CXO CDFS J033260.0-274748: A quasar with unusual spectra possibly blueshifted?1This paper is being published without benefit of authors’ corrections.

CXO CDFS J033260.0-274748 is a quasi-stellar object (QSO) and identification of several emission lines observed in its optical spectrum has led to the determination of its redshift as 2.579. On the other hand, the Chandra ACIS-I spectrum has detected a strong absorption feature at the observed wavelength around 6.3 keV that cannot be identified under normal physical conditions. The authors have invoked an unusually large outflow bulk velocity of 0.7c–0.8c to explain the feature. However, such extraordinarily high bulk velocities are unprecedented in the extragalactic literature. We show here that the optical emission lines and the X-ray absorption feature can be identified with search lines of longer wavelengths that have been blueshifted and do not need any unusual physical conditions to be invoked. The blueshifted spectra are explained as being due to the net motion of the QSO along with the absorbing cloud towards the observer. Two scenarios are proposed, namely, the ejection mechanism and the multiverse.

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Intriguing X-ray and optical variations of the γ Cassiopeiae analog HD 45314

Astronomy and Astrophysics ◽

10.1051/0004-6361/201731782 ◽

2018 ◽

Vol 615 ◽

pp. A44 ◽

Cited By ~ 6

Author(s):

G. Rauw ◽

Y. Nazé ◽

M. A. Smith ◽

A. S. Miroshnichenko ◽

J. Guarro Fló ◽

...

Keyword(s):

Optical Spectrum ◽

Optical Emission ◽

Magnetic Interaction ◽

Emission Lines ◽

Magnetic Star ◽

Optical Monitoring ◽

X Ray ◽

Direct Association ◽

Intensity Changes ◽

Observed Behaviour

Context. A growing number of Be and Oe stars, named the γ Cas stars, are known for their unusually hard and intense X-ray emission. This emission could either trace accretion by a compact companion or magnetic interaction between the star and its decretion disk. Aims. To test these scenarios, we carried out a detailed optical monitoring of HD 45314, the hottest member of the class of γ Cas stars, along with dedicated X-ray observations on specific dates. Methods. High-resolution optical spectra were taken to monitor the emission lines formed in the disk, while X-ray spectroscopy was obtained at epochs when the optical spectrum of the Oe star was displaying peculiar properties. Results. Over the last four years, HD 45314 has entered a phase of spectacular variations. The optical emission lines have undergone important morphology and intensity changes including transitions between single- and multiple-peaked emission lines as well as shell events, and phases of (partial) disk dissipation. Photometric variations are found to be anti-correlated with the equivalent width of the Hα emission. Whilst the star preserved its hard and bright X-ray emission during the shell phase, the X-ray spectrum during the phase of (partial) disk dissipation was significantly softer and weaker. Conclusions. The observed behaviour of HD 45314 suggests a direct association between the level of X-ray emission and the amount of material simultaneously present in the Oe disk as expected in the magnetic star-disk interaction scenario.

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1ES 1927+654: Persistent and rapid X-ray variability in an AGN with low intrinsic neutral X-ray absorption and narrow optical emission lines

Astronomy and Astrophysics ◽

10.1051/0004-6361:20021520 ◽

2002 ◽

Vol 397 (2) ◽

pp. 557-564 ◽

Cited By ~ 10

Author(s):

Th. Boller ◽

W. Voges ◽

M. Dennefeld ◽

I. Lehmann ◽

P. Predehl ◽

...

Keyword(s):

Optical Emission ◽

Emission Lines ◽

X Ray ◽

X Ray Absorption

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Effects of the soft X-ray burst from SN 1987A on its circumstellar medium

Highlights of Astronomy ◽

10.1017/s1539299600007826 ◽

1989 ◽

Vol 8 ◽

pp. 223-228

Author(s):

Peter Lundqvist ◽

Claes Fransson

Keyword(s):

Optical Emission ◽

Emission Lines ◽

X Ray ◽

Physical Conditions ◽

Sn 1987A ◽

Circumstellar Medium

AbstractThe observations of the narrow UV and optical emission lines from SN 1987A are modelled as reprocessed radiation in a shell around the supernova, heated and ionized by the soft X-ray and EUV radiation at the shock breakout. Constraints on the early soft X-ray burst are discussed, as well as the physical conditions and abundances in the shell.

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DETERMINATION OF FERRIC-FERROUS RATIO IN PYROXENES WITH X-RAY ABSORPTION SPECTROSCOPY

10.1130/abs/2018am-319797 ◽

2018 ◽

Author(s):

Cody J. Steven ◽

◽

M. Darby Dyar ◽

Molly C. McCanta

Keyword(s):

Absorption Spectroscopy ◽

X Ray ◽

X Ray Absorption

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Theoretical and experimental investigation of point defects in cubic boron nitride

MRS Advances ◽

10.1557/adv.2017.53 ◽

2017 ◽

Vol 2 (29) ◽

pp. 1545-1550 ◽

Cited By ~ 1

Author(s):

Nicholas L. McDougall ◽

Jim G. Partridge ◽

Desmond W. M. Lau ◽

Philipp Reineck ◽

Brant C. Gibson ◽

...

Keyword(s):

Boron Nitride ◽

Cubic Boron Nitride ◽

Optical Emission ◽

Wide Band ◽

Wide Band Gap ◽

Edge Structure ◽

X Ray ◽

Substitutional Defects ◽

X Ray Absorption ◽

Annealing Experiments

ABSTRACTCubic boron nitride (cBN) is a synthetic wide band gap material that has attracted attention due to its high thermal conductivity, optical transparency and optical emission. In this work, defects in cBN have been investigated using experimental and theoretical X-ray absorption near edge structure (XANES). Vacancy and O substitutional defects were considered, with O substituted at the N site (ON) to be the most energetically favorable. All defects produce unique signatures in either the B or N K-edges and can thus be identified using XANES. The calculations coupled with electron-irradiation / annealing experiments strongly suggest that ON is the dominant defect in irradiated cBN and remains after annealing. This defect is a likely source of optical emission in cBN.

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