A dataset provided by the European Space Agency

Name GT1_abenz_1
Title Completing the OH ladder for HH 46


DOI https://doi.org/10.5270/esa-50bzcph
Author European Space Agency
Description First results from PACS observations towards the low-mass protostar HH 46 show
surprisingly bright OH lines. The hydroxyl radical OH plays important roles in
the water and oxygen chemistry of star-forming regions and their cooling.
Furthermore, the hydroxyl-to-water line ratios are interesting tracers for
ionizing radiation.
We propose a nearly complete observation of the OH ladder in low-mass star formation
for the first time. Four OH transitions in the class I object HH 46 were detected by
PACS. We propose complementary observations towards the source in PACS line spectroscopy mode at 53, 56, 65,
71, 96, 115 and 135 micron. We gain insight in the origin and formation of OH from
the PACS spatial information. The completeness of the OH ladder allows a reliable
determination of the OH abundance and thus constrains water chemistry and cooling
contribution more precisely.
In addition, we propose HIFI observations of the OH transition at 163.4 micron to resolve the three hyperfine components for the first time.
This will allow to determine optical depths of OH and test the hypothesis of
asymmetries between the two closely spaced triplets, as the second triplet will be
observed within the HIFI priority science program.

Note: This proposal is submitted under the Swiss part of the HIFI guaranteed
time program; HIFI PI: Frank Helmich, HIFI Swiss Lead CoI: Arnold O. Benz
Publication Origin of warm and hot gas emission from low-mass protostars: Herschel-HIFI observations of CO J = 16-15. I. Line profiles, physical conditions, and H2O abundance . Kristensen L. E. et al. . Astronomy & Astrophysics, Volume 605, id.A93, 19 pp. . 605 . 10.1051\/0004-6361\/201630127 . 2017A&A...605A..93K ,
Instrument HIFI_HifiPoint_dbs, PACS_PacsLineSpec_large
Temporal Coverage 2010-12-04T00:25:54Z/2011-05-07T20:37:47Z
Version SPG v14.2.0
Mission Description Herschel was launched on 14 May 2009! It is the fourth 'cornerstone' mission in the ESA science programme. With a 3.5 m Cassegrain telescope it is the largest space telescope ever launched. It is performing photometry and spectroscopy in approximately the 55-671 µm range, bridging the gap between earlier infrared space missions and groundbased facilities.
Creator Contact https://support.cosmos.esa.int/h®erschel/
Date Published 2011-12-15T00:00:00Z
Publisher And Registrant European Space Agency
Credit Guidelines European Space Agency, 2011, Completing The Oh Ladder For Hh 46, SPG v14.2.0, European Space Agency, https://doi.org/10.5270/esa-50bzcph