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Hβ and Hγ Absorption-line Profile Inconsistencies in Laboratory Experiments Performed at White Dwarf Photosphere Conditions

Journal Article · · The Astrophysical Journal (Online)
 [1];  [2];  [2];  [2];  [3];  [3]
  1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); The Univ. of Texas at Austin, Austin, TX (United States). Astronomy Dept.; Sandia National Laboratories
  2. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
  3. The Univ. of Texas at Austin, Austin, TX (United States). Dept. of Astronomy and McDonald Observatory

The spectroscopic method relies on hydrogen Balmer absorption lines to infer white dwarf (WD) masses. These masses depend on the choice of atmosphere model, hydrogen atomic line shape calculation, and which Balmer series members are included in the spectral fit. In addition to those variables, spectroscopic masses disagree with those derived using other methods. Here we present laboratory experiments aimed at investigating the main component of the spectroscopic method: hydrogen line shape calculations. These experiments use X-rays from Sandia National Laboratories’ Z-machine to create a uniform ~15 cm3 hydrogen plasma and a ~4 eV backlighter that enables recording high-quality absorption spectra. The large plasma, volumetric X-ray heating that fosters plasma uniformity, and the ability to collect absorption spectra at WD photosphere conditions are improvements over past laboratory experiments. Analysis of the experimental absorption spectra reveals that electron density (ne) values derived from the Hγ line are ~34% ± 7.3% lower than from Hβ. Two potential systematic errors that may contribute to this difference were investigated. A detailed evaluation of self-emission and plasma gradients shows that these phenomena are unlikely to produce any measurable Hβ–Hγ ne difference. WD masses inferred with the spectroscopic method are proportional to the photosphere density. Hence, the measured Hβ–Hγ ne difference is qualitatively consistent with the trend that WD masses inferred from their Hβ line are higher than that resulting from the analysis of Hβ and Hγ. In conclusion, this evidence may suggest that current hydrogen line shape calculations are not sufficiently accurate to capture the intricacies of the Balmer series.

Research Organization:
The Univ. of Texas at Austin, Austin, TX (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA)
Grant/Contract Number:
NA0003843
OSTI ID:
1574124
Alternate ID(s):
OSTI ID: 1595035
Journal Information:
The Astrophysical Journal (Online), Journal Name: The Astrophysical Journal (Online) Journal Issue: 1 Vol. 885; ISSN 1538-4357
Publisher:
Institute of Physics (IOP)Copyright Statement
Country of Publication:
United States
Language:
English

References (51)

Hydrogen Stark broadening calculations with the unified classical path theory journal September 1970
Computer simulated Balmer-alpha, -beta and -gamma Stark line profiles for non-equilibrium plasmas diagnostics journal August 2003
SPECT3D – A multi-dimensional collisional-radiative code for generating diagnostic signatures based on hydrodynamics and PIC simulation output journal May 2007
An experimental platform for creating white dwarf photospheres in the laboratory journal March 2013
An experimental platform for creating white dwarf photospheres in the laboratory: Preliminary results journal December 2015
HELIOS-CR – A 1-D radiation-magnetohydrodynamics code with inline atomic kinetics modeling journal May 2006
The Gaia mission journal November 2016
Masses of the Hyades white dwarfs: A gravitational redshift measurement⋆ journal July 2019
Extended VCS Stark broadening tables for hydrogen – Lyman to Brackett series journal April 1997
Dynamics and characteristics of a 215-eV dynamic-hohlraum x-ray source on Z journal August 2002
The ZR Refurbishment Project conference January 2002
Dynamic hohlraum radiation hydrodynamics journal May 2006
ZAPP: The Z Astrophysical Plasma Properties collaboration journal May 2014
X-ray power and yield measurements at the refurbished Z machine journal August 2014
Stark Profile Calculations for the Hβ Line of Hydrogen. journal January 1962
Measurements of the Stark Broadening of Hγ journal August 1969
A spectroscopic determination of the mass distribution of DA white dwarfs journal July 1992
An independent method for determining the age of the universe journal April 1987
Hydrogen Stark-Broadening Tables journal January 1973
The Potential of White Dwarf Cosmochronology
  • Fontaine, G.; Brassard, P.; Bergeron, P.
  • Publications of the Astronomical Society of the Pacific, Vol. 113, Issue 782 https://doi.org/10.1086/319535
journal April 2001
Spectroscopic Analysis of da White Dwarfs: Stark Broadening of Hydrogen Lines Including Nonideal Effects journal April 2009
A Gravitational Redshift Determination of the mean mass of White Dwarfs. da Stars journal March 2010
An Improved Spectroscopic Analysis of da White Dwarfs from the Sloan Digital sky Survey data Release 4 journal March 2011
On the Interplay Between star Formation and Feedback in Galaxy Formation Simulations journal April 2015
LABORATORY MEASUREMENTS OF WHITE DWARF PHOTOSPHERIC SPECTRAL LINES: H β journal June 2015
INITIAL–FINAL MASS RELATION FOR 3 TO 4 M PROGENITORS OF WHITE DWARFS FROM THE SINGLE CLUSTER NGC 2099 journal July 2015
New plasma diagnosis tables of hydrogen Stark broadening including ion dynamics journal October 1996
New white dwarf stars in the Sloan Digital Sky Survey Data Release 10 journal December 2014
The gravitational redshift of Sirius B journal September 2018
A Gaia Data Release 2 catalogue of white dwarfs and a comparison with SDSS
  • Gentile Fusillo, Nicola Pietro; Tremblay, Pier-Emmanuel; Gänsicke, Boris T.
  • Monthly Notices of the Royal Astronomical Society, Vol. 482, Issue 4 https://doi.org/10.1093/mnras/sty3016
journal November 2018
Fundamental parameter accuracy of DA and DB white dwarfs in Gaia Data Release 2 journal November 2018
Measurement of Stark Profiles of Neutral and Ionized Helium and Hydrogen Lines from Shock-Heated Plasmas in Electromagnetic T Tubes journal January 1962
Stark Broadening of H β , H γ , and H δ : A Comparison of Theory and Experiment journal March 1971
Hydrogen spectral lines with the inclusion of dense-plasma effects journal November 1991
Detailed Study of the Stark Broadening of Balmer Lines in a High-Density Plasma journal September 1972
Effect of higher-order multipole moments on the Stark line shape journal August 2016
Density-matrix correlations in the relaxation theory of electron broadening journal July 2018
Three-dimensional electromagnetic model of the pulsed-power Z -pinch accelerator journal January 2010
The ZR refurbishment project
  • McDaniel, D. H.; Mazarakis, M. G.; Bliss, D. E.
  • Conference Record of the Twenty-Fifth International Power Modulator Symposium and 2002 High-Voltage Workshop. International Power Modulator Conference, Conference Record of the Twenty-Fifth International Power Modulator Symposium, 2002 and 2002 High-Voltage Workshop. https://doi.org/10.1109/modsym.2002.1189464
conference January 2002
TWO MASSIVE WHITE DWARFS FROM NGC 2323 AND THE INITIAL–FINAL MASS RELATION FOR PROGENITORS OF 4–6.5 M journal February 2016
A Comprehensive Spectroscopic and Photometric Analysis of DA and DB White Dwarfs from SDSS and Gaia journal January 2019
On the Measurement of Fundamental Parameters of White Dwarfs in the Gaia Era journal May 2019
A Novel Approach to Constrain Rotational Mixing and Convective-core Overshoot in Stars Using the Initial–Final Mass Relation journal January 2019
Spectroscopic Analysis of DA White Dwarfs: Stark Broadening of Hydrogen Lines Including Non-Ideal Effects text January 2009
An Improved Spectroscopic Analysis of DA White Dwarfs from the Sloan Digital Sky Survey Data Release 4 text January 2011
An Experimental Platform for Creating White Dwarf Photospheres in the Laboratory text January 2012
New white dwarf stars in the Sloan Digital Sky Survey Data Release 10 text January 2014
A $Gaia$ Data Release 2 catalogue of white dwarfs and a comparison with SDSS text January 2018
The gravitational redshift of Sirius B text January 2018
Fundamental parameter accuracy of DA and DB white dwarfs in Gaia Data Release 2 text January 2018
On the Measurement of Fundamental Parameters of White Dwarfs in the Gaia Era text January 2019

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