Search results for "LONG"
showing 10 items of 3969 documents
AB Dor A VLBI images
2020
The fast rotator, pre-main sequence star AB Dor A is a strong and persistent radio emitter. The extraordinary coronal flaring activity is thought to be the origin of compact radio emission and other associated phenomena, such as large slingshot prominences. We aim to investigate the radio emission mechanism and the milliarcsecond radio structure around AB Dor A. We performed phase-referenced VLBI observations at 22.3GHz, 8.4GHz, and 1.4GHz over more than one decade using the Australian VLBI array. Our 8.4GHz images show a double core-halo morphology, similar at all epochs, with emission extending at heights between 5 and 18 stellar radii. Furthermore, the sequence of the 8.4GHz maps shows a…
TANAMI monitoring of Centaurus A.
2015
Centaurus A (Cen A) is the closest radio-loud active galactic nucleus. Very Long Baseline Interferometry (VLBI) enables us to study the spectral and kinematic behavior of the radio jet-counterjet system on milliarcsecond scales, providing essential information for jet emission and propagation models. In the framework of the TANAMI monitoring, we investigate the kinematics and complex structure of Cen A on subparsec scales. We have been studying the evolution of the central parsec jet structure of Cen A for over 3.5-years. The proper motion analysis of individual jet components allows us to constrain jet formation and propagation and to test the proposed correlation of increased high-energy …
The gNLS1 galaxy PKS 2004-447. VLBI images
2016
Gamma-ray-detected radio-loud narrow-line Seyfert 1 (g-NLS1) galaxies constitute a small but interesting sample of the g-ray-loud AGN. The radio-loudest g-NLS1 known, PKS 2004-447, is located in the southern hemisphere and is monitored in the radio regime by the multiwavelength monitoring programme TANAMI. We aim for the first detailed study of the radio morphology and long-term radio spectral evolution of PKS 2004-447, which are essential for understanding the diversity of the radio properties of g-NLS1s. The TANAMI VLBI monitoring program uses the Australian Long Baseline Array (LBA) and telescopes in Antarctica, Chile, New Zealand, and South Africa to monitor the jets of radio-loud activ…
Catching the radio flare in CTA 102
2013
Very Long Baseline Interferometry (VLBI) observations can resolve the radio structure of active galactic nuclei (AGN) and provide estimates of the structural and kinematic characteristics on parsec-scales in their jets. The changes in the kinematics of the observed jet features can be used to study the physical conditions in the innermost regions of these sources. We performed multifrequency multiepoch Very Long Baseline Array (VLBA) observations of the blazar CTA102 during its 2006 radio flare, the strongest ever reported for this source. These observations provide an excellent opportunity to investigate the evolution of the physical properties of blazars, especially during these flaring e…
COMPORTAMIENTO A LARGO PLAZO DE LAS OFERTAS PÚBLICAS DE VENTA SUBSIGUIENTES EN EL MERCADO ESPAÑOL
2002
This research investigates the long¿run after¿performance of firms conducting seasoned equity offering in the Spanish market during the period 1993¿1999. Due to statistical and conceptual problems related to the estimation and contrast of long¿horizon returns, we analyse the robustness of results to different methodologies. We obtain evidence that issuers experience negative abnormal returns economically and statistically significant during the year after the event. These results are robust to different metrics, estimations and tests used. Finally, underperformance is more severe in small, growth firms. En este trabajo estudiamos si las empresas cotizadas que realizan un oferta pública de v…
Unravelling Church Land : Transformations in the Relations between Church, State and Community in Uganda
2019
Christian churches control substantial areas of land in Africa. While intensifying struggles over their holdings are partly due to the increased pressure on land in general, they also reflect transformations in the relations through which churches’ claims to land are legitimized, the increased association of churches with business, and churches’ unique positioning as both institutions and communities. This article presents the trajectory of relations between church, state and community in Uganda from the missionary acquisition of land in the colonial era to the unravelling of church landholding under Museveni. Drawing on long‐term ethnographic fieldwork, the authors argue that claims to chu…
Ennustaako kulttuurin ja taiteen harrastaminen pitkäikäisyyttä?
2013
TIIVISTELMÄ Ennustaako taiteen ja kulttuurin harrastaminen pitkäikäisyyttä? Tuula Niemeläinen Pro gradu-tutkielma Gerontologia ja kansanterveys Jyväskylän yliopisto, liikuntatieteellinen tiedekunta, terveystieteiden laitos Kevät 2013, 36 sivua Tässä tutkimuksessa pitkäikäisellä tarkoitetaan vähintään 90-vuotiaiksi eläneitä henkilöitä. Kulttuuri- ja taideharrastamisella tarkoitetaan esim. kuorolaulua ja teatteria. Kulttuuri- ja taideharrastamisen on todettu olevan yhteydessä terveyteen, ennustavan pidempää elinikää ja ehkäisevän dementoitumista. Taidetoiminnan vaikutukset hyvinvointiin nähdään kokemuksen tuottamana elämyksenä, nautintona, yhteytenä hyvään terveyteen, yhteisöllisyyteen ja elä…
Antecedents and Consequences of Student-Athletes’ Identity Profiles in Upper Secondary School
2020
The present study examined the identity profiles that upper-secondary-school Finnish student-athletes show, and the extent to which these profiles were associated with their athletic and academic achievements and withdrawal from sports and school. A total of 391 adolescent athletes (51% females) completed assessments of student and athletic identity four times during their time in upper secondary school. Using growth mixture modeling, three groups were identified: (a) dual identity (77%), (b) changing identity (5%), and (c) athletic identity (18%). The higher the academic achievement was at Time 1, the more likely the athletes were to show dual identity than athletic identity profile. Simil…
Trajectory subgroups of perceived emotional support from teachers : Associations with change in mastery climate and intentions to quit upper secondar…
2022
The aims of this three-wave longitudinal study were to identify and describe trajectories of perceived emotional support from teachers and investigate whether these trajectories were related to the development of intentions to quit upper secondary school via change in perceived mastery climate. Among 1379 Norwegian upper secondary school students, three trajectory subgroups were identified: stable high (84.9%), decreasing (7.8%), and low increasing (7.3%). The subgroups differed in levels of achievement ambition and academic self-concept. Further, a parallel process latent growth curve model revealed essential associations with change in intentions to quit school. Specifically, students wit…
Development of Participation in and Identification With School: Associations With Truancy
2020
This longitudinal study covering two educational transitions examined 1,821 Finnish students’ participation in and identification with school and their associations with students’ academic achievement and truancy. The students were surveyed (a) at the end of primary school, (b) at the beginning of lower secondary school, (c) at the end of lower secondary school, and (d) in the first year of upper secondary education. In alignment with the participation-identification model, higher levels of participation in school activities at the end of primary school predicted higher levels of identification (i.e., feelings of belonging and valuing school) at the end of lower secondary school. This asso…