Infrared spectroscopy of the Be / X - ray transient A 0535 + 26
نویسندگان
چکیده
AB S T R AC T We present infrared spectroscopy of the Be/X-ray binary HDE 245770/A0535+26 obtained over the period 1992–1995. The spectra show significant variability, reflecting changes in the circumstellar environment during this time. A reduction in the flux observed in the Paschen series lines between 1993 December and 1994 September correlates with a similar reduction in both the strength of Ha and the optical continuum emission, which can be attributed to a reduction in the emission measure of the disc. A turnover between optically thin and thick emission is seen for both Paschen and Brackett series lines, and allows an estimate of the disc density as 110 cm. Echelle spectroscopy reveals strong similarities between the He I 1.008, 2.058 lm, Ha and Paschen series line profiles, suggesting their formation in a similar (and asymmetric) region of the disc. In contrast, the line profile of He I 6678 Å indicates that it is formed at smaller radii than the other transitions.
منابع مشابه
Detection of X-ray pulsations from the Be/X-ray transient A 0535+26 during a disc loss phase of the primary
Using the RossiXTE experiment, we detect weak Xray emission from the recurrent Be/X-ray transient A 0535+26 at a time when the optical counterpart V725 Tau displayed Hα in absorption, indicating the absence of a circumstellar disc. The X-ray radiation is strongly modulated at the 103.5-s pulse period of the neutron star, confirming that it originates from A 0535+26. The source is weaker than in...
متن کاملDisc loss and renewal in A 0535 + 26
This paper presents observations of the Be/X-ray binary system A0535+26 revealing the first observed loss of its circumstellar disc, demonstrated by the loss of its JHK infrared excess and optical/IR line emission. However optical/IR spectroscopy reveals the formation of a new inner disc with significant density and emission strength at small radii; the disc has proven to be stable over 5 month...
متن کاملSnCl4/nano-sawdust as an Efficient Bio-based Catalyst for the Synthesis of 2-Substituted Benzothiazoles and Benzimidazoles
SnCl4/nano-sawdust was prepared as a carbohydrate-based catalyst containing of tin bearing cellulose units. The catalyst was characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDS). The catalyst was applied successfully as a readily available, inexpensive, biodeg...
متن کاملساخت و ویژگییابی نانوپوسته های طلا برای کاربردهای پزشکی
Gold nanoshells are a new type of nanoparticles including dielectric cores with a continuous thin layer of gold. By varying the core diameter, shell thickness, and the ratio of these parameters, the optical properties of gold nanoshells can be tuned to have maximum absorption in the visible and near infrared spectrum range. The purpose of this research was to synthesize gold coated SiO2 nanos...
متن کاملA 0535 + 26 : back in business
In May/June 2005, after 10 years of inactivity, the Be/X-ray binary system A 0535+26 underwent a major X-ray outburst. In this paper data are presented from 10 years of optical, IR and X-ray monitoring showing the behaviour of the system during the quiescent epoch and the lead up to the new outburst. The results show the system going through a period when the Be star in the system had a minimal...
متن کامل