arXiv subjects

Robert Antonucci

Publications and source records attributed to Robert Antonucci.

At least 19 recordsLinked to original sources

arXiv2025

The central engine of low-luminosity radio galaxy 3C 270 (NGC 4261)

We present the polarization spectra of the nucleus of 3C~270. We confirm that the polarization angle of both the continuum and the emission lines are close to perpendicular to the jet direction after careful correction of interstellar polarization, which indicates polar scattering. The Stokes flux spectrum resembles the total flux spectrum, with no need for a broad component from the Broad Line Region. Over 94\% of a sample of Seyfert I broad line profile would be significantly detected if present in our polarized flux spectrum. We favor the hypothesis that we are observing the continuum including any contribution from Radiatively Inefficient Accretion Flow and beamed synchrotron instead of a Big Blue Bump, as well as the innermost Narrow Line Region, through reflection. This makes 3C~270 the third known case, after NGC~4258 and Centaurus~A, where only narrow lines (and the continuum, if present) are scattered, with no evidence of an underlying Big Blue Bump.

astro-ph.GA↗

arXiv2023

Cygnus A Obscuring Torus: Ionized, Atomic or Molecular?

The prototypical powerful FR \Romannum{2} radio galaxy Cygnus A fits extremely well into the quasar/radio galaxy unified model: high polarization with an angle almost perpendicular to the radio jet and polarized flux showing broad permitted lines. It has been claimed that ionized gas in the torus reveals a very clear torus shape via Bremmstrahlung emission. We rule out the later with an energetic argument, and we constrain the molecular and atomic gas properties with existing observations. The atomic absorption against the core has been shown to match the X-ray column only if the spin temperature is an implausible $T_{\rm s} = 1\times 10^6$ K. This points to a molecular medium for the X-ray column $\log(N_{\rm H} ~[\rm{cm^{-2}}]) \sim 23.5$. Yet not low-J CO absorption is detected to sensitive limits. The non-detection is surprising given that this powerful radio galaxy hosts a luminous, dust-obscured active nucleus and copious warm molecular hydrogen. These conditions suggest a detectable level of emission. Furthermore, the torus X-ray column density suggests detectable absorption. We explore various possibilities to explain the lack of a signature from warm CO (200-250K). Specifically, that the radiative excitation by the radio core renders low-J CO absorption below current sensitivities, and that high-J levels are well populated and conducive to producing absorption. We test this hypothesis using archival \textit{Hershel}/SPIRE FTS observations of Cygnus A of high-J CO lines ($14 \geq J \geq 4$ transitions). Still high-J CO lines are not detected. We suggest that ALMA observations near its high frequency limit can be critical to obtain the signature of molecular line of the torus of Cygnus A.

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arXiv2023

On the origin of radio-loudness in active galactic nuclei using far-infrared polarimetric observations

The dichotomy between radio-loud (RL) and radio-quiet (RQ) active galactic nuclei (AGN) is thought to be intrinsically related to radio jet production. This difference may be explained by the presence of a strong magnetic field (B-field) that enhances, or is the cause of, the accretion activity and the jet power. Here, we report the first evidence of an intrinsic difference in the dust polarized emission cores of four RL and five RQ obscured AGN using 89 $μ$m polarization with HAWC+/SOFIA. We find that the thermal polarized emission increases with the nuclear radio-loudness, $R_{20} = L_{\rm 5GHz}/ L_{\rm 20μm}$. The dust emission cores of RL AGN are measured to be polarized, $\sim5-11$%, while RQ AGN are unpolarized, $<1$%. For RQ AGN, our results are consistent with the observed region being filled with an unmagnetized or highly turbulent, disk and/or expanding outflow at scales of $5-130$ pc from the AGN. For RL AGN, the measured $89$ $μ$m polarization arises primarily from magnetically aligned dust grains associated with a $5-130$ pc-scale dusty obscuring structure with a toroidal B-field orientation highly offset, $65\pm22^{\circ}$, with respect to the jet axis. Our results indicate that the size and strength of the B-fields surrounding the AGN are intrinsically related to the strength of the jet power -- the stronger the jet power is, the larger and stronger the toroidal B-field is. The detection of a $\le130$ pc-scale ordered toroidal B-field suggests that a) the infalling gas that fuels RL AGN is magnetized, b) there is a magnetohydrodynamic wind that collimates the jet, and/or c) the jet is able to magnetize its surroundings.

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arXiv2022

The dust sublimation region of the Type 1 AGN NGC4151 at a hundred micro-arcsecond scale as resolved by the CHARA Array interferometer

The nuclear region of Type 1 AGNs has only been partially resolved so far in the near-infrared (IR) where we expect to see the dust sublimation region and the nucleus directly without obscuration. Here we present the near-IR interferometric observation of the brightest Type 1 AGN NGC4151 at long baselines of ~250 m using the CHARA Array, reaching structures at hundred micro-arcsecond scales. The squared visibilities decrease down to as low as ~0.25, definitely showing that the structure is resolved. Furthermore, combining with the previous visibility measurements at shorter baselines but at different position angles, we show that the structure is elongated *perpendicular* to the polar axis of the nucleus, as defined by optical polarization and a linear radio jet. A thin-ring fit gives a minor/major axis ratio of ~0.7 at a radius ~0.5 mas (~0.03 pc). This is consistent with the case where the sublimating dust grains are distributed preferentially in an equatorial plane in a ring-like geometry, viewed at an inclination angle of ~40 deg. Recent mid-IR interferometric finding of polar-elongated geometry at a pc scale, together with a larger-scale polar outflow as spectrally resolved by the HST, would generally suggest a dusty, conical and hollow outflow being launched presumably in the dust sublimation region. This might potentially lead to a polar-elongated morphology in the near-IR, as opposed to the results here. We discuss a possible scenario where an episodic, one-off anisotropic acceleration formed a polar-fast and equatorially-slow velocity distribution, having lead to an effectively flaring geometry as we observe.

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arXiv2022

NGC 3147: a prototypical low-luminosity active galactic nucleus with double-peaked optical and ultraviolet lines

A previous narrow-slit ($0.1$ arcsec) Hubble Space Telescope observation unveiled a broad relativistic H$α$ profile in NGC3147, a low-luminosity ($\mathrm{L_{bol}}\sim10^{42}$ erg s$^{-1}$), low-Eddington ratio ($\mathrm{L_{bol}/L_{Edd}}\sim10^{-4}$) active galactic nucleus (AGN), formerly believed to be a candidate true type 2 AGN intrinsically lacking the broad-line region. The new observations presented here confirm the double-peaked profile of the H$α$ line, which further shows variability both in flux and in the inner radius of the emitting disc with respect to the previous epoch. Similar disc line profiles are also found in prominent ultraviolet (UV) lines, in particular Ly$α$ and C IV. The new data also allow us to build a simultaneous subarcsec optical-to-X-ray spectral energy distribution of NGC3147, which is characterized by the absence of a thermal UV bump, and an emission peak in the X-rays. The resulting very flat $α_{ox}=-0.82$ is typical of low-luminosity AGN, and is in good agreement with the extrapolation to low luminosities of the well-known trend with luminosity observed in standard AGN. Indeed, we are possibly observing the accretion disc emission in NGC3147 in the optical, close to the expected peak. On the other hand, the steep -2 UV power law may be Comptonization of that cold disc by a warm corona, what is instead generally observed as a `soft excess' in more luminous AGN.

astro-ph.HE↗

arXiv2021

Unravelling the origin of extended radio emission in narrow-line Seyfert 1 galaxies with the JVLA

Narrow-line Seyfert 1 (NLS1) galaxies are believed to be active galactic nuclei (AGN) in the early stages of their evolution. Some dozens of them have been found to host relativistic jets, whilst the majority has not even been detected in radio, emphasising the heterogeneity of the class in this band. In this paper, our aim is to determine the predominant source of radio emission in a sample of 44 NLS1s, selected based on their extended kpc-scale radio morphologies at 5.2 GHz. We accomplish this by analysing their spatially resolved radio spectral index maps, centred at 5.2 GHz. In addition, we utilise several diagnostics based on mid-infrared emission to estimate the star formation activity of their host galaxies. These data are complemented by archival data to draw a more complete picture of each source. We find an extraordinary diversity among our sample. Approximately equal fractions of our sources can be identified as AGN-dominated, composite, and host-dominated. Among the AGN-dominated sources are a few NLS1s with very extended jets, reaching distances of tens of kpc from the nucleus. One of these, J0814+5609, hosts the most extended jets found in an NLS1 so far. We also identify five NLS1s that could be classified as compact steep-spectrum sources. We further conclude that due to the variety seen in NLS1s simple proxies, such as the star formation diagnostics also employed in this paper, and the radio loudness parameter, are not ideal tools for characterising NLS1s. We emphasise the necessity of examining NLS1s as individuals, instead of making assumptions based on their classification. When these issues are properly taken into account, NLS1s offer an exceptional environment to study the interplay of the host galaxy and several AGN-related phenomena, such as jets and outflows. [Abstract abridged.]

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arXiv2021

Beyond Simple AGN Unification with Chandra-observed 3CRR Sources

Low-frequency radio selection finds radio-bright galaxies regardless of the amount of obscuration by gas and dust. We report \chandra\ observations of a complete 178~MHz-selected, and so orientation unbiased, sample of 44 $0.5<z<1$ 3CRR sources. The sample is comprised of quasars and narrow-line radio galaxies (NLRGs) with similar radio luminosities, and the radio structure serves as both an age and an orientation indicator. Consistent with Unification, intrinsic obscuration (measured by \nh, X-ray hardness ratio, and X-ray luminosity) generally increases with inclination. However, the sample includes a population not seen in high-$z$ 3CRR sources: NLRGs viewed at intermediate inclination angles with \nh~$<10^{22}$~cm$^{-2}$. Multiwavelength analysis suggests these objects have lower $L/L_{\rm Edd}$ than typical NLRGs at similar orientation. Thus both orientation and $L/L_{\rm Edd}$ are important, and a "radiation-regulated Unification" provides a better explanation of the sample's observed properties. In comparison with the 3CRR sample at $1<z<2$, our lower-redshift sample shows a higher fraction of Compton-thin NLRGs (45\% vs.\ 29\%) but similar Compton-thick fraction (20\%), implying a larger covering factor of Compton-thin material at intermediate viewing angles and so a more "puffed-up" torus atmosphere. We posit that this is due to a range of $L/L_{\rm Edd}$ extending to lower values in this sample. In contrast, at high redshifts the narrower range and high $L/L_{\rm Edd}$ values allowed orientation (and so simple Unification) to dominate the sample's observed properties.

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arXiv2019

HST unveils a compact mildly relativistic Broad Line Region in the candidate true type 2 NGC 3147

NGC 3147 has been considered the best case of a true type 2 AGN: an unobscured AGN, based on the unabsorbed compact X-ray continuum, which lacks a broad line region (BLR). However, the very low luminosity of NGC 3147 implies a compact BLR, which produces very broad lines, hard to detect against the dominant background host galaxy. Narrow (0.1"x0.1") slit HST spectroscopy allowed us to exclude most of the host galaxy light, and revealed an H$α$ line with an extremely broad base (FWZI$\sim27\,000$ km s$^{-1}$). The line profile shows a steep cutoff blue wing and an extended red wing, which match the signature of a mildly relativistic thin accretion disk line profile. It is indeed well fit with a nearly face on thin disk, at $i\sim23^\circ$, with an inner radius at $77\pm15$ r$_g$, which matches the prediction of $62^{+18}_{-14}$ r$_g$ from the $R_{\rm BLR} \sim L^{1/2}$ relation. This result questions the very existence of true type 2 AGN. Moreover, the detection of a thin disk, which extends below 100 r$_g$ in an $L/L_{\rm Edd}\sim10^{-4}$ system, contradicts the current view of the accretion flow configuration at extremely low accretion rates.

astro-ph.HE↗

arXiv2019

Exploring Active Supermassive Black Holes at 100 Micro-arcsecond Resolution

Super-high spatial resolution observations in the infrared are now enabling major advances in our understanding of supermassive black hole systems at the centers of galaxies. Infrared interferometry, reaching resolutions of milliarcseconds to sub-milliarcseconds, is drastically changing our view of the central structure from a static to a very dynamic one by spatially resolving to the pc-scale. We are also starting to measure the dynamical structure of fast moving gas clouds around active supermassive black holes at a scale of less than a light year. With further improvements on resolution and sensitivity, we will be able to directly image the exact site of the black hole's feedback to its host galaxy, and quantify the effect of such interaction processes. Near-future high angular resolution studies will definitely advance our mass determinations for these black holes, and we might even witness the existence of binary black hole systems at the center of galaxies.

astro-ph.GA↗

arXiv2018

The highly polarized dusty emission core of Cygnus A

We report the detection of linearly polarized emission at 53 and 89 $μ$m, from the radio-loud active galactic nucleus (AGN) Cygnus A using HAWC+ onboard SOFIA. We measure a highly polarized core of $11\pm3$% and $9\pm2$% with a position angle (P.A.) of polarization of $43\pm8^{\circ}$ and $39\pm7^{\circ}$ at 53 and 89 $μ$m, respectively. We find (1) a synchrotron dominated core with a flat spectrum ($+0.21\pm0.05$) and a turn-over at $543\pm120$ $μ$m, which implies synchrotron emission is insignificant in the infrared (IR), and (2) a $2-500$ $μ$m bump peaking at $\sim40$ $μ$m described by a blackbody component with color temperature of $107\pm9$ K. The polarized SED has the same shape as the IR bump of the total flux SED. We observe a change in the P.A. of polarization of $\sim20^{\circ}$ from 2 to 89 $μ$m, which suggests a change of polarization mechanisms. The ultraviolet, optical and near-IR polarization has been convincingly attributed to scattering by polar dust, consistent with the usual torus scenario, though this scattered component can only be directly observed from the core in the near-IR. By contrast, the gradual rotation by $\sim20^{\circ}$ towards the far-IR, and the near-perfect match between the total and polarized IR bumps, indicate that dust emission from aligned dust grains becomes dominant at $10-100$ $μ$m, with a large polarization of 10% at a nearly constant P.A. This result suggests that a coherent dusty and magnetic field structure dominates the $10-100$ $μ$m emission around the AGN.

astro-ph.GA↗

arXiv2016

A robust derivation of the tight relationship of radio core dominance to inclination angle in high redshift 3CRR sources

It is believed that, in radio-loud active galactic nuclei (AGN), the core radio flux density can be normalized to the flux density of the extended lobe emission to infer the orientation of a radio source. However very little is known about the reliability and precision of this method, and we are unaware of any robust conversion recipe to infer the inclination from the core dominance. Investigating whether or not the radio core dominance parameter R separates the quasars from the radio-galaxies in the $z \ge$~1 3CRR catalog, we found excellent agreement of R with optical type, infrared flux ratios and optical polarization. This indicates that probably both R and optical classification are very good orientation indicators, and the unified model is strongly predictive for these objects. The relative number densities indicate half-opening angles close to 60$^\circ$, as expected from large surveys. The separations of optical types according to radio core dominance as well as NIR/MIR ratios, which are essentially perfect, means that there can be only a small dispersion of torus half-opening angles. Also, even though torus dust is thought to be clumpy, there is an almost zero probability to see a type-1 source at high inclination. Finally, using only the Copernican Principle, i,e, the assumption that solid angle is filled uniformly with source axis orientations, we estimated a semi-empirical relation between core dominance and AGN inclination. This makes it possible to use R to infer the inclination of a source to an accuracy of $\sim$ 10 degrees or less, at least for this type of object.

astro-ph.GA↗

arXiv2015

Active Galactic Nuclei and Quasars: Why Still a Puzzle after 50 years?

The first part of this article is a historical and physical introduction to quasars and their close cousins, called Active Galactic Nuclei (AGN). In the second part, I argue that our progress in understanding them has been unsatisfactory and in fact somewhat illusory since their discovery fifty years ago, and that much of the reason is a pervasive lack of critical thinking in the research community. It would be very surprising if other fields do not suffer similar failings.

astro-ph.GA↗

arXiv2013

Evidence for a receding dust sublimation region around a supermassive black hole

The near-IR emission in Type 1 AGNs is thought to be dominated by the thermal radiation from dust grains that are heated by the central engine in the UV/optical and are almost at the sublimation temperature. A brightening of the central source can thus further sublimate the innermost dust, leading to an increase in the radius of the near-IR emitting region. Such changes in radius have been indirectly probed by the measurements of the changes in the time lag between the near-IR and UV/optical light variation. Here we report direct evidence for such a receding sublimation region through the near-IR interferometry of the brightest Type 1 AGN in NGC4151. The increase in radius follows a significant brightening of the central engine with a delay of at least a few years, which is thus the implied destruction timescale of the innermost dust distribution. Compiling historic flux variations and radius measurements, we also infer the reformation timescale for the inner dust distribution to be several years in this galactic nucleus. More specifically and quantitatively, we find that the radius at a given time seems to be correlated with a long-term average of the flux over the previous several (~6) years, instead of the instantaneous flux. Finally, we also report measurements of three more Type 1 AGNs newly observed with the Keck interferometer, as well as the second epoch measurements for three other AGNs.

astro-ph.CO↗

arXiv2013

Dust in the polar region as a major contributor to the IR emission of AGN

(abridged) It is generally assumed that the distribution of dust on parsec scales forms a geometrically- and optically-thick entity in the equatorial plane around the accretion disk and broad-line region - dubbed "dust torus" - that emits the bulk of the sub-arcsecond-scale IR emission and gives rise to orientation-dependent obscuration. Here we report detailed interferometry observations of the unobscured (type 1) AGN in NGC 3783 that allow us to constrain the size, elongation, and direction of the mid-IR emission with high accuracy. The mid-IR emission is characterized by a strong elongation toward position angle PA -52 deg, closely aligned with the polar axis (PA -45 deg). We determine half-light radii along the major and minor axes at 12.5 μm of (4.23 +/- 0.63) pc x (1.42 +/- 0.21) pc, which corresponds to intrinsically-scaled sizes of (69.4 +/- 10.8) rin x (23.3 +/- 3.5) rin for the inner dust radius of rin = 0.061 pc as inferred from near-IR reverberation mapping. This implies an axis ratio of 3:1, with about 60-90% of the 8-13 μm emission associated with the polar-elongated component. These observations are difficult to reconcile with the standard interpretation that most of the parsec-scale mid-IR emission in AGN originates from the torus and challenges the justification of using simple torus models to model the broad-band IR emission. It is quite likely that the hot-dust emission in NGC 3783 as recently resolved by near-IR interferometry is misaligned with the mid-IR emitting source, which also finds a correspondence in the two distinct 3-5 μm and 20 μm bumps seen in the high-angular resolution spectral energy distribution (SED). We conclude that these observations support a scenario where the majority of the mid-IR emission in Seyfert AGN originates from a dusty wind in the polar region of the AGN.

astro-ph.CO↗

arXiv2013

Revealing the heavily obscured AGN population of High Redshift 3CRR Sources with Chandra X-ray Observations

Chandra observations of a complete, flux-limited sample of 38 high-redshift (1 0) indicating obscuration (log N_H ~ 22-24 cm^-2). These properties and the correlation between obscuration and radio core-fraction are consistent with orientation-dependent obscuration as in Unification models. About half the NLRGs have soft X-ray hardness ratios and/or high [OIII] emission line to X-ray luminosity ratio suggesting obscuration by Compton thick (CT) material so that scattered nuclear or extended X-ray emission dominates (as in NGC1068). The ratios of unobscured to Compton-thin (10^{22}< N_H(int) < 1.5 x 10^{24} cm^-2) to CT (N_H(int) > 1.5 x 10^{24} cm^-2) is 2.5:1.4:1 in this high luminosity, radio-selected sample. The obscured fraction is 0.5, higher than is typically reported for AGN at comparable luminosities from multi-wavelength surveys (0.1-0.3). Assuming random nuclear orientation, the unobscured half-opening angle of the disk/wind/torus structure is ~ 60deg and the obscuring material covers 30deg of which ~ 12deg is Compton thick. The multi-wavelength properties reveal that many NLRGs have intrinsic absorption 10-1000x higher than indicated by their X-ray hardness ratios, and their true L_X values are ~10--100x larger than the hardness-ratio absorption corrections would indicate.

astro-ph.CO↗

arXiv2012

A panchromatic review of thermal and nonthermal active galactic nuclei

The first short part of this review is a general, but very detailed, critique of the literature advocating a class of Seyfert galaxies intrinsically lacking broad emission lines. My conclusion is that there is little or no evidence for such objects. Panchromatic properties of all types of radio loud AGN are then reviewed in detail. Radio galaxies usually show subparsec-scale radio core sources, jets, and a pair of giant radio lobes. The optical spectra sometimes show only relatively weak lines of low-ionization ionic species, and no clear nuclear continuum in the optical or UV region of the spectrum. Some show strong high-ionization narrow lines. Finally, a few radio galaxies add broad bases onto the permitted lines. These spectral categories are the same as those for radio-quiet AGN and quasars. By the 1980s, data from optical polarization and statistics of the radio properties required that many narrow line radio galaxies do in fact produce strong optical/UV continuum. This continuum and the broad line emission are hidden from the line of sight by dusty, roughly toroidal gas distributions, but they are seen in polarized flux. The radio galaxies with hidden quasars are referred to as "thermal." Do all radio galaxies harbor hidden quasars? We now know the answer using the radio, infrared, optical and X-ray properties. Near the top of the radio luminosity function, for FRII, GPS, and CSS galaxies, the answer is yes. At somewhat lower luminosities, many do not. At the lowest radio luminosities, most do not. Instead these "nonthermal" weakly-accreting galaxies manifest their energetic output only as kinetic energy in the form of synchrotron jets. This applies to all types of radio galaxies, big FR II doubles, as well as the small young GPS and CSS sources. Only a few FR I sources are of the thermal type.

astro-ph.CO↗

arXiv2012

Parsec-scale dust emission from the polar region in the type 2 nucleus of NGC 424

Advancements in infrared IR open up the possibility to spatially resolve AGN on the parsec-scale level and study the circumnuclear dust distribution, commonly referred to as the "dust torus", that is held responsible for the type 1/type 2 dichotomy of AGN. We used the mid-IR beam combiner MIDI together with the 8m telescopes at the VLTI to observe the nucleus of the Seyfert 2 galaxy NGC 424, achieving an almost complete coverage of the uv-plane accessible by the available telescope configurations. We detect extended mid-IR emission with a relatively baseline- and model-independent mid-IR half-light radius of (2.0 \pm 0.2) pc \times (1.5 \pm 0.3) pc (averaged over the 8-13 μm wavelength range). The extended mid-IR source shows an increasing size with wavelength. The orientation of the major axis in position angle -27deg is closely aligned with the system axis as set by optical polarization observations. Torus models typically favor extension along the mid-plane at mid-IR wavelengths instead. Therefore, we conclude that the majority of the pc-scale mid-IR emission (>~60%) in this type 2 AGN originates from optically-thin dust in the polar region of the AGN, a scenario consistent with the near- to far-IR SED. We suggest that a radiatively-driven dusty wind, possibly launched in a puffed-up region of the inner hot part of the torus, is responsible for the polar dust. In this picture, the torus dominates the near-IR emission up to about 5 μm, while the polar dust is the main contributor to the mid-IR flux. Our results of NGC 424 are consistent with recent observations of the AGN in the Circinus galaxy and resemble large-scale characteristics of other objects. If our results reflect a general property of the AGN population, the current paradigm for interpreting and modeling the IR emission of AGN have to be revised. (abridged)

astro-ph.CO↗

arXiv2012

Probing the innermost dusty structure in AGN with mid-IR and near-IR interferometers

With mid-IR and near-IR long-baseline interferometers, we are now mapping the radial distribution of the dusty accreting material in AGNs at sub-pc scales. We currently focus on Type 1 AGNs, where the innermost region is unobscured and its intrinsic structure can be studied directly. As a first systematic study of Type 1s, we obtained mid-/near-IR data for small samples over ~3-4 orders of magnitudes in UV luminosity L of the central engine. Here we effectively trace the structure by observing dust grains that are radiatively heated by the central engine. Consistent with a naive expectation for such dust grains, the dust sublimation radius R_in is in fact empirically known to be scaling with L^1/2 from the near-IR reverberation measurements, and this is also supported by our near-IR interferometry. Utilizing this empirical relationship, we normalize the radial extent by R_in and eliminate the simple L^1/2 scaling for a direct comparison over the samples. We then find that, in the mid-IR, the overall size in units of R_in seems to become more compact in higher luminosity sources. More specifically, the mid-IR brightness distribution is rather well described by a power-law, and this power-law becomes steeper in higher luminosity objects. The near-IR flux does not seem to be a simple inward extrapolation of the mid-IR power-law component toward shorter wavelengths, but it rather comes from a little distinct brightness concentration at the inner rim region of the dust distribution. Its structure is not well constrained yet, but there is tentative evidence that this inner near-IR-emitting structure has a steeper radial distribution in jet-launching objects. All these should be scrutinized with further observations.

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