Search Publications
Members of Centaurus OB1 and NGC 4755: new spectroscopic and astrometric studies
Orellana, R. B.; Corti, M. A.
Context. An OB association is a gravitationally unbound group of stars. The identification of the members of the association is an important aspect of its study. There are few astrometric membership studies for OB associations, but the combination of these studies with astrophysical techniques becomes a very powerful tool for this type of research…
Formation of a penumbra in a decaying sunspot
Puschmann, K. G.; Mathew, S. K.; Beck, C. +2 more
Context. Penumbrae are an important characteristic of sunspots, whose formation is intricately related to the nature of sub-photospheric magnetic fields.
Aims: We study the formation of a penumbra in a decaying sunspot and compare its properties with those seen during the development of a proto-spot.
Methods: High-resolution spectropolar…
Study of a sample of faint Be stars in the exofield of CoRoT. I. Spectroscopic characterization
Frémat, Y.; Zorec, J.; Hubert, A. M. +4 more
Context. Be stars are probably the most rapid rotators among stars in the main sequence (MS) and, as such, are excellent candidates to study the incidence of the rotation on the characteristics of their non-radial pulsations, as well as on their internal structure. Pulsations are also thought to be possible mechanisms that help the mass ejection n…
A simple prescription for simulating and characterizing gravitational arcs
da Costa, L. N.; Maia, M. A. G.; Santiago, B. X. +6 more
Simple models of gravitational arcs are crucial for simulating large samples of these objects with full control of the input parameters. These models also provide approximate and automated estimates of the shape and structure of the arcs, which are necessary for detecting and characterizing these objects on massive wide-area imaging surveys. We he…
CEN 34 - high-mass YSO in M 17 or background post-AGB star?
Fang, Min; Chen, Zhiwei; Jiang, Zhibo +3 more
We investigate the proposed high-mass young stellar object (YSO) candidate CEN 34, thought to be associated with the star-forming region M 17. Its optical to near-infrared (550-2500 nm) spectrum reveals several photospheric absorption features, such as Hα, the Ca ii triplet, and the CO bandhead, but lacks emission lines. The spectral features in t…
Mapping of interstellar clouds with infrared light scattered from dust: TMC-1N
Juvela, M.; Malinen, J.; Pelkonen, V. -M. +1 more
Context. Mapping of the near-infrared (NIR) scattered light is a recent method for the study of interstellar clouds, complementing other, more commonly used methods, like dust emission and extinction.
Aims: Our goal is to study the usability of this method on larger scale, and compare the properties of a filamentary structure using infrared s…
The XMM-Newton Wide Angle Survey (XWAS)
Esquej, P.; Ebrero, J.; Carrera, F. J. +16 more
Aims: This programme is aimed at obtaining one of the largest X-ray selected samples of identified active galactic nuclei to date in order to characterise such a population at intermediate fluxes, where most of the Universe's accretion power originates. We present the XMM-Newton Wide Angle Survey (XWAS), a new catalogue of almost a thousand X…
Star formation, structure, and formation mechanism of cometary globules: near-infrared observations of CG 1 and CG 2
Haikala, L. K.; Mäkelä, M. M.
Context. Cometary globule (CG) 1 and CG 2 are "classic" cometary globules in the Gum Nebula. They have compact heads and long dusty tails that point away from the centre of the Gum Nebula.
Aims: We study the structure of CG 1 and CG 2 and the star formation in them to find clues to the CG formation mechanism. The two possible CG formation mec…
Active galactic nuclei behind the SMC selected from radio and X-ray surveys
Pietsch, W.; Haberl, F.; Filipović, M. D. +8 more
Context. The XMM-Newton survey of the Small Magellanic Cloud (SMC) revealed 3053 X-ray sources with the majority expected to be active galactic nuclei (AGN) behind the SMC. However, the high stellar density in this field often does not allow assigning unique optical counterparts and hinders source classification. On the other hand, the association…
The distribution of warm gas in the G327.3-0.6 massive star-forming region
van Dishoeck, E. F.; Güsten, R.; van der Tak, F. +3 more
Aims: Most studies of high-mass star formation focus on massive and/or luminous clumps, but the physical properties of their larger scale environment are poorly known. In this work, we aim at characterising the effects of clustered star formation and feedback of massive stars on the surrounding medium by studying the distribution of warm gas …