Abstract. Optical and near infrared spectroscopy of the stars DQ Ser and DT Ser are presented. DQ Ser shows a late-type continuum (M3 − M5) with emission lines of Balmer series, HeI, HeII, [OIII], OI and CaII triplet while DT Ser presents a earlier spectral type with emission of Balmer lines, HeI, HeII and [OIII]. DT Ser is a faint V = 15.4 star 5 arcsec from a V = 12.8 G companion. We suggest it to be a yellow symbiotic star.
The results of an optical monitoring campaign on the active nucleus in the luminous Seyfert 1 galaxy Fairall 9 are presented. This campaign was undertaken in parallel with ultraviolet spectroscopic monitoring with the IUE satellite which is described in a separate paper. The primary purpose of this program is to measure the response times (or "" lags ÏÏ) of the emission lines to continuum variations and thus to extend the range in luminosity of active galactic nuclei (AGNs) for which such measurements have been made. The main conclusions of this work are as follows :1. Continuum (at 5340 variations of amplitude D12% are detected on timescales as short as D20 A ) days. These variations are much larger than the typical uncertainties in the measurements, which are of order D2%. Over D94 days, a factor of 2 change in the nuclear continuum was observed.2. The optical continuum light curve resembles that of the UV continuum, showing two "" events ÏÏ of low-amplitude variations with a duration of D70 days and with no measurable lag between the UV and optical continuum light curves. The UV data show a third larger amplitude event that occurred after the optical monitoring had terminated and unfortunately went unobserved in the optical.3. The Hb emission-line Ñux also underwent signiÐcant, low-amplitude (º20%) variations. Crosscorrelation analysis reveals that Hb lags behind the UV continuum by about 23 days, a value much smaller than what was previously suggested by earlier variability studies. However, this small lag is consistent with the lags for the UV lines during this campaign in the sense that the Hb lag is approximately 50% larger than that of Lya j1216, as it has been found for lower luminosity AGNs.4. The Hb di †erence proÐle produced by subtracting the low-state from the high-state data can be described as a two-component structure with blue and red components of similar width (D2500 km s~1) and that appear to vary in phase.
We observed the narrow-line Seyfert 1 galaxies IRAS 20181-2244 and IRAS 13324-3809 with a new spectropolarimeter on the RC spectrograph at the CTIO 4m telescope. Previously it had been suggested that IRAS 20181-2244 was a Type 2 QSO and thus might contain an obscured broad-line region which could be detected by the presence of broad Balmer lines in the polarized flux. We found the object to be polarized at about 2%, and constant with wavelength, (unlike most narrow-line Seyfert 1s), but with no evidence of broad Balmer lines in polarized flux. The spectropolarimetry indicates that the scattering material is inside the BLR. IRAS 13224-3809, notable for its high variability in X-ray and UV wavelengths, has a low polarization consistent with a Galactic interstellar origin.
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