High-Resolution M-band Spectroscopy of CO towards the Massive Young Stellar Binary W3 IRS5
| Autor: | Adwin Boogert, Alexander Tielens, Andrew Barr, Jialu Li |
|---|---|
| Rok vydání: | 2022 |
| Předmět: |
Space and Planetary Science
Star formation Astrophysics - astrophysics of galaxies Astrophysics of Galaxies (astro-ph.GA) FOS: Physical sciences Infrared sources Astronomy and Astrophysics Interstellar molecules Astrophysics - solar and stellar astrophysics Solar and Stellar Astrophysics (astro-ph.SR) |
| Zdroj: | The Astrophysical Journal, 935(2):161 |
| DOI: | 10.48550/arxiv.2206.13638 |
| Popis: | We present in this paper the results of high spectral resolution ($R$=88,100) spectroscopy at 4.7 $\mu$m with iSHELL/IRTF of hot molecular gas close to the massive binary protostar W3 IRS5. The binary was spatially resolved and the spectra of the two sources (MIR1 and MIR2) were obtained simultaneously for the first time. Hundreds of $^{12}$CO $\nu$=0-1, $\nu$=1-2 lines, and $\nu$=0-1 transitions of the isotopes of $^{12}$CO were detected in absorption, and are blue-shifted compared to the cloud velocity $v_{LSR}=-$38 km/s. We decompose and identify kinematic components from the velocity profiles, and apply rotation diagram and curve of growth analyses to determine their physical properties. Temperatures and column densities of the identified components range from 30$-$700 K and 10$^{21}-$10$^{22}$ cm$^{-2}$, respectively. Our curve of growth analyses consider two scenarios. One assumes a foreground slab with a partial covering factor, which well reproduces the absorption of most of the components. The other assumes a circumstellar disk with an outward decreasing temperature in the vertical direction, and reproduces the absorption of all the hot components. We attribute the physical origins of the identified components to the foreground envelope ($ Comment: Accepted for publication in ApJ. 26 pages, 12 figures, and 9 tables. Comments are more than welcome! |
| Databáze: | OpenAIRE |
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