Mstar relation. There is a much larger scatter in SFR averaged over 10 Myr versus 100 Myr, demonstrating that SF is bursty. In an example with a low SFR10 value, the SFR100 was still high, showing that it is in a lull of SF and isn't necessarily a slow grower.
- (Watanabe+ 2023; Isobe+ 2023) High N/O ratios could be a signature of a top-heavy IMF, TDEs, Wolf-Rayet stars, or supermassive stars.
- (Fukushima+ 2024) Zoom-in simulation of first galaxies, inspecting their chemical enrichment -- the target galaxy is similar to GN-z11.
- (Toyouchi+ 2023) Cloud-scale fragmentation.
- (in prep) Looking at compressed and collapsing filaments due to streaming velocities. It's an intermediate scenario between collapsing minihalos and SMS formation in ACHs.
- Set of zoom-ins 120, 6 varying streaming velocities to 20 different random realizations. DM particle mass = 0.14 Msun. Considers a stiff EOS to prevent collapse below 10^6 cm^-3 to track clump formation for 2 Myr.
- As many as 25 clumps form in a single filament. The core mass function is between 100 and 3e4 Msun. Slight increase in number of cores per filament with increasing streaming velocities.
- 10 of 120 models host SMSs (>10^4 Msun) with a max mass of 3.9e4 Msun.
Elia Pizzati - High-z black holes in extreme environments: interpreting quasar clustering measurements with large-volume cosmological simulations
- (Pizzati+ 2024b) FLAMINGO-10k simulation in a 3 comoving Gpc box, trying to capture a z~6 QSO host with a host halo mass of 10^13 Msun. Can resolve QSOs and galaxies at the same time -- produces auto/cross-correlation functions for AGN and galaxies.
- QSOs typically live in moderately massive halos with log M ~ 12.4, and the duty cycle is low ~1%.
- Galaxies (OIII-emitters) live in ~10^11 Msun halos and have a higher (~20%) duty cycle.
Sunmyon Chon - Radiation Hydrodynamic Simulations of Supermassive Star Formation by Super-competitive Accretion
- Can SMSs / DCBHs form in metal-enriched environments?
- GADGET-3 cosmo simulations collapsing down to 1e16 /cm^3 in various metal-enriched environments (1e-2 -> 1e-6 Zsun).
- SMS formation occurs at Z <= 1e-3 Zsun. Ionizing radiation doesn't prevent formation.
- Super-competitive accretion -- SMSs share mass with, but dominate over lower mass stars.
- (Chiaki+ 2023) Extending this to work to number density estimates, finding 1.5e-3 DCBHs per Mpc^3 for 1e-6 and 1e-5 Zsun, 3e-3 for 1e-4 Zsun, and 5e-2 for 1e-3 Zsun. The latter value is similar to the SMBH density in the local universe.
- (Upton Sanderbeck+ 2023) SAM for SMBH growth with varying reionization times
Alice Young - Constraining super massive black hole seeding mechanisms using photometric variability at early times
- (in prep; also see Singh+ 2023 and Hayes+ 2024) Modeling SMBH number densities from Pop III vs DCBH seeds, using observational constraints.
- Corrected for AGN variablity, Lyu+ (2021) calculate the SMBH number density is 1.1e-3 cMpc^-3.
Anna Frebel - Population III stars: abundance, properties, fate, and connection to near-field probes
- (Andales+ 2024) Low n-capture SASS stars -> oldest accreted stars to probe Pop III. SASS = Small Accreted Stellar Systems, usually in retrograde orbits.
- Ancient Atari (stream): full of MP stars. 34 EMP stars, 5 stars with [Fe/H] < -4.
- (Chiti+ 2018, 2024) Most MP stars in Scupltor, LMC, and Atari aren't C-enhanced, i.e. [C/Fe] < -0.7. Carbon history in these objects are different than the MW halo.
- Implies that there are little to no C producers (faint SNe, fast rotator winds) as the proto-MW. UFD stars are similar to halo stars.
- (Fialkov+ 2023) Largest reionization / 21cm simulation at 1.2 Gpc
- (Gessey-Jones+ 2022) Impact of Pop III IMF on the 21cm signal, using Z=0 MESA models and TLUSTY stellar atmospheres to calculate the Lya coupling among other things.
- (Sartorio+ 2023) Pop III X-ray binary impact on 21cm for several IMFs. They also added radio background (i.e. to account for EDGES) in addition to the CMB.
- (Gessey-Jones+ in prep) Looking at the global signature on different IMFs and binaries, combining the work of the two papers above.
- (Pochinda+ 2023) Constraints on Pop II/III stars from current 21cm data.
- (Hsiao+ 2023ab, 2024) MACS0647-JD -- JWST resolved an HST detected z=10 galaxy into two components (30 Myr and 100 Myr) and also have NIRSpec and MIRI spectra. ~13% Zsun. SFR ~ 5 Msun/yr.
- (Abdurro'uf+ 2024) Resolved [OII] doublet of the same object
- (d'Eugenio+ 2023) Super-solar C/O (+0.15) in z=12.5 galaxy. Pop III enrichment?
- (Adamo+ 2024) Cosmic Gems arcs (mu ~ 60), lensing resolves 1pc stellar clusters with masses ~2e6 Msun that are probably proto-GCs
James Trussler - Searching for Population III and nebular-dominated galaxies with JWST: Signatures of a top-heavy IMF in the early Universe
- (Trussler+ 2023) Pop III spectral templates with emission lines. For HeII 1640 line, need medium-band photometry because of its weakness (EW ~ 50A).
- Another Pop III signature is the two-photon continum emission (2s -> 1s) that results in a "turnover," dipping as you get close to Lya that starts around 2000 A.
- (Cameron & Katz 2023) However if any galaxy has a high ionization efficiency, which could be caused by a top-heavy IMF, it will have a UV turnover, which has been observed in a z=5.9 galaxy. It could also be a DLA or AGN, not necessarily exotic stars.
- The turnover will be very hard to detect, but the Balmer jump is a more prominent feature and unique to massive (Pop III) stars. Also need medium-band.
- (in prep) Searching JADES for Balmer jumps. Found several out of ~1000 objects. These usually have very strong H-alpha lines. Some have flat or blue UV continuum, where the former is preferred for a nebular-dominated object.
Grace Telford - Extremely Metal-Poor O Stars in Nearby Galaxies as Analogs of Ionizing Photon Producers in the Early Universe
- (Telford+ 2021) Targeted three MP (3,6,14% Zsun) O-stars in dwarfs. Two are fast rotators. Good local O-stars for empirical checks on models to use in the high-z universe.
- (Telford+ 2023) Keck spectra of LP26 (O-star in Leo P -- the 3% star in the previous study), which has an HII region and is the only O-star in Leo P. T_eff = 37.5 kK, log10(L/Lsun) = 5.05.
- (Koutsouridou+ 2023) Metallicity (with a focus on carbon [C/Fe]) distribution of halo stars and its constraint on the Pop III IMF
- Search for PISN signatures: in the MW bulge (Pagnini+ 2023) or DLAs (Vanni+ 2024)
- (Mowla+ 2024) Firefly Sparkle: resolved ~10 stellar clusters in a lensed z=8.3 galaxy.
- (Rusta+ in prep) Looked for Firefly Sparkle analogs in their SAM. Mstar ~ 10^5 Msun, SFR ~ 0.1 Msun/yr, bursty SF
- (Kiyuna+ 2023) First cold streams occur at the atomic cooling limit.
- (Kiyuna+ in prep) At T ~ 8000 K, the halo initially forms typically massive Pop III stars, which then create a HII region. The cold streams then penetrate this warm gas and after the initial stars die, supermassive stars form at T > 10^4 K.
- (Kimura+ 2023) Accreting protostar in 3D simulation.
- (in prep) SMS formation, rapid growth 0.01-0.1 Msun/yr (without SN feedback). Fragmentation only into 3-5 objects because stellar radiation destroys H2.
- Cold accretion + radiative feedback could cause the sequential formation of multiple SMSs
- (Sadanari+) If B-fields reach equipartition with turbulence before protostar formation, the B-field effects can reduce the number of fragments, leading to a top-heavy IMF. B-pressure and AM transport by magnetic torques stability disks.
- (Vanni+ 2023ab, 2024) Pop III imprints on the gas from both PISNe and CCSN in several chemical diagnostics.
- (Bosman+ 2022) Scatter in Lya forest opacitites between QSOs show that reionization is patchy even at z = 5-6, using XQR-30
- (Zhu+ 2023) Rapid evolution at z=5-6 signals photo-evaporation of optically thick absorbers, i.e. the ionizing photon mean-free path is smaller than what's expected in a fully ionized IGM
- (Meyer+ 2019) Galaxy-absorber connection through 2PCF. Enhanced Lya forest transition near galaxies? Suggests that galaxies drive reionization.
- (Kashino+ 2023) Now JWST is finding many more galaxies in QSO sightlines, supporting the previous point.
- (Becker+ 2024) Used simulated proximity zones to constrain the size of a possible neutral island at z=5.86 to 7.5 cMpc/h. Not a galaxy DLA, no metals, no nearby galaxies (Eilers+ 2024). Direct evidence that reionization is still incomplete at z~6. Was this region recently reionized?
- (Zhu+ 2024; Spina+ 2024) Stacking damping wings from dark gaps -> Mean neutral fraction > 6+/-4 % at z=5.8 -> neutral islands
- (Flury+ 2022ab) LzLCS (Low-z LyC survey). First statistical sample of LyC galaxies. 50/89 galaxies have LyC. With this sample, they can test different LyC diagnostics.
- (Izotov+ 2021; Flury+ 2022b; Saldana-Lopez+ 2022; Chisholm+ 2022) They have small Lya peak separation, high ionization, compact SF, weak ISM absorption lines, and patchy / dust-poor ISM.
- (Amorin+ 2024; Bait+ 2024) Correlation between broad H-alpha and UV escape fraction. Stronger outflows -> higher fesc
- (in prep) Lya and LyC Origins Survey (LaCOS) adds onto LzLCS. High fesc have compact Lya morphologies suggest a HI gasless. Consistent with SPHINX20 (Choustikov+ 2024)
- How can we explain the large scatter in Lya opacity at z = 5.5-6? The problem with invoking (e.g. tuning mean-free path, temperature) one cause is that it is difficult to meet other constraints.
- (Qin+ in prep) Try to explain it with a self-consistent, multi-tiered approach. Supplement 21cmFAST with small-scale structure from Sherwood simulations within a parameter sweep of several 21cmFAST parameters.
- This gives a conditional probability distribution of a forest line that can be used in a MC realization of many sightlines.
- Their results give a reionization history starting at 10% ionized at z
11 to 90% at z6. The 50% ionization state occurs at z=7.65, and it's completely ionized at z~5.4. - Also considered other models, e.g. galaxies in minihalos, constant fesc (instead of time-evolving). fesc decreases with increasing mass.
- The CGM ionization is significantly different at z=5.5 than z=6. Using XQR-30 to measure these CGM properties -- metal content, abundances, ionization state, etc.
- (Davies+ 2023b) Cosmic mass density of CIV at z=4.5-6, steeply declining with redshift. Caused by both metal enrichment and changei n ionization. They also show how each carbon ion traces different environments in a system.
- (Sebastian+ 2024) OI (13.6eV ionization) absorbers go up after z ~ 5.5, concurrent with HI
- (Christensen+ 2023) JWST observations (1 that's in XQR-30) of z=6.5-7.5 QSOs. However the lower-res spectra (R=2700 vs R=1e4 in X-Shooter) makes it hard to detect weak lines.
- Outstanding questions: Did the CGM remain self-shielded while the local IGM underwent reionization? Does a self-shielded CGM contribute to efficient SF?
Kai-Feng Chen - Mapping Cosmic Dawn with HERA: Improved Constraints on IGM Heating and the First X-ray Sources
- In 2022-23, they had Phase II 3rd season with 140 nights and 140 "good" antennae that can now observe from z=5.5-27 where previous phases had small frequency windows (Breitman+ 2023)
- (HERA Collaboration 2023) Constraints on X-ray heating sources from Phase I. Rules out high-metallicity HMXBs but becomes weaker if Pop III stars are included. Also demonstrated that the IGM was heated by z=10.4.
- (Rath+ 2024) Trying to quantify and model the systematics that are now showing through the noise.
- Using Explainable Boosting Machine (ML) to model Lya optical depth.
- Inputs: Two feature sets: HI number density, temperature, and baryon number density, photoionization rate (background + point sources), and temperature.
- Baryon density is the most important feature at z
5 with very small important on point sources. At z6.5, the point sources become a little more important (5-10%) where the density importance decreases. Nearly 30% come from pairwise interactions.
Xiangyu Jin - Probing the connection between IGM transmission and galaxies during cosmic reionization
- (in prep) Inspecting influence radii around [OIII] emitters. Finds an excess in IGM transmission around z<6.1 emitters.
- (Kashino+ 2023) At z<5.7, the IGM transmission steadily increases until 15 Mpc, but at higher redshifts, it peaks at 5 Mpc.
- (in prep) Stacked Lya transmission and also finds higher transition around [OIII] emitters.
- (Durovcikova+ 2024) Constrain QSO lifetimes between 3-10 Myr (CROC) or 0.1-1 Myr (ATON) with IGM transmission.
- (Mondal & Barkana 2023) Low-frequency 21cm during the Dark Ages (z > 30) and the signal's sensitivity to cosmological parameters.
- (Barro+ 2023; Labbe+ 2023) Large samples of little red dots (LRDs). Peculiar SEDs, and ALMA rules out dusty SF.
- (Greene+ 2023; Furtak+ 2023) LRD spectra, including a triply lensed source (r < 30 pc). High number densities. A few percent and ~20% of AGN are LRDs.
- (Kokorev+ 2023) Overly massive BH: ~1e8 Msun in a ~1e9 Msun stellar system
- (Wang+ 2023) Prominent Balmer lines and break in them.
- (Ma+ in prep) Very red AGN, best fit with super-Eddington SEDs, with the compact (r < 30 pc) stellar component dominant.
- What are LRDs? (1) AGN with lots of dense clouds (Maiolino+) = UV/X-ray obscured, (2) ...
- (Welsh+ 2022) Discovered new Z-poor DLAs with a very weak OI line.
- (Welsh+ submitted) [O/Fe] vs [Fe/H] in the most Z-poor DLAs. Flat between -2 and -3 but then rises below [Fe/H] = -3. More scatter in EMP ([Fe/H] < -3) DLAs than VMP ([Fe/H] < -2) DLAs, showing that the EMP systems are being enriched by fewer SNe.
- EMP DLAs are consistent with 1-2 enriching events. E_exp = 1.6e51 erg. M_Max = 32 Msun of metal ejecta.
- (Welsh+ 2019) Inferred EMP DLA properties: Mstar ~ 1e4 Msun, Mgas ~ 1e6 Msun.
- (Zaidi+ 2024) From galaxy clustering and using a halo occupation distribution, they obtain a stellar mass / halo mass relation at various redshift bins out to z=4.5.
- When they jointly fit all of the z-bins instead of independently, the error bars in the SMHM relation shrink dramatically. The peak halo mass is maximal at z~2. Caused by changing AGN feedback?
- UFDs have truncated SF histories at reionization (obs: Sacchi+ 2021; theory: Jeon+ 2017)
- (Jeon+ 2023) 6 target UFD host halos that fall toward a MW-like galaxy. They compare SFHs between uniform versus patchy reionization. The latter case can extend the SF down to z~5 instead of being totally quenched at z=7 when the UVB is turned on.
- It takes about 400-500 Myr for the UFD progenitors' SF to be quenched, which is comparable to the difference between the Magellanic UFD SFHs and non-Magellanic UFD SFHs, i.e.
$\tau_90$ the lookback time to 90% of the current stellar mass form. - The uniform reion model have lower Mstar and metallicity, compared to the patchy reionization model.
- (Ou+ 2024) Hercules is getting disrupted. Through foreground and binary removal, they can dynamically model Hercules while studying its extended stellar halo. They found signatures of tidal disruption.
Nozomu Tominaga - Narrow-band metal-poor star surveys with Subaru/Hyper Suprime Cam and Tomo-e Gozen Camera
- Previous narrow-band surveys for EMPs: Skymapper (Keller+) and Pristine (Starkenberg+)
- (Martin+ 2023) ZERO (Zero Enrichment Rare Objects) survey. Ultimate goal = Discover low-mass Pop III stars and understand the structure and evolution of the MW. Full survey complete in 2025.
- (Roederer+ 2022) Measurements of rare elements and abundance patterns of EMP stars. The ZERO survey wants to replicate such analysis for even a larger sample of EMP / Pop III(?) stars
- (Übler+ 2023; Ji+ 2024) Broad-line AGN (GS_3073) at z~5.5 with high S/N without X-ray (also see Maiolino+ 2023)
- (Perna+ 2023) Dual AGN candidates in GA-NIFS.
- (Übler+ 2024) Off-center MBH at z=7.15 by ~620pc from the stellar [OIII] component.
- (Mazzolari+ 2024) New AGN line diagnostic: [OIII]4363/Hg vs [OIII]5007?/[OIII]4363
- (Maiolino+ 2023) Possible Pop III signature in the halo of GN-z11 with a HeII 1640 detection that's spatially distinct from the main source. Could be powered by 2e5 Msun Pop III cluster or a DCBH.
- (Tee+ 2023) Selection methods for high-z QSOs, which has a success rate of ~30% at z=6-6.5 but it becomes worse at z=7
- Predicts 10-30 QSOs at z>8 with Roman and
16 with EUCLID and even up to z9
- (Lucey+ 2022) Early r-process detections within the inner MW
- (Verwohlt+ 2024) With HERA, the two parameters in ETHOS can be constrained and they studied dark acoustic oscillations (DAOs)
- (Hegde & Furlanetto 2023) Pop III SAM, including the newest results on the critical halo mass for Pop III formation. Also see Hegde+ (2024) for overmassive BHs at high-z.
- (Ji, Curtis+ 2024) Extremely unusual abundance pattern of J0931+0038. Low odd elements, low Sc/Ti/V, high Fe group, and high 1st peak r-process but extremely low Ba. Clear preference for >50Msun progenitor but no single model works well.
