We present emission-line ratios from a sample of 27 Lyman-break galaxies from
z
∼ 5.5 − 9.5 with −17.0 <
M
1500
< −20.4, measured from ultra-deep JWST/NIRSpec multi-object spectroscopy from the ...JWST Advanced Deep Extragalactic Survey (JADES). We used a combination of 28 h deep PRISM/CLEAR and 7 h deep
G
395
M
/
F
290
LP
observations to measure, or place strong constraints on, ratios of widely studied rest-frame optical emission lines including H
α
, H
β
, O
II
λλ
3726, 3729, Ne
III
λ
3869, O
III
λ
4959, O
III
λ
5007, O
I
λ
6300, N
II
λ
6583, and S
II
λλ
6716, 6731 in individual
z
> 5.5 spectra. We find that the emission-line ratios exhibited by these
z
∼ 5.5 − 9.5 galaxies occupy clearly distinct regions of line-ratio space compared to typical
z
∼ 0 − 3 galaxies, instead being more consistent with extreme populations of lower-redshift galaxies. This is best illustrated by the O
III
/O
II
ratio, tracing interstellar medium (ISM) ionisation, in which we observe more than half of our sample to have O
III
/O
II
> 10. Our high signal-to-noise spectra reveal more than an order of magnitude of scatter in line ratios such as O
II
/H
β
and O
III
/O
II
, indicating significant diversity in the ISM conditions within the sample. We find no convincing detections of N
II
λ
6583 in our sample, either in individual galaxies, or a stack of all
G
395
M
/
F
290
LP
spectra. The emission-line ratios observed in our sample are generally consistent with galaxies with extremely high ionisation parameters (log
U
∼ −1.5), and a range of metallicities spanning from ∼0.1 ×
Z
⊙
to higher than ∼0.3 ×
Z
⊙
, suggesting we are probing low-metallicity systems undergoing periods of rapid star formation, driving strong radiation fields. These results highlight the value of deep observations in constraining the properties of individual galaxies, and hence probing diversity within galaxy population.
We explore the kinematic gas properties of six 5.5 < z < 7.4 galaxies in the JWST Advanced Deep Extragalactic Survey (JADES), using high-resolution JWST/NIRSpec multi-object spectroscopy of the ...rest-frame optical emission lines O III and H α . The objects are small and of low stellar mass (∼1 kpc; M * ∼ 10 7 − 9 M ⊙ ), less massive than any galaxy studied kinematically at z > 1 thus far. The cold gas masses implied by the observed star formation rates are about ten times higher than the stellar masses. We find that their ionised gas is spatially resolved by JWST, with evidence for broadened lines and spatial velocity gradients. Using a simple thin-disc model, we fit these data with a novel forward-modelling software that accounts for the complex geometry, point spread function, and pixellation of the NIRSpec instrument. We find the sample to include both rotation- and dispersion-dominated structures, as we detect velocity gradients of v ( r e )∼100 − 150 km s −1 , and we find velocity dispersions of σ 0 ∼ 30 − 70 km s −1 that are comparable to those at cosmic noon. The dynamical masses implied by these models ( M dyn ∼ 10 9 − 10 M ⊙ ) are higher than the stellar masses by up to a factor 40, and they are higher than the total baryonic mass (gas + stars) by a factor of ∼3. Qualitatively, this result is robust even if the observed velocity gradients reflect ongoing mergers rather than rotating discs. Unless the observed emission line kinematics is dominated by outflows, this implies that the centres of these galaxies are dominated by dark matter or that star formation is three times less efficient, leading to higher inferred gas masses.
We present a study of the environments of 17 Lyman-
α
emitting galaxies (LAEs) in the reionisation-era (5.8 <
z
< 8) identified by JWST/NIRSpec as part of the JWST Advanced Deep Extragalactic ...Survey (JADES). Unless situated in sufficiently (re)ionised regions, Lyman-
α
emission from these galaxies would be strongly absorbed by neutral gas in the intergalactic medium (IGM). We conservatively estimate sizes of the ionised regions required to reconcile the relatively low Lyman-
α
velocity offsets (Δ
v
Ly
α
< 300 km s
−1
) with moderately high Lyman-
α
escape fractions (
f
esc, Ly
α
> 5%) observed in our sample of LAEs, suggesting the presence of ionised hydrogen along the line of sight towards at least eight out of 17 LAEs. We find minimum physical ‘bubble’ sizes of the order of
R
ion
∼ 0.1–1 pMpc are required in a patchy reionisation scenario where ionised bubbles containing the LAEs are embedded in a fully neutral IGM. Around half of the LAEs in our sample are found to coincide with large-scale galaxy overdensities seen in FRESCO at
z
∼ 5.8–5.9 and
z
∼ 7.3, suggesting Lyman-
α
transmission is strongly enhanced in such overdense regions, and underlining the importance of LAEs as tracers of the first large-scale ionised bubbles. Considering only spectroscopically confirmed galaxies, we find our sample of UV-faint LAEs (
M
UV
≳ −20 mag) and their direct neighbours are generally not able to produce the required ionised regions based on the Lyman-
α
transmission properties, suggesting lower-luminosity sources likely play an important role in carving out these bubbles. These observations demonstrate the combined power of JWST multi-object and slitless spectroscopy in acquiring a unique view of the early Universe during cosmic reionisation via the most distant LAEs.
We investigate the incidence and properties of ionised gas outflows in a sample of 52 galaxies with stellar masses between 10 7 M ⊙ and 10 9 M ⊙ observed with ultra-deep JWST/NIRSpec MSA spectroscopy ...as part of the JWST Advanced Deep Extragalactic Survey (JADES). The high-spectral resolution (R2700) NIRSpec observations allowed us to identify for the first time the potential signature of outflows in the rest-frame optical nebular lines in low-mass galaxies at z > 4. The incidence fraction of ionised outflows, traced by broad components, is about 25–40%, depending on the intensity of the emission lines. The low incidence fraction might be due to both the sensitivity limit and the fact that outflows are not isotropic, but have a limited opening angle, which only results in detection when this is directed toward our line of sight. Evidence for outflows increases slightly with stellar mass and star formation rate. The median velocity and mass-loading factor (i.e. the ratio of the mass outflow rate and star formation rate) of the outflowing ionised gas are 350 km s −1 and η = 2.0 −1.5 +1.6 , respectively. These are 1.5 and 100 times higher than the typical values observed in local dwarf galaxies. Some of these high-redshift outflows can escape the gravitational potential of the galaxy and dark matter halo and enrich the circumgalactic medium and possibly even the intergalactic medium. Our results indicate that outflows can significantly impact the star formation activity in low-mass galaxies within the first 2 Gyr of the Universe.
Finding the emergence of the first metals in the early Universe and identifying their origin are some of the most important goals of modern astrophysics. We present deep spectroscopy of a galaxy at ...z=12.5, in which we report the detection of the nebular emission line. This represents the most distant detection of a metal transition, and the most distant redshift determination based on emission lines. In addition, we report tentative detections of and and possibly By using the accurate redshift obtained from we can model the drop to reliably measure an absorbing column density of hydrogen of $ $, which is too high for an IGM origin and implies an abundant neutral ISM in or in the CGM around it. We tentatively infer a lower limit for the neutral gas mass of about $10^7 M_ which, compared with the galaxy stellar mass of $ 10^7 M_ implies a gas fraction higher than about 0.2--0.5. By comparing the measured emission lines with model-based diagnostic diagrams, we derive a solar or even super-solar carbon-to-oxygen ratio, tentatively $ (C/O) > -0.21$ dex ($ while a Bayesian modelling of the spectrum indicates $ (C/O) This is higher than the C/O measured in galaxies discovered by at $z=6 9$, and higher than the C/O arising from Type II supernovae enrichment. Asymptotic giant branch stars can hardly contribute to the observed carbon enrichment at these early epochs and low metallicities. Such a high C/O in a galaxy observed 350 Myr after the Big Bang may thus be explained by the yields of extremely metal-poor stars, and may even be the heritage of the first generation of supernovae from Population III progenitors. A robust determination of the total metallicity in this galaxy is essential to constrain these scenarios.
Background: The availability of multimodal patient data, such as demographics, clinical, imaging, treatment, quality of life, outcomes and wearables data, as well as genome sequencing, have paved the ...way for the development of multimodal clinical solutions that introduce personalized or precision medicine. The clinical report is an information layer that contains relevant information about the disease in addition to the patient's point of view. Natural language processing (NLP) is a branch of artificial intelligence (AI) and its pre-trained language models are the key technology for extracting value from this data layer. Aims: This project was conducted by GenoMed4all and Synthema EU consortia, with the aim to: 1) Build an AI language model specific for the hematology domain. 2) Use NLP technology to extract relevant information from clinical reports and perform unsupervised stratification of patients, in order to 3) demonstrate that the clinical report is earlier access to data relative to disease clinical phenotype and biology and provide important information for patient stratification and prediction of clinical outcomes. Methods: To translate text sentences into numerical embeddings, we implemented bidirectional encoder representations from transformers (BERT) framework. To learn text representations and correlations within data, we performed domain-adaptation by fine-tuned pre-trained model on hematological clinical reports of patients with myeloproliferative neoplasms (MPN), myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Patient stratification was performed by HDBSCAN clustering on text embedding encoded by BERT (HematoBERT). Clusters validation was performed by assessing patients' diagnosis and survival probability. Finally, we compared domain-tuned HematoBERT vs pre-trained non-contextualized models. Results: We implemented HematoBERT based on the bert-base-multilingual-uncased version of BERT. Training data were hematological text reports of 1,328 patients. During fine-tuning, texts were tokenized, then we randomly replaced 15% of the tokens with masked tokens, training the model to predict them. We performed stratification using clinical reports from a validation cohort of 360 patients. We identified 7 clusters, defined according to similar words in meaning that were placed in a specific topic. We extracted the most important words and concepts for each cluster (topic) and we summarized them into effective descriptions for each group of patients. Two clusters included MDS patients with excess blasts, and without excess blasts with ring sideroblasts and del5q (n=69, n=115). One cluster included patients with excess blasts and MDS/MPN (n= 33). Two clusters included MPN patients with primary and secondary myelofibrosis, and MPN patients most including subjects affected with polycythemia vera and essential thrombocythemia (n=35, n=46). Two clusters included patients with AML from MDS and therapy-related AML, and patients with de novo AML (n=22, n=42). Clinical validation was performed based on the diagnosis and survival probability of patients assigned to clusters. Patients' diagnoses were compatible with the cluster assignment (Figure 1). Frequency of gene mutations (as assessed by targeted Next-Generation Sequencing) among different clusters reflected the well-known genotypic-phenotypic associations in MDS, MPN and AML. Kaplan-Maier curves indicated significative risk stratification in clusters in terms of survival probability (Figure 2), similar to stratifications performed on clinical and genomic data. Finally, we evaluate the domain adaptation by comparing the model to other pre-trained non-contextualized ones. Pseudo perplexity score (PPS), accuracy and F1 score were calculated to quantify how good the models are when they see new data, predicting the next word given the context of the sentence. HematoBERT obtained high PPS, accuracy and F1 scores, outperforming the other models also trained on generic clinical domains. Conclusion: Domain-adapted language models are able to understand contexts and correlations in documents. HematoBERT can be used to extract relevant features from clinical reports. This data layer is relevant to perform disease stratification of patients based on clinical and genomic information and could be integrated into next-generation multimodal models of personalized medicine.
Local and low-redshift (z < 3) galaxies are known to broadly follow a bimodal distribution: actively star-forming galaxies with relatively stable star-formation rates and passive systems. These two ...populations are connected by galaxies in relatively slow transition. By contrast, theory predicts that star formation was stochastic at early cosmic times and in low-mass systems
. These galaxies transitioned rapidly between starburst episodes and phases of suppressed star formation, potentially even causing temporary quiescence-so-called mini-quenching events
. However, the regime of star-formation burstiness is observationally highly unconstrained. Directly observing mini-quenched galaxies in the primordial Universe is therefore of utmost importance to constrain models of galaxy formation and transformation
. Early quenched galaxies have been identified out to redshift z < 5 (refs.
) and these are all found to be massive (M
> 10
M
) and relatively old. Here we report a (mini-)quenched galaxy at z = 7.3, when the Universe was only 700 Myr old. The JWST/NIRSpec spectrum is very blue (U-V = 0.16 ± 0.03 mag) but exhibits a Balmer break and no nebular emission lines. The galaxy experienced a short starburst followed by rapid quenching; its stellar mass (4-6 × 10
M
) falls in a range that is sensitive to various feedback mechanisms, which can result in perhaps only temporary quenching.
