<i>Herschel</i>/HIFI observations of high-J CO lines in the NGC 1333 low-mass star-forming region

Yildiz, UMUT; van Dishoeck, E.; Kristensen, L.; Visser, R.; Jorgensen, J.; Herczeg, G.; van Kempen, T.; Hogerheijde, M.; Doty, S.; Benz, A.; Bruderer, S.; Wampfler, S.; Deul, E.; Bachiller, R.; Baudry, A.; Benedettini, M.; Bergin, E.; Bjerkeli, P.; Blake, G.; Bontemps, S.; Braine, J.; Caselli, P.; Cernicharo, J.; Codella, C.; Daniel, F.; di Giorgio, A.; Dominik, C.; Encrenaz, P.; Fich, M.; Fuente, A.; Giannini, T.; Goicoechea, J.; de Graauw, Th.; Helmich, F.; Herpin, F.; Jacq, T.; Johnstone, D.; Larsson, B.; Lis, D.; Liseau, R.; Liu, F.; Marseille, M.; McCoey, C.; Melnick, G.; Neufeld, D.; Nisini, B.; Olberg, M.; Parise, B.; Pearson, J.; Plume, R.; Risacher, C.; Santiago-Garcia, J.; Saraceno, P.; Shipman, R.; Tafalla, M.; Tielens, A.; van der Tak, F.; Wyrowski, F.; Dieleman, P.; Jellema, W.; Ossenkopf, V.; Schieder, R.; Stutzki, J.

doi:10.1051/0004-6361/201015119

<i>Herschel</i>/HIFI observations of high-J CO lines in the NGC 1333 low-mass star-forming region

Yildiz U., van Dishoeck E. F., Kristensen L. E., Visser R., Jorgensen J. K., Herczeg G. J., ...Daha Fazla

ASTRONOMY & ASTROPHYSICS, cilt.521, 2010 (SCI-Expanded, Scopus)

Yayın Türü: Makale / Tam Makale
Cilt numarası: 521
Basım Tarihi: 2010
Doi Numarası: 10.1051/0004-6361/201015119
Dergi Adı: ASTRONOMY & ASTROPHYSICS
Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
Orta Doğu Teknik Üniversitesi Adresli: Hayır

Özet

Herschel/HIFI observations of high-J lines (up to J(u) = 10) of (CO)-C-12, (CO)-C-13 and (CO)-O-18 are presented toward three deeply embedded low-mass protostars, NGC 1333 IRAS 2A, IRAS 4A, and IRAS 4B, obtained as part of the Water In Star-forming regions with Herschel (WISH) key program. The spectrally-resolved HIFI data are complemented by ground-based observations of lower-J CO and isotopologue lines. The (CO)-C-12 10-9 profiles are dominated by broad (FWHM 25-30 km s(-1)) emission. Radiative transfer models are used to constrain the temperature of this shocked gas to 100-200 K. Several CO and (CO)-C-13 line profiles also reveal a medium-broad component (FWHM5-10 km s(-1)), seen prominently in H2O lines. Column densities for both components are presented, providing a reference for determining abundances of other molecules in the same gas. The narrow (CO)-O-18 9-8 lines probe the warmer part of the quiescent envelope. Their intensities require a jump in the CO abundance at an evaporation temperature around 25 K, thus providing new direct evidence for a CO ice evaporation zone around low-mass protostars.