arXiv subjects

José Afonso

Publications and source records attributed to José Afonso.

At least 19 recordsLinked to original sources

arXiv2026

Nebular continuum in high-redshift galaxies with JWST

Studying the relevance of accounting for both stellar and nebular continuum emission when performing optical spectral fitting has been mainly limited to galaxies in the local Universe. The high-quality spectroscopy provided by JWST is now opening the possibility of carrying out these studies in the younger Universe. We aim to estimate the nebular continuum contribution (X$_{\text{neb}}$) of high-redshift star-forming (SF) galaxies, explore its relation to common tracers and galaxy properties, and test the previously established threshold for significant nebular contribution (X$_{\text{neb}}$ $=$ 8%). We select a sample of 54 SF galaxies from the DAWN JWST Archive meeting quality criteria required for spectral fitting with the population synthesis code FADO. The selected galaxies cover the 1.7 $<$ $z$ $<$ 3.9 range and we fit their rest-frame optical spectra to estimate the stellar and nebular continuum emission, plus the physical and evolutionary properties. We show that the H$α$ and H$β$ equivalent widths remain suitable tracers of X$_{\text{neb}}$ at high redshift. We also confirm the X$_{\text{neb}}$ $=$ 8% threshold, above which neglecting the nebular continuum can significantly bias spectral modelling. Galaxies above this threshold are generally less massive, younger, exhibit higher SF activity and lower dust extinction relative to those below it. Moreover, these galaxies are light and mass dominated by stellar populations younger than 20 Myr, although their mass contribution is likely overestimated due to the outshining effect. Considering the growing amount of galaxy spectroscopic data at Cosmic Noon from JWST and future facilities, such as MOONS, this work reveals the importance of properly accounting for both stellar and nebular continuum emission when performing optical spectral fitting to obtain reliable stellar population and physical properties estimates.

astro-ph.GA↗

arXiv2026

Deblending the MIGHTEE-COSMOS survey with XID+: The resolved radio source counts to $S_{1.4}\approx 5μ$Jy

Deep radio continuum surveys provide fundamental constraints on galaxy evolution, but source confusion limits sensitivity to the faintest sources. We present a complete framework for producing high-fidelity deblended radio catalogs from the confused MIGHTEE maps using the probabilistic deblending framework XID+ and prior positions from deep multi-wavelength data in the COSMOS field. To assess performance, we construct MIGHTEE-like simulations based on the Tiered Radio Extragalactic Continuum Simulation (T-RECS) radio source population, ensuring a realistic distribution of star-forming galaxies and active galactic nuclei (AGN) for validation. Through these simulations, we show that prior catalog purity is the dominant factor controlling deblending accuracy: a high-purity prior, containing only sources with a high likelihood of radio detection, recovers accurate flux densities and reproduces input source counts down to $\sim 3σ$ (where $σ= $ thermal noise). On the other hand, a complete prior overestimates the source counts due to spurious detections. Our optimal strategy combines the high-purity prior with a mask that removes sources detected above $50~μ$Jy. Applied to the $\sim$1.3\,deg$^2$ area of the MIGHTEE-COSMOS field defined by overlapping multi-wavelength data, this procedure yields a deblended catalog of 89,562 sources. The derived 1.4\,GHz source counts agree with independent P(D) analyses and indicate that we resolve the radio background to $\sim 4.8\,μ$Jy. We also define a recommended high-fidelity sample of 20,757 sources, based on detection significance, flux density, and goodness-of-fit, which provides reliable flux densities for individual sources in the confusion-limited regime.

astro-ph.GA↗

arXiv2026

Stochastic hierarchical data-driven optimization: application to plasma-surface kinetics

This work introduces a stochastic hierarchical optimization framework inspired by Sloppy Model theory for the efficient calibration of physical models. Central to this method is the use of a reduced Hessian approximation, which identifies and targets the stiff parameter subspace using minimal simulation queries. This strategy enables efficient navigation of highly anisotropic landscapes, avoiding the computational burden of exhaustive sampling. To ensure rigorous inference, we integrate this approach with a probabilistic formulation that derives a principled objective loss function directly from observed data. We validate the framework by applying it to the problem of plasma-surface interactions, where accurate modelling is strictly limited by uncertainties in surface reactivity parameters and the computational cost of kinetic simulations. Comparative analysis demonstrates that our method consistently outperforms baseline optimization techniques in sample efficiency. This approach offers a general and scalable tool for optimizing models of complex reaction systems, ranging from plasma chemistry to biochemical networks.

cs.LG↗

arXiv2026

Conditional Denoising Model as a Physical Surrogate Model

Surrogate modeling for complex physical systems typically faces a trade-off between data-fitting accuracy and physical consistency. Physics-consistent approaches typically treat physical laws as soft constraints within the loss function, a strategy that frequently fails to guarantee strict adherence to the governing equations, or rely on post-processing corrections that do not intrinsically learn the underlying solution geometry. To address these limitations, we introduce the {Conditional Denoising Model (CDM)}, a generative model designed to learn the geometry of the physical manifold itself. By training the network to restore clean states from noisy ones, the model learns a vector field that points continuously towards the valid solution subspace. We introduce a time-independent formulation that transforms inference into a deterministic fixed-point iteration, effectively projecting noisy approximations onto the equilibrium manifold. Validated on a low-temperature plasma physics and chemistry benchmark, the CDM achieves higher parameter and data efficiency than physics-consistent baselines. Crucially, we demonstrate that the denoising objective acts as a powerful implicit regularizer: despite never seeing the governing equations during training, the model adheres to physical constraints more strictly than baselines trained with explicit physics losses.

cs.LG↗

arXiv2025

The evolution of obscured AGN across cosmic time -- A large quasar survey for the 2040s

We propose a large quasar demographic optical multi-object spectroscopic (MOS) survey targeting over 50 million AGN candidates up to the highest redshifts possible in the optical (z~6.5), with repeat visits, using a variety of selection criteria available by 2040. A large MOS survey combining all AGN selection methods is the only way to unify a diverse range of different obscured AGN populations within a single, variability- and spectroscopy-based framework, rather than as disjoint classes selected by different methods.

astro-ph.GA↗

arXiv2025

Through the fog: a complementary optical galaxy classification scheme for 'intermediate' redshifts

Understanding galaxy classification depends on our interpretation of their spectra. To date, the hydrogen Balmer lines remain the most consistent way to classify galaxies, but at 'intermediate' redshifts ($1.5 < z < 2.5$), galaxies are hard to parse in the BPT diagram (and its siblings) because the crucial H$α$ emission line is out of range of ground-based optical spectographs. In this work, we re-explore a known diagram, which we call the OB-I diagram, that compares the equivalent width of H$β$ with the emission line ratio of [OIII]$λ$5007/H$β$, and breathe new life into it, as it has the potential to 'illuminate the fog' that permeates galaxy classification in the restframe optical spectra. Using data from SDSS, LEGA-C, VANDELS, JADES, 3D-HST and MOSDEF, we explore galaxy classification in the OB-I diagram at a wide range of redshifts ($0 < z < 2.7$). We find that, at $z < 0.4$, the OB-I diagram clearly separates galaxies between two distinct types, which we divide with an empirical fit: one dominated by AGN and a second made up of a mixed population of SF galaxies and AGN activity. This mixed population can be partially separated from a pure SF population, with a simple semi-empirical fit derived from a comparison with theoretical models and the BPT diagrams. At higher redshifts, we find that the majority of AGNs identified by other classification schemes are correctly recovered by the OB-I diagram, potentially making this diagram resistant to the 'cosmic shift' that plagues most optical classification schemes. Overall, the OB-I diagram, which only requires two emission lines to be implemented, is a useful tool at separating galaxies that possess a dominating AGN component in their emission from others, from the Local Universe ($z < 0.1$) to the Cosmic Noon ($z \sim 2$), without any need for significant adjustments in our empirical fit.

astro-ph.GA↗

arXiv2025

Importance of modelling the nebular continuum in galaxy spectra

The neglect of modelling both stellar and nebular emission significantly affects the derived physical properties of galaxies, particularly those with high star formation rates. While this issue has been studied, it has not been established a clear threshold for a significant impact on the estimated physical properties of galaxies due to accounting for both stellar and nebular emission. We analyse galaxies from SDSS-DR7 across a wide range of star-forming activity levels, comparing the results obtained from two spectral fitting tools: FADO (which considers both stellar and nebular continuum) and STARLIGHT (only considers the stellar continuum). A strong linear correlation is found between the rest-frame H$α$ and H$β$ equivalent widths (EWs) and the optical nebular contribution, identifying these as reliable tracers. The results show that when the nebular contribution exceeds 8% (corresponding to EW(H$α$)$\simeq$500 Å and EW(H$β$)$\simeq$110 Å), there is a significant impact on the estimation of galaxy properties, namely stellar mass, age and metallicity. Our results highlight the importance of taking into account both the stellar and nebular continuum when analysing the optical spectra of star-forming galaxies. In particular, this is a fundamental aspect for galaxies with a rest-frame EW(H$α$)$\gtrsim$500 Å (or the scaled value of 375 Å for pseudo-continuum measures). At low redshifts, this mostly impacts extreme emission line galaxies, while at higher redshifts it becomes a dominant aspect given the higher star-forming activity in the younger Universe. In light of current JWST observations and future instruments designed for high-redshift observations, such as MOONS, this reveals as a critical issue to take into consideration.

astro-ph.GA↗

arXiv2025

Unveiling faint X-ray AGN populations in the NewAthena era: Insights from cosmological simulations

Recent observations expanded our understanding of galaxy formation and evolution, yet key challenges persist in the X-ray regime, crucial for studying Active Galactic Nuclei (AGN). These limitations drive the development of next-generation observatories such as ESA's NewAthena. Now in phase B (preliminary design), the mission requires extensive testing to ensure compliance with its scientific goals, particularly given the uncertainties surrounding high redshift AGN. This work leverages the IllustrisTNG cosmological simulation to build an X-ray AGN mock catalogue and assess the performance of NewAthena's WFI. We created a Super Massive Black Hole (SMBH) light cone, spanning 10 deg2, with corrections to account for the limited resolution of the simulation and X-ray properties derived in post-processing. The resulting catalogue reveals a 5* overabundance of faint AGN compared to current X-ray constraints, an inconsistency potentially resolved by invoking a higher Compton-thick (CTK) fraction and intrinsic X-ray weakness, as suggested by recent JWST findings. An end-to-end survey simulation using SIXTE predicts 250000 AGN detections, including 20,000 at z > 3 and 35 in the Epoch of Reionization (z > 6); notably, only AGN with LX > 43.5 erg/s are detectable at z > 6. The analysis also forecasts a significant population of detectable CTK AGN, even beyond z > 4. These findings suggest X-ray observations will, for the first time, probe a significant AGN population in the EoR, offering new insights into SMBH growth. They also provide key input for refining NewAthena's mission design and optimizing its survey strategy.

astro-ph.GA↗

arXiv2025

MIGHTEE: exploring the relationship between spectral index, redshift and radio luminosity

It has been known for many years that there is an apparent trend for the spectral index (α) of radio sources to steepen with redshift z, which has led to attempts to select high-redshift objects by searching for radio sources with steep spectra. In this study we use data from the MeerKAT, LOFAR, GMRT, and uGMRT telescopes, particularly using the MIGHTEE and superMIGHTEE surveys, to select compact sources over a wide range of redshifts and luminosities. We investigate the relationship between spectral index, luminosity and redshift and compare our results to those of previous studies. Although there is a correlation between α and z in our sample for some combinations of frequency where good data are available, there is a clear offset between the α-z relations in our sample and those derived previously from samples of more luminous objects; in other words, the α-z relation is different for low and high luminosity sources. The relationships between α and luminosity are also weak in our sample but in general the most luminous sources are steeper-spectrum and this trend is extended by samples from previous studies. In detail, we argue that both a α-luminosity relation and an α-z relation can be found in the data, but it is the former that drives the apparent α-z relation observed in earlier work, which only appears because of the strong redshift-luminosity relation in bright, flux density-limited samples. Steep-spectrum selection should be applied with caution in searching for high-z sources in future deep surveys.

astro-ph.GA↗

arXiv2024

EMU/GAMA: A Technique for Detecting Active Galactic Nuclei in Low Mass Systems

We propose a new method for identifying active galactic nuclei (AGN) in low mass ($\rm M_*\leq10^{10}M_\odot$) galaxies. This method relies on spectral energy distribution (SED) fitting to identify galaxies whose radio flux density has an excess over that expected from star formation alone. Combining data in the Galaxy and Mass Assembly (GAMA) G23 region from GAMA, Evolutionary Map of the Universe (EMU) early science observations, and Wide-field Infrared Survey Explorer (WISE), we compare this technique with a selection of different AGN diagnostics to explore the similarities and differences in AGN classification. We find that diagnostics based on optical and near-infrared criteria (the standard BPT diagram, the WISE colour criterion, and the mass-excitation, or MEx diagram) tend to favour detection of AGN in high mass, high luminosity systems, while the ``ProSpect'' SED fitting tool can identify AGN efficiently in low mass systems. We investigate an explanation for this result in the context of proportionally lower mass black holes in lower mass galaxies compared to higher mass galaxies and differing proportions of emission from AGN and star formation dominating the light at optical and infrared wavelengths as a function of galaxy stellar mass. We conclude that SED-derived AGN classification is an efficient approach to identify low mass hosts with low radio luminosity AGN.

astro-ph.GA↗

arXiv2022

An investigation of the star-forming main sequence considering the nebular continuum emission at low-z

The code FADO is the first publicly available population spectral synthesis tool that treats the contribution from ionised gas to the observed emission self-consistently. We study the impact of the nebular contribution on the determination of the star formation rate (SFR), stellar mass, and consequent effect on the star-forming main sequence (SFMS) at low redshift. We applied FADO to the spectral database of the SDSS to derive the physical properties of galaxies. As a comparison, we used the data in the MPA-JHU catalogue, which contains the properties of SDSS galaxies derived without the nebular contribution. We selected a sample of SF galaxies with H$α$ and H$β$ flux measurements, and we corrected the fluxes for the nebular extinction through the Balmer decrement. We then calculated the H$α$ luminosity to estimate the SFR. Then, by combining the stellar mass and SFR estimates from FADO and MPA-JHU, the SFMS was obtained. The H$α$ flux estimates are similar between FADO and MPA-JHU. Because the H$α$ flux was used as tracer of the SFR, FADO and MPA-JHU agree in their SFR. The stellar mass estimates are slightly higher for FADO than for MPA-JHU on average. However, considering the uncertainties, the differences are negligible. With similar SFR and stellar mass estimates, the derived SFMS is also similar between FADO and MPA-JHU. Our results show that for SDSS normal SF galaxies, the additional modelling of the nebular contribution does not affect the retrieved fluxes and consequentially also does not influence SFR estimators based on the extinction-corrected H$α$ luminosity. For the stellar masses, the results point to the same conclusion. These results are a consequence of the fact that the vast majority of normal SF galaxies in the SDSS have a low nebular contribution.

astro-ph.GA↗

arXiv2022

Revisiting stellar properties of star-forming galaxies with stellar and nebular spectral modelling

Spectral synthesis is a powerful tool for interpreting the physical properties of galaxies by decomposing their spectral energy distributions into the main luminosity contributors (e.g. stellar populations or ionised gas). However, the impact nebular emission has on the inferred properties of star-forming (SF) galaxies has been largely overlooked over the years. The objective of this work is to estimate the relations between stellar properties of SF galaxies from SDSS DR7 by simultaneously fitting the stellar and nebular continua with FADO and comparing them to the results derived using STARLIGHT, a representative of purely stellar population synthesis codes. Differences between codes regarding average mass, mean age and mean metallicity values can go as high as $\sim$0.06 dex for the overall population of galaxies and $\sim$0.12 dex for SF galaxies (galaxies with EW(H$α$)>3 Å), with the most prominent difference between both codes in the light-weighted mean stellar age. A closer look into the average light- and mass-weighted star formation histories of intensively SF galaxies (EW(H$α$)>75 Å) suggests that STARLIGHT is underestimating the average light-weighted age of intensively SF galaxies by up to $\sim$0.17 dex and overestimating the light-weighted metallicity by up to $\sim$0.13 dex compared to FADO (or vice versa). The comparison between the average stellar properties of passive, SF and intensively SF galaxy samples also reveals that differences between codes increase with increasing EW(H$α$) and decreasing total stellar mass. This work finds indirect evidence that a purely stellar population synthesis approach negatively impacts the inferred stellar properties of galaxies with relatively high star formation rates. In turn, this can bias interpretations of fundamental relations such as the mass-age or mass-metallicity.

astro-ph.GA↗

arXiv2022

The VMC Survey -- XLIX. Discovery of a population of quasars dominated by nuclear dust emission behind the Magellanic Clouds

Following the discovery of SAGE0536AGN ($z \sim$ 0.14), with the strongest 10-$μ$m silicate emission ever observed for an Active Galactic Nucleus (AGN), we discovered SAGE0534AGN ($z \sim$ 1.01), a similar AGN but with less extreme silicate emission. Both were originally mistaken as evolved stars in the Magellanic Clouds. Lack of far-infrared emission, and therefore star-formation, implies we are seeing the central engine of the AGN without contribution from the host galaxy. They could be a key link in galaxy evolution. We used a dimensionality reduction algorithm, t-SNE (t-distributed Stochastic Neighbourhood Embedding) with multi-wavelength data from Gaia EDR3, VISTA survey of the Magellanic Clouds, AllWISE and the Australian SKA Pathfinder to find these two unusual AGN are grouped with 16 other objects separated from the rest, suggesting a rare class. Our spectroscopy at SAAO/SALT and literature data confirm at least 14 of these objects are extragalactic ($0.13 < z < 1.23$), all hosting AGN. Using spectral energy distribution fitter CIGALE we find that the majority of dust emission ($> 70 \%$) in these sources is due to the AGN. Host galaxies appear to be either in or transitioning into the green valley. There is a trend of a thinning torus, increasing X-ray luminosity and decreasing Eddington ratio as the AGN transition through the green valley, implying that as the accretion supply depletes, the torus depletes and the column density reduces. Also, the near-infrared variability amplitude of these sources correlates with attenuation by the torus, implying the torus plays a role in the variability.

astro-ph.GA↗

arXiv2021

The Nature and Likely Redshift of GLEAM J0917-0012

We previously reported a putative detection of a radio galaxy at z=10.15, selected from the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey. The redshift of this source, GLEAM J0917-0012, was based upon three weakly detected molecular emission lines observed with the Atacama Large Millimetre Array (ALMA). In order to confirm this result, we conducted deep spectroscopic follow-up observations with ALMA and the Karl Jansky Very Large Array (VLA). The ALMA observations targeted the same CO lines previously reported in Band 3 (84-115GHz) and the VLA targeted the CO(4-3) and [CI(1-0)] lines for an independent confirmation in Q-band (41 and 44GHz). Neither observation detected any emission lines, removing support for our original interpretation. Adding publicly available optical data from the Hyper Suprime-Cam survey, WISE and Herschel Space Observatory in the infrared, as well as <10GHz polarisation and 162MHz inter-planetary scintillation observations, we model the physical and observational characteristics of GLEAM J0917-0012 as a function of redshift. Comparing these predictions and observational relations to the data, we are able to constrain its nature and distance. We argue that if GLEAM J0917-0012 is at z<3 then it has an extremely unusual nature, and that the more likely solution is that the source lies above z=7.

astro-ph.GA↗

arXiv2021

Exploring New Redshift Indicators for Radio-Powerful AGN

Active Galactic Nuclei (AGN) are relevant sources of radiation that might have helped reionising the Universe during its early epochs. The super-massive black holes (SMBHs) they host helped accreting material and emitting large amounts of energy into the medium. Recent studies have shown that, for epochs earlier than $z~{\sim}~5$, the number density of SMBHs is on the order of few hundreds per square degree. Latest observations place this value below $300$ SMBHs at $z~{\gtrsim}~6$ for the full sky. To overcome this gap, it is necessary to detect large numbers of sources at the earliest epochs. Given the large areas needed to detect such quantities, using traditional redshift determination techniques -- spectroscopic and photometric redshift -- is no longer an efficient task. Machine Learning (ML) might help obtaining precise redshift for large samples in a fraction of the time used by other methods. We have developed and implemented an ML model which can predict redshift values for WISE-detected AGN in the HETDEX Spring Field. We obtained a median prediction error of $σ_{z}^{N} = 1.48 \times (z_{\mathrm{Predicted}} - z_{\mathrm{True}}) / (1 + z_{\mathrm{True}}) = 0.1162$ and an outlier fraction of $η= 11.58 \%$ at $(z_{\mathrm{Predicted}} - z_{\mathrm{True}}) / (1 + z_{\mathrm{True}}) > 0.15$, in line with previous applications of ML to AGN. We also applied the model to data from the Stripe 82 area obtaining a prediction error of $σ_{z}^{N} = 0.2501$.

astro-ph.GA↗

arXiv2021

Self-consistent population spectral synthesis with FADO: II. Star formation history of galaxies in spectral synthesis methods

The field of galaxy evolution will make a great leap forward in the next decade as a consequence of the huge effort by the scientific community in multi-object spectroscopic facilities. To maximise the impact of such incoming data, the analysis methods must also step up, extracting reliable information from the available spectra. In this paper, we aim to investigate the limits and the reliability of different spectral synthesis methods in the estimation of the mean stellar age and metallicity. The main question this work aims to address is which signal-to-noise ratios (S/N) are needed to reliably determine the mean stellar age and metallicity from a galaxy spectrum and how this depends on the tool used to model the spectra. To address this question we built a set of realistic simulated spectra containing stellar and nebular emission, reproducing the evolution of a galaxy in two limiting cases: a constant star formation rate and an exponentially declining star formation. We degraded the synthetic spectra built from these two star formation histories (SFHs) to different S/N and analysed them with three widely used spectral synthesis codes, namely FADO, STECKMAP, and STARLIGHT. For S/N < 5 all three tools show a large diversity in the results. The FADO and STARLIGHT tools find median differences in the light-weighted mean stellar age of ~0.1 dex, while STECKMAP shows a higher value of ~0.2 dex. Detailed investigations of the best-fit spectrum for galaxies with overestimated mass-weighted quantities point towards the inability of purely stellar models to fit the observed spectra around the Balmer jump. Our results imply that when a galaxy enters a phase of high specific star formation rate the neglect of the nebular continuum emission in the fitting process has a strong impact on the estimation of its SFH when purely stellar fitting codes are used, even in presence of high S/N spectra.

astro-ph.GA↗

arXiv2019

Structural analysis of massive galaxies using HST deep imaging at z < 0.5

Taking advantage of HST CANDELS data, we analyze the lowest redshift (z<0.5) massive galaxies in order to disentangle their structural constituents and study possible faint non-axis-symmetric features. Due to the excellent HST spatial resolution for intermediate-z objects, they are hard to model by purely automatic parametric fitting algorithms. We performed careful single and double Sérsic fits to their galaxy surface brightness profiles. We also compare the model color profiles with the observed ones and also derive multi-component global effective radii attempting to obtain a better interpretation of the mass-size relation. Additionally, we test the robustness of our measured structural parameters via simulations. We find that the Sérsic index does not offer a good proxy for the visual morphological type for our sample of massive galaxies. Our derived multi-component effective radii give a better description of the size of our sample galaxies than those inferred from single Sérsic models with GALFIT. Our galaxy population lays on the scatter of the local mass-size relation, indicating that these massive galaxies do not experience a significant growth in size since z~0.5. Interestingly the few outliers are late-type galaxies, indicating that spheroids must reach the local mass-size relation earlier. For most of our sample galaxies, both single and multi-component Sérsic models with GALFIT show substantial systematic deviations from the observed SBPs in the outskirts. These residuals may be partly due to several factors, namely a non-optimal data reduction for low surface brightness features, the existence of prominent stellar haloes for massive galaxies and could also arise from conceptual shortcomings of parametric 2D image decomposition tools. They consequently propagate into galaxy color profiles.

astro-ph.GA↗

arXiv2019

The mid-infrared and CO gas properties of an extreme star-forming FeLoBAL quasar

We present a detailed study of a high-redshift iron low-ionization broad absorption line (FeLoBAL) quasar (SDSS1214 at $z = 1.046$), including new interferometric $^{12}$CO $J$=2-1 observations, optical through far-infrared photometry, and mid-infrared spectroscopy. The CO line is well-fit by a single Gaussian centered 40 kms$^{-1}$ away from the systemic velocity and implies a total molecular gas mass of $M_\textrm{gas} = 7.3 \times 10^{10} \textrm{M}_\odot$. The infrared SED requires three components: an active galactic nucleus (AGN) torus, an AGN polar dust component, and a starburst. The starburst dominates the infrared emission with a luminosity of log($L_\textrm{SB}[\textrm{L}_\odot]) = 12.91^{+0.02}_{-0.02}$, implying a star formation rate of about 2000 $\textrm{M}_{\odot}$yr$^{-1}$, the highest known among FeLoBAL quasars. The AGN torus and polar dust components are less luminous, at log($L_\textrm{AGN}[\textrm{L}_\odot]) = 12.36^{+0.14}_{-0.15}$ and log($L_\textrm{dust}[\textrm{L}_\odot]) = 11.75^{+0.26}_{-0.46}$, respectively. If all of the molecular gas is used to fuel the ongoing star formation, then the lower limit on the subsequent duration of the starburst is 40 Myr. We do not find conclusive evidence that the AGN is affecting the CO gas reservoir. The properties of SDSS1214 are consistent with it representing the endpoint of an obscured starburst transitioning through a LoBAL phase to that of a classical quasar.

astro-ph.GA↗