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In order to measure automatically the equivalent width of the Balmer lines in a database of 40,000 atmosphere models, we have developed a program that mimics the work of an astronomer in terms of identifying and eliminating secondary spectral lines mixed with the Balmer lines. The equivalent widths measured have average errors of 5 percent, which makes them very reliable. As part of the FITspec code, this program improves the automatic adjustment of an atmosphere model to the observed spectrum of a massive star.
An analysis of H alpha and H beta spectra in a sample of 30 cool dwarf and subgiant stars is presented using MARCS model atmospheres based on the most recent calculations of the line opacities. A detailed quantitative comparison of the solar flux spe
We discovered non-stellar Balmer absorption lines in two many-narrow-trough FeLoBALs (mntBALs) by the near-infrared spectroscopy with Subaru/CISCO. Presence of the non-stellar Balmer absorption lines is known to date only in the Seyfert galaxy NGC 41
Our knowledge of circumstellar disks has traditionally been based on studies of dust. However, gas dominates the disk mass and its study is key to understand the star and planet formation process. Spitzer can access gas emission lines in the mid-infr
The Stark-induced shift and asymmetry, the so-called pressure shift (PS) of $H_alpha$ and $H_beta$ Balmer lines in spectra of DA white dwarfs (WDs), as masking effects in measurements of the gravitational red shift in WDs, have been examined in detai
Our preliminary results from laboratory experiments studying white dwarf (WD) photospheres show a systematic difference between experimental plasma conditions inferred from measured H$beta$ absorption line profiles versus those from H$gamma$. One hyp