Double-peaked line profiles in AGNs-searching for reverberation from an accretion disk

1992 ◽  
Author(s):  
M. Eracleous ◽  
J. Halpern
Keyword(s):  
Accretion Disk ◽  
Line Profiles

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 Interacting Nuclei in Distant Galaxies

1990 ◽  
Vol 124 ◽  
pp. 251-253
Author(s):  
Wei Zheng ◽  
Steven A. Grandi
Keyword(s):  
Emission Line ◽  
Active Galactic Nuclei ◽  
Accretion Disk ◽  
Outer Part ◽  
Line Emission ◽  
Galactic Nuclei ◽  
Balmer Line ◽  
Line Profiles ◽  
Double Peaks ◽  
Distant Galaxies

The interaction of galaxies not only occurs in galactic scales, but also may be linked to the binary cores in active galactic galaxies. The presence of a binary in the center of galaxies was suggested by Begelman, Blandford and Rees (1980). Gaskell (1983) suggests that supermassive binaries may account for the observed structure of emission line profiles such as double peaks displaced by a significant velocity difference. Collin-Souffrin, et al. (1986) argue that line emission may be formed in the outer part of an accretion disk. The resultant profile, as expected from rotational motion, would be very broad and often possess a double-horn shape. However, the emission line profiles in most active galactic nuclei do not share such a resemblance, and there are only two reported cases, 3C390.3 (Pérez et al. 1987) and Arp102B (Chen, Halpern and Filippenko 1989), in which the broad Balmer line profile may be of such a shape. Therefore, the assumption for accretion disk is to be verified with care.

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 Neutron Star Radius-to-mass Ratio from Partial Accretion Disk Occultation as Measured through Fe Kα Line Profiles

2020 ◽  
Vol 893 (2) ◽  
pp. 129
Author(s):  
Riccardo La Placa ◽  
Luigi Stella ◽  
Alessandro Papitto ◽  
Pavel Bakala ◽  
Tiziana Di Salvo ◽  
...  
Keyword(s):  
Neutron Star ◽  
Accretion Disk ◽  
Line Profiles ◽  
Mass Ratio ◽  
Neutron Star Radius

scholarly journals Form of a microlensed line from accretion disk in the linear caustic approximation

2018 ◽  
pp. 27-31
Author(s):  
V. Zhdanov ◽  
E. Fedorova ◽  
M. Khelashvili
Keyword(s):  
Black Hole ◽  
Spectral Line ◽  
Numerical Simulations ◽  
Accretion Disk ◽  
Accretion Disks ◽  
Gravitational Lens ◽  
Emission Lines ◽  
Line Profiles ◽  
Lens System ◽  
Central Black Hole

The line profiles like that of the fluorescent Fe K or Co K lines in the X-ray spectra of the active galactic nuclei (AGN) reflect characteristics of the central regions of these objects. These lines can be formed in the accretion disks around central supermassive black holes and their shapes are connected with the central black hole spin and the accretion disk inclination angle to the line-of-the-sight. If an AGN is a source of a gravitational lens system with microlensing events, one can get an additional important information about both the accretion disk parameters and gravitational lens parameters as well. Microlensing processes were observed in such gravitational lens systems, as PKS 1830-211, B0218+357, RX J1131-1231 i HE1104-1805, Q2237+0305 and we can suspect to observe there also the spectral appearances of microlensing. Here we performed the numerical simulations of the microlensed relativistic spectral line profiles formed in the AGN accretion disks. Using the inear caustic model we show that the time dependence of the profile is determined essentially by the angle between to the disk axis and the caustic. This gives us an opportunity to assess this orientation. Microlens caustics magnify some parts of the accretion disk more prominently than others. Due to the Doppler effects and differences in the rotation direction this leads to the frequency-dependent magnification which distorts the profile of a relativistic spectral line. Such deformations are variable with time due to relative motions of the source and the microlens, and they can give us possibility to obtain some additional information about the disk brightness profile and caustic orientation relatively to the disk. Here we consider the thin disk model, Schwarzschild black hole, and the linear caustic approximation as well. The numerical simulations of the relativistic emission line profiles distorted by strong gravitational microlensing effect were performed for several different orientations of the linear caustic relatively to the disk, as well as several inclinations of the disk to the line-of-the-sight. Basic presumptions for the numerical modeling were the following: (a) AGN is a source in the gravitational lens system and it its inner parts the luminescent emission lines with relativistic profiles are being emitted; (b) this line is formed in the thin accretion disk quite far away from the central black hole and can be calculated with no taking into account the relativistic effects; (c) the caustic can be considered as a linear one. We show that the relative orientation of the caustic and the disk can be determined from emission lines profiles. Our numerical simulations demonstrate that the difference between profiles corresponding to different caustic orientations appears to be more prominent during the first half of the strong microlensing event, namely, before the crossing the disk center, and this dependence is irrespective to the accretion disk brightness profile. We show that for the spectral accuracy level high enough we have a perspective to determine the caustic orientation from the observational data.

scholarly journals The Orbital Period of G61-29

1979 ◽  
Vol 53 ◽  
pp. 453-457 ◽  
Author(s):  
R. E. Nather ◽  
E. L. Robinson ◽  
R. J. Stover
Keyword(s):  
Emission Line ◽  
Accretion Disk ◽  
Orbital Period ◽  
High Speed ◽  
Orbital Motion ◽  
Close Binary System ◽  
Close Binary ◽  
Line Profiles ◽  
High Speed Photometry ◽  
Emission Line Spectrum

The proper-motion star G61-29 (Giclas et al 1971) was discovered to have an emission-line spectrum consisting entirely of helium by Burbidge and Strittmatter (1971), who noted that the very broad lines (ca. 32 Å at λ4471) seemed to have variable profiles. Warner (1972) suggested that the star might be a close binary system, with the emission lines arising from an accretion disk surrounding a white dwarf, and searched for evidence of binary motion using high speed photometry. He suggested a tentative orbital period of 6h 16m, which subsequent observations were unable to confirm. Smak (1975) studied the star spectroscopically and agreed with Warner’s accretion disk hypothesis based on his analysis of the emission line profiles, but was also unable to derive evidence of orbital motion from his spectra, which were exposed for about 40 minutes each. Greenstein et al.(1977) also observed profile variations in spectra with shorter exposures, but evidently did not search for periodicities.

scholarly journals How Does One Detect An Accretion Disk?

1992 ◽  
Vol 151 ◽  
pp. 175-183
Author(s):  
Ronald H. Kaitchuck
Keyword(s):  
Binary System ◽  
Emission Line ◽  
Accretion Disk ◽  
Variable Stars ◽  
Emission Lines ◽  
New Technique ◽  
Cataclysmic Variable ◽  
Line Profiles ◽  
Doppler Tomography ◽  
History Of

The history of the first detection of an accretion disk in a interacting binary system is presented. The nature of transient and permanent disks in Algol-type binaries is discussed as are the problems associated with the interpretation of emission line profiles from the disks in cataclysmic variable stars. The new technique of eclipse mapping from continuum photometry is reviewed. Some results of Doppler tomography of emission lines are presented.

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