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We present a comparative study of the circumstellar disks in Be/X-ray binaries and isolated Be stars based upon the H-alpha emission line. From this comparison it follows that the overall structure of the disks in the Be/X-ray binaries is similar to the disks of other Be stars, i.e. they are axisymmetric and rotationally supported. The factors for the line broadening (rotation and temperature) in the disks of the Be stars and the Be/X-ray binaries seem to be identical. However, we do detect some intriguing differences between the envelopes. On average, the circumstellar disks of the Be/X-ray binaries are twice as dense as the disks of the isolated Be stars. The different distribution of the Be/X-ray binaries and the Be stars seen in the full width at half maximum (FWHM) versus peak separation diagram indicates that the disks in Be/X-ray binaries have on average a smaller size, probably truncated by the compact object., accepted in A&A

We present VLT–ISAAC spectra of unprecedented S/N and resolution for the Hβ region in a sample of n = 17 quasars in the range z = 0.8–2.5. The data represent our first attempt to test source occupation and line properties for the Eigenvector 1 parameter space that was defined using a sample of sources with z < 0.8. We find no strong luminosity/redshift dependent effects with the possible exception of an increase in the minimum broad line profile width from 1000 to 3000 km s between MB ≈ −20 and −28. We have obtained high S/N spectra of the Hβ region of a sample of 17 HE quasars with intermediate redshift (0.85 z 2.5) and high luminosity (−26 MB −30). For the first time we have a sample of NIR spectra with resolution and S/N comparable to those obtained for 200+ lower-redshift Type 1 AGN (Marziani et al. 2003 (M03)). Spectra (Fig. 1) were obtained between 2001 November and 2002 February using ESO/VLT1+ISAAC providing a resolution of ∼ 300 km s in all bands (Z, sZ, J, H). The observations represent our first attempt to test the robustness of the Eigenvector 1 (E1) parameter space previously defined using lower redshift sources (Boroson & Green 1992; Sulentic et al. 2000). Our goals include testing: 1) domain space occupation in the optical E1 plane and 2) the apparent luminosity independence of all E1 properties. The VLT spectra enable us to measure both E1 optical parameters: FWHM(Hβ) and the broad-line equivalent width ratio W(FeIIopt)/W(Hβ) = RFe, where W(FeIIopt) measures the λ4570 blend. Broad Hβ, and the narrow [OIII]λλ5007,4959, were isolated by subtracting appropriately scaled FeII emission from the spectra using a template based on IZw1. FeII emission properties show no differences from our lower-redshift sample (M03) and the FeII template works equally well at these high redshifts. We find no significant differences in source occupation for the optical plane of E1 as defined previously (Fig. 2a). There may be a slight tendency for higher redshift source to displace towards the upper right but this requires verification with a much larger sample. The results are consistent with our previous suggestion that E1 occupation is driven neither by source luminosity nor BH mass but rather by the Eddington ratio convolved with source orientation to the line of sight. Figure 2b shows possible evidence for a systematic increase in minimum observed FWHM(Hβ) with source luminosity. A general increase in FWHM(Hβ) with luminosity is not certain because radio-loud sources are over-represented in the higher luminosity † Based on observations collected at the European Southern Observatory, Chile. Proposal ref.: ESO 68.B–0364(A)

The Be massive X-ray binary LSI+61°303 is a 26.5 days periodic radiosource (Taylor & Gregory, 1984), exhibiting radio outbursts maxima between phases 0.6-0.8. Evidence of a photometric period of similar value has also been reported (Paredes & Figueras, 1986; Mendelson & Mazeh, 1989). The previous spectroscopic radial velocity observations of Hutchings & Crampton (1981) are in agreement with the radio period, and give support to the presence of a companion. We present new optical and infrared photometric observations and high resolution Hα spectra of LSI+61°303.

DESPITE its interesting behaviour1,2, the object MWC560 has been little studied since its discovery 50 years ago during the Mount Wilson Observatory Hα emission-line surveys3. To rectify this situation we have made systematic spectral and photometric observations of this star. Spectra of the hydrogen absorption Balmer lines show remarkable variability: they indicate that some components have radial velocities as large as −6,000 km s−1, and the profiles are complex, showing pronounced variability on times-cales of a few days. Photometric observations show that the V-band brightness of the star has risen by about three magnitudes over the past 20 years; during our own observations, this brightness was seen to change by a few tenths of a magnitude. We speculate that MWC560 may be a binary system containing a red giant and a compact companion—possibly a white dwarf—and exhibiting jet-like ejections along the line of sight4.

We report on the long-term variability of the Be/X-ray binary LS I +61 235/RX J0146.9+6121. New optical spectroscopic and infrared photometric observations confirm the presence of global one-arm oscillations in the circumstellar disc of the Be star and allow us to derive a V/R quasi-period of 1240+-30 days. Pronounced shell events, reminiscent of the spectacular variations in Be stars, are also seen. We have found that the J, H and K infrared photometric bands vary in correlation with the spectroscopic V/R variations, implying that the one-armed disc oscillations are prograde. The effect of the oscillations is not only seen in the Halpha line but also in the He I6678 and Paschen lines. Since these lines are formed at different radii in the equatorial disc of the Be star, such effect confirms the global nature of the perturbation. The Keplerian disc has been found to be denser than the average of a sample of isolated Be stars, which may be indicative of some kind of interaction with the compact companion. Finally, from a Rossi X-ray Timing Explorer observation we derive a spin period of the neutron star of 1404.5+-0.5 s., Comment: 6 pages, 3 figures, accepted for publication in MNRAS

We report simultaneous observations of the flaring behaviour of the cataclysmic variable star AE Aqr. The observations are in Johnson B and V bands. The colour-magnitude diagrams (B-V versus V and B-V vs. B) show that the star becomes blues as it becomes brighter. In our model AE Aqr behaviour can be explained with flares (fireballs) with 0.03 < B-V < 0.30 and temperature in the interval 8000 < T < 12000., 6 pages, accepted in Astronomische Nachrichten