Color Excess Research Articles

Mapping dust in the giant molecular cloud Orion A

ABSTRACT The Sun is located close to the Galactic mid-plane, meaning that we observe the Galaxy through significant quantities of dust. Moreover, the vast majority of the Galaxy’s stars also lie in the disc, meaning that dust has an enormous impact on the massive astrometric, photometric and spectroscopic surveys of the Galaxy that are currently underway. To exploit the data from these surveys we require good three-dimensional maps of the Galaxy’s dust. We present a new method for making such maps in which we form the best linear unbiased predictor of the extinction at an arbitrary point based on the extinctions for a set of observed stars. This method allows us to avoid the artificial inhomogeneities (so-called ‘fingers of God’) and resolution limits that are characteristic of many published dust maps. Moreover, it requires minimal assumptions about the statistical properties of the interstellar medium. In fact, we require only a model of the first and second moments of the dust density field. The method is suitable for use with directly measured extinctions, such as those provided by the Rayleigh–Jeans colour excess method, and inferred extinctions, such as those provided by hierarchical Bayesian models like StarHorse. We test our method by mapping dust in the region of the giant molecular cloud Orion A. Our results indicate a foreground dust cloud at a distance of 350 pc, which has been identified in work by another author.

A photometric in-depth look at the core-collapsed globular cluster NGC 6284

High-resolution Hubble Space Telescope (HST) optical observations have been used to perform the deepest photometric study of the poorly studied Galactic globular cluster NGC 6284. The deep colour-magnitude diagram (CMD) that we obtained reaches 6 mag below the main-sequence turnoff. We provide the first determination of the gravitational centre (Cgrav) and density profile of the system from resolved stars. We note that the gravitational centre is significantly offset (by 1.5 − 3″) from the values in the literature. The density profile shows the presence of a steep central cusp, unambiguously indicating that the cluster experienced the core-collapse phase. Updated values of the structural parameters and relaxation times of the system are provided. We also constructed the first high-resolution reddening map in the cluster direction, which allowed us to correct the evolutionary sequences in the CMD for the effects of differential reddening. Isochrone fitting to the corrected CMD provided us with new estimates of the cluster age, average colour excess, metallicity, and distance. We find an absolute age of 13.3 ± 0.4 Gyr, an average colour excess E(B − V) = 0.32 ± 0.01, a metallicity [Fe/H] = −1.36 ± 0.01, and a true distance modulus (m − M)0 = 15.61 ± 0.04 that sets the cluster distance at 13.2 ± 0.2 kpc from the Sun. The superb quality of the CMD allowed a clear-cut identification of the red giant branch (RGB) bump, which is clearly distinguishable along the narrow RGB. The absolute magnitude of this feature turns out to be ∼0.2 mag fainter than the previous identification.

Deep learning prediction of galaxy stellar populations in the low-redshift Universe

ABSTRACT The increasing size and complexity of data provided by both ongoing and planned galaxy surveys greatly contribute to our understanding of galaxy evolution. Deep learning methods are particularly well suited for handling the complex and massive data. We train a convolutional neural network (CNN) to simultaneously predict the stellar populations in galaxies: age, metallicity, colour excess E(B − V), and central velocity dispersion (VD) using spectra with redshift ≤ 0.3 from the Sloan Digital Sky Survey. This is the first time to use spectra based on deep learning to derive the four galaxy properties. The testing results show that our CNN predictions of galaxy properties are in good consistent with values by the traditional stellar population synthesis method with little scatters (0.11 dex for age and metallicity, 0.018 mag for E(B − V), and 31 km s−1 for VD). In terms of the computational time, our method reduces by more than 10 times compared to traditional method. We further evaluate the performance of our CNN prediction model using spectra with different signal-to-noise ratios (S/Ns), redshifts, and spectral classes. We find that our model generally exhibits good performance, although the errors at different S/Ns, redshifts, and spectral classes vary slightly. Our well-trained CNN model and related codes are publicly available on https://github.com/sddzwll/CNNforStellarp.

CCD UBV and Gaia DR3 Analyses of the Open Clusters King 6 and NGC 1605

A detailed analysis of ground-based CCD UBV photometry and space-based Gaia Data Release 3 (DR3) data for the open clusters King 6 and NGC 1605 was performed. Using the pyUPMASK algorithm on Gaia astrometric data to estimate cluster membership probabilities, we have identified 112 stars in King 6 and 160 stars in NGC 1605 as the statistically most likely members of each cluster. We calculated reddening and metallicity separately using UBV two-color diagrams to estimate parameter values via independent methods. The color excess E(B − V) and photometric metallicity [Fe/H] for King 6 are 0.515 ± 0.030 mag and 0.02 ± 0.20 dex, respectively. For NGC 1605, they are 0.840 ± 0.054 mag and 0.01 ± 0.20 dex, respectively. With reddening and metallicity kept constant, we have estimated the distances and cluster ages by fitting PARSEC isochrones to color–magnitude diagrams based on the Gaia and UBV data. The photometric distances are 723 ± 34 pc for King 6 and 3054 ± 243 pc for NGC 1605. The cluster ages are 200 ± 20 Myr and 400 ± 50 Myr for King 6 and NGC 1605, respectively. The mass function slopes were found to be 1.29 ± 0.18 and 1.63 ± 0.36 for King 6 and NGC 1605, respectively. These values are in good agreement with the value of Salpeter. The relaxation times were estimated as 5.8 Myr for King 6 and 60 Myr for NGC 1605. These indicate that both clusters are dynamically relaxed since these times are less than the estimated cluster ages. A Galactic orbit analysis shows that both clusters formed outside the solar circle and are members of the young thin-disk population.

An R V Map of the Milky Way Revealed by LAMOST

The total-to-selective extinction ratio, R V, is a key parameter for tracing the properties of interstellar dust, as it directly determines the variation of the extinction curve with wavelength. By utilizing accurate color excess measurements from the optical to the mid-infrared range, we have derived R V values for approximately three million stars from LAMOST data release 7 using a forward-modeling technique. This extensive data set enables us to construct a comprehensive 2D R V map of the Milky Way within the LAMOST footprint at a spatial resolution of ∼27.′5. Based on reliable sight lines of E(B − V) > 0.1, we find that R V exhibits a Gaussian distribution centered around 3.25 with a standard deviation of 0.25. The spatial variability of R V in the Galactic disk exhibits a wide range, spanning from small scales within individual molecular clouds to large scales up to kiloparsecs. A striking correlation is observed between the distribution of R V and molecular clouds. Notably, we observe lower R V values within the regions of nearby molecular clouds compared to their surrounding areas. Furthermore, we have investigated the relationships between R V and various parameters, including dust temperature, dust emissivity spectral index, column densities and ratios of atomic and molecular hydrogen, as well as the gas-to-dust ratio. We find that these relationships vary with the level of extinction. These analyses provide new insights into the properties and evolution of dust grains in diverse interstellar environments and also hold significant importance for achieving accurate extinction corrections.

The Ultraviolet to Mid-infrared Extinction Law of the Taurus Molecular Cloud Based on the Gaia DR3, GALEX, APASS, Pan-STARRS1, 2MASS, and WISE Surveys

Interstellar-dust extinction law is essential for interpreting observations. In this work, we investigate the ultraviolet (UV)–mid-infrared (IR) extinction law of the Taurus molecular cloud and its possible variations. We select 504,988 dwarf stars (4200 K ≤ T eff ≤ 8000 K) and 4757 giant stars (4200 K ≤ T eff ≤ 5200 K) based on the stellar parameters of Gaia DR3 as tracers. We establish the T eff–intrinsic color relations and determine the intrinsic color indices and color excesses for different types of stars. In the determination of color excess ratios (CERs), we analyze and correct the curvature of CERs and derive the UV–mid-IR CERs of 16 bands. We consider different effective wavelengths for different types of stars when converting CERs to relative extinction and obtain the extinction law with a better wavelength resolution. In addition, we analyze the possible regional variation of extinction law and derive the average extinction law of R V = 3.13 ± 0.32 for the Taurus molecular cloud. Only 0.9% of subregions have deviations >3σ, indicating limited regional variation in the extinction law. We also discuss the effect of Gaia T eff overestimation on the determination of the Taurus extinction law and find that the effect is negligible.

Relation between photometric and parameter errors of star clusters

ABSTRACT Many observations supply only photometry data with large uncertainties. The study of star clusters based on such data is important for astrophysical studies, although photometric uncertainty affects the accuracy of results. In order to estimate the parameter uncertainties that are caused by photometric errors, this work quantifies the influence of photometric error on the uncertainties of some basic parameters when colour-magnitude diagram (CMD) fitting is used to determine these parameters. The observed data are derived from Hubble Space Telescope (HST) observations with the WFPC2 in four bands because of the large coverage of photometric error. The photometric errors that are estimated by Artificial Star Test (AST) are taken, and a binary star stellar population synthesis model and the Powerful CMD code are adopted to determine the parameters of star clusters. Two popular types of stellar population models, i.e. binary star simple stellar population (bsSSP) and single star simple stellar population (ssSSP), are used. The effects of photometric errors on the uncertainties of distance modulus (m − M), colour excess (E), metallicity (Z), and age (t), i.e. Δm − M, ΔE, ΔZ, and Δt, are studied via 19 globular clusters. The results show that Δm − M, ΔE, ΔZ, and Δt have positive correlations with photometric error. Some linear fitting formulae are given to make the results easy to use. The results can be used to estimate the errors of parameters that are caused by photometric error when determining the parameters by CMD fitting, for star clusters with relatively large photometric uncertainties (>∼0.01 mag).

Astrophysical Parameters of the Open Cluster NGC 2509

This study presents structural and fundamental astrophysical parameters of poorly studied open cluster NGC 2509. We used the third photometric and astrometric data release of the Gaia (Gaia DR3) to perform analyses. By taking into account the Gaia DR3 astrometric data, we calculated the membership probabilities of the stars in the region of NGC 2509. As a result of the membership analysis, 244 stars with membership probabilities P  50% were determined as the physical members of the cluster. The colour excess, distance and age were obtained simultaneously by fitting solar metallicity PARSEC isochrones to G×GBP-GRP colour-magnitude diagram. We considered the most likely cluster member stars during the fitting procedure and calculated the colour excess, distance and age of the NGC 2509 as E(GBP-GRP) = 0.100±0.184 mag, d = 2518±667 pc and t = 1.5±0.1 Gyr, respectively.

EMPRESS. XI. SDSS and JWST Search for Local and z ∼4–5 Extremely Metal-poor Galaxies (EMPGs): Clustering and Chemical Properties of Local EMPGs

We search for local extremely metal-poor galaxies (EMPGs), selecting photometric candidates by broadband color excess and machine-learning techniques with the SDSS photometric data. After removing stellar contaminants by shallow spectroscopy with Seimei and Nayuta telescopes, we confirm that three candidates are EMPGs with 0.05–0.1 Z ⊙ by deep Magellan/MagE spectroscopy for faint [Oiii] λ4363 lines. Using a statistical sample consisting of 105 spectroscopically confirmed EMPGs taken from our study and the literature, we calculate the cross-correlation function (CCF) of the EMPGs and all SDSS galaxies to quantify environments of EMPGs. Comparing another CCF of all SDSS galaxies and comparison of SDSS galaxies in the same stellar-mass range (107.0–108.4 M ⊙), we find no significant (>1σ) difference between these two CCFs. We also compare mass–metallicity relations (MZRs) of the EMPGs and those of galaxies at z ∼ 0–4 with a steady chemical evolution model and find that the EMPG MZR is comparable with the model prediction on average. These clustering and chemical properties of EMPGs are explained by a scenario of stochastic metal-poor gas accretion on metal-rich galaxies showing metal-poor star formation. Extending the broadband color excess technique to a high-z EMPG search, we select 17 candidates of z ∼ 4–5 EMPGs with the deep (≃30 mag) near-infrared JWST/NIRCam images obtained by ERO and ERS programs. We find galaxy candidates with negligible [Oiii] λ λ 4959,5007 emission weaker than the local EMPGs and known high-z galaxies, suggesting that some of these candidates may fall in the range of 0–0.01 Z ⊙, which potentially breaks the lowest metallicity limit known to date.

Astrophysical Parameters of the Open Cluster Berkeley 6

In this study, the structural and basic astrophysical parameters of poorly studied open cluster Berkeley 6 is calculated. Analyses of the cluster are carried out using the third photometric, spectroscopic and astrometric data release of Gaia (Gaia DR3). The membership probabilities of stars located through the cluster region are calculated by considering their astrometric data. Thus, we identified 119 physical members for Berkeley 6. The colour excess, distance and age of the cluster are determined simultaneously on the colour-magnitude diagram. We fitted solar metallicity PARSEC isochrones to the colour-magnitude diagram by considering the most probable member stars and obtained E(GBP-GRP) colour excess as 0.918±0.145 mag. Distance and age of the cluster are determined as d=2625±337 pc and t=350±50 Myr, respectively.

Blanco DECam Bulge Survey (BDBS). VI. Extinction Maps Toward Southern Galactic Bulge Globular Clusters

We present wide-field, high resolution maps of the color excess for 14 globular clusters toward the Southern Galactic bulge. The maps were derived using Gaia EDR3 astrometry and stellar photometry from the Blanco DECam Bulge Survey, which is a deep, wide-field ugrizY photometric survey of the southern Galactic bulge. Comparisons with WISE 12 μm images of thermal continuum emission demonstrate that the maps presented here trace interstellar extinction by dust down to 5″ scales. We use the reddening-corrected photometry of proper motion-selected cluster stars to build color–magnitude diagrams for the target globular clusters, which show residual broadening in excess of that expected from the photometric errors alone. This residual broadening is likely to be driven by star-to-star elemental abundance variations.

Early Results from GLASS-JWST. XX. Unveiling a Population of “Red Excess” Galaxies in Abell2744 and in the Coeval Field

We combine JWST/NIRCam imaging and MUSE data to characterize the properties of galaxies in different environmental conditions in the cluster Abell2744 (z = 0.3064) and in its immediate surroundings. We investigate how galaxy colors, morphology, and star-forming fractions depend on wavelength and on different parameterizations of environment. Our most striking result is the discovery of a “red excess” population in F200W−F444W colors in both the cluster regions and the field. These galaxies have normal F115W−F150W colors but are up to 0.8 mag redder than red sequence galaxies in F200W−F444W. They also have rather blue rest-frame B−V colors. Galaxies in the field and at the cluster virial radius are overall characterized by redder colors, but galaxies with the largest color deviations are found in the field and in the cluster core. Several results suggest that mechanisms taking place in these regions might be more effective in producing these colors. Looking at their morphology, many cluster galaxies show signatures consistent with ram pressure stripping, while field galaxies have features resembling interactions and mergers. Our hypothesis is that these galaxies are characterized by dust-enshrouded star formation: a JWST/NIRSpec spectrum for one of the galaxies is dominated by a strong PAH at 3.3 μm, suggestive of dust-obscured star formation. Larger spectroscopic samples are needed to understand whether the color excess is due exclusively to dust-obscured star formation, as well as the role of environment in triggering it.

CCD UBV and Gaia DR3 based analysis of NGC 189, NGC 1758 and NGC 7762 open clusters

This paper presents photometric, astrometric, and kinematic analyses of the open clusters NGC 189, NGC 1758 and NGC 7762 based on CCD UBV photometric and Gaia Data Release 3 (DR3) data. According to membership analyses, we identified 32, 57 and 106 most probable member stars with membership probabilities P⩾0.5 in NGC 189, NGC 1758 and NGC 7762, respectively. The color excesses and photometric metallicities of each cluster were determined separately using UBV two-color diagrams. The color excess E(B-V) is 0.590±0.023 mag for NGC 189, 0.310±0.022 mag for NGC 1758 and 0.640±0.017 mag for NGC 7762. The photometric metallicity [Fe/H] is -0.08±0.03 dex for both NGC 189 and NGC 1758, and -0.12±0.02 dex for NGC 7762. Distance moduli and ages of the clusters were obtained by comparing PARSEC isochrones with the color-magnitude diagrams constructed from UBV and Gaia photometric data. During this process, we kept as constant color excess and metallicity for each cluster. The estimated isochrone distance is 1201±53 pc for NGC 189, 902±33 pc for NGC 1758 and 911±31 pc for NGC 7762. These are compatible with the values obtained from trigonometric parallax. Ages of the clusters are 500±50 Myr, 650±50 Myr and 2000±200 Myr for NGC 189, NGC 1758 and NGC 7762, respectively. Galactic orbit integration of the clusters showed that NGC 1758 completely orbits outside the solar circle, while NGC 189 and NGC 7762 enter the solar circle during their orbits.

Physical Characterization of Early Galaxies in the Webb’s First Deep Field SMACS J0723.3-7327

This paper highlights initial photometric analyses of JWST NIRCam imaging data in the sightline of SMACS0723, aiming to identify galaxies at redshift z > 7. By applying a conservative Lyman-break selection followed by photometric-redshift analysis and visual inspection, we identify four F090W-dropout and two F150W-dropout sources, three of which were recently confirmed in an independent spectroscopic analysis to z = 7.663, 7.665, and 8.499. We then supplement our sample with a photometric-redshift selection, and identify five additional candidates at 7 < z phot < 13. The NIRCam images clearly resolve all sources and reveal their subgalactic components that were not resolved/detected in the previous imaging by Hubble Space Telescope. Our spectral energy distribution analysis reveals that the selected galaxies are characterized by young stellar populations (median age of ∼50 Myr) of subsolar metallicity (∼0.2 Z ⊙) and little dust attenuation (A V ∼ 0.5). In several cases, we observe extreme Hβ+[O iii] lines being captured in the F444W band and seen as color excess, which is consistent with their observed high star formation rate surface density. Eight of the 11 sources identified in this study appear in at least one of the recent studies (Adams et al.; Atek et al.; Donnan et al.; Harikane et al.; Yan et al.) of the same fields, implying the high fidelity of our selection. We crossmatch all high-z galaxy candidates presented in the five studies with our catalog and discuss the possible causes of discrepancy in the final lists.

A photoelectric study of the eclipsing binary EG Serpentis

ABSTRACT A ubvy photoelectric study of the early A-type, detached eclipsing binary EG Serpentis (EG Ser) has been undertaken at Mount Laguna Observatory. Simultaneous observation on two telescopes has been employed for the first time at the observatory. Approximately 2000 standardized differential magnitudes are presented along with standardized colours and V magnitudes of the EG Ser field. A new ephemeris is determined that indicates a small positive displacement of secondary eclipse. The photometric elements are solved for using the NDE model, and the presence of a small, but non-zero, orbital eccentricity is confirmed. The photometry is combined with published spectroscopy to obtain absolute parameters for the system. The colour excess of and distance to the binary are determined. An approximate age is estimated. The results are compared with the only other published solution (of about the same vintage) and recent light-curve solutions by the author of this study.

Extinction of Taurus, Orion, Perseus, and California Molecular Clouds Based on the LAMOST, 2MASS, and Gaia Surveys. I. 3D Extinction and Structure

The 3D extinction and structure are studied for the Taurus, Orion, Perseus, and California molecular clouds based on the LAMOST spectroscopy. Stellar color excess is calculated with the intrinsic color index derived from the atmospheric parameters in the LAMOST DR8 catalog and the observed color index in the Gaia EDR3 and the 2MASS PSC. In combination with the distance from the Gaia EDR3 parallax, the 3D dust extinction maps are retrieved in the color excesses and with an uncertainty of ∼0.03 mag and ∼0.07 mag respectively. The extinction maps successfully separate the clouds that overlap in the sky area and manifest the structure of the individual cloud. Meanwhile, a bow-like structure is found with a distance range from 175 to 250 pc, half of which is a part of the Per-Tau Shell in similar coordinates and distance while the other half is not. Three low-extinction rings are additionally discovered and briefly discussed.

LISC Catalog of Star Clusters. II. High Galactic Latitude Open Clusters in Gaia EDR3

It is well known that there are few open clusters (OCs) in the high-latitude region of the Milky Way galaxy, because most star formation takes place in the thin disk. It is therefore crucial to look for high Galactic latitude OCs, in order to understand OCs and the Galactic parts outside the plane well. This work looks for high Galactic latitude OCs in Gaia Early Data Release 3, and determines their basic parameters from color–magnitude diagrams (CMDs) if the main sequence is included in CMDs. The friend-of-friend method is applied to the determination of the membership of stars. Star groups with more than 20 bright (G < 18 mag) stars are taken as OC candidates, and these candidates are finally verified by the observed CMDs including stars fainter than 18 mag in the G band. After crossmatching with previous catalogs, 56 new OC candidates are found in the high Galactic latitude region with ∣b∣ ≥ 25°, in which 35 have somewhat clear CMDs and are suggested as newly discovered OCs. Finally, eight of the new OCs are confirmed again by the pyUPMASK technique. The new sample increases the total number of known high Galactic latitude OC candidates significantly. The distance modulus, color excess, metallicity, age, and binary fraction of 35 newly discovered OCs are determined by fitting their observed CMDs to the ASPS stellar population models. All the results are included in the new star cluster catalog, LISC, as its second part (LISC II).

PHANGS–JWST First Results: Dust-embedded Star Clusters in NGC 7496 Selected via 3.3 μm PAH Emission

The earliest stages of star formation occur enshrouded in dust and are not observable in the optical. Here we leverage the extraordinary new high-resolution infrared imaging from JWST to begin the study of dust-embedded star clusters in nearby galaxies throughout the Local Volume. We present a technique for identifying dust-embedded clusters in NGC 7496 (18.7 Mpc), the first galaxy to be observed by the PHANGS–JWST Cycle 1 Treasury Survey. We select sources that have strong 3.3 μm PAH emission based on a F300M − F335M color excess and identify 67 candidate embedded clusters. Only eight of these are found in the PHANGS-HST optically selected cluster catalog, and all are young (six have SED fit ages of ∼1 Myr). We find that this sample of embedded cluster candidates may significantly increase the census of young clusters in NGC 7496 from the PHANGS-HST catalog; the number of clusters younger than ∼2 Myr could be increased by a factor of 2. Candidates are preferentially located in dust lanes and are coincident with the peaks in the PHANGS-ALMA CO (2–1) maps. We take a first look at concentration indices, luminosity functions, SEDs spanning from 2700 Å to 21 μm, and stellar masses (estimated to be between ∼104 and 105 M ⊙). The methods tested here provide a basis for future work to derive accurate constraints on the physical properties of embedded clusters, characterize the completeness of cluster samples, and expand analysis to all 19 galaxies in the PHANGS–JWST sample, which will enable basic unsolved problems in star formation and cluster evolution to be addressed.

Photometry of the Four Anti-Galactocentric Old Open Clusters: Czernik 30, Berkeley 34, Berkeley 75, and Berkeley 76

We present a BVI photometric study of four old open clusters (OCs) in the the Milky Way, Czernik 30, Berkeley 34, Berkeley 75, and Berkeley 76 using the observation data obtained with the Small and Moderate Aperture Research Telescope System 1.0 m telescope at the Cerro Tololo Inter-American Observatory, Chile. These four OCs are located at the anti-Galactocentric direction and in the Galactic plane. We determine the fundamental physical parameters for the four OCs, such as age, metallicity, distance modulus, and color excess, using red clump and PARSEC isochrone fitting methods after finding center and size of the four OCs. These four old OCs are 2–3 Gyr old and 6–8 kpc away from the Sun. The metallicity ([Fe/H]) values of the four OCs are between −0.6 and 0.0 dex. We combine data for these four OCs with those for old OCs from five literatures resulting in 236 objects to investigate Galactic radial-metallicity distribution. The gradient of a single linear fit for this Galactocentric [Fe/H] distribution is −0.052 ± 0.004 dex kpc−1. If we assume the existence of a discontinuity in this radial-metallicity distribution, the gradient at Galactocentric radius <12 kpc is −0.070 ± 0.006 dex kpc−1, while that at the outer part is −0.016 ± 0.010 which is flatter than that of the inner part. Although there are not many sample clusters at the outer part, the broken linear fit seems to better follow the observation data.

A Candidate for the Least-massive Black Hole in the First 1.1 Billion Years of the Universe

We report a candidate of a low-luminosity active galactic nucleus (AGN) at z = 5 that was selected from the first near-infrared images of the JWST CEERS project. This source, named CEERS-AGN-z5-1 at absolute 1450 Å magnitude M 1450 = −19.5 ± 0.3, was found via a visual selection of compact sources from a catalog of Lyman break galaxies at z > 4, taking advantage of the superb spatial resolution of the JWST/NIRCam images. The 20 photometric data available from CFHT, Hubble Space Telescope, Spitzer, and JWST suggest that the continuum shape of this source is reminiscent of that for an unobscured AGN, and there is a clear color excess in the filters where the redshifted Hβ+[O iii] and Hα are covered. The estimated line luminosity is L Hβ+[O III] = 1043.0 erg s−1 and L Hα = 1042.9 erg s−1 with the corresponding rest-frame equivalent width EWHβ+[O III] = 1100 Å and EWHα = 1600 Å, respectively. Our spectral energy distribution fitting analysis favors the scenario that this object is either a strong broad-line emitter or even a super-Eddington accreting black hole (BH), although a possibility of an extremely young galaxy with moderate dust attenuation is not completely ruled out. The bolometric luminosity, L bol = 2.5 ± 0.3 × 1044 erg s−1, is consistent with those of z < 0.35 broad-line AGNs with M BH ∼ 106 M ⊙ accreting at the Eddington limit. This new AGN population in the first 1.1 billion years of the universe may close the gap between the observed BH mass range at high redshift and that of BH seeds. Spectroscopic confirmation is awaited to secure the redshift and its AGN nature.