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XMM-Newton observations of the BL Lac MS 0205.7+3509: A dense, low-metallicity absorber
Hanlon, L.; McBreen, B.; Smith, N. +5 more
The high-frequency-peaked BL Lac, MS 0205.7+3509 was observed twice with XMM-Newton. Both X-ray spectra are synchrotron-dominated, with mean 0.2-10 keV fluxes of 2.80±0.01 and 3.34±0.02×10-12 erg cm-2 s-1. The X-ray spectra are well fit by a power-law with absorption above the Galactic value, however no absorption …
XMM-Newton observations of OY Car III: OM light curve modelling, X-ray timing and spectral studies
Ramsay, G.; Hakala, P.
We revisit the XMM-Newton observations of the dwarf nova OY Car taken in July 2000 which occured shortly after an outburst. Ramsay et al. (\cite{Ramsay2001a}) found a prominent energy dependent modulation at a period of 2240 s: this modulation was only seen for ∼1/3 of the observation duration. In our new analysis, we examine this time interval in…
The distance to NGC 5904 (M 5) via the subdwarf main sequence fitting method
Testa, V.; Marconi, G.; Andreuzzi, G. +2 more
We present a determination of the distance modulus of the globular cluster NGC 5904 (M 5), obtained by means of the subdwarf main-sequence fitting on the (V,V-I) color-magnitude diagram. The subdwarf sample has been selected from the HIPPARCOS catalog in a metallicity range homogeneous with the cluster ([Fe/H] ≃ -1.1). Both the cluster and the sub…
Properties and nature of Be stars. XXII. Long-term light and spectral variations of the new bright Be star HD 6226
Buil, C.; Harmanec, P.; Yang, S. +8 more
Photometric and spectroscopic monitoring of the B star HD 6226 resulted in the finding that this object is a new bright Be star with a clear positive correlation between the brightness and emission-line strength. The emission-line episodes are relatively short and seem to repeat frequently which makes this star an ideal target for studying the cau…
Assessing the galaxy population out to z ∼ 2 using the Hubble Deep Field South
Horellou, C.; Wiegert, T.; de Mello, D. F.
In this work we use the Hubble Deep Field South (HDF-S) version 2 images to assess the galaxy population out to z ∼ 2. We have used two methods of templates fitting of the spectral energy distributions to obtain photometric redshifts and classify the objects. The Bayesian photometric redshifts gave better results when compared with 54 spectroscopi…
An unusual high-ionization nebula in NGC 55
Rosa, M. R.; Tüllmann, R.
We report on the detection of a previously unknown extended low-density nebula of very high temperature and excitation, TR 001507.7-391206, located above the midplane of NGC 55. The nebular emission line spectrum, in which He II is present, is consistent with photoionization by about 3 very hot massive O3 or WR-type stars. There are no indications…
Initial mass function in the South-Western part of M 31
Borisov, G.; Nedialkov, P.; Veltchev, T.
We derive an average initial mass function (IMF) for 50 OB associations in the South-Western part of Andromeda galaxy, combining ultraviolet photometry of Hill et al. (\cite{Hill95}, ApJ, 98, 595) and two datasets HST photometry with JHKs photometry from the 2MASS + I band photometry from Magnier et al. (\cite{Magnier92}, A&A, 96, 3…
1WGA J2223.7-0206: A Narrow-Line Quasi-Stellar Object in the XMM-Newton field of view of 3C 445
Palazzi, E.; Masetti, N.; Grandi, P. +1 more
We report the discovery of a Narrow Line QSO located at about 1.3' from the Broad Line Radio Galaxy 3C 445. The source, 1WGA J2223.7-0206, although already revealed by ROSAT, has never been optically identified previously. An XMM-Newton observation of 3C 445 has allowed, for the first time, an accurate X-ray spectral study of 1WGA J2223.7-0206, re…
High-resolution spectroscopy of flat-spectrum quasars. I. Redshifted emission and absorption in PKS 2145+067
Black, J. H.; Tappe, A.
We report Very Large Telescope (VLT) observations of the quasar
High-resolution near-infrared speckle interferometry and radiative transfer modeling of the OH/IR star OH 104.9+2.4
Weigelt, G.; Hofmann, K. -H.; Men'shchikov, A. B. +3 more
We present near-infrared speckle interferometry of the OH/IR star