1000 resultados para Plateau Mont-Royal


Relevância:

20.00% 20.00%

Publicador:

Resumo:

commissioned by Adventures in Motion Pictures (Matthew Bourne) for Dance Umbrella Festival< London

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We present the results of a photometric and spectroscopic monitoring campaign of SN 2012ec, which exploded in the spiral galaxy NGC 1084, during the photospheric phase. The photometric light curve exhibits a plateau with luminosity L = 0.9 x 10(42) erg s(-1) and duration similar to 90 d, which is somewhat shorter than standard Type II-P supernovae (SNe). We estimate the nickel mass M(Ni-56) = 0.040 +/- 0.015 M-circle dot from the luminosity at the beginning of the radioactive tail of the light curve. The explosion parameters of SN 2012ec were estimated from the comparison of the bolometric light curve and the observed temperature and velocity evolution of the ejecta with predictions from hydrodynamical models. We derived an envelope mass of 12.6 M-circle dot, an initial progenitor radius of 1.6 x 10(13) cm and an explosion energy of 1.2 foe. These estimates agree with an independent study of the progenitor star identified in pre-explosion images, for which an initial mass of M = 14-22 M-circle dot was determined. We have applied the same analysis to two other Type II-P SNe (SNe 2012aw and 2012A), and carried out a comparison with the properties of SN 2012ec derived in this paper. We find a reasonable agreement between the masses of the progenitors obtained from pre-explosion images and masses derived from hydrodynamical models. We estimate the distance to SN 2012ec with the standardized candle method (SCM) and compare it with other estimates based on other primary and secondary indicators. SNe 2012A, 2012aw and 2012ec all follow the standard relations for the SCM for the use of Type II-P SNe as distance indicators.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

SN 2012ec is a Type IIP supernova (SN) with a progenitor detection and comprehensive photospheric phase observational coverage. Here, we present Very Large Telescope and Public ESO Spectroscopic Survey of Transient Objects observations of this SN in the nebular phase. We model the nebular [O I] lambda lambda 6300, 6364 lines and find their strength to suggest a progenitor main-sequence mass of 13-15 M-circle dot. SN2012ec is unique among hydrogen-rich SNe in showing a distinct line of stable nickel [Ni II] lambda 7378. This line is produced by Ni-58, a nuclear burning ash whose abundance is a sensitive tracer of explosive burning conditions. Using spectral synthesis modelling, we use the relative strengths of [Ni II] lambda 7378 and [Fe II] lambda 7155 (the progenitor of which is Ni-56) to derive a Ni/Fe production ratio of 0.20 +/- 0.07 (by mass), which is a factor 3.4 +/- 1.2 times the solar value. High production of stable nickel is confirmed by a strong [Ni II] 1.939 mu m line. This is the third reported case of a core-collapse SN producing a Ni/Fe ratio far above the solar value, which has implications for core-collapse explosion theory and galactic chemical evolution models.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We present early photometric and spectroscopic observations of SN 2013ej, a bright Type IIP supernova (SN) in M74. SN 2013ej is one of the closest SNe ever discovered. The available archive images and the early discovery help to constrain the nature of its progenitor. The earliest detection of this explosion was on 2013 July 24.125 UT and our spectroscopic monitoring with the FLOYDS spectrographs began on July 27.7 UT, continuing almost daily for two weeks. Daily optical photometric monitoringwas achieved with the 1mtelescopes of the Las Cumbres Observatory Global Telescope (LCOGT) network, and was complemented by UV data from Swift and near-infrared spectra from Public ESO Spectroscopic Survey of Transient Objects and Infrared Telescope Facility. The data from our monitoring campaign show that SN 2013ej experienced a 10 d rise before entering into a well-defined plateau phase. This unusually long rise time for a Type IIP has been seen previously in SN 2006bp and SN 2009bw. A relatively rare strong absorption blueward of Hα is present since our earliest spectrum. We identify this feature as Si II, rather than high-velocity Hα as sometimes reported in the literature. 

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We present new data for five underluminous Type II-plateau supernovae (SNe IIP), namely SN 1999gn, SN 2002gd, SN 2003Z, SN 2004eg and SN 2006ov. This new sample of lowluminosity SNe IIP (LL SNe IIP) is analysed together with similar objects studied in the past. All of them show a flat light-curve plateau lasting about 100 d, an underluminous late-time exponential tail, intrinsic colours that are unusually red, and spectra showing prominent and narrow P Cygni lines. A velocity of the ejected material below 103 km s-1 is inferred from measurements at the end of the plateau. The 56Ni masses ejected in the explosion are very small (≤10-2 M⊙). We investigate the correlations among 56Ni mass, expansion velocity of the ejecta and absolute magnitude in the middle of the plateau, confirming the main findings of Hamuy, according to which events showing brighter plateau and larger expansion velocities are expected to produce more 56Ni. We propose that these faint objects represent the LL tail of a continuous distribution in parameters space of SNe IIP. The physical properties of the progenitors at the explosion are estimated through the hydrodynamical modelling of the observables for two representative events of this class, namely SN 2005cs and SN 2008in. We find that the majority of LL SNe IIP, and quite possibly all, originate in the core collapse of intermediate-mass stars, in the mass range 10-15 M⊙. 

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We present the identification of the progenitor of the Type IIP SN 2012ec in archival pre-explosion Hubble Space Telescope Wide Field Planetary Camera 2 (WFPC2) and Advanced Camera for Surveys Wide Field Channel F814W images. The properties of the progenitor are further constrained by non-detections in pre-explosion WFPC2 F450W and F606W images. We report a series of early photometric and spectroscopic observations of SN 2012ec. The r'-band light curve shows a plateau with M_{r^' }}=-17.0. The early spectrum is similar to the Type IIP SN 1999em, with the expansion velocity measured at Hα absorption minimum of -11 700 km s-1 (at 1 d post-discovery). The photometric and spectroscopic evolution of SN 2012ec shows it to be a Type IIP SN, discovered only a few days post-explosion (

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Archbishop James Ussher's manuscript notebooks allow us to observe the making of a Calvinist absolutist and to orientate the archbishop's beliefs about royal power within European Reformed thought as a whole. By 1643, Ussher was preaching a polished and complete theory of absolute royal power, and it is possible to track the development of this political theory forward from his undergraduate days in the 1590s. Throughout his life Ussher engaged anxiously with Reformed theologians abroad, who generally favored limited rather than absolute monarchy. Nevertheless, Ussher shared with these Reformed colleagues both an antipathy to aspects of Aristotelian politics and a commitment to the divine institution of royal power. Finally, despite Ussher's hostility to Laudian innovations in the Irish Church, his heartfelt political beliefs made him a firm supporter of Stuart absolutism throughout the Three Kingdoms.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background: In 2006, the Buttimer report highlighted the paucity of demographic data on those applying for and entering postgraduate medical education and training (PGMET) in Ireland. Today, concerns that there is an "exodus" of graduates of Irish medical schools are at the forefront of national discussion, however, published data on PGMET remains inadequate.

Aims: The objectives of this study were to collate existing data relating to trainees and training programmes at three stages of training and to examine the career plans of junior trainees.

Methods: Data from application forms for training programmes, commencing July 2012, under the Royal College of Physicians of Ireland (n = 870), were integrated with data from other existing sources. Candidates entering basic specialist training were surveyed with regard to career plans. Descriptive and comparative analysis was performed in SPSS version 18.

Results: Graduates of Irish medical schools made up over 70 % of appointees. Over 80 % of BST trainees aspired to work as consultants in Ireland, but 92.5 % planned to spend time working abroad (response rate 77 %). Decisions to leave the Irish system were linked to lifestyle, but also to failure to be appointed to higher specialist training. Significant numbers of trainees return to Ireland after a period abroad.

Conclusions: The trainee "exodus" is more complex than is often portrayed. The desire to spend time working outside Ireland must be accounted for in workforce planning and configuration of training programmes. Expansion of HST is a potential solution to reduce the numbers of graduates leaving Ireland post-BST.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This research project documents the occurrence of the Royal Dublin Society (RDS) classical music recitals which were established in 1886 for the promotion of chamber music. Some 120 years of recitals spanning from 1886 to 2006 are recorded in the archives extant in the RDS Library and Archives, Ballsbridge, Dublin. The year 1925 marked the opening of the current concert hall (The Members’ Hall) and the initial phase of this research project focuses on the period 1925 to 1950. The archive documents appearances in Dublin by internationally renowned musicians in addition to the first Dublin performances of several twentieth-century works. Examination of the archive contributes to knowledge of chamber music performance in Dublin from the late nineteenth to the early twenty-first century and facilitates analysis of networks, repertory and reception.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

PTF11iqb was initially classified as a TypeIIn event caught very early after explosion. It showed narrow Wolf-Rayet (WR) spectral features on day 2, but the narrow emission weakened quickly and the spectrum morphed to resemble those of Types II-L and II-P. At late times, Halpha emission exhibited a complex, multipeaked profile reminiscent of SN1998S. In terms of spectroscopic evolution, we find that PTF11iqb was a near twin of SN~1998S, although with weaker interaction with circumstellar material (CSM) at early times, and stronger CSM interaction at late times. We interpret the spectral changes as caused by early interaction with asymmetric CSM that is quickly (by day 20) enveloped by the expanding SN ejecta photosphere, but then revealed again after the end of the plateau when the photosphere recedes. The light curve can be matched with a simple model for weak CSM interaction added to the light curve of a normal SN~II-P. This plateau requires that the progenitor had an extended H envelope like a red supergiant, consistent with the slow progenitor wind speed indicated by narrow emission. The cool supergiant progenitor is significant because PTF11iqb showed WR features in its early spectrum --- meaning that the presence of such WR features in an early SN spectrum does not necessarily indicate a WR-like progenitor. [abridged] Overall, PTF11iqb bridges SNe~IIn with weaker pre-SN mass loss seen in SNe II-L and II-P, implying a continuum between these types.