scholarly journals An XMM–Newton observation of the symbiotic star AG Peg: the X-ray emission after the end of its 2015 outburst

2018 ◽  
Vol 481 (4) ◽  
pp. 5156-5162
Author(s):  
Svetozar A Zhekov ◽  
Toma V Tomov
Keyword(s):  
Symbiotic Star ◽  
X Ray

scholarly journals Regulation of accretion by its outflow in a symbiotic star: the 2016 outflow fast state of MWC 560

2020 ◽  
Vol 492 (3) ◽  
pp. 3107-3127 ◽  
Author(s):  
Adrian B Lucy ◽  
J L Sokoloski ◽  
U Munari ◽  
Nirupam Roy ◽  
N Paul M Kuin ◽  
...  
Keyword(s):  
Symbiotic Star ◽  
Fast State ◽  
Low Velocity ◽  
X Ray ◽  
Broad Absorption Line ◽  
Multi Wavelength ◽  
Order Of Magnitude ◽  
The Stability ◽  
Ultraviolet Observations ◽  
Optical Flux

ABSTRACT How are accretion discs affected by their outflows? To address this question for white dwarfs accreting from cool giants, we performed optical, radio, X-ray, and ultraviolet observations of the outflow-driving symbiotic star MWC 560 (≡V694 Mon) during its 2016 optical high state. We tracked multi-wavelength changes that signalled an abrupt increase in outflow power at the initiation of a months-long outflow fast state, just as the optical flux peaked: (1) an abrupt doubling of Balmer absorption velocities; (2) the onset of a 20 μJy per month increase in radio flux; and (3) an order-of-magnitude increase in soft X-ray flux. Juxtaposing to prior X-ray observations and their coeval optical spectra, we infer that both high-velocity and low-velocity optical outflow components must be simultaneously present to yield a large soft X-ray flux, which may originate in shocks where these fast and slow absorbers collide. Our optical and ultraviolet spectra indicate that the broad absorption-line gas was fast, stable, and dense (≳106.5  cm−3) throughout the 2016 outflow fast state, steadily feeding a lower density (≲105.5 cm−3) region of radio-emitting gas. Persistent optical and ultraviolet flickering indicate that the accretion disc remained intact. The stability of these properties in 2016 contrasts to their instability during MWC 560’s 1990 outburst, even though the disc reached a similar accretion rate. We propose that the self-regulatory effect of a steady fast outflow from the disc in 2016 prevented a catastrophic ejection of the inner disc. This behaviour in a symbiotic binary resembles disc/outflow relationships governing accretion state changes in X-ray binaries.

An Extremely Massive White Dwarf of the Symbiotic Classical Nova V407 Cyg as Suggested by the RS Oph and U SCO Models

2012 ◽  
Vol 21 (1-2) ◽  
Author(s):  
I. Hachisu ◽  
M. Kato
Keyword(s):  
Light Curve ◽  
White Dwarf ◽  
Early Phase ◽  
Symbiotic Star ◽  
X Ray ◽  
Classical Nova ◽  
Optical Light Curve ◽  
Nova Outburst

AbstractWe have analyzed the optical light curve of the symbiotic star V407 Cyg that underwent a classical nova outburst in 2010 March. Being guided by a supersoft X-ray phase observed during days 20-40 after the nova outburst, we are able to reproduce the light curve during a very early phase of the nova outburst. Our model consists of an outbursting white dwarf and an extended equatorial disk. An extremely massive white dwarf of 1.35-1.37 M

scholarly journals Optical spectroscopy and X-ray observations of the D-type symbiotic star EF Aql

2020 ◽  
Vol 495 (1) ◽  
pp. 1461-1467
Author(s):  
K A Stoyanov ◽  
K Iłkiewicz ◽  
G J M Luna ◽  
J Mikołajewska ◽  
K Mukai ◽  
...  
Keyword(s):  
High Resolution ◽  
Optical Spectroscopy ◽  
Chemical Elements ◽  
Mass Loss Rate ◽  
X Rays ◽  
Symbiotic Star ◽  
Optical Telescope ◽  
X Ray ◽  
V Band ◽  
Periodogram Analysis

ABSTRACT We performed high-resolution optical spectroscopy and X-ray observations of the recently identified Mira-type symbiotic star EF Aql. Based on high-resolution optical spectroscopy obtained with the Southern African Large Telescope (SALT), we determine the temperature (∼55 000 K) and the luminosity (∼5.3 L⊙) of the hot component in the system. The heliocentric radial velocities of the emission lines in the spectra reveal possible stratification of the chemical elements. We also estimate the mass-loss rate of the Mira donor star. Our Swift observation did not detect EF Aql in X-rays. The upper limit of the X-ray observations is 10−12 erg cm−2 s−1, which means that EF Aql is consistent with the faintest X-ray systems detected so far. Otherwise we detected it with the UltraViolet and Optical Telescope (UVOT) instrument with an average UVM2 magnitude of 14.05. During the exposure, EF Aql became approximately 0.2 UVM2 magnitudes fainter. The periodogram analysis of the V-band data reveals an improved period of 320.4 ± 0.3 d caused by the pulsations of the Mira-type donor star.

X-ray detection of the symbiotic star AG Draconis

1981 ◽  
Vol 247 ◽  
pp. L127 ◽  
Author(s):  
C. M. Anderson ◽  
J. P. Cassinelli ◽  
W. T. Sanders
Keyword(s):  
Symbiotic Star ◽  
X Ray

scholarly journals X-Ray and Ultraviolet Observations of AG Draconis during Quiescence and Outburst

1987 ◽  
Vol 93 ◽  
pp. 763-763
Author(s):  
A. Cassatella ◽  
F.A. Córdova ◽  
M. Friedjung ◽  
J. Kenyom ◽  
L. Piro ◽  
...  
Keyword(s):  
Orbital Motion ◽  
Uv Light ◽  
Low Energy ◽  
Emission Lines ◽  
Symbiotic Star ◽  
Symbiotic Stars ◽  
Uv Spectrum ◽  
X Ray ◽  
High Ionization ◽  
Ultraviolet Observations

AbstractWe describe the first X-ray monitoring of a symbiotic star during phases of enhanced activity. AG Dra is a Pop II object with a composite spectrum, characterized by a cool K-type component, prominent high ionization emission lines and a strong UV continuum which is attributed to a hot dwarf companion. Periodic variability of the UV radiation during minimum could be attributed to the orbital motion of the system. In April 1980 HEAO-2 detected an intense, soft X-ray flux from AG Dra, stronger than in other symbiotic stars. After one major outburst of November 1980, which continued until 1983, two more outbursts occurred in February 1985 and January 1986, and coordinated X-ray (EXOSAT) and ultraviolet (IUE) observations were organized to study the behaviour of AG Dra during different activity phases. EXOSAT observations made during decline after the 1985 outburst, revealed a weak X-ray flux in the Thin Lexan filter of the Low Energy dedtector. Observations made during minimum, in June and November 1985, at phases 0.22 and 0.50 of the UV light curve, disclosed the presence of an intense X-ray flux, which was not occulted in November. AG Dra was again observed with EXOSAT in February 1986 when the stellar luminosity was still at maximum. No X-ray flux was detected, in spite of the prominent, high ionization UV spectrum observed with IUE.A detailed discussion of the X-ray and ultraviolet results on AG Dra in the light of possible models is in progress.

scholarly journals X-ray detection of the symbiotic star AG Draconis

1982 ◽  
Vol 70 ◽  
pp. 117-121
Author(s):  
Christopher M. Anderson ◽  
Joseph P. Cassinelli ◽  
Nancy A. Oliversen ◽  
Roy V. Myers ◽  
W.T. Sanders
Keyword(s):  
Proportional Counter ◽  
X Rays ◽  
Symbiotic Star ◽  
X Ray ◽  
Intense Source

AbstractThe symbiotic star AG Draconis was observed by the HEAO-2 Imaging Proportional Counter (IPC) and found to be an unusually intense source of very soft X-rays.

scholarly journals The B[e] Star MWC 84 (CI Cam)

2000 ◽  
Vol 175 ◽  
pp. 83-86 ◽  
Author(s):  
Carlos Jaschek ◽  
Yvette Andrillat
Keyword(s):  
Emission Line ◽  
Near Infrared ◽  
Symbiotic Star ◽  
Optical Counterpart ◽  
X Ray

The star MWC 84 (CI Cam) was first discovered to be an emission line object classified Bep (Merrill & Burwell, 1933), then classified as a symbiotic star and finally identified as the possible optical counterpart of the X-ray transient XTE J0421+560 (Wagner & Starrfield, 1998)We have observed MWC 84 at the Haute Provence Observatory (CNRS) with a resolution of about 1.3 Å in 1992 (wavelength regions Hα and near infrared), 1998 and 1999 (from 4080 to 8880 Å).

scholarly journals XMM–Newton study of X-ray sources in the field of Willman 1 dwarf spheroidal galaxy★

2020 ◽  
Vol 499 (3) ◽  
pp. 3111-3129
Author(s):  
Sara Saeedi ◽  
Manami Sasaki
Keyword(s):  
Active Galactic Nuclei ◽  
Cross Correlation ◽  
Flux Ratio ◽  
Galactic Nuclei ◽  
Symbiotic Star ◽  
X Ray ◽  
Dwarf Spheroidal Galaxies ◽  
Infrared Wavelengths ◽  
Optical Flux ◽  
M Dwarf

ABSTRACT We present the results of the analysis of three XMM–Newton observations of the Willman 1 dwarf spheroidal galaxy (Wil 1). X-ray sources are classified on the basis of spectral analysis, hardness ratios, X-ray-to-optical flux ratio, X-ray variability, and cross-correlation with available catalogues in optical and infrared wavelengths. We catalogued 97 sources in the field of Wil 1. Our classification shows the presence of a β-type symbiotic star in Wil 1. We classified one M dwarf foreground star in the field of Wil 1. Moreover, 54 sources are classified as background active galactic nuclei and galaxies. Our study shows that the luminosity of the X-ray sources of Wil 1 does not exceed ∼1034 erg s−1 in the energy range of 0.2–12.0 keV, which is similar to observed luminosities of sources in nearby dwarf spheroidal galaxies.

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