A research team at Xi'an Jiaotong University (XJTU) has proposed a new way of measuring white dwarf-like conditions that positively influences astrophysics research.

The team created a dense plasma gas similar to that in the atmosphere of White Dwarf H1504+65 by using a Starlight III laser. The research provides data support for the determination of basic state parameters and related theoretical modeling.

The team was led by Professor Zhao Yongtao at XJTU. They also collaborated with top academies and universities in China, such as the Chinese Academy of Sciences, the Chinese Academy of Engineering, Shenzhen Technology University (SZTU), and the University of the Chinese Academy of Sciences.

The team found hundreds of high-resolution spectra in the soft X-ray and EUV bands, marked several new spectral lines, filled in the gap of astronomical observations in the 15-90nm band and provided a new approach for laboratory astrophysical research under a wider range of conditions. 

White dwarfs are the final product of the evolution of low and medium mass stars. Measuring the simulated conditions of white dwarfs helps explain the phenomena observed by telescopes, determine the state and lifetime of stars, and predict the evolution of the universe.

White Dwarf H1504+65 is very special. Based on observations by NASA's Chandra X-ray and Far Ultraviolet telescopes, White Dwarf H1504+65 has a surface temperature of about 200,000K (359,540°F), making it the hottest White Dwarf ever found.

(a) Experimental design and diagnostic layout diagram of White Dwarf H1504+65-like atmospheric state materials 

(b) A comparison of spectral Chandra data and laboratory observations

The research results were published online in The Astrophysical Journal in an article entitled "Laboratory Observation of C and O Emission Lines of the White Dwarf H1504+65-like Atmosphere Model".

Ma Bubo, a PhD student of XJTU, Ren Jieru, an associate professor of XJTU and Wang Shaoyi, an assistant researcher of the Research Center of Laser Fusion are the co-first authors. Zhao Yongtao, SZTU Professor Cao Leifeng, as well as Weimin Zhou of the Research Center of Laser Fusion, are the corresponding authors.

The research was funded by the National Natural Science Foundation of China.

Link to the paper: https://doi.org/10.3847/1538-4357/ac18c3