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 G alactic L egacy I nfrared M id- P lane S urvey E xtraordinaire (GLIMPSE) –Mid-Plane Galactic longitude ±10° to ±60° and latitude ±1°. –Infrared 3.6 microns 4.5 microns 5.8 microns 8.0 microns

Motivation

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/ and July 3/ –3 different configurations 4 twenty minute exposures for each field. Spectrum is from 3800 Angstroms to 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 O6-7 III-V O7-8 I-II O8 II-III O9-9.5 Ia O9-9.5 I-II B0-0.5 IV B2 V B5 I-III 185 stars classified!

Product (O Stars)

Product (B Stars)

Product (A Stars)

Product (F Stars)

Product (G Stars)

Product (K Stars)

Product (M Stars)

Acknowledgements Chip Kobulnicky Bob Benjamin Ed Churchwell Kyle Westfall REU Students (and Jana)