scholarly journals Variable oxygen emission from the accretion disk of Mrk 110

2021 ◽  
Vol 649 ◽  
pp. L3
Author(s):  
J. N. Reeves ◽  
D. Porquet ◽  
V. Braito ◽  
N. Grosso ◽  
A. Lobban
Keyword(s):  
Accretion Disk ◽  
Line Emission ◽  
Broad Line ◽  
Broad Component ◽  
Line Region ◽  
Inner Radius ◽  
The Mean ◽  
First Time ◽  
Reflection Grating ◽  
The Continuum

Six XMM-Newton observations of the bright narrow line Seyfert 1, Mrk 110, from 2004–2020, are presented. The analysis of the grating spectra from the Reflection Grating Spectrometer (RGS) reveals a broad component of the He-like Oxygen (O VII) line, with a full width at half maximum of 15 900 ± 1800 km s−1 measured in the mean spectrum. The broad O VII line in all six observations can be modelled with a face-on accretion disk profile, where from these profiles the inner radius of the line emission is inferred to lie between about 20–100 gravitational radii from the black hole. The derived inclination angle, of about 10 degrees, is consistent with studies of the optical Broad Line Region in Mrk 110. The line also appears variable and for the first time, a significant correlation is measured between the O VII flux and the continuum flux from both the RGS and EPIC-pn data. Thus the line responds to the continuum, being brightest when the continuum flux is highest, similar to the reported behaviour of the optical He II line. The density of the line emitting gas is estimated to be ne ∼ 1014 cm−3, consistent with an origin in the accretion disk.

scholarly journals Investigations of Broad Line Region Structure and Kinematics Using Variability

1989 ◽  
Vol 134 ◽  
pp. 93-95
Author(s):  
C. Martin Gaskell ◽  
Anuradha P. Koratkar ◽  
Linda S. Sparke
Keyword(s):  
Time Series ◽  
Cross Correlation ◽  
Sampling Interval ◽  
Broad Line ◽  
Line Flux ◽  
Line Region ◽  
Cross Correlations ◽  
The Mean ◽  
The Cross ◽  
The Continuum

Gaskell and Sparke (1986) showed that one can determine the sizes of BLRs more accurately that the mean sampling interval by cross-correlating the continuum flux time series with a line flux time series. The position of the peak in the cross-correlation function (CCF) and its shape give an indication of the BLR size. The technique is explained in detail in Gaskell and Peterson (1987). The widely propagated misunderstanding is that the method involves simply interpolating both time series and cross-correlating them (in which case the CCF is dominated by the cross-correlations of “made-up” data). Actually the method involves cross correlating the observed points in one time series (continuum, say) with the linear interpolations of the other series (line flux). The line flux time series must always be smoother than the continuum time series it is derived from. We have usually employed the method with the interpolation done both ways round and averaged them (to reduce errors due to the interpolation) and we can intercompare the two results (to investigate errors).

scholarly journals The broad line emission from the AGN 3C 390.3: complex broad-line region and perturbation in accretion disk

2012 ◽  
Vol 8 (S290) ◽  
pp. 205-206
Author(s):  
Ilić Dragana ◽  
Luka Č. Popović ◽  
Alla I. Shapovalova ◽  
Alexander N. Burenkov ◽  
Vahram H. Chavushyan ◽  
...  
Keyword(s):  
Emission Line ◽  
Accretion Disk ◽  
Radio Galaxy ◽  
Dominant Role ◽  
Line Emission ◽  
Broad Line ◽  
Line Profiles ◽  
Broad Emission ◽  
Line Region ◽  
Present Part

AbstractFrom 13-years of the spectral optical monitoring of a well-known broad-line radio galaxy 3C 390.3 we concluded that the geometry of the broad emission-line region is complex, while still the main part of the emission is coming from the accretion disk. Here we present part of the analysis of the broad Hα and Hβ emission lines, which are showing highly variable double-peaked profiles during the monitoring period (1995-2007), with the aim to probe the accretion disk properties. The disk-like geometry plays a dominant role, but the variability of Hα and Hβ line profiles and intensities shows a presence of an additional emission-line region, that has a different nature for different periods, e.g. in one period the observed variation can be well modeled if one assumes changes in position and size of the emitting disk along the accretion disk.

scholarly journals Microlensing Induced Spectral Variability In Q2237+0305

1996 ◽  
Vol 173 ◽  
pp. 241-246
Author(s):  
Geraint F. Lewis ◽  
Mike J. Irwin ◽  
Paul C. Hewett
Keyword(s):  
Emission Line ◽  
Line Emission ◽  
Emission Lines ◽  
Broad Line ◽  
Spectral Variability ◽  
Broad Emission ◽  
Quasar Spectra ◽  
Line Region ◽  
Broad Emission Line ◽  
The Continuum

The degree of microlensing induced amplification is dependent upon the size of a source. As quasar spectra consist of the sum of emission from different regions this scale dependent amplification can produce spectral differences between the images of a macrolensed quasar. This paper presents the first direct spectroscopic evidence for this effect, providing a limit on the scale of the continuum and the broad line emission regions at the center of a source quasar (2237+0305). Lack of centroid and profile differences in the emission lines indicate that substructure in the broad emission line region is > 0.05 parsecs.

scholarly journals An extended size–luminosity relation for the reverberation-mapped AGNs: the role of the accretion rate

2019 ◽  
Vol 491 (4) ◽  
pp. 5881-5896 ◽  
Author(s):  
Li-Ming Yu ◽  
Bi-Xuan Zhao ◽  
Wei-Hao Bian ◽  
Chan Wang ◽  
Xue Ge
Keyword(s):  
Accretion Rate ◽  
Broad Line ◽  
Line Flux ◽  
Profile Parameter ◽  
Line Region ◽  
Accretion Rates ◽  
The Mean ◽  
Single Epoch ◽  
The Continuum

ABSTRACT For a compiled sample of 120 reverberation-mapped AGNs, the bivariate correlations of the broad-line region (BLR) size (RBLR) with the continuum luminosity at 5100 Å (L5100) and the dimensionless accretion rates ($\dot{\mathscr {M}}$) are investigated. Using our recently calibrated virial factor f, and the velocity tracer from the H β full width at half-maximum (FWHM(H β)) or the line dispersion (σH β) measured in the mean spectra, three kinds of supermassive black hole (SMBH) masses and $\dot{\mathscr {M}}$ are calculated. An extended RBLR(H β)–L5100 relation including $\dot{\mathscr {M}}$ is found to be stronger than the canonical RBLR(H β)–L5100 relation, showing smaller scatters. The observational parameters, RFe (the ratio of optical Fe ii to H β line flux) and the line profile parameter DH β ($D_{\rm H\,\beta } =\rm FWHM(H\,\beta)/\sigma _{\rm H\,\beta }$), have relations with three kinds of $\dot{\mathscr {M}}$. Using RFe and DH β to substitute $\dot{\mathscr {M}}$, extended empirical RBLR(Hβ)–L5100 relations are presented. RFe is a better ‘fix’ for the RBLR(H β)–L5100 offset than the H β shape DH β. The extended empirical RBLR(H β)–L5100 relation including RFe can be used to calculate RBLR, and thus the single-epoch SMBH mass MBH. Our measured accretion rate dependence is not consistent with the simple model of the accretion disc instability leading the BLR formation. The BLR may instead form from the inner edge of the torus, or from some other means in which BLR size is positively correlated with accretion rate and the SMBH mass.

scholarly journals Long-term optical spectroscopic variations in blazar 3C 454.3

2019 ◽  
Vol 631 ◽  
pp. A4 ◽  
Author(s):  
Krzysztof Nalewajko ◽  
Alok C. Gupta ◽  
Mai Liao ◽  
Krzysztof Hryniewicz ◽  
Maitrayee Gupta ◽  
...  
Keyword(s):  
Spectral Energy Distribution ◽  
Line Emission ◽  
Spectral Energy ◽  
Broad Line ◽  
Line Flux ◽  
Broad Line Region ◽  
Relativistic Jet ◽  
Line Region ◽  
The Continuum

Aims. Characterisation of the long-term variations in the broad line region in a luminous blazar, where Comptonisation of broad-line emission within a relativistic jet is the standard scenario for production of γ-ray emission that dominates the spectral energy distribution. Methods. We analysed ten years of optical spectroscopic data from the Steward Observatory for the blazar 3C 454.3, as well as γ-ray data from the Fermi Large Area Telescope (LAT). The optical spectra are dominated by a highly variable non-thermal synchrotron continuum with a prominent Mg II broad emission line. The line flux was obtained by spectral decomposition including significant contribution from the Fe II pseudo-continuum. Three methods were used to characterise variations in the line flux: (1) stacking of the continuum-subtracted spectra, (2) subtracting the running mean light curves calculated for different timescales, and (3) evaluating potential time delays via the discrete correlation function (DCF). Results. Despite very large variations in the γ-ray and optical continua, the line flux changes only moderately (<0.1 dex). The data suggest that the line flux responds to a dramatic change in the blazar activity from a very high state in 2010 to a deep low state in 2012. Two interpretations are possible: either the line flux is anti-correlated with the continuum or the increase in the line luminosity is delayed by ∼600 days. If this time delay results from the reverberation of poorly constrained accretion disc emission in both the broad-line region (BLR) and the synchrotron emitting blazar zone within a relativistic jet, we would obtain natural estimates for the BLR radius RBLR, MgII ≳ 0.28 pc and for the supermassive black hole mass MSMBH ∼ 8.5 × 108 M⊙. We did not identify additional examples of short-term “flares” of the line flux, in addition to the previously reported case observed in 2010.

scholarly journals The broad line region of AGN: Kinematics and physics

2006 ◽  
pp. 1-11 ◽  
Author(s):  
L.C. Popovic
Keyword(s):  
Electron Temperature ◽  
Accretion Disk ◽  
Emission Lines ◽  
Physical Parameters ◽  
Broad Line ◽  
Physical Conditions ◽  
Broad Line Region ◽  
Broad Emission ◽  
Line Region

In this paper a discussion of kinematics and physics of the Broad Line Region (BLR) is given. The possible physical conditions in the BLR and problems in determination of the physical parameters (electron temperature and density) are considered. Moreover, one analyses the geometry of the BLR and the probability that (at least) a fraction of the radiation in the Broad Emission Lines (BELs) originates from a relativistic accretion disk.

scholarly journals Detection of a double-peaked H α component from the accretion disc of NGC 4958

2019 ◽  
Vol 486 (1) ◽  
pp. 1138-1145
Author(s):  
T V Ricci ◽  
J E Steiner
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Outer Radius ◽  
Accretion Disc ◽  
Line Of Sight ◽  
Broad Component ◽  
Line Region ◽  
Inner Radius ◽  
The Galaxy ◽  
Narrow Line Region

Abstract Active Galactic Nuclei are objects associated with the presence of an accretion disc around supermassive black holes found in the very central region of galaxies with a well-defined bulge. In the optical range of the spectrum, a possible signature of the accretion disc is the presence of a broad double-peaked component that is mostly seen in H α. In this paper, we report the detection of a double-peaked feature in the H α line in the nucleus of the galaxy NGC 4958. The narrow-line region of this object has an emission that is typical of a low-ionization nuclear emission-line region galaxy, which is the usual classification for double-peaked emitters. A central broad component, related to the broad-line region of this object, is seen in H α and also in H β. We concluded that the double-peaked emission is emitted by a circular relativistic Keplerian disc with an inner radius ξi  = 570 ± 83, an outer radius ξo  = 860 ± 170 (both in units of GMSMBH/c2), an inclination to the line of sight i = 27.2 ± 0.7° and a local broadening parameter σ  = 1310 ± 70 km s−1.

scholarly journals The peculiar star RX Puppis

1982 ◽  
Vol 70 ◽  
pp. 203-206
Author(s):  
M. Kafatos ◽  
A.G. Michalitsianos
Keyword(s):  
Accretion Disk ◽  
Line Emission ◽  
Wavelength Region ◽  
High Dispersion ◽  
Line Profiles ◽  
Peculiar Star ◽  
Dynamic Activity ◽  
Circumstellar Material ◽  
International Ultraviolet Explorer ◽  
The Continuum

AbstractWe have obtained the first high dispersion observations of RX Puppis in the wavelength region 1200 - 3200 A with the “International Ultraviolet Explorer” (IUE). The anomalies we observed in lines such as He II, C III], C IV, N III], N IV], 0 III], and Si III], that show split line profiles, Doppler displaced component(s) suggest dynamic activity in circumstellar material that probably has the form of rings and/or gas streamers between the cool giant and the hot companion, the Mg II lines show P-Cygni structure arising in the Mira primary. The continuum cannot be due to a star earlier than A0 II and it may arise in an accretion disk around the hot secondary. Moreover, the line emission requires photoionization either from a hot subdwarf or the inner accretion disk.

scholarly journals The Infrared, Optical and Ultraviolet Properties of Active Nuclei

1984 ◽  
Vol 110 ◽  
pp. 73-83
Author(s):  
Marie-Helene Ulrich
Keyword(s):  
Energy Distribution ◽  
Temporal Variations ◽  
Optical Polarization ◽  
Broad Line ◽  
Continuum Spectrum ◽  
Broad Line Region ◽  
Line Region ◽  
The Continuum

We review the important properties of active nuclei, in particular (i) the optical polarization and its relation to the jets found by VLBI (ii) the energy distribution and the temporal variations of the continuum spectrum and (iii) the distribution of the matter in the broad line region.

scholarly journals Space Telescope and Optical Reverberation Mapping Project: A Leap Forward in Reverberation Mapping

2016 ◽  
Vol 12 (S324) ◽  
pp. 215-218 ◽  
Author(s):  
Bradley M. Peterson
Keyword(s):  
World Wide ◽  
Hubble Space Telescope ◽  
Line Emission ◽  
Broad Line ◽  
Space Telescope ◽  
Reverberation Mapping ◽  
Significant Challenge ◽  
Past Behavior ◽  
Line Region ◽  
Mapping Program

AbstractIn 2014, a 179-orbit allocation of Hubble Space Telescope time anchored a massive reverberation-mapping program on the well-studied Seyfert 1 galaxy NGC 5548. Supporting imaging and spectrophotometric observations were provided by Swift, Chandra, Spitzer, and a world-wide network of ground-based telescopes. Understanding the data remains a significant challenge, partly because the level of detail is far beyond what has been seen before and partly because the behavior of the AGN was not typical of its past behavior. Based on analysis to date, the following conclusions can be reached: (1) the AGN accretion disk has a temperature profile that is consistent with that predicted by the Shakura–Sunyaev model, but is about three times larger than expected; (2) at least part of the broad-line region appears to be a Keplerian disk seen at intermediate inclination, and (3) the broad-line emission response from the far side of the disk is weaker than expected.

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