scholarly journals Yet another UFO in the X-ray spectrum of a high-z lensed QSO

2018 ◽  
Vol 610 ◽  
pp. L13 ◽  
Author(s):  
M. Dadina ◽  
C. Vignali ◽  
M. Cappi ◽  
G. Lanzuisi ◽  
G. Ponti ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Gravitational Lensing ◽  
Galactic Nuclei ◽  
Resonant Absorption ◽  
Host Galaxy ◽  
Host Galaxies ◽  
Massive Black Hole ◽  
X Ray ◽  
Robust Detection ◽  
Test Feedback

Aim. Ultra-fast outflows (UFO) appear to be common in local active galactic nuclei (AGN) and may be powerful enough (Ėkin ≥ 1% of Lbol) to effectively quench the star formation in their host galaxies. To test feedback models based on AGN outflows, it is mandatory to investigate UFOs near the peak of AGN activity, that is, at high-z where only a few studies are available to date. Methods. UFOs produce Fe resonant absorption lines measured above ≈7 keV. The most critical problem in detecting such features in distant objects is the difficulty in obtaining X-ray data with sufficient signal-to-noise. We therefore selected a distant QSO that gravitational lensing made bright enough for these purposes, the z = 2.64 QSO MG J0414+0534, and observed it with XMM-Newton for ≈78 ks. Results. The X-ray spectrum of MG J0414+0534 is complex and shows signatures of cold absorption (NH ≈ 4 × 1022 cm−2) and of the presence of an iron emission line (E ≈ 6.4 keV, EW = 95 ± 53 eV) consistent with it originating in the cold absorber. Our main result, however, is the robust detection (more than 5σ) of an absorption line at Eint ≈ 9.2 keV (Eobs ≈ 2.5 keV observer frame). If interpreted as due to FeXXVI, it implies gas outflowing at vout ≈ 0.3c. To our knowledge, this is the first detection of an UFO in a radio-loud quasar at z ≥ 1.5. We estimated that the UFO mechanical output is Ėkin ≈ 2.5Lbol with ṗout∕ṗrad ≈ 17 indicating that it is capable of installing significant feedback between the super-massive black hole and the bulge of the host galaxy. We argue that this also suggests a magnetic driving origin of the UFO.

scholarly journals X-ray emission of z > 2.5 active galactic nuclei can be obscured by their host galaxies

2019 ◽  
Vol 623 ◽  
pp. A172 ◽  
Author(s):  
C. Circosta ◽  
C. Vignali ◽  
R. Gilli ◽  
A. Feltre ◽  
F. Vito ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
High Redshift ◽  
Galactic Nuclei ◽  
Far Infrared ◽  
Host Galaxy ◽  
Spectral Energy ◽  
X Rays ◽  
Host Galaxies ◽  
X Ray ◽  
Stellar Masses

We present a multiwavelength study of seven active galactic nuclei (AGN) at spectroscopic redshift >2.5 in the 7 Ms Chandra Deep Field South that were selected for their good far-infrared (FIR) and submillimeter (submm) detections. Our aim is to investigate the possibility that the obscuration observed in the X-rays can be produced by the interstellar medium (ISM) of the host galaxy. Based on the 7 Ms Chandra spectra, we measured obscuring column densities NH,  X in excess of 7 × 1022 cm−2 and intrinsic X-ray luminosities LX >  1044 erg s−1 for our targets, as well as equivalent widths for the Fe Kα emission line EWrest ≳ 0.5−1 keV. We built the UV-to-FIR spectral energy distributions (SEDs) by using broadband photometry from the CANDELS and Herschel catalogs. By means of an SED decomposition technique, we derived stellar masses (M* ∼ 1011 M⊙), IR luminosities (LIR >  1012 L⊙), star formation rates (SFR ∼ 190−1680 M⊙ yr−1) and AGN bolometric luminosities (Lbol ∼ 1046 erg s−1) for our sample. We used an empirically calibrated relation between gas masses and FIR/submm luminosities and derived Mgas ∼ 0.8−5.4 × 1010 M⊙. High-resolution (0.3−0.7″) ALMA data (when available, CANDELS data otherwise) were used to estimate the galaxy size and hence the volume enclosing most of the ISM under simple geometrical assumptions. These measurements were then combined to derive the column density associated with the ISM of the host, which is on the order of NH,  ISM ∼ 1023−24 cm−2. The comparison between the ISM column densities and those measured from the X-ray spectral analysis shows that they are similar. This suggests that at least at high redshift, significant absorption on kiloparsec scales by the dense ISM in the host likely adds to or substitutes that produced by circumnuclear gas on parsec scales (i.e., the torus of unified models). The lack of unobscured AGN among our ISM-rich targets supports this scenario.

scholarly journals X-ray absorption in INTEGRAL active galactic nuclei

2020 ◽  
Vol 639 ◽  
pp. A5
Author(s):  
A. Malizia ◽  
L. Bassani ◽  
J. B. Stephen ◽  
A. Bazzano ◽  
P. Ubertini
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Axial Ratio ◽  
Host Galaxy ◽  
Host Galaxies ◽  
X Ray ◽  
Line Region ◽  
Absorbing Material

In this work the INTEGRAL hard X-ray selected sample of active galactic nuclei (AGN) has been used to investigate the possible contribution of absorbing material distributed within the host galaxies to the total amount of NH measured in the X-ray band. We collected all the available axial ratio measurements of the galaxies hosting our AGN together with their morphological information and found that for our hard X-ray selected sample as well there is a deficit of edge-on galaxies hosting type 1 AGN. We estimate that in our hard X-ray selected sample there is a deficit of 24% (±5%) of type 1 AGN. Possible bias in redshift has been excluded, as we found the same effect in a well-determined range of z where the number and the distributions of the two classes are statistically the same. Our findings clearly indicate that material located in the host galaxy on scales of hundreds of parsecs and not aligned with the putative absorbing torus of the AGN can contribute to the total amount of column density. This galactic absorber could be large enough to hide the broad line region of some type 1 AGN, thus causing their classification as type 2 objects and giving rise to the deficiency of type 1 objects in edge-on galaxies.

scholarly journals Host galaxy properties of X-ray active galactic nuclei in the local Universe

2021 ◽  
Author(s):  
L. Koutoulidis ◽  
G. Mountrichas ◽  
I. Georgantopoulos ◽  
E. Pouliasis ◽  
M. Plionis
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Host Galaxy ◽  
Local Universe ◽  
X Ray

scholarly journals Proper motion in lensed radio jets at redshift 3: A possible dual super-massive black hole system in the early Universe

2019 ◽  
Vol 630 ◽  
pp. A108 ◽  
Author(s):  
C. Spingola ◽  
J. P. McKean ◽  
D. Massari ◽  
L. V. E. Koopmans
Keyword(s):  
Active Galactic Nuclei ◽  
Early Universe ◽  
Gravitational Lensing ◽  
Proper Motion ◽  
Galactic Nuclei ◽  
Massive Black Hole ◽  
Radio Jets ◽  
Long Baseline ◽  
Multi Wavelength ◽  
Low Probability

In this paper, we exploit the gravitational lensing effect to detect proper motion in the highly magnified gravitationally lensed source MG B2016+112. We find positional shifts up to 6 mas in the lensed images by comparing two Very Long Baseline Interferometric (VLBI) radio observations at 1.7 GHz that are separated by 14.359 years, and provide an astrometric accuracy of the order of tens of μas. From lens modelling, we exclude a shift in the lensing galaxy as the cause of the positional change of the lensed images, and we assign it to the background source. The source consists of four sub-components separated by ∼175 pc, with proper motion of the order of tens μas yr−1 for the two components at highest magnification (μ ∼ 350) and of the order of a few mas yr−1 for the two components at lower magnification (μ ∼ 2). We propose single active galactic nuclei (AGN) and dual AGN scenarios to explain the source plane. Although, the latter interpretation is supported by the archival multi-wavelength properties of the object. In this case, MG B2016+112 would represent the highest redshift dual radio-loud AGN system discovered thus far, and would support the merger interpretation for such systems. Also, given the low probability (∼10−5) of detecting a dual AGN system that is also gravitationally lensed, if confirmed, this would suggest that such dual AGN systems must be more abundant in the early Universe than currently thought.

scholarly journals Chandra COSMOS Legacy Survey: Clustering dependence of Type 2 active galactic nuclei on host galaxy properties

2019 ◽  
Vol 632 ◽  
pp. A88
Author(s):  
V. Allevato ◽  
A. Viitanen ◽  
A. Finoguenov ◽  
F. Civano ◽  
H. Suh ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Large Scale ◽  
Formation Rate ◽  
Galactic Nuclei ◽  
Stellar Mass ◽  
Host Galaxy ◽  
X Ray ◽  
Normal Galaxies ◽  
Massive Halos

Aims. We perform clustering measurements of 800 X-ray selected Chandra COSMOS Legacy (CCL) Type 2 active galactic nuclei (AGN) with known spectroscopic redshift to probe the halo mass dependence on AGN host galaxy properties, such as galaxy stellar mass Mstar, star formation rate (SFR), and specific black hole accretion rate (BHAR; λBHAR) in the redshift range z = [0−3]. Methods. We split the sample of AGN with known spectroscopic redshits according to Mstar, SFR and λBHAR, while matching the distributions in terms of the other parameters, including redshift. We measured the projected two-point correlation function wp(rp) and modeled the clustering signal, for the different subsamples, with the two-halo term to derive the large-scale bias b and corresponding typical mass of the hosting halo. Results. We find no significant dependence of the large-scale bias and typical halo mass on galaxy stellar mass and specific BHAR for CCL Type 2 AGN at mean z ∼ 1, while a negative dependence on SFR is observed, i.e. lower SFR AGN reside in richer environment. Mock catalogs of AGN, matched to have the same X-ray luminosity, stellar mass, λBHAR, and SFR of CCL Type 2 AGN, almost reproduce the observed Mstar − Mh, λBHAR − Mh and SFR–Mh relations, when assuming a fraction of satellite AGN fAGNsat ∼ 0.15. This corresponds to a ratio of the probabilities of satellite to central AGN of being active Q ∼ 2. Mock matched normal galaxies follow a slightly steeper Mstar − Mh relation, in which low mass mock galaxies reside in less massive halos than mock AGN of similar mass. Moreover, matched mock normal galaxies are less biased than mock AGN with similar specific BHAR and SFR, at least for Q >  1.

Density diagnostics of photoionized outflows in active galactic nuclei

2019 ◽  
Vol 15 (S350) ◽  
pp. 274-277
Author(s):  
Junjie Mao
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
State Of The Art ◽  
Density Measurement ◽  
Galactic Nuclei ◽  
Next Generation ◽  
Host Galaxies ◽  
Current Generation ◽  
X Ray ◽  
The Impact

AbstractPhotoionized outflows in active galactic nuclei (AGNs) are thought to influence their circumnuclear and host galactic environment. However, the distance of the outflow with respect to the black hole is poorly constrained, which limits our understanding of the kinetic power by the outflow. Therefore, the impact of AGN outflows on their host galaxies is uncertain. If the density of the outflow is known, its distance can be derived. Density measurement via variability studies and density sensitive lines have been used, albeit not very effective in the X-ray band. Good measurements are rather demanding or challenging for the current generation of (grating) spectrometers. The next generation of spectrometers will certainly provide data with better quality and large quantity, leading to tight constraints on the location and the kinetic power of AGN outflows. This contribution summarizes the state-of-the-art in this field.

scholarly journals Line-driven disc wind in near-Eddington active galactic nuclei: decrease of mass accretion rate due to powerful outflow

2020 ◽  
Vol 494 (3) ◽  
pp. 3616-3626 ◽  
Author(s):  
Mariko Nomura ◽  
Ken Ohsuga ◽  
Chris Done
Keyword(s):  
Black Holes ◽  
Mass Loss ◽  
Active Galactic Nuclei ◽  
Accretion Rate ◽  
Galactic Nuclei ◽  
Host Galaxy ◽  
Radiation Hydrodynamics ◽  
Iterative Technique ◽  
X Ray ◽  
Mass Accretion Rate

ABSTRACT Based on recent X-ray observations, ultrafast outflows from supermassive black holes are expected to have enough energy to dramatically affect their host galaxy but their launch and acceleration mechanisms are not well understood. We perform two-dimensional radiation hydrodynamics simulations of UV line-driven disc winds in order to calculate the mass-loss rates and kinetic power in these models. We develop a new iterative technique that reduces the mass accretion rate through the inner disc in response to the wind mass-loss. This makes the inner disc less UV bright, reducing the wind power compared to previous simulations which assumed a constant accretion rate with radius. The line-driven winds in our simulations are still extremely powerful, with around half the supplied mass accretion rate being ejected in the wind for black holes with mass 108–$10^{10}\, \mathrm{ M}_\odot$ accreting at L/LEdd = 0.5–0.9. Our results open up the way for estimating the growth rate of supermassive black hole and evaluating the kinetic energy ejected into the interstellar medium (active galactic nuclei feedback) based on a physical model of line-driven disc winds.

scholarly journals Using AGN Variability Surveys to explore the AGN-Galaxy Connection

2013 ◽  
Vol 9 (S304) ◽  
pp. 385-390
Author(s):  
Vicki L. Sarajedini
Keyword(s):  
Conference Proceedings ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Optical Variability ◽  
Host Galaxies ◽  
X Ray ◽  
Galaxy Surveys ◽  
Successful Technique

AbstractVariability is a successful technique used to identify active galactic nuclei in both ground and space-based galaxy surveys. Optical variability surveys using HST have uncovered a number of AGN in deep extragalactic fields extending to z ~ 3 and probing intrinsically faint sources. Mid-IR variability surveys using Spitzer have identified a significant number of AGN and are particularly sensitive to obscured sources. Many variability-detected AGN are not strong X-ray sources or lack the characteristic colors of AGN and would thus be unidentified using other selection techniques. In this conference proceedings, I discuss the nature of the variable sources and their host galaxies identified in deep extragalactic optical and mid-IR surveys.

Erratum: “Host Galaxies of Hard X‐Ray–Selected Type 2 Active Galactic Nuclei at Intermediate Redshifts” (ApJ, 647, 892 [2006])

2006 ◽  
Vol 653 (2) ◽  
pp. 1583-1583
Author(s):  
Gaku Kiuchi ◽  
Kouji Ohta ◽  
Masayuki Akiyama ◽  
Kentaro Aoki ◽  
Yoshihiro Ueda
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Host Galaxies ◽  
X Ray ◽  
Intermediate Redshifts

scholarly journals Active Galactic Nuclei: Variability at Many Wavelengths

1998 ◽  
Vol 11 (2) ◽  
pp. 808-811
Author(s):  
Thierry J.-L. Courvoisier
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Thermal Emission ◽  
Galactic Nuclei ◽  
Gravitational Energy ◽  
Heating Process ◽  
Massive Black Hole ◽  
Ultraviolet Emission ◽  
X Ray ◽  
Accretion Process

Active Galactic Nuclei (AGN) are thought to be powered by accretion onto a massive black hole. Understanding how gravitational energy freed by the infall of matter into the black hole is transferred to the radiating regions of the nucleus is one of the main challenges of AGN research. The question is made very complex by the presence of several cooling mechanisms with very diverse physical properties: We observe synchrotron radiation, thermal emission from hot dust, possibly thermal optical and ultraviolet emission and Comptonization processes in the X-ray domain. For each component the radiation is a signature of the cooling process rather than of the heating process. It is our hope that by observing the links and correlations between the emission of the different components we will be able to understand how they are interrelated and how they get their energy supply from the accretion process.

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