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dc.creatorFalcon, Ross E.en_US
dc.creatorRochau, G. A.en_US
dc.creatorBailey, J. E.en_US
dc.creatorGomez, Thomas A.en_US
dc.creatorMontgomery, Michael H.en_US
dc.creatorWinget, D. E.en_US
dc.creatorNagayama, T.en_US
dc.date.accessioned2016-04-28T19:36:23Z
dc.date.available2016-04-28T19:36:23Z
dc.date.issued2015-06en
dc.identifierdoi:10.15781/T2FF8M
dc.identifier.citationFalcon, Ross E., G. A. Rochau, J. E. Bailey, T. A. Gomez, M. H. Montgomery, D. E. Winget, and T. Nagayama. "Laboratory Measurements of White Dwarf Photospheric Spectral Lines: H $ beta$." arXiv preprint arXiv:1505.03801 (Jun., 2015).en_US
dc.identifier.issn0004-637Xen_US
dc.identifier.urihttp://hdl.handle.net/2152/34885
dc.description.abstractWe spectroscopically measure multiple hydrogen Balmer line profiles from laboratory plasmas to investigate the theoretical line profiles used in white dwarf (WD) atmosphere models. X-ray radiation produced at the Z Pulsed Power Facility at Sandia National Laboratories initiates plasma formation in a hydrogen-filled gas cell, replicating WD photospheric conditions. Here we present time-resolved measurements of H beta and fit this line using different theoretical line profiles to diagnose electron density, n(e), and n = 2 level population, n2. Aided by synthetic tests, we characterize the validity of our diagnostic method for this experimental platform. During a single experiment, we infer a continuous range of electron densities increasing from n(e) similar to 4 to similar to 30 x 10(16) cm(-3) throughout a 120-ns evolution of our plasma. Also, we observe n(2) to be initially elevated with respect to local thermodynamic equilibrium (LTE); it then equilibrates within similar to 55 ns to become consistent with LTE. This supports our electrontemperature determination of T-e similar to 1.3 eV (similar to 15,000 K) after this time. At n(e) greater than or similar to 10(17) cm(-3), we find that computer-simulation-based line-profile calculations provide better fits (lower reduced chi(2)) than the line profiles currently used in the WD astronomy community. The inferred conditions, however, are in good quantitative agreement. This work establishes an experimental foundation for the future investigation of relative shapes and strengths between different hydrogen Balmer lines.en_US
dc.description.sponsorshipLaboratory Directed Research and Development programen_US
dc.description.sponsorshipUnited States Department of Energy DE-AC04-94AL85000, DE-SC0010623en_US
dc.description.sponsorshipNational Science Foundation DGE-1110007en_US
dc.language.isoEnglishen_US
dc.relation.ispartofen_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.subjectline: profilesen_US
dc.subjectmethods: laboratory: atomicen_US
dc.subjectplasmasen_US
dc.subjecttechniques:en_US
dc.subjectspectroscopicen_US
dc.subjectwhite dwarfsen_US
dc.subjectstark-broadening tablesen_US
dc.subjectspectroscopic analysisen_US
dc.subjectbalmer linesen_US
dc.subjecthydrogenen_US
dc.subjectplasmaen_US
dc.subjectprofilesen_US
dc.subjectmassen_US
dc.subjectdiagnosticsen_US
dc.subjectopacityen_US
dc.subjecthgammaen_US
dc.subjectseriesen_US
dc.subjectastronomy & astrophysicsen_US
dc.titleLaboratory Measurements Of White Dwarf Photospheric Spectral Lines: H Betaen_US
dc.typeArticleen_US
dc.description.departmentAstronomyen_US
dc.identifier.Filename2015_06_laboratorymeasurements.pdfen_US
dc.rights.restrictionOpenen_US
dc.identifier.doi10.1088/0004-637x/806/2/214en_US
dc.contributor.utaustinauthorFalcon, Ross E.en_US
dc.contributor.utaustinauthorGomez, Thomas A.en_US
dc.contributor.utaustinauthorMontgomery, Michael H.en_US
dc.contributor.utaustinauthorWinget, D. E.en_US
dc.relation.ispartofserialAstrophysical Journalen_US


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