The First Optical Spectra of Wolf Rayet Stars in M101 Revealed with Gemini/GMOS
نویسندگان
چکیده
Deep narrow-band HST imaging of the iconic spiral galaxy M101 has revealed over a thousand new Wolf Rayet (WR) candidates. We report spectrographic confirmation of 10 He iiemission line sources hosting 15 WR stars. We find WR stars present at both sub– and super– solar metalicities with WC stars favouring more metal-rich regions compared to WN stars. We investigate the association of WR stars with H ii regions using archival HST imaging and conclude that the majority of WR stars are in or associated with H ii regions. Of the 10 emission lines sources, only one appears to be unassociated with a star-forming region. Our spectroscopic survey provides confidence that our narrow-band photometric candidates are in fact bonafide WR stars, which will allow us to characterise the progenitors of any core-collapse supernovae that erupt in the future in M101.
منابع مشابه
A Massive Star Odyssey , from Main Sequence to
We present new narrow-band imaging and optical spectroscopy of Wolf-Rayet stars in the Local Group dwarf galaxy IC10 (Gemini-N GMOS) and Sculptor group spiral galaxy NGC300 (VLT FORS2). 1. Gemini-N GMOS observations of IC10 IC10 is a moderately reddened dwarf irregular (or blue compact dwarf) at a distance of 0.9Mpc, with a metal content of log(O/H) 8:2 and an unusually high WC/WN ratio of 2, v...
متن کاملThe Wolf–Rayet population of the nearby barred spiral galaxy NGC 5068 uncovered by the Very Large Telescope and Gemini
We present a narrow-band Very Large Telescope/Focal Reduced Low-dispersion Spectrograph #1 imaging survey of the SAB(rs)cd spiral galaxy NGC 5068, located at a distance of 5.45 Mpc, from which 160 candidate Wolf–Rayet sources have been identified, of which 59 cases possess statistically significant λ4686 excesses. Follow-up Gemini Multi-Object Spectrograph spectroscopy of 64 candidates, represe...
متن کاملSearching for hidden Wolf-Rayet stars in the Galactic Plane – 15 new Wolf-Rayet stars
We report the discovery of fifteen previously unknown Wolf-Rayet (WR) stars found as part of an infrared broad-band study of candidate WR stars in the Galaxy. We have derived an empirically-based selection algorithm which has selected ∼5000 WR candidate stars located within the Galactic Plane drawn from the GLIMPSE (midinfrared) and 2MASS (near-infrared) catalogues. Spectroscopic follow-up of 1...
متن کاملDetection of additional Wolf - Rayet stars in the starburst cluster Westerlund 1 with SOAR ⋆
We report the detection of 3 additional Wolf-Rayet stars in the young cluster Westerlund 1. They were selected as emission-line star candidates based on 1μm narrow-band imaging of the cluster carried out at OPD/LNA (Brazil), and then confirmed as Wolf-Rayet stars by K-band spectroscopy performed at the 4.1 m SOAR telescope (Chile). Together with previous works, this increases the population of ...
متن کاملOn the Baldwin effect of He II emission lines in WR (WN) stars
We investigate the relation between the equivalent width of He ii emission lines and the monochromatic continuum luminosity at the line wavelength in the spectra of Wolf-Rayet stars. Model stellar atmospheres and spectra are used to show that the equivalent width inversely correlates with the monochromatic continuum luminosity. We find the effect in Wolf-Rayet star models over a large range of ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2017