Origin and Evolution of Dust-obscured Galaxies in Galaxy Mergers

Yutani, Naomichi; Toba, Yoshiki; Baba, Shigeo; Wada, Keiichi

doi:10.3847/1538-4357/ac87a2

Cited by 15 publications

(12 citation statements)

References 69 publications

(132 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We observe that approximately half of our eFEDS-W4-X subsample, including ELIRG, is not covered by evolutionary tracks. This is probably because the assumed M BH in Yutani et al (2021) is smaller than that of objects considered in this work. The typical M BH for objects with spectroscopically derived M BH is log (M BH /M ) ∼ 9.3.…”

Section: Evolutionary Stage Of the Erosita-detected Mir Galaxiesmentioning

confidence: 86%

“…The typical M BH for objects with spectroscopically derived M BH is log (M BH /M ) ∼ 9.3. Indeed, Yutani et al (2021) could not reproduce objects with L IR > 10 13 L under the condition described above, which may indicate that more massive BH mergers are required to reproduce the λ Edd -N H distribution for our sample. Additionally, we find that the track moves around significantly on the λ Edd -N H plot.…”

Section: Evolutionary Stage Of the Erosita-detected Mir Galaxiesmentioning

confidence: 88%

“…The pink shaded area represents the blow-out region, in which the dusty gas that produces the nuclear obscuration is expected to be pushed away by radiation pressure (i.e., λ Edd > λ eff Edd ). The solid line shows the evolutionary track calculated by Yutani et al (2021), color-coded by time in units of Myr.…”

Section: Consistency Of Stellar Mass Based On the Host Flux Densitiesmentioning

confidence: 99%

“…3), we may need more sample spectra to determine whether this increasing trend is real. Yutani et al (2021) performed high-resolution N-body-SPH simulations with the ASURA code (Saitoh et al 2008(Saitoh et al , 2009 and investigated the time evolution of the SEDs of galaxy mergers using the radiative transfer simulation code RADMC-3D (Dullemond et al 2012). Although our eFEDS-W4-X sources may not always experience galaxy mergers in their lifetimes, it is still worth comparing observational results with model predictions.…”

Section: Evolutionary Stage Of the Erosita-detected Mir Galaxiesmentioning

confidence: 99%

“…The advent of the Wide-field Infrared Survey Explorer (WISE; Wright et al 2010) has provided an avenue for detecting an enormous number of MIR AGN (see e.g., Assef et al 2018). In particular, MIR-bright ( f 22 > a few mJy) but optically faint WISE objects (which are often called dust-obscured galaxies (DOGs) 1 ), have been reported to harbor a strong AGN surrounded by a large amount of dust (e.g., Eisenhardt et al 2012;Wu et al 2012;Toba et al 2015Toba et al , 2017aToba & Nagao 2016;Noboriguchi et al 2019;Yutani et al 2021). A&A 661, A15 (2022) Some dusty AGN are located at 1 < z < 4, where the cosmic SFR density and BH mass-accretion rate density reach a maximum (e.g., Madau & Dickinson 2014;Ueda et al 2014).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

The eROSITA Final Equatorial-Depth Survey (eFEDS)

Toba

Liu

Urrutia

et al. 2022

A&A

View full text Add to dashboard Cite

Aims. We investigate the physical properties – such as the stellar mass (M*), star-formation rate, infrared (IR) luminosity (LIR), X-ray luminosity (LX), and hydrogen column density (NH) – of mid-IR (MIR) galaxies and active galactic nuclei (AGN) at z < 4 in the 140 deg2 field observed by eROSITA on SRG using the Performance-and-Verification-Phase program named the eROSITA Final Equatorial Depth Survey (eFEDS). Methods. By cross-matching the WISE 22 μm (W4)-detected sample and the eFEDS X-ray point-source catalog, we find that 692 extragalactic objects are detected by eROSITA. We have compiled a multiwavelength dataset extending from X-ray to far-IR wavelengths. We have also performed (i) an X-ray spectral analysis, (ii) spectral-energy-distribution fitting using X-CIGALE, (iii) 2D image-decomposition analysis using Subaru Hyper Suprime-Cam images, and (iv) optical spectral fitting with QSFit to investigate the AGN and host-galaxy properties. For 7088 WISE 22 μm objects that are undetected by eROSITA, we have performed an X-ray stacking analysis to examine the typical physical properties of these X-ray faint and probably obscured objects. Results. We find that (i) 82% of the eFEDS–W4 sources are classified as X-ray AGN with log LX > 42 erg s−1 ; (ii) 67 and 24% of the objects have log(LIR/L⊙) > 12 and 13, respectively; (iii) the relationship between LX and the 6 μm luminosity is consistent with that reported in previous works; and (iv) the relationship between the Eddington ratio and NH for the eFEDS–W4 sample and a comparison with a model prediction from a galaxy-merger simulation indicates that approximately 5.0% of the eFEDS–W4 sources in our sample are likely to be in an AGN-feedback phase, in which strong radiation pressure from the AGN blows out the surrounding material from the nuclear region. Conclusions. Thanks to the wide area coverage of eFEDS, we have been able to constrain the ranges of the physical properties of the WISE 22 μm-selected sample of AGNs at z < 4, providing a benchmark for forthcoming studies on a complete census of MIR galaxies selected from the full-depth eROSITA all-sky survey.

show abstract

Section: Evolutionary Stage Of the Erosita-detected Mir Galaxiesmentioning

confidence: 86%

Section: Evolutionary Stage Of the Erosita-detected Mir Galaxiesmentioning

confidence: 88%

Section: Consistency Of Stellar Mass Based On the Host Flux Densitiesmentioning

confidence: 99%

Section: Evolutionary Stage Of the Erosita-detected Mir Galaxiesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

The eROSITA Final Equatorial-Depth Survey (eFEDS)

Toba

Liu

Urrutia

et al. 2022

A&A

View full text Add to dashboard Cite

show abstract

A new discovery space opened by eROSITA

Musiimenta,

Brusa,

Liu

et al. 2023

A&A

View full text Add to dashboard Cite

Context. In the context of an evolutionary model, the outflow phase of an active galactic nucleus (AGN) occurs at the peak of its activity, once the central supermassive black hole (SMBH) is massive enough to generate sufficient power to counterbalance the potential well of the host galaxy. This outflow feedback phase plays a vital role in galaxy evolution. Aims. Our aim in this paper is to apply various selection methods to isolate powerful AGNs in the feedback phase, trace and characterise outflows in these AGNs, and explore the link between AGN luminosity and outflow properties. Methods. We applied a combination of methods to the Spectrum Roentgen Gamma (SRG) eROSITA Final Equatorial Depth survey (eFEDS) catalogue and isolated ∼1400 candidates at z > 0.5 out of ∼11 750 AGNs (∼12%). Furthermore, we narrowed down our selection to 427 sources that have 0.5 < z < 1. We tested the robustness of our selection on the small subsample of 50 sources with available good quality SDSS spectra at 0.5 < z < 1 and, for which we fitted the [OIII] emission line complex and searched for the presence of ionised gas outflow signatures. Results. Out of the 50 good quality SDSS spectra, we identified 23 quasars (∼45%) with evidence of ionised outflows based on the presence of significant broad and/or shifted components in [OIII]λ5007 Å. They are on average more luminous (log Lbol ∼ 45.2 erg s−1) and more obscured (NH ∼ 1022 cm−2) than the parent sample of ∼427 candidates, although this may be ascribed to selection effects affecting the good quality SDSS spectra sample. By adding 118 quasars at 0.5 < z < 3.5 with evidence of outflows reported in the literature, we find a weak correlation between the maximum outflow velocity and the AGN bolometric luminosity. On the contrary, we recovered strong correlations between the mass outflow rate and outflow kinetic power with the AGN bolometric luminosity. Conclusions. About 30% of our sample have kinetic coupling efficiencies, Ė/Lbol > 1%, suggesting that the outflows could have a significant effect on their host galaxies. We find that the majority of the outflows have momentum flux ratios lower than 20 which rules out an energy-conserving nature. Our present work points to the unequivocal existence of a rather short AGN outflow phase, paving the way towards a new avenue to dissect AGN outflows in large samples within eROSITA and beyond.

show abstract

Identifying type II quasars at intermediate redshift with few-shot learning photometric classification

Cunha,

Humphrey,

Brinchmann

et al. 2024

A&A

View full text Add to dashboard Cite

A sub-population of AGNs where the central engine is obscured are known as type II quasars (QSO2s). These luminous AGNs have a thick and dusty torus that obscures the accretion disc from our line of sight. Thus, their special orientation allows for detailed studies of the AGN-host co-evolution. Increasing the sample size of QSO2 sources in critical redshift ranges is crucial for understanding the interplay of AGN feedback, the AGN-host relationship, and the evolution of active galaxies. We aim to identify QSO2 candidates in the `redshift desert' using optical and infrared photometry. At this intermediate redshift range (i.e. $1 z 2$), most of the prominent optical emission lines in QSO2 sources (e.g. CIV$ OIII 4959, 5008$) fall either outside the wavelength range of the SDSS optical spectra or in particularly noisy wavelength ranges, making QSO2 identification challenging. Therefore, we adopted a semi-supervised machine learning approach to select candidates in the SDSS galaxy sample. Recent applications of machine learning in astronomy focus on problems involving large data sets, with small data sets often being overlooked. We developed a `few-shot' learning approach for the identification and classification of rare-object classes using limited training data (200 sources). The new AMELIA pipeline uses a transfer-learning based approach with decision trees, distance-based, and deep learning methods to build a classifier capable of identifying rare objects on the basis of an observational training data set. We validated the performance of AMELIA by addressing the problem of identifying QSO2s at $1 z 2$ using SDSS and WISE photometry, obtaining an F1-score above 0.8 in a supervised approach. We then used AMELIA to select new QSO2 candidates in the `redshift desert' and examined the nature of the candidates using SDSS spectra, when available. In particular, we identified a sub-population of NeV emitters at $z which are highly likely to contain obscured AGNs. We used X-ray and radio cross-matching to validate our classification and investigated the performance of photometric criteria from the literature showing that our candidates have an inherent dusty nature. Finally, we derived physical properties for our QSO2 sample using photoionisation models and verified the AGN classification using an SED fitting. Our results demonstrate the potential of few-shot learning applied to small data sets of rare objects, in particular QSO2s, and confirms that optical-IR information can be further explored to search for obscured AGNs. We present a new sample of candidates to be further studied and validated using multi-wavelength observations.

show abstract

Origin and Evolution of Dust-obscured Galaxies in Galaxy Mergers

Cited by 15 publications

References 69 publications

The eROSITA Final Equatorial-Depth Survey (eFEDS)

The eROSITA Final Equatorial-Depth Survey (eFEDS)

A new discovery space opened by eROSITA

Identifying type II quasars at intermediate redshift with few-shot learning photometric classification

Contact Info

Product

Resources

About