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Multi-Fiber Optical Spectroscopy of Stars in the Direction of Galactic Star Formation Region W51. Travis Laurance Advisors: Chip Kobulnicky Bob Benjamin Ed Churchwell. Outline. Motivation Selecting Stars to Observe Preparing for Observations Observing Data Reduction
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Multi-Fiber Optical Spectroscopy of Stars in the Direction of Galactic Star Formation Region W51 Travis Laurance Advisors: Chip Kobulnicky Bob Benjamin Ed Churchwell
Outline • Motivation • Selecting Stars to Observe • Preparing for Observations • Observing • Data Reduction • Spectral Classification of Stars • Product
Motivation • Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) • Mid-Plane • Galactic longitude ±10° to ±60° and latitude ±1° . • Infrared • 3.6 microns • 4.5 microns • 5.8 microns • 8.0 microns
Selecting Stars to Observe • Hydra instrument on the WIYN 3.5 • 1° field of view. • We expected to observe ~300 stars in two nights. • It was important that these 300 stars cover the range of spectral types from O to M. Image compliments of Chip Kobulnicky
Selecting Stars to Observe • The spectral classifications of infrared point sources from 2MASS were to be estimated from color-color and color-magnitude plots. • In a 1° field centered around W51 there are over 40,000 infrared point sources!
Selecting Stars to Observe • 2MASS sources with optical counterparts. • Just over 800…. • Optical sources with magnitude less than 16. • 294!
Preparing for Observations • Formatting catalog for Hydra • Running hydrasim to configure cables
Observing • July 2/3 2002 and July 3/4 2002 • 3 different configurations • 4 twenty minute exposures for each field. • Spectrum is from 3800 Angstroms to 4500. • Over 200 spectra were obtained!
Data Reduction • Preparing files for dohydra • Bias subtraction • Combining exposures • Dividing by combined flat fields • Running dohydra • Aperture identification • Comparison lamp calibration • Normalizing extracted spectra
Spectral Classification of Stars • The presence and relative strength of specific absorption lines determines the class of the star. An Atlas of Representive Stellar Spectra Yamashita, Nariai, Norimoto, 1978
Product (Table) Class RA Dec Glon Glat Jmag Jerr Hmag Herr Kmag Kerr Rmag Bmag Class Aperture 063 202 19 25 4.342 14 6 29.66 49.2899 -0.8634 11.996 0.027 11.767 0.031 11.636 0.034 13.70 15.00 O6-7 III-V 071 154 19 24 3.881 14 17 33.94 49.3368 -0.5609 12.292 0.033 11.871 0.055 11.772 0.043 13.90 15.70 O7-8 I-II 082 209 19 22 20.491 14 5 43.73 48.9657 -0.2860 12.001 0.025 11.663 0.028 11.441 0.030 14.20 15.60 O8 II-III 091 160 19 23 33.313 14 20 24.47 49.3202 -0.4298 12.690 0.026 12.384 0.031 12.253 0.034 14.70 16.00 O9-9.5 Ia 091 162 19 25 27.815 14 11 22.41 49.4065 -0.9084 12.228 0.027 12.028 0.030 11.861 0.032 13.80 15.30 O9-9.5 I-II 104 108 19 23 47.540 14 26 43.93 49.4402 -0.4306 10.974 0.026 10.711 0.028 10.582 0.022 13.20 14.50 B0-0.5 IV 125 119 19 22 54.488 14 33 36.54 49.4401 -0.1878 11.679 0.024 11.353 0.030 11.201 0.034 14.30 15.60 B2 V 151 205 19 24 16.222 14 37 26.47 49.6522 -0.4481 12.406 0.022 12.074 0.026 11.866 0.028 14.30 15.20 B5 I-III 185 stars classified!
Acknowledgements • Chip Kobulnicky • Bob Benjamin • Ed Churchwell • Kyle Westfall • REU Students (and Jana)