Stephanie Cote

Stephanie Cote
National Research Council Canada | NRC · Herzberg Astronomy & Astrophysics

PhD

About

60
Publications
2,611
Reads
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1,316
Citations
Additional affiliations
August 1997 - November 2016
National Research Council Canada
Position
  • Senior Astronomer, Head of Canadian Gemini Office

Publications

Publications (60)
Article
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During pilot observations of the Virgo Environmental Survey Tracing Galaxy Evolution (VESTIGE), a blind narrow-band Halpha+[NII] imaging survey of the Virgo cluster carried out with MegaCam at the CFHT, we have observed the spiral galaxy NGC 4254 (M99). Deep Halpha+[NII] narrow-band and GALEX UV images revealed the presence of 60 compact (70-500 pc...
Article
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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. The survey covers the whole Virgo cluster region from its core to one virial radius (104 deg^2). The sensitivity of the survey is of f(Halpha) ~ 4 x 10^-17 erg sec-1...
Article
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The Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE) is a blind narrow-band H$\alpha$+[NII] imaging survey carried out with MegaCam at the CFHT. During pilot observations we have observed NGC 4330, an intermediate mass, edge-on star forming spiral currently falling into the core of the Virgo cluster. New deep observations revealed...
Article
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Gemini's Fast Turnaround program is intended to greatly decrease the time from having an idea to acquiring the supporting data. The scheme will offer monthly proposal submission opportunities, and proposals will be reviewed by the principal investigators or co-investigators of other proposals submitted during the same round. Here, we set out the de...
Article
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We examine the mid-infrared fluxes and spectral energy distributions for metal-poor stars with iron abundances [Fe/H] $\lesssim-5$, as well as two CEMP-no stars, to eliminate the possibility that their low metallicities are related to the depletion of elements onto dust grains in the formation of a debris disk. Six out of seven stars examined here...
Article
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We combine new deep and wide field of view Hα imaging of a sample of eight nearby (d ≈ 17 Mpc) spiral galaxies with new and archival H I and CO imaging to study the star formation and the star formation regulation in the outer disk. We find that, in agreement with previous studies, star formation in the outer disk has low covering fractions, and st...
Article
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The James Clerk Maxwell Telescope Nearby Galaxies Legacy Survey (NGLS) comprises an H i-selected sample of 155 galaxies spanning all morphological types with distances less than 25 Mpc. We describe the scientific goals of the survey, the sample selection and the observing strategy. We also present an atlas and analysis of the CO J=3 - 2 maps for th...
Article
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Dwarf irregular galaxies (dIs) in the nearby Centaurus A Group have been imaged in Halpha. We find that the dI star formation rates do not show any correlation with the distance of the dI to the nearest large galaxy of the group. There is a clear morphology-density relation in the Centaurus A Group, Sculptor Group, and Local Group, in the sense tha...
Article
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We present Halpha narrow-band imaging of 17 dwarf irregular galaxies (dIs) in the nearby Centaurus A Group. Although all large galaxies of the group have a current or recent enhanced star formation episode, the dIs have normal star formation rates and do not contain a larger fraction of dwarf starbursts than other nearby groups. Relative distances...
Article
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We have derived nebular abundances for 10 dwarf galaxies belonging to the M81 Group, including several galaxies which do not have abundances previously reported in the literature. For each galaxy, multiple H \ii regions were observed with GMOS-N at the Gemini Observatory in order to determine abundances of several elements (oxygen, nitrogen, sulfur...
Article
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We have derived nebular abundances for 10 dwarf galaxies belonging to the M81 Group, including several galaxies which do not have abundances previously reported in the literature. For each field, multiple HII regions were observed with GMOS-N at the Gemini Observatory in order to determine abundances of several elements (oxygen, nitrogen, sulfur, n...
Article
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Gaseous halos of nine nearby galaxies (with redshifts cz < 6000 km s-1) were probed at large galactocentric radii using background quasars observed with the Hubble Space Telescope Goddard High Resolution Spectrograph and the Space Telescope Imaging Spectrograph. The projected quasar-galaxy separations range from 55 to 387 h kpc. Lyα absorption line...
Article
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We present Australia Telescope Compact Array mosaic H I imaging of the Local Group dwarf irregular galaxy WLM. We find an integrated flux of 149 Jy km s-1 and a total H I mass of (3.2 ± 0.3) × 107 M. The major axis of the H I is aligned with the stellar component of the galaxy. The overall H I distribution is relatively smooth at our resolution and...
Article
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New results are presented for a mosaic mapping of the H I in the field of the Local Group dwarf galaxy Phoenix. The observations, obtained with the Australia Telescope Compact Array, cover an area of ~2° × 2°. Four velocity components are identified, at heliocentric velocities of -23, 7, 59, and 140 km s-1. While the gas at 7 km s-1 is of Galactic...
Article
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Neutral hydrogen (H I) has been detected in the Local Group dwarf spheroidal galaxy Sculptor with the 64 m Parkes single-dish telescope and mapped with the Australia Telescope synthesis array. Most of the detected H I is in two clouds ~15'–20' away from the optical center. The gas is observed at the same systemic velocity as the stars, but at ≥125...
Article
We investigate star formation in the outer disk of NGC 5964 by combining HI and R-band data with deep H alpha images. The rotation curve and column densities for the galaxy are derived from HI synthesis images. Additionally, H2 surface densities are approximated using a relation between R-band disk scale lengths and CO disk scale lengths. We calcul...
Article
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Gaseous halos of nine nearby galaxies (with redshifts cz < 6000 km s-1) were probed at large galacto-centric radii using background quasars observed with HST GHRS and STIS. The projected quasar-galaxy separations range from 55 to 387 h-175 kpc. Lyα absorption lines were successfully detected in the spectra of five quasars, at impact parameters of u...
Article
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We present HST/WFPC2 imaging of the nearby (D=3.9±0.2 Mpc) dwarf starburst galaxy NGC 625. This system is host to a young, massive star formation region, comparable in Halpha luminosity to 30 Doradus in the LMC. Halpha and Hbeta imaging reveals substantial and variable extinction (AV = 0.0-0.6 mags) within the major star formation regions. Using V...
Article
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We present new multi-configuration HI aperture synthesis imaging of the nearby dwarf starburst galaxy NGC 625 obtained with the Australia Telescope Compact Array. Total HI column density images show gas well-aligned with the optical major axis, and low-column density HI extending to > 6 optical scale lengths. The HI velocity field, on the other han...
Article
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We present ATCA neutral hydrogen mosaic imaging of the Local Group dwarf irregular galaxy WLM. The major axis of the HI is aligned with the stellar component of the galaxy, and, although the overall HI distribution is relatively smooth at our resolution, there is a double peaked central core not previously resolved. One of these peaks is aligned wi...
Article
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New HST/WFPC2 imaging of the dwarf starburst galaxy NGC 625 is presented. These data, 80% complete to V and I magnitudes of 26.0 and 25.3, respectively, allow us to study the recent star formation history of NGC 625. We derive a tip of the red giant branch (TRGB) distance modulus of 27.95+/-0.07, corresponding to a distance of 3.89+/-0.22 Mpc, and...
Article
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Millimeter and mid-infrared observations have been made of the dense clumps of dust and gas and of young stellar objects (YSOs) associated with the bright, compact submillimeter source G79.3+0.3 P1 in the relatively nearby MSX infrared-dark cloud G79.3+0.3. The Gemini mid-infrared observations reported here indicate the presence of three YSOs withi...
Article
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We present new H-alpha narrow band imaging of the HII regions in eight Sculptor Group dwarf irregular (dI) galaxies. Comparing the Sculptor Group dIs to the Local Group dIs, we find that the Sculptor Group dIs have, on average, lower values of SFR when normalized to either galaxy luminosity or gas mass (although there is considerable overlap betwee...
Article
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Using the CTIO 4-m telescope, we have obtained optical spectra of HII regions in five Sculptor Group dwarf irregular galaxies. We derive oxygen, nitrogen, and sulfur abundances from the HII region spectra. Oxygen abundances are derived via three different methods (the ``direct'' method, the empirical method guided by photoionization modeling of McG...
Article
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Millimeter and infrared observations have been made of the brightest compact SCUBA 850 micron sources in two MSX infrared-dark clouds (IRDCs). In both sources, IR observations indicate the presence of nearby massive stars. High-resolution BIMA observations indicate that the stars are interacting with the adjacent molecular gas, possibly triggering...
Article
We propose to investigate the outer dynamics of the nearby spiral galaxy NGC1398 at very large galactocentric radii by using the kinematical information from Ly-alpha absorption lines in the spectra of 3 background UV-bright objects {two Seyferts 1 and one QSO}. It is a unique opportunity to have 3 UV-bright objects surrounding one single isolated...
Article
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The Canadian Large Adaptive Reflector (CLAR) is a proposed prototype of a new concept for large, filled-aperture radio telescopes. The prototype would have a 300-metre aperture, working up to frequencies of at least 1.4 GHz, and would be equipped with a multi-beam phased array providing a field-of-view of 0.8deg at that frequency. The largest fully...
Article
We propose to obtain the chemical abundances of 20 dwarf irregular galaxies (dIs) of the nearby Centaurus A Group. Through H(alpha) CCD imaging (observed in May '99) we have discovered several HII regions in these galaxies, giving us the opportunity to obtain helium, oxygen, nitrogen, neon and sulfur abundances. We expect some of these galaxies to...
Article
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Some hot, massive, Population I Wolf-Rayet (W-R) stars of the carbon subclass are known to be prolific dust producers. How dust can form in such a hostile environment remains a mystery. Here we report the discovery of a relatively cool, extended, multiarc dust envelope around the star WR 112, most likely formed by wind-wind collision in a long-peri...
Article
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Eight dwarf irregular galaxies, in the two nearby groups of galaxies Sculptor and Centaurus A (at 2.5 Mpc and 3.5 Mpc), have been imaged in neutral hydrogen (H I) with the Australia Telescope and the Very Large Array. These galaxies have absolute magnitudes ranging from MB=-15.7 to -11.3. Yet they are mostly rotationally supported, with maximum vel...
Article
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Using the example of the Sd galaxy NGC 5585, it is shown that high-resolution, two-dimensional H II kinematical data are necessary to determine accurately the parameters of the mass (luminous and dark) distribution in spiral galaxies. New Canada-France-Hawaii Telescope Fabry-Perot Halpha observations are combined with low-resolution (20") Westerbor...
Article
The active Centaurus group is one of the nearest groups outside the Local group, at 3.5 Mpc, and is now known to contain numerous dwarf irregular galaxies (dIrrs). We propose to image in H(alpha) , with the 0.9m, the 20 dIrr members of the group. The H(alpha) fluxes will reveal their current global star formation rates. Comparing these rates to tho...
Article
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We present preliminary results of a neutral hydrogen (HI) redshift survey to find Low Surface Brightness (LSB) galaxies in the very nearby universe. Our sample consists of all galaxies in the APM catalog (Maddox et al. 1990) with a mean surface brightness of μ ≥ 24 mag/arcsec2, down to a magnitude limit of bj ≤ 17. With the Parkes 64m radiotelescop...
Article
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Five nearby dwarf irregular galaxies, amongst the recently surveyed dwarf members of the Sculptor and Centaurus A groups (at 2.5 Mpc and 3.5 Mpc), have been imaged in neutral hydrogen (HI) with the Australia Telescope and the Very Large Array. These objects have absolute magnitudes M_B in the range -14.9 to -12.7, yet they are clearly rotationally...
Article
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We report the discovery of a large population of dwarf irregular galaxies in the two nearest groups of galaxies outside the Local Group, the Sculptor and the Centaurus A groups (2.5 and 3.5 Mpc). Total areas of approximately 940 and 910 square degrees in these groups were scanned visually on the SRC J films to find dwarf candidates. Redshifts were...
Article
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The spectra of 34 galaxies within 20 arcmins (\sim 100 kpc) of the lenticular galaxy NGC 5084 have been obtained using the FOCAP system on the Anglo-Australian 3.9m telescope. Nine objects are found with projected separations \lesssim 80 kpc and with radial velocities within \pm 630 km/s of the parent galaxy redshift. Using various techniques, thei...
Article
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The authors present observations in the 21 cm line of five dwarf galaxies in the Centaurus A group of galaxies (NGC 5237, NGC 5264, NGC 5408, ESO 324-G24, ESO 383-G87) obtained with the Autralia Telescope Compact Array. The extended region (d ≍ 400 kpc) of X-ray emission around Cen A indicates the existence of a diffuse hot intra-group medium (IGM)...
Article
We propose to investigate the outer rotation curves of eight spiral galaxies at very large galactocentric radii by using the kinematical information from Ly-alpha absorption lines in the spectra of background quasars. This will enable us to measure the disk rotation up to ~ 7 times greater radius than what is possible in HI at 21cm. By constraining...
Thesis
This thesis describes a successful survey to find dwarf irregular galaxies in the two most nearby southern groups of galaxies, the Sculptor group at 2.5 Mpc and the Centaurus A group at 3.5 Mpc. Candidates were selected from a visual search on ESO SRC J films, then observed in neutral hydrogen (HI) at Parkes, as well as in Ha. In the Sculptor group...
Article
Full-text available
We present neutral hydrogen observations of eight nearby dwarf spirals and dwarf irregulars galaxies with absolute magnitude M_B in the range -15.5 to -11. NGC625, SDig, ESO471-G6 and ESO245-G5 are members of the Sculptor Group, the most nearby group of galaxies outside the Local Group at 2.5 Mpc; DDO161, ESO325-G11, ESO381-G20, and ESO444-G84 are...
Article
Neutral hydrogen was detected in the Local Group dwarf galaxy Phoenix. The 21-cm H-I-line emission, observed at a heliocentric radial velocity of 56 km/s, is clearly separated from a much larger scale component at about 140 km/s which was previously associated with the Magellanic Stream. The profile width, combined with the high inclination of the...
Article
Results are presented of an experimental study tracing the light distribution, the H I kinematics, and the mass distribution of NGC 5585, a late-type spiral in the M101 group. From the photometry, an extrapolated central surface brightness of 21.94 mag/sq arcsec and a scale length of 1.4 kpc are derived for the stellar disk. The H I distribution re...
Article
During 1990 we surveyed the southern sky using a multi-beam receiver at frequencies of 4850 and 843 MHz. The half-power beamwidths were 4 and 25 arcmin respectively. The finished surveys cover the declination range between +10 and −90 degrees declination, essentially complete in right ascension, an area of 7.30 steradians. Preliminary analysis of t...
Article
Millimeter and mid-infrared observations have been made of the brightest compact SCUBA 850-micron sources in the MSX infrared-dark clouds (IRDCs) G28.34+0.06, G11.11-0.12, and G79.3+0.3. In two of these sources, Gemini and IRTF observations indicate the presence of nearby massive stars. High-resolution BIMA observations indicate that these stars ar...