A5082346987- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Galaxies: Formation, Evolution, Phenomena
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Astro and Planetary Science
- Adaptive optics and wavefront sensing
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- History and Developments in Astronomy
- Calibration and Measurement Techniques
- Spectroscopy and Laser Applications
- Geophysics and Gravity Measurements
- Pulsars and Gravitational Waves Research
- Atmospheric Ozone and Climate
- Optical Polarization and Ellipsometry
- Solar and Space Plasma Dynamics
- Planetary Science and Exploration
- Photocathodes and Microchannel Plates
- Astronomical and nuclear sciences
- Scientific Research and Discoveries
- Superconducting Materials and Applications
- Laser Design and Applications
- Advanced optical system design
Université Laval
2015-2024
Centre for Research in Astrophysics of Québec
2014-2024
Université de Montréal
1987-2024
University of Hawaii at Hilo
2017-2024
Canada–France–Hawaii Telescope
1997-2024
Research Canada
2006
Space Telescope Science Institute
1991-2002
Association of Universities For Research In Astronomy
2002
University of Hawaii System
1997-1999
National Academies of Sciences, Engineering, and Medicine
1997-1999
view Abstract Citations (365) References (107) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Deposition of Mass, Momentum, and Energy by Massive Stars into the Interstellar Medium Leitherer, Claus ; Robert, Carmelle Drissen, Laurent The study presents models for integrated output mass, momentum, energy from a population massive stars. An extensive grid radiative wind is computed hot stars, scaling parameters are derived mass-loss rates velocities as...
High-quality, blue-violet spectroscopic data are collected for 24 stars that have been classified as type O3 and display the hallmark N IV V lines. A new member of class is presented; it second known in Cyg OB2 association, only northern hemisphere. New digital also presented several other stars. Although inhomogeneous, uniform plots by subcategory reveal some interesting relationships. Several issues concerning classification hottest O-type spectra discussed, five original dwarfs Carina...
view Abstract Citations (166) References (17) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Spectroscopic Evidence for Rapid Blob Ejection in Wolf-Rayet Stars Moffat, Anthony F. J. ; Drissen, Laurent Lamontagne, Robert Robert, Carmelle The authors have monitored the five bright Cygnus WN stars unblended He II λ5411 emission line at high spectral resolution and signal-to-noise ratio during four or nights. Typical data are presented here two single WN6 HD...
We present deep Hubble Space Telescope/Wide Field and Planetary Camera 2 photometry of the young HD 97950 star cluster in giant H ii region NGC 3603. The data were obtained 1997 2007 permitting us to derive membership based on proper motions stars. Our are consistent with an age 1 Myr for cluster. A possible spread, if cluster, appears be small. global slope incompleteness-corrected mass function member stars within 60'' is Γ = −0.88 ± 0.15, which flatter than value a Salpeter −1.35....
We present an overview of SITELLE, Imaging Fourier Transform Spectrometer (iFTS) available at the 3.6-meter Canada-France-Hawaii Telescope. SITELLE is a Michelson-type interferometer able to reconstruct spectrum every light source within its 11' field view in filter-selected bands visible (350 900 nm). The spectral resolution can be adjusted up R = 10 000 and spatial seeing-limited sampled 0.32 arcsec per pixel. describe design instrument as well data reduction analysis process. To...
We present spectrograms of 14 individual luminous stars in RD 97950, the core (r≤4"=0.12 pc) dense galactic starburst NGC 3603, obtained with Faint Object Spectrograph aboard refurbished Hubble Space Telescope. In a volume less than cubic light year, three hydrogen-rich WNL+abs cohabit six O3 [including two III (f<SUP>*</SUP>)] and other early O stars; 97950 is therefore densest concentration very massive known Galaxy. The close physical association between WNL + abs stars, as well evolution...
view Abstract Citations (117) References (41) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Polarization Variability among Wolf-Rayet Stars. III. A New Way to Derive Mass-Loss Rates for Stars in Binary Systems St. -Louis, Nicole ; Moffat, Anthony F. J. Drissen, Laurent Bastien, Pierre Robert, Carmelle We present new results from the polarimetric monitoring of two W-R + O binaries (HD 186943 and HD 211853) three suspected low-amplitude single-line 177230,...
ABSTRACT We have produced for the first time a detailed velocity map of giant filamentary nebula surrounding NGC 1275, Perseus cluster’s brightest galaxy, and revealed previously unknown rich structure across entire nebula. These new observations were obtained with optical imaging Fourier transform spectrometer SITELLE at CFHT. With its wide field view ( ∼11 arcmin × 11 arcmin), is only integral unit spectroscopy instrument able to cover 80 kpc 55 3.8 2.6 arcmin) large in 1275. Our analysis...
This is the first paper of a series dedicated to nebular physics and chemical evolution nearby galaxies by investigating large samples HII regions with CFHT imaging spectrograph SITELLE. We present technique adapted spectroscopy identify extract parameters from 4285 region candidates found in disc NGC628. Using both spatial spectral capabilities SITELLE, our enables extraction position, dust extinction, velocity, Halpha profile, diffuse ionised gas (DIG) background, luminosity, size,...
The Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE) is a blind narrow-band Halpha+[NII] imaging survey carried out with MegaCam at the Canada-France-Hawaii Telescope. covers whole cluster region from its core to one virial radius (104 deg^2). sensitivity of f(Halpha) ~ 4 x 10^-17 erg sec-1 cm^-2 (5 sigma detection limit) for point sources and Sigma (Halpha) 2 10^-18 sec^-1 arcsec^-2 (1 limit 3 arcsec resolution) extended sources, making VESTIGE deepest largest nearby...
SIGNALS, the Star formation, Ionized Gas, and Nebular Abundances Legacy Survey, is a large observing program designed to investigate massive star formation HII regions in sample of local extended galaxies. The will use imaging Fourier transform spectrograph SITELLE at Canada-France-Hawaii Telescope. Over 355 hours (54.7 nights) have been allocated beginning fall 2018 for eight consecutive semesters. Once completed, SIGNALS provide statistically reliable laboratory including over 50 000...
Abstract We present new high-spectral-resolution observations ( R = λ /Δ 7000) of the filamentary nebula surrounding NGC 1275, central galaxy Perseus cluster. These have been obtained with SITELLE, an imaging Fourier transform spectrometer installed on Canada–France–Hawai Telescope a field view <?CDATA $11^{\prime} \times 11^{\prime} $?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>11</mml:mn> <mml:mo accent="false">′</mml:mo> <mml:mo>×</mml:mo>...
Abstract We present JWST observations of the Crab Nebula, iconic remnant historical SN 1054. The include NIRCam and MIRI imaging mosaics plus MIRI/MRS spectra that probe two select locations within ejecta filaments. derive a high-resolution map dust emission show grains are concentrated in innermost, high-density These dense filaments coincide with multiple synchrotron bays around periphery Crab's pulsar wind nebula (PWN). measure spectral index changes small-scale features PWN’s torus...
As part of the SIGNALS survey, which comprises a sample approximately 40 nearby galaxies observed with Fourier transform spectrometer SITELLE, we present study metal mixing in spiral galaxy NGC 6946. Taking advantage blue sensitivity our setup, measure oxygen and nitrogen abundances 638 H II regions, focus analysis on abundance fluctuations about radial gradients. We detect an azimuthal variation 0.1 dex these across NE arm, leading edge being more metal-poor than trailing edge. This result...
Abstract As part of the SIGNALS survey, which comprises a sample approximately 40 nearby galaxies observed with Fourier transform spectrometer SITELLE, we present study metal mixing in spiral galaxy NGC 6946. Taking advantage blue sensitivity our setup, measure oxygen and nitrogen abundances 638 H ii regions, focus analysis on abundance fluctuations about radial gradients. We detect an azimuthal variation 0.1 dex these across NE arm, leading edge being more metal-poor than trailing edge....
We analyze the atmospheric "eclipse" light curves of all 13 short-period (P<30<SUP>d</SUP>) Galactic binary WR+O systems with solved orbits, excluding 3 known photospheric eclipsers. Some are based on newly obtained data; others taken from literature. Most show V-shaped dips in their curves. When accurate orbital ephemerides available, maximum attenuation is reached when 0 star passes farthest behind WR star. The can be explained by phase-dependent electron scattering opacity 0-star...
view Abstract Citations (91) References (84) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Polarization Variability among Wolf-Rayet Stars. V. Linear of the Bright Cygnus Stars and an Anticorrelation with Wind Speed Robert, Carmelle ; Moffat, Anthony F. J. Bastien, Pierre Drissen, Laurent St. -Louis, Nicole This paper presents polarimetric data for seven eight bright WR stars in Cygnus. Six show only random, low-amplitude modulation on time scales hours to...
view Abstract Citations (102) References (58) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Polarization Variability among Wolf-Rayet Stars. I. Linear of a Complete Sample Southern Galactic WC Stars St. -Louis, Nicole ; Drissen, Laurent Moffat, Anthony F. J. Bastien, Pierre Tapia, Santiago As the first in series investigations on polarization variability (W-R) stars, this paper presents extensive time-dependent linear observations seven known southern W-R...
The discovery of new Wolf–Rayet (WR) stars in our Galaxy via large-scale narrowband optical surveys has been severely limited by dust extinction. Recent improvements infrared technology have made narrowband–broadband imaging viable again. We report a J, K, and survey 300 deg2 the plane Galaxy, spanning 150 degrees Galactic longitude reaching 1 degree above below plane. useful limiting magnitude K = 15 over most observed plane, 14 within few center. Thousands emission line candidates...
An analysis of the kinematics NGC 6720 is performed on commissioning data obtained with SITELLE, Canada–France–Hawaii Telescope's new imaging Fourier transform spectrometer. In order to measure carefully small broadening effect a shell expansion an unresolved emission line, we have determined computationally robust implementation convolution Gaussian sinc instrumental line shape which avoids arithmetic overflows. This model can be used typically few km s−1 even at low spectral resolution (R...
view Abstract Citations (100) References (23) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS NGC 3603 and Its Wolf-Rayet Stars: Galactic Clone of R136 at the Core 30 Doradus, but without Massive Surrounding Cluster Halo Moffat, Anthony F. J. ; Drissen, Laurent Shara, Michael M. HST/PC images dense stellar cluster center Galaxy's most massive visible H II region, 3603, reveal remarkable similarity to core in Local Group's Giant Dor. The projected star density...
view Abstract Citations (78) References (43) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Spectroscopic and Polarimetric Parameters of the Runaway WN7 Binary System HD 197406: Is Secondary an X-Ray--quiet Black Hole? Drissen, L. ; Lamontagne, R. Moffat, A. F. J. Bastien, P. Seguin, M. New spectroscopic polarimetric data for single-line binary 197406 are presented. We derive a more accurate period mass function from improved radial velocity orbit based on...
Abstract The origin of the magnetic fields in neutron stars, and physical differences between magnetars strongly magnetized radio pulsars are still under vigorous debate. It has been suggested that properties progenitors stars (the massive OB stars), such as rotation, mass, may play an important role outcome core collapse leading to Type II supernovae. Therefore, knowing progenitor would be asset for constraining models stellar evolution birth a star. We present here beginning broad study...