Observations and asteroseismological analysis of the rapid subdwarf B pulsator EC 09582-1137 (2009)
Randall, S. K., Van Grootel, V., Fontaine, G., Charpinet, S., Brassard, P.
We made photometric and spectroscopic observations of the rapidly pulsating subdwarf B star EC 09582-1137 with the aim of determining the target's fundamental structural parameters from...
A NLTE model atmosphere analysis of the pulsating sdO star SDSS J1600+0748 (2009)
Latour, M., Fontaine, G., Brassard, P., Chayer, P., Green, E. M.
We started a program to construct several grids of suitable model atmospheres and synthetic spectra for hot subdwarf O stars computed, for comparative purposes, in LTE, NLTE, with and without metals....
Follow-up Observations of the Second and Third Known Pulsating Hot DQ White Dwarfs (2009)
Dufour, P., Green, E. M., Fontaine, G., Brassard, P., Francoeur, M., Latour, M.
We present follow-up time-series photometric observations that confirm and extend the results of the significant discovery made by Barlow et al.(2008) that the Hot DQ white dwarfs SDSS...
Follow-up Studies of the Pulsating Magnetic White Dwarf SDSS J142625.71+575218.3 (2009)
Green, E. M., Dufour, P., Fontaine, G., Brassard, P.
We present a follow-up analysis of the unique magnetic luminosity-variable carbon-atmosphere white dwarf SDSS J142625.71+575218.3. This includes the results of some 106.4 h of integrated light...
Pulsation in carbon-atmosphere white dwarfs: A new chapter in white dwarf asteroseismology (2009)
Fontaine, G., Brassard, P., Dufour, P., Green, E. M., Liebert, J.
We present some of the results of a survey aimed at exploring the asteroseismological potential of the newly-discovered carbon-atmosphere white dwarfs. We show that, in certains regions of parameter...
Brassard, P., Seifert, T., Secher, N. H.
Background Vasopressor agents are commonly used to increase mean arterial pressure (MAP) in order to secure a pressure gradient to perfuse vital organs. The influence of norepinephrine on cerebral...
c ○ ESO 2005 Astronomy Astrophysics (2008)
S. Charpinet, G. Fontaine, P. Brassard, M. Billères, E. M. Green, P. Chayer
Structural parameters of the hot pulsating B subdwarf
Fontaine, G., Brassard, P., Green, E. M., Chayer, P., Charpinet, S., Andersen, M., ...
Context. SDSS J160043.6+074802.9 (J1600+0748 for short) is the only hot sdO star for which unambiguous multiperiodic luminosity variations have been reported so far. These rapid variations, with...
Might Carbon-Atmosphere White Dwarfs Harbour a New Type of Pulsating Star? (2008)
Fontaine, G., Brassard, P., Dufour, P.
In the light of the recent and unexpected discovery of a brand new type of white dwarfs, those with carbon-dominated atmospheres, we examine the asteroseismological potential of such stars. The...
Observations and asteroseismic analysis of the rapidly pulsating hot B subdwarf PG 0911+456 (2007)
Randall, S. K., Green, E. M., Van Grootel, V., Fontaine, G., Charpinet, S., Lesser, M., ...
The principal aim of this project is to determine the structural parameters of the rapidly pulsating subdwarf B star PG 0911+456 from asteroseismology. Our work forms part of an ongoing programme to...
Evidence for a merger of binary white dwarfs: the case of GD 362 (2007)
Garcia-Berro, E., Loren-Aguilar, P., Pedemonte, A. G., Isern, J., Bergeron, P., Dufour, P., ...
GD 362 is a massive white dwarf with a spectrum suggesting a H-rich atmosphere which also shows very high abundances of Ca, Mg, Fe and other metals. However, for pure H-atmospheres the diffusion...
The Boundaries of the GW Vir Stars in the Effective Temperature - Surface Gravity Domain (2006)
We derive the theoretical red edge of the pulsating GW Vir stars by using full evolutionary calculations that involve mass loss and diffusion. We put the emphasis on the fact that the specific mass...
Fontaine, G., Brassard, P., Bergeron, P., Randall, S. K.
We present a quantitative and homogeneous analysis of the broadband multicolor photometric data sets gathered so far on rapidly pulsating hot B subdwarf stars. This concerns seven distinct data sets...
The Potential of Multi-Colour Photometry for Pulsating Subdwarf B Stars (2005)
Randall, S. K., Fontaine, G., Brassard, P., Bergeron, P.
We investigate the potential of multi-colour photometry for partial mode identification in both long- and short-period variable subdwarf B stars. The technique presented is based on the fact that the...
The Nature of the Driving Mechanism in the Pulsating Hybrid PG 1159 Star Abell 43 (2005)
We extend our previous pulsational stability analyses of PG 1159 stars by modeling the hybrid PG 1159 type star Abell 43. We show that the standard kappa-mechanism due to the ionization of C and O in...
Structural Parameters of the Hot Pulsating B Subdwarf PG 1219+534 from Asteroseismology (2005)
Charpinet, S., Fontaine, G., Brassard, P., Green, E. M., Chayer, P.
We have carried out a detailed asteroseismic analysis of PG 1219+534. Our analysis leads to the identification of the (k,l) indices of nine periods observed in the star PG 1219+534, and to the...
Discovery of A New Class of Pulsating Stars: Gravity-mode Pulsators among Subdwarf B Stars (2002)
Green, E. M., Fontaine, G., Reed, M. D., Callerame, K., Seitenzahl, I. R., White, B. A., ...
During the course of an ongoing CCD monitoring program to investigate low-level light variations in subdwarf B (sdB) stars, we have serendipitously discovered a new class of low amplitude, multimode...
Charpinet, S., Fontaine, G., Brassard, P., Dorman, B.
We present new results of a stability analysis of realistic models of post-extreme horizontal branch stars. We find that g-mode instabilities develop in some of these models as a result of a potent...
Incidence of tuberculosis among reported AIDS cases in Quebec from 1979 to 1996
BACKGROUND: The impact of HIV infection on tuberculosis (TB) rates in Quebec has not been fully established. Because concurrent HIV infection is the single most important factor in TB reactivation,...
Prevalence of diabetes mellitus among the James Bay Cree of northern Quebec.
Brassard, P, Robinson, E, Lavallée, C
OBJECTIVE: To determine the prevalence of diabetes mellitus among the James Bay Cree in northern Quebec. DESIGN: Chart survey of physician-diagnosed cases of diabetes. The biochemical criteria of the...
Incidence of tuberculosis among reported AIDS cases in Quebec from 1979 to 1996
BACKGROUND: The impact of HIV infection on tuberculosis (TB) rates in Quebec has not been fully established. Because concurrent HIV infection is the single most important factor in TB reactivation,...
Prevalence of diabetes mellitus among the James Bay Cree of northern Quebec.
Brassard, P, Robinson, E, Lavallée, C
OBJECTIVE: To determine the prevalence of diabetes mellitus among the James Bay Cree in northern Quebec. DESIGN: Chart survey of physician-diagnosed cases of diabetes. The biochemical criteria of the...
Brassard, P., Frisch, F., Lavoie, F., Cyr, D., Bourbonnais, A., Cunnane, S. C., ...
Context: Abnormal plasma nonesterified fatty acid (NEFA) metabolism may play a role in the development of type 2 diabetes.