L1448-MM Observations by the Herschel Key Program, "Dust, Ice, and Gas in Time" (DIGIT)

dc.contributor.utaustinauthorGreen, Joel D.en_US
dc.contributor.utaustinauthorEvans, Neal J., IIen_US
dc.creatorLee, Jinheeen_US
dc.creatorLee, Jeong-Eunen_US
dc.creatorLee, Seokhoen_US
dc.creatorGreen, Joel D.en_US
dc.creatorEvans, Neal J., IIen_US
dc.creatorChoi, Minhoen_US
dc.creatorKristensen, Larsen_US
dc.creatorDionatos, Odysseasen_US
dc.creatorJorgensen, Jes K.en_US
dc.creatorDigit Teamen_US
dc.description.abstractWe present Herschel/Photodetector Array Camera and Spectrometer (PACS) observations of L1448-MM, a Class 0 protostar with a prominent outflow. Numerous emission lines are detected at 55< gimel < 210 mu m including CO, OH, H2O, and [O I]. We investigate the spatial distribution of each transition to find that lines from low energy levels tend to distribute along the outflow direction while lines from high energy levels peak at the central spatial pixel. Spatial maps reveal that OH emission lines are formed in a relatively small area, while [O I] emission is extended. According to the rotational diagram analysis, the CO emission can be fitted by two (warm and hot) temperature components. For H2O, the ortho-to-para ratio is close to 3. The non-LTE large velocity gradient (LVG) calculations suggest that CO and H2O lines could instead be formed in a high kinetic temperature (T > 1000 K) environment, indicative of a shock origin. For OH, IR-pumping processes play an important role in the level population. The molecular emission in L1448-MM is better explained with a C-shock model, but the atomic emission of PACS [O I] and Spitzer/Infrared Spectrograph [Si II] emission is not consistent with C-shocks, suggesting multiple shocks in this region. Water is the major line coolant of L1448-MM in the PACS wavelength range, and the best-fit LVG models predict that H2O and CO emit (50%-80%) of their line luminosity in the PACS wavelength range.en_US
dc.description.sponsorshipHerschel Open Time Key Project Programen_US
dc.description.sponsorshipJet Propulsion Laboratory, California Institute of Technologyen_US
dc.description.sponsorshipBasic Science Research Program through the National Research Foundation of Korea (NRF)en_US
dc.description.sponsorshipMinistry of Education of the Korean government NRF-2010-0008704, NRF-2012R1A1A2044689en_US
dc.description.sponsorshipCore Research Program of NRFen_US
dc.description.sponsorshipMinistry of Science, ICTen_US
dc.description.sponsorshipFuture Planning of the Korean government NRF-2011-0015816en_US
dc.description.sponsorshipKorea Astronomy and Space Science Instituteen_US
dc.description.sponsorshipKorean government (MEST)en_US
dc.identifier.citationLee, Jinhee, Jeong-Eun Lee, Seokho Lee, Joel D. Green, Neal J. Evans, Minho Choi, Lars Kristensen, Odysseas Dionatos, and Jes K. Jørgensen. "L1448-MM Observations by the Herschel Key Program." The Astrophysical Journal Supplement Series, Vol. 209, No. 1 (Nov., 2013): 4.en_US
dc.relation.ispartofserialAstrophysical Journal Supplement Seriesen_US
dc.rightsAdministrative deposit of works to Texas ScholarWorks: This works author(s) is or was a University faculty member, student or staff member; this article is already available through open access or the publisher allows a PDF version of the article to be freely posted online. The library makes the deposit as a matter of fair use (for scholarly, educational, and research purposes), and to preserve the work and further secure public access to the works of the University.en_US
dc.subjectindividual objectsen_US
dc.subjectl1448-mm - ismen_US
dc.subjectjets and outflows - ismen_US
dc.subjectmolecules - starsen_US
dc.subjectprotostars techniquesen_US
dc.subjectstar-forming regionsen_US
dc.subjectlow-mass protostarsen_US
dc.subjectinfrared spectrographen_US
dc.subjectprotostellar outflowsen_US
dc.subjectspectroscopic surveyen_US
dc.subjectmolecular bulletsen_US
dc.subjectpacs spectroscopyen_US
dc.subjectbipolar outflowen_US
dc.subjectexciting sourceen_US
dc.subjectastronomy & astrophysicsen_US
dc.titleL1448-MM Observations by the Herschel Key Program, "Dust, Ice, and Gas in Time" (DIGIT)en_US

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