Stellar populations of a sample of far-infrared AGN and non-AGN green valley galaxies

Mahoro, Antoine; Pović, M.; Vaïsänen, P.; Nkundabakura, Pheneas; Heyden, K. van der

doi:10.1093/mnras/stac1134

Cited by 3 publications

(5 citation statements)

References 168 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Finally, we note that the three unambiguous cases of outflows in the FIR AGN green valley galaxies are situated within, or just at the border, of the MS of starforming galaxies. This suggests the possibility that we are witnessing the influence of the AGNs on their host galaxies in this sample (such as possible positive feedback), in line with results we have reported previously in Mahoro et al (2017Mahoro et al ( , 2019Mahoro et al ( , 2022. Nevertheless, we consider this a preliminary result, and plan further observations of larger samples, and using data obtained with a new generation of telescopes, including other wavelengths and with higher spatial resolution (e.g., JWST/NIRSpec or the Atacama Large Millimeter/ submillimeter Array).…”

Section: Discussionsupporting

confidence: 91%

“…This particular result in this paper, based on the study of the [O III] λ5007 emission line profiles of a small sample of optically selected green valley AGNs with FIR emission, is thus very much in line with that obtained using photometric techniques of statistical samples in Mahoro et al (2017Mahoro et al ( , 2019Mahoro et al ( , 2022, where we suggested the possibility of ongoing positive AGN feedback in FIR green valley galaxies. It will be interesting to distinguish further whether we indeed are witnessing positive feedback by the AGNs on the star formation activities of the host galaxies, or, for example, whether any star formation quenching has not yet started in these galaxies, and if so, why, and what the exact physical role of gas outflows is.…”

Section: Discussionsupporting

confidence: 89%

“…This has been observed independently when examining their morphology (Mahoro et al 2019). In addition, we did not find older stellar populations in AGN hosts, when studying stellar ages and populations of a subsample of AGNs and non-AGNs (Mahoro et al 2022), nor signs of star formation quenching, as suggested previously in X-ray and optical studies (e.g., Nandra et al 2007;Pović et al 2012;Ellison et al 2016;Leslie et al 2016). Therefore, our results may suggest that if AGN feedback influences the star formation in green valley galaxies with X-ray detected AGNs and FIR emission, it is positive AGN feedback rather than negative feedback.…”

Section: Introductionsupporting

confidence: 70%

See 2 more Smart Citations

The [O iii] Profiles of Far-infrared Active and Inactive Optically Selected Green Valley Galaxies

Mahoro

Vaïsänen

Pović

et al. 2023

ApJ

Self Cite

View full text Add to dashboard Cite

We present a study of the [O iii] λ5007 line profile in a subsample of eight active galactic nuclei (AGNs) and six non-AGNs in the optically selected green valley at z < 0.5 using long-slit spectroscopic observations obtained with the 11 m Southern African Large Telescope. Gaussian decomposition of the line profile was performed to study its different components. We observe that the AGN profiles are more complex than the non-AGN ones. In particular, in most AGNs (5/8) we detect a blue wing of the line. We derive the FWHM velocities of the wing and systemic component, and find that the AGNs show higher FWHM velocities than the non-AGNs in their core component. We also find that the AGNs show blue wings with a median velocity width of approximately 600 km s−1, and a velocity offset from the core component in the range −90 to −350 km s−1, in contrast to the non-AGN galaxies, where we do not detect blue wings in any of their [O iii] λ5007 line profiles. Using the spatial information in our spectra, we show that at least three of the outflow candidate galaxies have centrally driven gas outflows extending across the whole galaxy. Moreover, these are also the galaxies which are located on the main sequence of star formation, raising the possibility that the AGNs in our sample are influencing the star formation of their host galaxies (such as positive feedback). This is in agreement with our previous work where we studied the star formation, morphology, and stellar population properties of a sample of green valley AGNs and non-AGN galaxies.

show abstract

Section: Discussionsupporting

confidence: 91%

Section: Discussionsupporting

confidence: 89%

Section: Introductionsupporting

confidence: 70%

See 1 more Smart Citation

The [O iii] Profiles of Far-infrared Active and Inactive Optically Selected Green Valley Galaxies

Mahoro

Vaïsänen

Pović

et al. 2023

ApJ

Self Cite

View full text Add to dashboard Cite

show abstract

“…L  , older than any dwarf sample. In Mahoro et al (2022), however, 77% of the 17 X-ray selected, far-IR detected AGN-host galaxies have á ñ < t log 9…”

Section: Mean Stellar Agementioning

confidence: 99%

Stellar Populations of AGN-host Dwarf Galaxies Selected with Different Methods

Li,

Zhao 赵,

Bai

2024

Res. Astron. Astrophys.

View full text Add to dashboard Cite

In this paper we investigate the stellar populations and star formation histories of 235 active galactic nuclei (AGN)-host dwarf galaxies, consisting of four samples identified separately with different methods (i.e., radio, X-ray, mid-IR and variability), utilizing the synthesis code STARLIGHT and spectra from the Sloan Digital Sky Survey (SDSS) Data Release 8. Our results show that the variability sample is the oldest, while the mid-IR sample is the youngest, for which the luminosity at 4020 Å is dominated (>50%) by the young population (t<108 yr). The light-weighted mean stellar age of the whole sample is in general about 0.7 dex younger than the optical sample studie in Cai et al. We compare the population results between fitting models with and without a power-law (PL) component and find that the neglect of a PL component would lead to an under- and over-estimation by 0.2 and 0.1 dex for the light- and mass-weighted mean stellar age, respectively, for our sample of dwarf galaxies, which has a mean fractional contribution of ∼16% from the AGN. In addition, we obtain further evidence for a possible suppression of star formation in the host galaxy by the central AGN. We also find that there exists an anti-correlation between the extinction-corrected O[III] luminosity and light-weighted mean stellar age, confirming our previous finding that there is a physical connection between AGN and star-forming activies in AGN-host dwarfs.

show abstract

“…Shin et al (2019) reported a positive feedback scenario in NGC 5728, due to higher SFRs in the encountering region where the ionized gas outflows encounter the star formation ring at 1 kpc radius. Mahoro et al (2022) showed that there are no apparent signs of negative AGN feedback, after comparing host galaxy properties of far-infrared AGN and non-AGN green valley galaxies. Therefore, it is interesting to provide further clues on the contradictory effects of AGN feedback on star formations, through different methods, which is the main objective of this manuscript.…”

Section: Introductionmentioning

confidence: 99%

Different Dependence of Narrow Hα Line Luminosity on Optical Continuum Luminosity between Star-forming Galaxies and Type 2 Active Galactic Nuclei: Globally Negative AGN Feedback in Local Type 2 AGN?

Zhang

2024

ApJ

View full text Add to dashboard Cite

In this manuscript, clues are provided to support globally negative active galactic nuclei (AGN) feedback on star formation in the host galaxies of the local low-redshift Sloan Digital Sky Survey (SDSS) Type 2 AGN, based on the different dependence of narrow Hα line luminosity L Hα on optical continuum luminosity λ L cont between star-forming galaxies and Type 2 AGN. Through the measured L Hα and λ L cont in SDSS star-forming galaxies, there is a strong linear correlation between λ L cont and L Hα , accepted as a standard correlation without the effects of AGN activity. Meanwhile, considering the apparent contribution of AGN activity to the narrow Hα line emissions in Type 2 AGN, the correlation between λ L cont and L Hα in the SDSS Type 2 AGN leads to a statistically lower L Hα in Type 2 AGN than in star-forming galaxies, with a significance level higher than 5σ, even after considering necessary effects (including effects of host galaxy properties), leading to the accepted conclusion on the globally negative AGN feedback in the local Type 2 AGN. Meanwhile, the properties of Dn(4000) and Hδ A can provide indirect clues to support the globally negative AGN feedback in local Type 2 AGN, due to older stellar ages in Type 2 AGN. Moreover, it is interesting to expect more than 50% narrow Hα emissions globally suppressed in the host galaxies of Type 2 AGN relative to the star-forming galaxies. The results not only support globally negative AGN feedback in local Type 2 AGN, but also show further clues on the quantification of suppressions of star formation by the globally negative AGN feedback.

show abstract

Stellar populations of a sample of far-infrared AGN and non-AGN green valley galaxies

Cited by 3 publications

References 168 publications

The [O iii] Profiles of Far-infrared Active and Inactive Optically Selected Green Valley Galaxies

The [O iii] Profiles of Far-infrared Active and Inactive Optically Selected Green Valley Galaxies

Stellar Populations of AGN-host Dwarf Galaxies Selected with Different Methods

Different Dependence of Narrow Hα Line Luminosity on Optical Continuum Luminosity between Star-forming Galaxies and Type 2 Active Galactic Nuclei: Globally Negative AGN Feedback in Local Type 2 AGN?

Contact Info

Product

Resources

About