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Massive young stellar objects in the galactic center. 1; spectroscopic identification from spitzer/irs observations
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Ramirez, Solange V. Sellgren Sr., Kris Schultheis Sr., Mathias An, Deokkeun Smith, Howard A. Robitaille, Thomas P. Boogert, A. C. Adwin Cotera, Angela S. Arendt, Richard G. Stolovy, Susan R. |
| Copyright Year | 2011 |
| Description | We present results from our spectroscopic study, using the Infrared Spectrograph (IRS) onboard the Spitzer Space Telescope, designed to identify massive young stellar objects (YSOs) in the Galactic Center (GC). Our sample of 107 YSO candidates was selected based on IRAC colors from the high spatial resolution, high sensitivity Spitzer/IRAC images in the Central Molecular Zone (CMZ), which spans the central approximately 300 pc region of the Milky Way Galaxy. We obtained IRS spectra over 5 micron to 35 micron using both high- and low-resolution IRS modules. We spectroscopically identify massive YSOs by the presence of a 15.4 micron shoulder on the absorption profile of 15 micron CO2 ice, suggestive of CO2 ice mixed with CH30H ice on grains. This 15.4 micron shoulder is clearly observed in 16 sources and possibly observed in an additional 19 sources. We show that 9 massive YSOs also reveal molecular gas-phase absorption from C02, C2H2, and/or HCN, which traces warm and dense gas in YSOs. Our results provide the first spectroscopic census of the massive YSO population in the GC. We fit YSO models to the observed spectral energy distributions and find YSO masses of 8 - 23 solar Mass, which generally agree with the masses derived from observed radio continuum emission. We find that about 50% of photometrically identified YSOs are confirmed with our spectroscopic study. This implies a preliminary star formation rate of approximately 0.07 solar mass/yr at the GC. |
| File Size | 2287837 |
| Page Count | 24 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20110015481 |
| Archival Resource Key | ark:/13960/t55f3t39z |
| Language | English |
| Publisher Date | 2011-01-01 |
| Access Restriction | Open |
| Subject Keyword | Astrophysics Spectroscopy Stellar Composition Star Formation Stellar Mass Milky Way Galaxy Space Infrared Telescope Facility Stellar Evolution Infrared Astronomy Interstellar Matter Star Formation Rate Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
