Search for associations containing young stars (SACY). VII. New stellar and substellar candidate members in the young associations

Context. The young associations offer us one of the best opportunities to study the properties of young stellar and substellar objects and to directly image planets thanks to their proximity (<200 pc) and age (≈5−150 Myr). However, many previous works have been limited to identifying the brighter, more active members (≈1 M_⊙) owing to photometric survey sensitivities limiting the detections of lower mass objects. Aims. We search the field of view of 542 previously identified members of the young associations to identify wide or extremely wide (1000−100 000 au in physical separation) companions. Methods. We combined 2MASS near-infrared photometry (J, H, K) with proper motion values (from UCAC4, PPMXL, NOMAD) to identify companions in the field of view of known members. We collated further photometry and spectroscopy from the literature and conducted our own high-resolution spectroscopic observations for a subsample of candidate members. This complementary information allowed us to assess the efficiency of our method. Results. We identified 84 targets (45: 0.2−1.3 M_⊙, 17: 0.08−0.2 M_⊙, 22: <0.08 M_⊙) in our analysis, ten of which have been identified from spectroscopic analysis in previous young association works. For 33 of these 84, we were able to further assess their membership using a variety of properties (X-ray emission, UV excess, Hα, lithium and K I equivalent widths, radial velocities, and CaH indices). We derive a success rate of 76–88% for this technique based on the consistency of these properties. Conclusions. Once confirmed, the targets identified in this work would significantly improve our knowledge of the lower mass end of the young associations. Additionally, these targets would make an ideal new sample for the identification and study of planets around nearby young stars. Given the predicted substellar mass of the majority of these new candidate members and their proximity, high-contrast imaging techniques would facilitate the search for new low-mass planets.

The World Heritage vs. Local Comnuty : identifying the sources of conflicts

The presented work is an essay rather than a scientific dissertation. The author wants to put an impact on the source of conflicts regarding the complex subject of heritage management and conservation in comparison with the local needs and the given context. The paper attempts to show the role of local communities and their cooperation with authorities as well as the effects of such cooperation. The area of research comprises the problems arising in the field of implementing external rules on the local field, challenges appearing regarding the needs of local communities and the efforts of official authorities trying to implement the principles of the conventions. The problems arise when local communities display the lack of understanding and do not share the common idea of heritage conservation. This is caused mainly by the decreasing possibilities of comfortable life. The author tries to identify the main and wrongful approaches as ‘Gone with the Wind’, ‘The Prince and The Pauper’, ‘Heart of Darkness’ or ‘Scarlet letter’. The focus will be put to explain what the areas are where a mutual misunderstanding arise and why all parts to the problem present different points of view. What creates a value? Is it a heritage object or maybe the other values need a stronger protection? When the general duty and the need to protect the heritage is regarded as a controversy and when it is considered as a value within a given community? The international public interest in heritage protection is often regarded as an attempt to diminish the sovereign power of the community and provokes severe controversies and tensions. The major problem envisaged today seems to be the massive and increasing urbanisation and the destruction of the vestiges still existing of traditional cultures, when we consider century urban post-industrial districts of Upper Silesia in Poland, the medieval cities in Western Europe, the traditional nomad Masaya villages in Kenya or the remains of vanished cultures in various regions of Asia. The preferred platform of cooperation between the parts of the conflict includes divergent needs, beliefs and practices of communities and the possible fields of reconciling the abovementioned. Chosen examples of the best practices considering mutual cooperation will be underlined.