scholarly journals An eccentric wave in the circumstellar disc of the Be/X-ray binary X Persei

2020 ◽  
Vol 499 (3) ◽  
pp. 3650-3659
Author(s):  
R K Zamanov ◽  
K A Stoyanov ◽  
U Wolter ◽  
D Marchev ◽  
N A Tomov ◽  
...  
Keyword(s):  
Line Profile ◽  
Emission Lines ◽  
Planetary Rings ◽  
Peak Ratio ◽  
Detailed Understanding ◽  
X Ray ◽  
Innermost Part ◽  
Spectroscopic Observations ◽  
R Ratio ◽  
Wide Range

ABSTRACT We present spectroscopic observations of the Be/X-ray binary X Per obtained during the period 2017 December–2020 January (MJD 58095–58865). In 2017 December, the H α, H β, and He i 6678 emission lines were symmetric with violet-to-red peak ratio V/R ≈ 1. During the first part of the period (2017 December–2018 August), the V/R ratio decreased to 0.5 and the asymmetry developed simultaneously in all three lines. In 2018 September, a third component with velocity ≈250 km s−1 appeared on the red side of the He i line profile. Later, this component emerged in H β, accompanied by the appearance of a red shoulder in H α. Assuming that it is due to an eccentric wave in the circumstellar disc, we find that the eccentric wave appeared first in the innermost part of the disc, it spreads out with outflowing velocity vwave ≈ 1.1 ± 0.2 km s−1, and the eccentricity of the eccentric wave is ewave ≈ 0.29 ± 0.07. A detailed understanding of the origin of such eccentricities would have applications to a wide range of systems from planetary rings to AGNs.

AGN1 vs AGN2 dichotomy as seen from the point of view of ionized outflows

2019 ◽  
Vol 15 (S356) ◽  
pp. 96-96
Author(s):  
Eleonora Sani
Keyword(s):  
Accretion Rate ◽  
Point Of View ◽  
Emission Lines ◽  
Black Hole Mass ◽  
X Ray ◽  
Bolometric Luminosity ◽  
Wide Range ◽  
Strong Contrast

AbstractI present a detailed study of ionized outflows in a large sample of 650 hard X-ray detected AGN. Taking advantage of the legacy value of the BAT AGN Spectroscopic Survey (BASS, DR1), we are able to reveal the faintest wings of the [OIII] emission lines associated with outflows. The sample allows us to derive the incidence of outflows covering a wide range of AGN bolometric luminosity and test how the outflow parameters are related with various AGN power tracers, such as black hole mass, Eddington ratio, luminosity. I’ll show how ionized outflows are more frequently found in type 1.9 and type 1 AGN (50% and 40%) with respect to the low fraction in type 2 AGN (20%). Within such a framework, I’ll demonstrate how type 2 AGN outflows are almost evenly balanced between blue- and red-shifted winds. This, in strong contrast with type 1 and type 1.9 AGN outflows which are almost exclusively blue-shifted. Finally, I’ll prove how the outflow occurrence is driven by the accretion rate, whereas the dependence of outflow properties with respect to the other AGN power tracers happens to be quite mild.

scholarly journals H2 Emission from External Galaxies

1992 ◽  
Vol 150 ◽  
pp. 103-107
Author(s):  
Kimiaki Kawara
Keyword(s):  
Uv Radiation ◽  
Supernova Remnants ◽  
Emission Lines ◽  
Hot Stars ◽  
Shock Excitation ◽  
X Ray ◽  
Spectroscopic Observations ◽  
Near Ir ◽  
Bare Nucleus ◽  
External Galaxies

2 μm spectroscopic observations by many authors have revealed significant rotation-vibrational H2 emission is widespread from starburst to bare nucleus galaxies. Near-IR H2 emission lines can arise from various excitation sources: UV radiation by hot stars, shock excitation by supernova remnants or AGN driven winds, and UV/X-ray radiation by an AGN. In this review recent data will be compared with such H2 excitation models.

scholarly journals Call H and K Emission in the Secondary Component of U Cephei

1988 ◽  
Vol 108 ◽  
pp. 219-220
Author(s):  
Akira Okazaki ◽  
Yasuhisa Nakamura ◽  
Jun-Ichi Katahira
Keyword(s):  
Emission Lines ◽  
Secondary Component ◽  
Eclipsing Binary ◽  
Image Tube ◽  
X Ray ◽  
Spectroscopic Observations ◽  
The Third ◽  
Total Eclipse ◽  
Hot Corona ◽  
Made In

U Cephei (V = 6.8–9.0, P = 2.493 d) is an eclipsing binary consisting of a B7V primary and a G8III-IV secondary component. This binary is one of the semidetached Algol systems showing soft X-ray emission which is probably associated with a hot corona surrounding the secondary component (White and Marshall 1983).We made spectroscopic observations of U Cep with the coudé image-tube spectrograph of the 1.9-m telescope at Okayama Astrophysical Observatory on October 14, 1986. We obtained four spectrograms with a dispersion of 16 Å mm-1 covering λ λ3700—4300 Å during the primary eclipse. The first two exposures were made in a total eclipse, while the last two were slightly after the third contact. The CaII H and K emission lines appear clearly in all the spectrograms. Figure 1 represents an intensity tracing of one of these spectrograms.

scholarly journals Magnetic fields in O-type stars measured with FORS 1 at the VLT

2008 ◽  
Vol 4 (S259) ◽  
pp. 381-382
Author(s):  
Swetlana Hubrig ◽  
M. Schöller ◽  
R. S. Schnerr ◽  
I. Ilyin ◽  
H. F. Henrichs ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Massive Stars ◽  
Emission Lines ◽  
X Ray ◽  
Wind Variability ◽  
Thermal Radio ◽  
Wide Range ◽  
Long Time ◽  
Hα Emission ◽  
Chemical Peculiarity

AbstractThe presence of magnetic fields in O-type stars has been suspected for a long time. The discovery of such fields would explain a wide range of well documented enigmatic phenomena in massive stars, in particular cyclical wind variability, Hα emission variations, chemical peculiarity, narrow X-ray emission lines and non-thermal radio/X-ray emission. Here we present the results of our studies of magnetic fields in O-type stars, carried out over the last years.

Line Profile Analysis (LPA) Methods: Systematic Ranking of the Quality of their Basic Assumptions

2004 ◽  
Vol 443-444 ◽  
pp. 127-130
Author(s):  
Arnold C. Vermeulen ◽  
Rob Delhez
Keyword(s):  
Line Profile ◽  
Profile Analysis ◽  
Line Profile Analysis ◽  
Line Profiles ◽  
Qualitative Comparison ◽  
New Developments ◽  
X Ray ◽  
Basic Assumptions ◽  
Wide Range

All methods of analyzing the broadening of XRD line profiles have to take into account two basic effects: broadening by the instrument - including the X-ray spectrum - and the characteristics of broadening by size effects and by lattice defects - including their interaction. These effects are handled in practice by a wide range of auxiliary assumptions. In this paper these assumptions and their quality with respect to "appropriateness of purpose" are listed and compared. By systematic ranking of these assumptions in accordance with their quality, a 2-dimensional map can be constructed that visualizes the differences in the quality of the assumptions. This 2-dimensional map brings a new viewpoint to the various methods for line profile analysis, because it enables a qualitative comparison of the assumptions of existing methods and new developments.

scholarly journals Results of Optical Monitoring of the Dwarf Nova SS Cyg During the 1993 Campaign of co-ordinated Observations with the Asca Satellite

1996 ◽  
Vol 158 ◽  
pp. 73-74
Author(s):  
Irina Voloshina
Keyword(s):  
Cataclysmic Variable ◽  
Optical Monitoring ◽  
X Ray ◽  
Dwarf Nova ◽  
Spectroscopic Observations ◽  
Photometric And Spectroscopic Observations ◽  
Wide Range

SS Cyg is the brightest known and therefore best studied classical dwarf nova and it was the first one from which X-ray radiation was discovered. SS Cyg is unique because it has been detected at very wide range of energies, from a few eV up to ~ 10 keV (Jones & Watson 1992). It was chosen as the first cataclysmic variable for X-ray observations with the Japanese satellite ASCA. Simultaneous optical photometric and spectroscopic observations were also provided for completeness of the study.

scholarly journals Red-skewed Kα iron lines in GX 13+1

2019 ◽  
Vol 625 ◽  
pp. A8 ◽  
Author(s):  
T. Maiolino ◽  
P. Laurent ◽  
L. Titarchuk ◽  
M. Orlandini ◽  
F. Frontera
Keyword(s):  
Statistical Method ◽  
Accretion Disk ◽  
Compact Object ◽  
Emission Lines ◽  
Statistical Point ◽  
Significance Level ◽  
Central Source ◽  
X Ray ◽  
Innermost Part ◽  
Run Test

Context. Broad, asymmetric, and red-skewed Fe Kα emission lines have been observed in the spectra of low-mass X-ray binaries hosting neutron stars (NSs) as a compact object. Because more than one model is able to describe these features, the explanation of where and how the red-skewed Fe lines are produced is still a matter of discussion. It is broadly accepted that the shape of the Fe Kα line is strongly determined by the special and general relativistic effects occurring in the innermost part of the accretion disk. In this relativistic framework, the Fe fluorescent lines are produced in the innermost part of the accretion disk by reflection of hard X-ray photons coming from the central source (corona and/or NS surface). We developed an alternative and nonrelativistic model, called the WINDLINE model, that is capable to describe the Fe line features. In this nonrelativistic framework, the line photons are produced at the bottom of a partly ionized outflow (wind) shell as a result of illumination by the continuum photons coming from the central source. In this model the red-skewness of the line profile is explained by repeated electron scattering of the photons in a diverging outflow. Aims. Examining the asymmetry of the fluorescent Fe K emission line evident in the XMM-Newton EPIC-pn spectra of the NS source GX 13+1, we aim to distinguish between the two line models. Because GX 13+1 is a well-known disk-wind source, it is a perfect target for testing the WINDLINE model and compare the spectral fits between the relativistic and nonrelativistic line models. Methods. We used two XMM-Newton EPIC-pn observations in which the Fe line profiles were previously reported in the literature. These observations are not strongly affected by pile-up, and the Fe emission lines appear very strong and red-skewed. In order to access the goodness of the fit and distinguish between the two line models, we used the run-test statistical method in addition to the canonical χ2 statistical method. Results. The DISKLINE and WINDLINE models both fit the asymmetric Fe line well that is present in the XMM-Newton energy spectra of GX 13+1. From a statistical point of view, for the two observations we analyzed, the run-test was not able to distinguish between the two Fe line models, at 5% significance level.

scholarly journals Optical spectroscopic observations of the Be/X-Ray binary A0535+262/V725 Tau during the giant outburst in 2009

2010 ◽  
Vol 6 (S272) ◽  
pp. 618-619
Author(s):  
Yuuki Moritani ◽  
Daisaku Nogami ◽  
Atsuo T. Okazaki ◽  
Akira Imada ◽  
Eiji Kambe ◽  
...  
Keyword(s):  
Emission Lines ◽  
X Ray ◽  
Spectroscopic Observations ◽  
Spectroscopic Monitoring

AbstractA giant outburst occurred in A0535+262/V725 Tau in November 2009, which lasted approximately 30 days. We carried out spectroscopic monitoring at OAO and GAO from November 2009 to March 2010, from before the giant outburst to the rising phase of the normal outburst which occurred after the next periastron. The obtained H-alpha, H-beta and He I emission lines exhibited drastic profile variability during the observations.

scholarly journals Inflowing gas in the central parsec of M81

2019 ◽  
Vol 488 (1) ◽  
pp. 1199-1210 ◽  
Author(s):  
Nick Devereux
Keyword(s):  
Hubble Space Telescope ◽  
Line Emission ◽  
Visible Spectrum ◽  
Emission Lines ◽  
Extended Source ◽  
Space Telescope ◽  
X Ray ◽  
Wide Range ◽  
Low Metallicity ◽  
Central Parsec

Abstract Spectroscopic observations of the Seyfert 1/Liner nucleus of M81, obtained recently with the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope(HST), have revealed an ultraviolet (UV)–visible spectrum rich with emission lines of a variety of widths, ionization potentials, and critical densities, including several in the UV that have not previously been reported. Even at the highest angular resolution currently achievable with HST, the broad-line region of M81 cannot be uniquely defined on the basis of commonly used observables such as the full width at half-maximum of the emission lines, or ratios of various emission lines. Numerous broad forbidden lines complicate interpretation of the spectra. At least three separate line-emitting components are inferred. Firstly, a large, highly ionized, low-density, low-metallicity H+ region producing the broad Balmer lines. Located within the H+ region are smaller condensations spanning a wide range in density, and the source of forbidden line emission through collisional excitation of the respective ions. Intermingled with the H+ region and the condensations is a curious extended source of time-variable C iv λ1548 emission. Collectively, these observations can be qualitatively understood in the context of a shock-excited jet cavity within a large H+ region that is photoionized by the central UV–X-ray source. The H+ region contains ∼500 M⊙ of low-metallicity gas that is dynamically unstable to inflow. At the current rate, the available H+ gas can sustain the advection-dominated accretion flow that powers the central UV–X-ray source for 105 yr.

Anticipated X-ray and VUV spectroscopic data from ITERwith appropriate diagnostic instrumentation

2008 ◽  
Vol 86 (1) ◽  
pp. 277-284 ◽  
Author(s):  
N J Peacock ◽  
M G O’Mullane ◽  
R Barnsley ◽  
M Tarbutt
Keyword(s):  
Line Profile ◽  
Atomic Data ◽  
Spectral Signature ◽  
Atomic Collisions ◽  
X Ray ◽  
The Core ◽  
Spectral Bands ◽  
Wide Range ◽  
Core Plasma ◽  
The Continuum

The radiation characteristics of anticipated sample elements, from H through W, in the International Thermonuclear Experimental Reactor (ITER) have been modelled using the diffusion equilibrium model SANCO for the ion concentrations coupled with the spectral signature of the ions, throughout the X-ray and VUV regions (0.1–100 keV), using the Atomic Data and Analysis Structure population code and database, ADAS. The spectral signature varies greatly depending on whether the viewing line-of-sight (LOS) encompasses the divertor and (or) core regions of the plasma volume. Bound–bound transitions required for line profile analyses of nonfuel core ions can locally dominate the continuum spectrum in the 0.1–10 keV region at acceptably low elemental concentrations. While the background continuum is the main source of noise in the line profile analyses, the intensity and features of the continuum when divided into many spectral bands covering 0.1–100 keV are themselves powerful diagnostics of the plasma composition, Zeff, and the electron temperature. The spectral signature of the divertor LOSs where 1 < Te < 300 eV is dominated typically and exclusively by lines in the XUV–VUV region, restricted in the case of W to λ > 40 Å. Appropriate instrumentation, relying on imaging Bragg reflectors and diffractors and position-sensitive energy-resolving detectors, is designed to cover the full spatial extent of the core plasma. Estimates of the core signal/noise based on experience with tritium experiments on the Joint European Torus indicates substantial signal levels with tolerable neutron-induced noise and component degradation. The divertor diagnostics make use of a suite of aspheric diffraction grating spectrometers designed to measure impurity ion influxes and are essential for plasma control. The EBIT could be conceived as a neutron-free adjunct facility to the ITER spectroscopic programme. At its simplest level, it provides standards for instrument performance and for the spectroscopic signature of selected ions subjected to electronic and atomic collisions over a wide range of ITER-relevant impacting energies.PACS Nos.: 52.58.Lq, 52.55.Fa, 52.70–m, 52.25.Vy, 87.64.Gb

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