bluuebunny/crossref_metadata_2025_split huggingface dataset:
Properties of galaxies at z ≈ 7 – 9 revealed by ALMA
Authors: Hashimoto Takuya 
Published: June 2020

AbstractUnderstanding properties of galaxies in the epoch of reionization (EoR) is a frontier in the modern astronomy. With the advent of ALMA, it has become possible to detect far-infrared fine structure lines (e.g. [CII] 158 μm and [OIII] 88 μm) and dust continuum emission in star-forming galaxies in the EoR. Among these lines, our team is focusing on [OIII] 88 μm observations in high-z galaxies. After the first detection of [OIII] in the epoch of reionization (EoR) in 2016 from our team at z = 7.21, there are now more than ten [OIII] detections at z > 6 up to z = 9.11. Interestingly, high-z galaxies typically have very high [OIII]-to-[CII] luminosity ratio ranging from 3 to 12 or higher, demonstrating [OIII] is a powerful tracer at high-z. The high luminosity ratios may imply that high-z galaxies have low gas-phase metallicity and/or high ionization states.
Interpreting galaxy properties with improved modelling
Authors: Stanway E. R. , Eldridge J. J. 
Published: June 2020

AbstractObservations of star-forming galaxies in the distant Universe have confirmed the importance of massive stars in shaping galaxy emission and evolution. Distant stellar populations are unresolved, and the limited data available must be interpreted in the context of stellar population models. Understanding these populations, and their evolution with age and heavy element content is key to interpreting processes such as supernovae, cosmic reionization and the chemical enrichment of the Universe. With the upcoming launch of JWST and observations of galaxies within a billion years of the Big Bang, the uncertainties in modelling massive stars - particularly their interactions with binary companions - are becoming increasingly important to our interpretation of the high redshift Universe. In turn, observations of distant stellar populations provide ever stronger tests against which to gauge the success of, and flaws in, current massive star models. Here we briefly review the current status binary stellar population synthesis.
FirstLight: Cosmological simulations of first galaxies at cosmic dawn
Authors: Ceverino Daniel 
Published: June 2020

AbstractCosmological hydrodynamical simulations have become an important theoretical tool for understanding the formation and evolution of the first galaxies during cosmic dawn, between redshifts 5 and 15. I will introduce the FirstLight database of about 300 zoom-in simulations with a resolution of 10 parsecs. This database agrees well with observed UV luminosity functions and stellar mass functions. I will discuss the origin and evolution of the star-forming main sequence of galaxies and the main drivers of the star formation histories at these early epochs. I will show simulated SEDs from UV to IR, including stellar and nebular emission. The rest-frame UV spectra show steep slopes and a high production efficiency of Lyman continuum photons. These properties are consistent with young stellar populations with low metallicities. Simulated recombination lines allow us to link the physical conditions of the gas around these stellar populations with observables, like equivalent widths in OIII or Hα or BPT diagrams at high-z. These simulations are making predictions that will be tested for the first time in future deep fields with the James Webb Space Telescope (JWST). I will finally discuss preliminary results involving JWST mock fields and predictions for ALMA observations by post-processing FirstLight snapshots with Powderday radiative transfer code.
Star-formation efficiency at 600Myr of cosmic time
Authors: Stefanon Mauro , Labbé Ivo , Bouwens Rychard , Oesch Pascal 
Published: June 2020

AbstractCurrent observations suggest an accelerated evolution of the cosmic star formation rate density for 8 < z < 10, indicating that galaxy assembly experienced an extremely intense phase during the first ∼600Myr years of cosmic time. We performed a systematic search of ultrabright star-forming galaxies at z ∼ 8 over the COSMOS/UltraVISTA survey, identifying 16 candidate Lyman-break galaxies. The still large uncertainties on the associated volume density do not yet allow us to ascertain whether a different star-formation efficiency (SFE) existed at early cosmic epochs. Leveraging the deepest Spitzer/IRAC data available from the GREATS program over the CANDELS/GOODS fields, we also constructed stacked SEDs of sub- L* LBGs at z ∼ 8. We find extreme nebular line emission (EW0 (Hα) ∼ 1000Å), high specific star-formation rates (∼10/Gyr) and indication of an inverse Balmer break. These results point toward very young ages (<100 Myr), and, combined with measurements at lower redshifts, that the SFE evolved only marginally during the first ∼1.5Gyr of cosmic history.
The AGN-galaxy connection: Low-redshift benchmark & lessons learnt
Authors: Juneau Stéphanie 
Published: June 2020

AbstractSeveral scenarios have been proposed to describe the physical connection between galaxies and their central active galactic nuclei (AGN). This connection could act on a range of spatial scales and vary across cosmic time. In these proceedings, we consider black hole and galaxy growth and whether that growth is affected by AGN feedback both based on statistical approaches – which reveal general population trends – and based on an individual case study – which gives us a more detailed insight on the physical processes at play. For the statistical approach, we showcase a low-redshift (0.04 < z < 0.2) SDSS sample with AGN classification based on a combination of emission-line diagnostic diagrams, and for which we account for sample selection by using a V/Vmax approach. The trends on the star formation rate - stellar mass (SFR – M*) plane suggest that the most likely connection is a common gas reservoir for star formation and AGN, and that they both decline as the gas reservoir is consumed. The trends established at low-redshift could act as a local benchmark against which to compare higher redshift studies. As a complementary approach, we use a detailed case study of a nearby AGN host with integral field spectroscopy from the VLT/MUSE instrument in order to spatially resolve the interplay between AGN feedback and the host galaxy. We find that the galaxy substructure likely plays a role by collimating and/or obscuring the outflows and radiation from the central engine. Ongoing and future work with 3D spectroscopy will enable us to learn more about galaxy and black hole coevolution. Lastly, we briefly discuss lessons learnt from both approaches.
New insight on the far-UV SED and He ii emission from low metallicity galaxies
Authors: Schaerer Daniel , Izotov Yuri , Fragos Tassos 
Published: June 2020

AbstractUnderstanding the ionizing spectrum of low-metallicity galaxies is of great importance for modeling and interpreting emission line observations of early/distant galaxies.Although a wide suite of stellar evolution, atmosphere, population synthesis, and photoionization models, taking many physical processes into account now exist, all models face a common problem: the inability to explain the presence of nebular Heii emission, which is observed in many low metallicity galaxies, both in UV and optical spectra. Several possible explanations have been proposed in the literature, including Wolf-Rayet (WR) stars, binaries, very massive stars, X-ray sources, or shocks. However, none has so far been able to explain the major observations.We briefly discuss the He ii problem, available empirical data, and observed trends combining X-ray, optical and other studies. We present a simple and consistent physical model showing that X-ray binaries could explain the long-standing nebular Heii problem. Our model, described in Schaerer et al. (2019), successfully explains the observed trends and strength of nebular He ii emission in large samples of low metallicity galaxies and in individual galaxies, which have been studied in detail and with multi-wavelength observations. Our results have in particular important implications for the interpretation of galaxy spectra in the early Universe, which will be obtained with upcoming and future facilities.
Lyα generation in intermediate velocity shock waves
Authors: Lehmann Andrew , Godard Benjamin , Pineau des Forêts Guillaume , Falgarone Edith 
Published: June 2020

AbstractWe update the Paris-Durham shock model, a state-of-the-art magnetohydrodynamic (MHD) shock code developed with a focus on molecular chemistry, in order to account for the self-generated UV field produced in shocks at velocities in the range 25-50 km/s. In these shocks there is significant excitation of atomic Hydrogen, with a large flux of Lyα photons escaping ahead of the shock to heat, ionize and drive molecular chemistry in a large slab of preshock gas.
The most distant quasars and their environments
Authors: Bañados Eduardo 
Published: June 2020

AbstractThe number of quasars known within the first billion years of the universe (z > 6) has increased significantly over the last five years. Many of these recently discovered quasars are ideal targets for observatories in the southern hemisphere such as ALMA. I will review the current status of the highest-redshift quasars and their environments, highlighting main achievements and limitations. I will then discuss how synergistic JWST/ALMA observations will shed light onto the properties and formation of some of the most extreme environments in the early universe.
Uncovering QSO-driven outflows and galaxy assembly at cosmic Dawn with ALMA
Authors: Bischetti Manuela 
Published: June 2020

AbstractI will present evidence of QSO-driven outflows in the early Universe, resulting from the stacking analysis of ALMA observations of the [CII] emission line for a sample of 50 QSOs at z ∼ 5 – 7. The high sensitivity reached by our analysis allowed us to assess that very broad wings are on average present in the [CII] profile, and extend beyond velocities of 1000 km/s in systems with low and high SFR. Such wings are therefore tracing QSO-driven [CII] outflows, with associated mass outflow rates of 100 – 200Mȯ / yr. I will discuss how these outflows relate to those observed in lower-z AGNs and give an estimate of their spatial extent. Furthermore, I will focus on the high-resolution ALMA observation of a hyper luminous QSO at z ∼ 4.5, revealing an exceptional overdensity with multiple companions as close as 2 kpc. These crowded surroundings, and the QSO host galaxy itself, are forming stars at a very high rate (hundreds of Mȯ / yr), suggesting that a significant fraction of the stellar mass assembly at early epochs might have taken place in the companions. I will discuss how the BH and host-galaxy masses are growing in this multi- source system, which likely represents the cradle of what would be a giant galaxy at z = 0.
Analogs of high redshift galaxies: Disentangling the complexity of the green peas
Authors: Amorin Ricardo 
Published: June 2020

AbstractYoung low-mass galaxies with extreme emission-line properties are ubiquitous at high redshift. However, a detailed characterisation of their physical properties, key for understanding cosmic reionisation and the early growth of galaxies, will be only possible with JWST and ELT observations. Rare lower-z analogues of these primeval galaxies provide us ideal laboratories to study in larger detail the complex physical mechanisms taking place in these extreme systems. In this talk, I will review key results from these high-z analogues, with an emphasis on lessons learned from deep spectroscopic observations of green pea galaxies at z ⩽ 0.3. New recent results based on high-dispersion Echelle and IFU spectroscopy of green peas will be presented. They illustrate current advantages and limitations of the chemodynamical analysis for a simultaneous study of the ionised gas kinematics, chemical enrichment and the escape of ionising photons in compact low-mass starbursts.
The role of the JWST near-infrared spectrograph NIRSpec in understanding the assembly and evolution of galaxies
Authors: Alves de Oliveira Catarina 
Published: June 2020

AbstractThe near-infrared spectrograph NIRSpec is one of four instruments aboard the James Webb Space Telescope (JWST). It offers seven dispersers covering the wavelength range from 0.6 to 5.3 micron with resolutions from R ∼ 100 to R ∼ 2700. Using an array of micro-shutters for target selection, the multi-object spectroscopy mode of NIRSpec will be capable of obtaining spectra from a few tens to more than 200 objects simultaneously. It also features an integral field unit with a 3 by 3 arcseconds field of view, and various slits for high contrast spectroscopy of individual objects. We will provide an overview of the capabilities and performances of these three observing modes highlighting how NIRSpec will contribute to the quest to further understand the assembly and evolution of galaxies from the end of re-ionisation epoch to the present day.
Late Paleoproterozoic to Early Mesoproterozoic Mafic Magmatism in the SW Yangtze Block: Mantle Plumes Associated With Nuna Breakup?
Authors: Lu Gui‐Mei , Wang Wei , Cawood Peter A. , Ernst Richard E. , Raveggi Massimo , Huang Si‐Fang , Xue Er‐Kun 
Published: June 2020

AbstractNumerous late Paleoproterozoic to early Mesoproterozoic mafic magmatic rocks are exposed in the southwestern Yangtze Block, corresponding to early breakup of the Nuna supercontinent. Geochronological data reveal three episodes of mafic magmatism at ~1,740, 1,700, and 1,500 Ma. The two older generations have MORB‐like Nb/Ta ratios and superchondritic Nd‐Hf isotopes, indicating that they were likely derived from partial melting of asthenospheric mantle. In contrast, the ~1,500 Ma mafic rocks possess OIB‐like Nb/Ta (16.7–19.1) and Zr/Hf (41.0–45.1) ratios, εNd (t) values (−0.8 to +0.1), and εHf (t) values (−3.3 to +8.4), suggesting that they originated from a mantle plume. These three pulses of mafic magmatic activity in the Yangtze Block have geochemical features (such as TiO2 contents, Nb/Y, and La/Yb values), similar to coeval mafic rocks in Siberia and Laurentia, consistent with detrital zircon provenance studies, which show a spatial linkage of the Yangtze Block with northern Laurentia in the Nuna configuration. Taking all synchronous mafic magmatism into account, a mantle plume beneath southern Siberia was considered to be initiated at ~1,750 Ma forming a broad region of mafic magmatism that extended into the Yangtze Block as well as beneath northern Laurentia and resulted in lithospheric extension. The Yangtze Block was possibly the nearest neighbor to northwestern Siberia at ~1,500 Ma and subsequently drifted from the Nuna supercontinent induced by the ~1,500 Ma Kuonamka mantle plume, heralding a period of limited magmatic activity and tectonic quiescence in the Yangtze Block that extended throughout the remainder of the Mesoproterozoic.
The Spatiotemporal Variability of Cloud Radiative Effects on the Greenland Ice Sheet Surface Mass Balance
Authors: Izeboud M. , Lhermitte S. , Van Tricht K. , Lenaerts J. T. M. , Van Lipzig N. P. M. , Wever N. 
Published: June 2020

AbstractTo better understand and quantify the impact of clouds on the Greenland Ice Sheet surface mass balance (SMB), we study the spatiotemporal variability of the cloud radiative effect (CRE). The total CRE is separated in short‐term and long‐term impacts by performing multiple simulations with the SNOWPACK model for 2001‐+2010. The annual total CRE is 16.8 ± 4.5 W m−2, reducing the SMB with −157 ± 3.8 Gt yr−1. Summer cloud radiative cooling is −6.4 ± 5.7 W m−2 in the ablation area, increasing the SMB with 121 ± 2.2 Gt yr−1. The annual integrated impact is cloud‐reduced SMB of −36 Gt yr−1. The short‐term effect dominates the opposing long‐term effects through the albedo‐melt feedback. A long‐term warming effect decreases the albedo and so preconditions the surface for enhanced (summer) melt. The impact of the CRE, determined by spatial, temporal and initial conditions, explains existing conflicted views on the role of cloud radiation and emphasizes the need for accurate cloud and albedo representations in future studies.
Distributed Acoustic Sensing of Seismic Properties in a Borehole Drilled on a Fast‐Flowing Greenlandic Outlet Glacier
Authors: Booth Adam D. , Christoffersen Poul , Schoonman Charlotte , Clarke Andy , Hubbard Bryn , Law Robert , Doyle Samuel H. , Chudley Thomas R. , Chalari Athena 
Published: June 2020

AbstractDistributed Acoustic Sensing (DAS) is a new technology in which seismic energy is detected, at high spatial and temporal resolution, using the propagation of laser pulses in a fiber‐optic cable. We show analyses from the first glaciological borehole DAS deployment to measure the englacial and subglacial seismic properties of Store Glacier, a fast‐flowing outlet of the Greenland Ice Sheet. We record compressional and shear waves in 1,043 m‐deep vertical seismic profiles, sampled at 10 m vertical resolution, and detect a transition from isotropic to anisotropic ice at 84% of ice thickness, consistent with the Holocene‐Wisconsin transition. We identify subglacial reflections originating from the base of a 20 m‐thick layer of consolidated sediment and, from attenuation measurements, interpret temperate ice in the lowermost 100 m of the glacier. Our findings highlight the promising potential of DAS technology to constrain the seismic properties of glaciers and ice sheets.
Role of Atmospheric Variability in Driving the “Warm‐Arctic, Cold‐Continent” Pattern Over the North America Sector and Sea Ice Variability Over the Chukchi‐Bering Sea
Authors: Guan Weina , Jiang Xianan , Ren Xuejuan , Chen Gang , Ding Qinghua 
Published: June 2020

AbstractWhile the observed decline of sea ice over the Chukchi‐Bering Sea (CBS) has coincided with the “warm‐Arctic, cold‐continent” (WACC) pattern over the North America (NA) sector, there is a debate on the causes of the WACC pattern. Here we present a very similar WACC pattern over the NA sector on both interannual and subseasonal time scales. Lead‐lag regression analyses on the shorter time scale indicate that an anomalous anticyclonic circulation over Alaska/Yukon in conjunction with the downward surface turbulent heat flux and long‐wave radiation anomalies over CBS leads the formation of the WACC pattern by about 1–2 days, while the latter further leads CBS sea ice reduction by about 3 days. These results indicate that atmospheric variability may play an active role in driving both the WACC pattern over NA and CBS sea ice variability.
Interaction Between Mesoscale Eddies and the Gyre Circulation in the Lofoten Basin
Authors: Raj R. P. , Halo I. , Chatterjee S. , Belonenko T. , Bakhoday‐Paskyabi M. , Bashmachnikov I. , Fedorov A. , Xie J. 
Published: June 2020

AbstractThe interaction between the mesoscale eddies and the cyclonic gyre circulation of the Lofoten Basin is studied using a suite of satellite altimeters, a regional coupled ocean‐sea‐ice data assimilation system (the TOPAZ reanalysis) and Argo float data. An automated method identified 5,373/5,589 individual anticyclonic/cyclonic eddies in the Lofoten Basin from more than 65,000 altimeter‐based eddy observations, of which 70–85% are found to be nonlinear. The nonlinearity of eddies is estimated from its translational and rotational velocities. The study found clustering of highly intense nonlinear eddies on either side of the Lofoten Basin. Further, we show the distinct cyclonic drift of the anticyclonic and cyclonic eddies, both confined to the western side of the basin, and its similarity to the middepth gyre circulation also confined to the same region. A well‐defined cyclonic drift pattern of eddies is found during the time period when the gyre circulation of the basin is strengthened, while a clear cyclonic drift of eddies is absent during a weakened gyre. Analysis of barotropic energy conversion in the reanalysis data shows maximum transfer of energy from the eddy field to the mean flow in the Lofoten Vortex region. Even though comparatively smaller (roughly 9 times) there is also notable transfer of energy from the mean flow to the eddies in the region located outside the Lofoten Vortex. Our study shows that the gyre circulation when strengthened, receives more energy from the Lofoten Vortex and loses less energy to those eddies circulating around the Lofoten Vortex.
Host dysbiosis negatively impacts IL-9-producing T-cell differentiation and antitumour immunity
Authors: Almeida Rafael Ribeiro , Vieira Raquel de Souza , Castoldi Angela , Terra Fernanda Fernandes , Melo Amanda Campelo L. , Canesso Maria Cecília Campos , Lemos Luísa , Cipelli Marcella , Rana Nisha , Hiyane Meire Ioshie , Pearce Erika L. , Martins Flaviano dos Santos , Faria Ana Maria Caetano de , Câmara Niels Olsen Saraiva 
Published: June 2020

Abstract
Background
Host–microbiota interactions shape T-cell differentiation and promote tumour immunity. Although IL-9-producing T cells have been described as potent antitumour effectors, their role in microbiota-mediated tumour control remains unclear.

Methods
We analysed the impact of the intestinal microbiota on the differentiation of colonic lamina propria IL-9-producing T cells in germ-free and dysbiotic mice. Systemic effects of the intestinal microbiota on IL-9-producing T cells and the antitumour role of IL-9 were analysed in a model of melanoma-challenged dysbiotic mice.

Results
We show that germ-free mice have lower frequency of colonic lamina propria IL-9-producing T cells when compared with conventional mice, and that intestinal microbiota reconstitution restores cell frequencies. Long-term antibiotic treatment promotes host dysbiosis, diminishes intestinal IL-4 and TGF-β gene expression, decreases the frequency of colonic lamina propria IL-9-producing T cells, increases the susceptibility to tumour development and reduces the frequency of IL-9-producing T cells in the tumour microenvironment. Faecal transplant restores intestinal microbiota diversity, and the frequency of IL-9-producing T cells in the lungs of dysbiotic animals, restraining tumour burden. Finally, recombinant IL-9 injection enhances tumour control in dysbiotic mice.

Conclusions
Host–microbiota interactions are required for adequate differentiation and antitumour function of IL-9-producing T cells.
Integrated analysis of the molecular pathogenesis of FDXR-associated disease
Authors: Slone Jesse D. , Yang Li , Peng Yanyan , Queme Luis F. , Harris Belinda , Rizzo Stacey J. Sukoff , Green Torrian , Ryan Jennifer L. , Jankowski Michael P. , Reinholdt Laura G. , Huang Taosheng 
Published: June 2020

AbstractThe mitochondrial flavoprotein ferredoxin reductase (FDXR) is required for biogenesis of iron–sulfur clusters and for steroidogenesis. Iron–sulfur (Fe–S) clusters are ubiquitous cofactors essential to various cellular processes, and an increasing number of disorders are associated with disruptions in the synthesis of Fe–S clusters. Our previous studies have demonstrated that hypomorphic mutations in FDXR cause a novel mitochondriopathy and optic atrophy in humans and mice, attributed in part to reduced function of the electron transport chain (ETC) as well as elevated production of reactive oxygen species (ROS). Inflammation and peripheral neuropathy are also hallmarks of this disease. In this paper, we demonstrate that FDXR mutation leads to significant optic transport defects that are likely to underlie optic atrophy, a major clinical presentation in FDXR patients, as well as a neurodegenerative loss of cells in the central nervous system (CNS). Molecular analysis indicates that FDXR mutation also leads to mitochondrial iron overload and an associated depolarization of the mitochondrial membrane, further supporting the hypothesis that FDXR mutations cause neurodegeneration by affecting FDXR’s critical role in iron homeostasis.