arXiv subjects

Yiseul Jeon

Publications and source records attributed to Yiseul Jeon.

At least 19 recordsLinked to original sources

arXiv2023

The Seoul National University AGN Monitoring Project III: H$β$ lag measurements of 32 luminous AGNs and the high-luminosity end of the size--luminosity relation

We present the main results from a long-term reverberation mapping campaign carried out for the Seoul National University Active Galactic Nuclei (AGN) Monitoring Project. High-quality data were obtained during 2015-2021 for 32 luminous AGNs (i.e., continuum luminosity in the range of $10^{44-46}$ erg s$^{-1}$) at a regular cadence, of 20-30 days for spectroscopy and 3-5 days for photometry. We obtain time lag measurements between the variability in the H$β$ emission and the continuum for 32 AGNs; twenty-five of those have the best lag measurements based on our quality assessment, examining correlation strength, and the posterior lag distribution. Our study significantly increases the current sample of reverberation-mapped AGNs, particularly at the moderate to high luminosity end. Combining our results with literature measurements, we derive a H$β$ broad line region size--luminosity relation with a shallower slope than reported in the literature. For a given luminosity, most of our measured lags are shorter than the expectation, implying that single-epoch black hole mass estimators based on previous calibrations could suffer large systematic uncertainties.

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arXiv2023

The Seoul National University AGN Monitoring Project IV: H$α$ reverberation mapping of 6 AGNs and the H$α$ Size-Luminosity Relation

The broad line region (BLR) size-luminosity relation has paramount importance for estimating the mass of black holes in active galactic nuclei (AGNs). Traditionally, the size of the H$β$ BLR is often estimated from the optical continuum luminosity at 5100\angstrom{} , while the size of the H$α$ BLR and its correlation with the luminosity is much less constrained. As a part of the Seoul National University AGN Monitoring Project (SAMP) which provides six-year photometric and spectroscopic monitoring data, we present our measurements of the H$α$ lags of 6 high-luminosity AGNs. Combined with the measurements for 42 AGNs from the literature, we derive the size-luminosity relations of H$α$ BLR against broad H$α$ and 5100\angstrom{} continuum luminosities. We find the slope of the relations to be $0.61\pm0.04$ and $0.59\pm0.04$, respectively, which are consistent with the \hb{} size-luminosity relation. Moreover, we find a linear relation between the 5100\angstrom{} continuum luminosity and the broad H$α$ luminosity across 7 orders of magnitude. Using these results, we propose a new virial mass estimator based on the H$α$ broad emission line, finding that the previous mass estimates based on the scaling relations in the literature are overestimated by up to 0.7 dex at masses lower than $10^7$~M$_{\odot}$.

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arXiv2022

The Infrared Medium-deep Survey. IX. Discovery of Two New $z\sim6$ Quasars and Space Density down to $M_{1450}\sim-23.5$ mag

We present the result of the Infrared Medium-deep Survey (IMS) $z\sim6$ quasar survey, using the combination of the IMS near-infrared images and the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) optical images. The traditional color-selection method results in 25 quasar candidates over $86$ deg$^{2}$. We introduce the corrected Akaike Information Criterion (AICc) with the high-redshift quasar and late-type star models to prioritize the candidates efficiently. Among the color-selected candidates, seven plausible candidates finally passed the AICc selection of which three are known quasars at $z\sim6$. The follow-up spectroscopic observations for the remaining four candidates were carried out, and we confirmed that two out of four are $z\sim6$ quasars. With this complete sample, we revisited the quasar space density at $z\sim6$ down to $M_{1450}\sim-23.5$ mag. Our result supports the low quasar space density at the luminosity where the quasar's ultraviolet ionizing emissivity peaks, favoring a minor contribution of quasars to the cosmic reionization.

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arXiv2020

The Infrared Medium-deep Survey. VIII. Quasar Luminosity Function at $z\sim5$

Faint $z\sim5$ quasars with $M_{1450}\sim-23$ mag are known to be the potentially important contributors to the ultraviolet ionizing background in the post-reionization era. However, their number density has not been well determined, making it difficult to assess their role in the early ionization of the intergalactic medium (IGM). In this work, we present the updated results of our $z\sim5$ quasar survey using the Infrared Medium-deep Survey (IMS), a near-infrared imaging survey covering an area of 85 deg$^{2}$. From our spectroscopic observations with the Gemini Multi-Object Spectrograph (GMOS) on the Gemini-South 8 m Telescope, we discovered eight new quasars at $z\sim5$ with $-26.1\leq M_{1450} \leq -23.3$. Combining our IMS faint quasars ($M_{1450}>-27$ mag) with the brighter Sloan Digital Sky Survey (SDSS) quasars ($M_{1450}<-27$ mag), we derive the $z\sim5$ quasar luminosity function (QLF) without any fixed parameters down to the magnitude limit of $M_{1450}=-23$ mag. We find that the faint-end slope of the QLF is very flat ($α=-1.2^{+1.4}_{-0.6}$), with a characteristic luminosity of $M^{*}_{1450}=-25.8^{+1.4}_{-1.1}$ mag. The number density of $z\sim5$ quasars from the QLF gives an ionizing emissivity at 912 $\unicode{x212B}$ of $ε_{912}=(3.7$--$7.1)\times10^{23}$ erg s$^{-1}$ Hz$^{-1}$ Mpc$^{-3}$ and an ionizing photon density of $\dot{n}_{\rm ion}=(3.0$--$5.7)\times10^{49}$ Mpc$^{-3}$ s$^{-1}$. These results imply that quasars are responsible for only 10-20% (up to 50% even in the extreme case) of the photons required to completely ionize the IGM at $z\sim5$, disfavoring the idea that quasars alone could have ionized the IGM at $z\sim5$.

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arXiv2020

The Infrared Medium-deep Survey. \Romannum{7}. Faint Quasars at $z \sim 5$ in the ELAIS-N1 Field

The intergalactic medium (IGM) at $z\sim$ 5 to 6 is largely ionized, and yet the main source for the IGM ionization in the early universe is uncertain. Of the possible contributors are faint quasars with $-26 \lesssim M_{\rm 1450} \lesssim -23$, but their number density is poorly constrained at $z\sim5$. In this paper, we present our survey of faint quasars at $z\sim5$ in the European Large-Area {\it ISO} Survey-North 1 (ELAIS-N1) field over a survey area of 6.51 deg$^2$ and examine if such quasars can be the dominant source of the IGM ionization. We use the deep optical/near-infrared data of the ELAIS-N1 field as well as the additional medium-band observations to find $z \sim 5$ quasars through a two-step approach using the broadband color selection, and SED fitting with the medium-band information included. Adopting Bayesian information criterion, we identify ten promising quasar candidates. Spectra of three of the candidates are obtained, confirming all of them to be quasars at $z\sim5$ and supporting the reliability of the quasar selection. Using the promising candidates, we derive the $z\sim5$ quasar luminosity function at $-26 \lesssim M_{\rm 1450} \lesssim -23$. The number density of faint $z\sim5$ quasars in the ELAIS-N1 field is consistent with several previous results that quasars are not the main contributors to the IGM-ionizing photons at $z\sim5$

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arXiv2019

The Seoul National University AGN monitoring project. II. BLR size and black hole mass of two AGNs

Active galactic nuclei (AGNs) show a correlation between the size of the broad line region (BLR) and the monochromatic continuum luminosity at 5100 Å, allowing black hole mass estimation based on single-epoch spectra. However, the validity of the correlation is yet to be clearly tested for high-luminosity AGNs. We present the first reverberation-mapping results of the Seoul National University AGN monitoring program (SAMP), which is designed to focus on luminous AGNs for probing the high end of the size-luminosity relation. We report time lag measurements of two AGNs, namely, 2MASS J10261389+5237510 and SDSS J161911.24+501109.2, using the light curves obtained over a $\sim$1000 day period with an average cadence of $\sim$10 and $\sim$20 days, respectively for photometry and spectroscopy monitoring. Based on a cross-correlation analysis and H$β$ line width measurements, we determine the H$β$ lag as $41.8^{+4.9}_{-6.0}$ and $52.6^{+17.6}_{-14.7}$ days in the observed-frame, and black hole mass as $3.65^{+0.49}_{-0.57} \times 10^7 M_{\odot}$ and $23.02^{+7.81}_{-6.56} \times 10^7 M_{\odot}$, respectively for 2MASS J1026 and SDSS J1619.

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arXiv2018

The Infrared Medium-deep Survey. VI. Discovery of Faint Quasars at $z\sim5$ with a Medium-band-based Approach

The faint quasars with $M_{1450}>-24$ mag are known to hold the key to the determination of the ultraviolet emissivity for the cosmic re-ionization. But only a few have been identified so far because of the limitations on the survey data. Here, we present the first results of the $z\sim5$ faint quasar survey with the Infrared Medium-deep Survey (IMS), which covers $\sim100$ deg$^{2}$ areas in $J$-band to the depths of $J_{\rm AB}\sim23$ mag. To improve selection methods, the medium-band follow-up imaging has been carried out using the SED camera for QUasars in Early uNiverse (SQUEAN) on the Otto Struve 2.1 m Telescope. The optical spectra of the candidates were obtained with 8-m class telescopes. We newly discovered 10 quasars with $-25<M_{1450}<-23$ at $z\sim5$, among which three have been missed in a previous survey using the same optical data over the same area, implying the necessity for improvements in high redshift faint quasars selection. We derived photometric redshifts from the medium-band data, and find that they have high accuracies of $\langle|Δz|/(1+z)\rangle=0.016$. The medium-band-based approach allows us to rule out many of the interlopers that contaminate $\gtrsim20~\%$ of the broad-band-selected quasar candidates. These results suggest that the medium-band-based approach is a powerful way to identify $z\sim5$ quasars and measure their redshifts at high accuracy (1-2 %). It is also a cost-effective way to understand the contribution of quasars to the cosmic re-ionization history.

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arXiv2018

The Infrared Medium-deep Survey. IV. Low Eddington Ratio of A Faint Quasar at $z\sim6$: Not Every Supermassive Black Hole is Growing Fast in the Early Universe

To date, most of the luminous quasars known at $z\sim6$ have been found to be in maximal accretion with the Eddington ratios, $λ_{\rm{Edd}}\sim1$, suggesting enhanced nuclear activities in the early universe. However, this may not be the whole picture of supermassive black hole (SMBH) growth since previous studies have not reached on faint quasars that are more likely to harbor SMBHs with low $λ_{\rm{Edd}}$. To gain a better understanding on the accretion activities in quasars in the early universe, we obtained a deep near-infrared (NIR) spectrum of a quasar, IMS J220417.92+011144.8 (hereafter IMS J2204+0112), one of the faintest quasars that have been identified at $z\sim6$. From the redshifted C IV $λ1549$ emission line in the NIR spectrum, we find that IMS J2204+0112 harbors a SMBH with about a billion solar mass and $λ_{\rm{Edd}} \sim 0.1$, but with a large uncertainty in both quantities (0.41 dex). IMS J2204+0112 has one of the lowest Eddington ratios among quasars at $z\sim6$, but a common value among quasars at $z\sim2$. Its low $λ_{\rm{Edd}}$ can be explained with two scenarios; the SMBH growth from a stellar mass black hole through short-duration super-Eddington accretion events or from a massive black hole seed ($\sim10^{5}\,M_{\odot}$) with Eddington-limited accretion. NIR spectra of more faint quasars are needed to better understand the accretion activities of SMBHs at $z \sim 6$.

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arXiv2017

The Infrared Medium-deep Survey. III. Survey of Luminous Quasars at 4.7 $\leq$ z $\leq$ 5.4

We present our first results of the survey for high redshift quasars at $5 \lesssim {\rm z} \lesssim 5.7$. The search for quasars in this redshift range has been known to be challenging due to limitations of filter sets used in previous studies. We conducted a quasar survey for two specific redshift ranges, 4.60 $\leq$ z $\leq$ 5.40 and 5.50 $\leq$ z $\leq$ 6.05, using multi-wavelength data that include observations using custom-designed filters, $is$ and $iz$. Using these filters and a new selection technique, we were able to reduce the fraction of interlopers. Through optical spectroscopy, we confirmed seven quasars at 4.7 $\leq$ z $\leq$ 5.4 with $-27.4 < M_{1450} < -26.4$ which were discovered independently by another group recently. We estimated black hole masses and Eddington ratios of four of these quasars from optical and near-infrared spectra, and found that these quasars are undergoing nearly Eddington-limited accretion which is consistent with the rapid growth of supermassive black holes in luminous quasars at z $\sim$ 5.

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arXiv2016

Development of SED Camera for Quasars in Early Universe (SQUEAN)

We describe the characteristics and performance of a camera system, Spectral energy distribution Camera for Quasars in Early Universe (SQUEAN). It was developed to measure SEDs of high redshift quasar candidates (z $\gtrsim$ 5) and other targets, e.g., young stellar objects, supernovae, and gamma-ray bursts, and to trace the time variability of SEDs of objects such as active galactic nuclei (AGNs). SQUEAN consists of an on-axis focal plane camera module, an auto-guiding system, and mechanical supporting structures. The science camera module is composed of a focal reducer, a customizable filter wheel, and a CCD camera on the focal plane. The filter wheel uses filter cartridges that can house filters with different shapes and sizes, enabling the filter wheel to hold twenty filters of 50 mm $\times$ 50 mm size, ten filters of 86 mm $\times$ 86 mm size, or many other combinations. The initial filter mask was applied to calibrate the filter wheel with high accuracy and we verified that the filter position is repeatable at much less than one pixel accuracy. We installed and tested 50 nm medium bandwidth filters of 600 -- 1,050 nm and other filters at the commissioning observation in 2015 February. We found that SQUEAN can reach limiting magnitudes of 23.3 - 25.3 AB mag at 5-$σ$ in a 1-hour total integration time. - 25.3 AB mag at 5-$σ$ in a 1-hour total integration time.

astro-ph.IM↗

arXiv2016

The Infrared Medium-Deep Survey. V. A New Selection Strategy for Quasars at z > 5 based on Medium-Band Observation with SQUEAN

Multiple color selection techniques have been successful in identifying quasars from wide-field broad-band imaging survey data. Among the quasars that have been discovered so far, however, there is a redshift gap at $5 \lesssim {\rm z} \lesssim 5.7$ due to the limitations of filter sets in previous studies. In this work, we present a new selection technique of high redshift quasars using a sequence of medium-band filters: nine filters with central wavelengths from 625 to 1025 nm and bandwidths of 50 nm. Photometry with these medium-bands traces the spectral energy distribution (SED) of a source, similar to spectroscopy with resolution R $\sim$ 15. By conducting medium-band observations of high redshift quasars at 4.7 $\leq$ z $\leq$ 6.0 and brown dwarfs (the main contaminants in high redshift quasar selection) using the SED camera for QUasars in EArly uNiverse (SQUEAN) on the 2.1-m telescope at the McDonald Observatory, we show that these medium-band filters are superior to multi-color broad-band color section in separating high redshift quasars from brown dwarfs. In addition, we show that redshifts of high redshift quasars can be determined to an accuracy of $Δ{\rm z}/(1+{\rm z}) = 0.002$ -- $0.026$. The selection technique can be extended to z $\sim$ 7, suggesting that the medium-band observation can be powerful in identifying quasars even at the re-ionization epoch.

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arXiv2015

Discovery of A Faint Quasar at z~6 and Implications for Cosmic Reionization

Recent studies suggest that faint active galactic nuclei may be responsible for the reionization of the universe. Confirmation of this scenario requires spectroscopic identification of faint quasars ($M_{1450}>-24$ mag) at $z \gtrsim6$, but only a very small number of such quasars have been spectroscopically identified so far. Here, we report the discovery of a faint quasar IMS J220417.92+011144.8 at z~6 in a 12.5 deg$^{2}$ region of the SA22 field of the Infrared Medium-deep Survey (IMS). The spectrum of the quasar shows a sharp break at $\sim8443~\rmÅ$, with emission lines redshifted to $z=5.944 \pm 0.002$ and rest-frame ultraviolet continuum magnitude $M_{1450}=-23.59\pm0.10$ AB mag. The discovery of IMS J220417.92+011144.8 is consistent with the expected number of quasars at z~6 estimated from quasar luminosity functions based on previous observations of spectroscopically identified low-luminosity quasars . This suggests that the number of $M_{1450}\sim-23$ mag quasars at z~6 may not be high enough to fully account for the reionization of the universe. In addition, our study demonstrates that faint quasars in the early universe can be identified effectively with a moderately wide and deep near-infrared survey such as the IMS.

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arXiv2015

Host Galaxy Properties and Black Hole Mass of Swift J164449.3+573451 from Multi-Wavelength Long-Term Monitoring and HST Data

We study the host galaxy properties of the tidal disruption object, Swift J164449.3+573451 using long-term optical to near-infrared (NIR) data. First, we decompose the galaxy surface brightness distribution and analyze the morphology of the host galaxy using high resolution \emph{HST} WFC3 images. We conclude that the host galaxy is a bulge-dominant galaxy that is well described by a single Sérsic model with Sérsic index $n=3.43\pm0.05$. Adding a disk component, the bulge to total host galaxy flux ratio (B/T) is $0.83\pm0.03$, which still indicates a bulge-dominant galaxy. Second, we estimate multi-band fluxes of the host galaxy through long-term light curves. Our long-term NIR light curves reveal the pure host galaxy fluxes $\sim500$ days after the burst. We fit spectral energy distribution (SED) models to the multi-band fluxes from the optical to NIR of the host galaxy and determine its properties. The stellar mass, the star formation rate, and the age of stellar population are $\log(M_{\star}/M_{\odot}) = 9.14^{+0.13}_{-0.10}$, $0.03^{+0.28}_{-0.03}\, M_{\odot}$/yr, and $0.63^{+0.95}_{-0.43}$ Gyr. Finally, we estimate the mass of the central super massive black hole which is responsible for the tidal disruption event. The black hole mass is estimated to be $10^{6.7\pm0.4}\, M_{\odot}$ from $M_{\mathrm{BH}}$ - $M_{\star,\mathrm{bul}}$ and $M_{\mathrm{BH}}$ - $L_{\mathrm{bul}}$ relations for the $K$ band, although a smaller value of $\sim10^5\, M_{\odot}$ cannot be excluded convincingly if the host galaxy harbors a pseudobulge.

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arXiv2015

Linking galaxies to dark matter haloes at $z\sim1$ : dependence of galaxy clustering on stellar mass and specific star formation rate

We study the dependence of angular two-point correlation functions on stellar mass ($M_{*}$) and specific star formation rate (sSFR) of $M_{*}>10^{10}M_{\odot}$ galaxies at $z\sim1$. The data from UKIDSS DXS and CFHTLS covering 8.2 deg$^{2}$ sample scales larger than 100 $h^{-1}$Mpc at $z\sim1$, allowing us to investigate the correlation between clustering, $M_{*}$, and star formation through halo modeling. Based on halo occupation distributions (HODs) of $M_{*}$ threshold samples, we derive HODs for $M_{*}$ binned galaxies, and then calculate the $M_{*}/M_{\rm halo}$ ratio. The ratio for central galaxies shows a peak at $M_{\rm halo}\sim10^{12}h^{-1}M_{\odot}$, and satellites predominantly contribute to the total stellar mass in cluster environments with $M_{*}/M_{\rm halo}$ values of 0.01--0.02. Using star-forming galaxies split by sSFR, we find that main sequence galaxies ($\rm log\,sSFR/yr^{-1}\sim-9$) are mainly central galaxies in $\sim10^{12.5} h^{-1}M_{\odot}$ haloes with the lowest clustering amplitude, while lower sSFR galaxies consist of a mixture of both central and satellite galaxies where those with the lowest $M_{*}$ are predominantly satellites influenced by their environment. Considering the lowest $M_{\rm halo}$ samples in each $M_{*}$ bin, massive central galaxies reside in more massive haloes with lower sSFRs than low mass ones, indicating star-forming central galaxies evolve from a low $M_{*}$--high sSFR to a high $M_{*}$--low sSFR regime. We also find that the most rapidly star-forming galaxies ($\rm log\,sSFR/yr^{-1}>-8.5$) are in more massive haloes than main sequence ones, possibly implying galaxy mergers in dense environments are driving the active star formation. These results support the conclusion that the majority of star-forming galaxies follow secular evolution through the sustained but decreasing formation of stars.

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arXiv2015

J and H-band Imaging of AKARI North Ecliptic Pole Survey Field

We present the J and H-band source catalog covering the AKARI North Ecliptic Pole field. Filling the gap between the optical data from other follow-up observations and mid-infrared (MIR) data from AKARI, our near-infrared (NIR) data provides contiguous wavelength coverage from optical to MIR. For the J and H-band imaging, we used the FLoridA Multi-object Imaging Near-ir Grism Observational Spectrometer (FLAMINGOS) on the Kitt Peak National Observatory 2.1m telescope covering a 5.1 deg2 area down to a 5 sigma depth of ~21.6 mag and ~21.3 mag (AB) for J and H-band with an astrometric accuracy of 0.14" and 0.17" for 1 sigma in R.A. and Decl. directions, respectively. We detected 208,020 sources for J-band and 203,832 sources for H-band. This NIR data is being used for studies including analysis of the physical properties of infrared sources such as stellar mass and photometric redshifts, and will be a valuable dataset for various future missions.

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arXiv2015

Color Variability of HBC 722 in the Post-Outburst Phases

We carried out photometric observations for HBC 722 in SDSS r, i and z bands from 2011 April to 2013 May with a Camera for Quasars in Early uNiverse attached to the 2.1m Otto Struve telescope at McDonald Observatory. The post-outburst phenomena were classified into five phases according to not only brightness but also color variations, which might be caused by physical changes in the emitting regions of optical and near-infrared bands. A series of spectral energy distribution (SED) is presented to support color variations and track the time evolution of SED in optical/near-infrared bands after the outburst. Given two years of data, possible periodicities of r, i and z bands were checked. We found out three families of signals around ~6, ~10 and ~1 days in three bands, which is broadly consistent with Green et al. (2013). We also examined short term variability (intra-day and day scales) to search for evidences of flickering by using the micro-variability method. We found clear signs of day scale variability and weak indications of intra-day scale fluctuations, which implies that the flickering event occurs in HBC 722 after outburst.

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arXiv2014

The Infrared Medium-Deep Survey II: How to Trigger Radio-AGN? Hints from Their Environments

Activity at the centers of galaxies, during which the central supermassive black hole is accreting material, is nowadays accepted to be rather ubiquitous and most probably a phase of every galaxy's evolution. It has been suggested that galactic mergers and interactions may be the culprits behind the triggering of nuclear activity. We use near-infrared data from the new Infrared Medium-Deep Survey (IMS) and the Deep eXtragalactic Survey (DXS) of the VIMOS-SA22 field and radio data at 1.4 GHz from the FIRST survey and a deep VLA survey to study the environments of radio-AGN over an area of ~25 sq. degrees and down to a radio flux limit of 0.1 mJy and a J-band magnitude of 23 mag AB. Radio-AGN are predominantly found in environments similar to those of control galaxies at similar redshift, J-band magnitude, and U-R rest-frame absolute color. However, a sub-population of radio-AGN is found in environments up to 100 times denser than their control sources. We thus preclude merging as the dominant triggering mechanism of radio-AGN. Through the fitting of the broadband spectral energy distribution of radio-AGN in the least and most dense environments, we find that those in the least dense environments show higher radio-loudness, higher star formation efficiencies, and higher accretion rates, typical of the so-called high-excitation radio-AGN. These differences tend to disappear at z>1. We interpret our results in terms of a different triggering mechanism for these sources that is driven by mass-loss through winds of young stars created during the observed ongoing star formation.

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arXiv2013

A tale of two feedbacks: star-formation in the host galaxies of radio-AGN

Several lines of argument support the existence of a link between activity at the nuclei of galaxies, in the form of an accreting supermassive black hole, and star-formation activity in these galaxies. The exact nature of this link is still under debate. Radio jets have long been argued to be an ideal mechanism that allows AGN to interact with their host galaxy and regulate star-formation. In this context, we are using a sample of radio sources in the North Ecliptic Pole (NEP) field to study the nature of the putative link between AGN activity and star-formation. This is done by means of spectral energy distribution (SED) fitting. We use the excellent spectral coverage of the AKARI infrared space telescope together with the rich ancillary data available in the NEP to build SEDs extending from UV to far-IR wavelengths. Through SED fitting we constrain both the AGN and host galaxy components. We find a significant AGN component in our sample of relatively faint radio-sources ($<$mJy), that increases in power with increasing radio-luminosity. At the highest radio-luminosities, the presence of powerful jets dominates the radio emission of these sources. A positive correlation is found between the luminosity of the AGN component and that of star-formation in the host galaxy, independent of the radio luminosity. By contrast, for a given redshift and AGN luminosity, we find that increasing radio-luminosity leads to a decrease in the specific star-formation rate. The most radio-loud AGN are found to lie on the main sequence of star-formation for their respective redshifts. For the first time, such a two-sided feedback process is seen in the same sample. We conclude that radio jets do suppress star-formation in their host galaxies but appear not to totally quench it. Our results therefore support the maintenance nature of "radio-mode" feedback from radio-AGN jets.

astro-ph.CO↗