Multi-line Herschel/HIFI observations of water reveal infall motions and chemical segregation around high-mass protostars
| hal.structure.identifier | SRON Netherlands Institute for Space Research [SRON] | |
| dc.contributor.author | VAN DER TAK, Floris | |
| hal.structure.identifier | SRON Netherlands Institute for Space Research [SRON] | |
| dc.contributor.author | SHIPMAN, Russ | |
| hal.structure.identifier | FORMATION STELLAIRE 2019 | |
| dc.contributor.author | JACQ, T. | |
| hal.structure.identifier | FORMATION STELLAIRE 2019 | |
| dc.contributor.author | HERPIN, Fabrice | |
| hal.structure.identifier | FORMATION STELLAIRE 2019 | |
| dc.contributor.author | BRAINE, J. | |
| hal.structure.identifier | Max-Planck-Institut für Radioastronomie [MPIFR] | |
| dc.contributor.author | WYROWSKI, Friedrich | |
| dc.date.issued | 2019 | |
| dc.identifier.issn | 0004-6361 | |
| dc.description.abstractEn | (Abridged) We use HIFI maps of the 987 GHz H2O 2(02)-1(11) emission to measure the sizes and shapes of 19 high-mass protostellar envelopes. To identify infall, we use HIFI spectra of the optically thin C18O 9-8 and H2O-18 1(11)-0(00) lines. The high-J C18O line traces the warm central material and redshifted H2O-18 1(11)-0(00) absorption indicates material falling onto the warm core. We probe small-scale chemical differentiation by comparing H2O 752 and 987 GHz spectra with those of H2O-18. Our measured radii of the central part of the H2O 2(02)-1(11) emission are 30-40% larger than the predictions from spherical envelope models, and axis ratios are <2, which we consider good agreement. For 11 of the 19 sources, we find a significant redshift of the H2O-18 1(11)-0(00) line relative to C18O 9-8. The inferred infall velocities are 0.6-3.2 km/s, and estimated mass inflow rates range from 7e-5 to 2e-2 M0/yr, with the highest mass inflow rates occurring toward the sources with the highest masses, and possibly the youngest ages. The other sources show either expanding motions or H2O-18 lines in emission. The H2O-18 1(11)-0(00) line profiles are remarkably similar to the "differences" between the H2O 2(02)-1(11) and 2(11)-2(02) profiles, suggesting that the H2O-18 line and the H2O 2(02)-1(11) absorption originate just inside the radius where water evaporates from grains, typically 1000-5000 au from the center. In some sources, the H2O-18 line is detectable in the outflow, where no C18O emission is seen. Together, the H2O-18 absorption and C18O emission profiles show that the water abundance around high-mass protostars has at least three levels: low in the cool outer envelope, high within the 100 K radius, and very high in the outflowing gas. Thus, despite the small regions, the combination of lines presented here reveals systematic inflows and chemical information about the outflows. | |
| dc.language.iso | en | |
| dc.publisher | EDP Sciences | |
| dc.subject.en | Astrophysics - Astrophysics of Galaxies | |
| dc.title.en | Multi-line Herschel/HIFI observations of water reveal infall motions and chemical segregation around high-mass protostars | |
| dc.type | Article de revue | |
| dc.identifier.doi | 10.1051/0004-6361/201833788 | |
| dc.subject.hal | Planète et Univers [physics]/Astrophysique [astro-ph]/Planétologie et astrophysique de la terre [astro-ph.EP] | |
| dc.identifier.arxiv | 1903.11305 | |
| bordeaux.journal | Astronomy and Astrophysics - A&A | |
| bordeaux.page | id.A103 | |
| bordeaux.volume | 625 | |
| bordeaux.peerReviewed | oui | |
| hal.identifier | hal-02082594 | |
| hal.version | 1 | |
| hal.popular | non | |
| hal.audience | Internationale | |
| hal.origin.link | https://hal.archives-ouvertes.fr//hal-02082594v1 | |
| bordeaux.COinS | ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Astronomy%20and%20Astrophysics%20-%20A&A&rft.date=2019&rft.volume=625&rft.spage=id.A103&rft.epage=id.A103&rft.eissn=0004-6361&rft.issn=0004-6361&rft.au=VAN%20DER%20TAK,%20Floris&SHIPMAN,%20Russ&JACQ,%20T.&HERPIN,%20Fabrice&BRAINE,%20J.&rft.genre=article |
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