Astronomy Studies Development https://pagepressjournals.org/index.php/asd <p><strong>Astronomy Studies Development</strong> is a new, peer-reviewed, Open Access journal publishing high quality, peer-reviewed, original manuscripts in all fields of astronomy and astrophysics, though with a particular focus on mathematical techniques and methodology and innovative ideas for instrumental development and modeling in astronomy and astrophysics. Our journal will include both full length research articles and letter articles, and its coverage extends over solar, stellar, galactic and extragalactic astronomy and astrophysics, and will report original research in all wavelength bands.</p> PAGEPress Scientific Publications, Pavia, Italy en-US Astronomy Studies Development 2038-9612 <p><strong>PAGEPress</strong> has chosen to apply the&nbsp;<a href="http://creativecommons.org/licenses/by-nc/4.0/" target="_blank" rel="noopener"><strong>Creative Commons Attribution NonCommercial 4.0 International License</strong></a>&nbsp;(CC BY-NC 4.0) to all manuscripts to be published.<br><br> An Open Access Publication is one that meets the following two conditions:</p> <ol> <li>the author(s) and copyright holder(s) grant(s) to all users a free, irrevocable, worldwide, perpetual right of access to, and a license to copy, use, distribute, transmit and display the work publicly and to make and distribute derivative works, in any digital medium for any responsible purpose, subject to proper attribution of authorship, as well as the right to make small numbers of printed copies for their personal use.</li> <li>a complete version of the work and all supplemental materials, including a copy of the permission as stated above, in a suitable standard electronic format is deposited immediately upon initial publication in at least one online repository that is supported by an academic institution, scholarly society, government agency, or other well-established organization that seeks to enable open access, unrestricted distribution, interoperability, and long-term archiving.</li> </ol> <p>Authors who publish with this journal agree to the following terms:</p> <ol> <li>Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.</li> <li>Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.</li> <li>Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work.</li> </ol> Advection schemes for capturing relativistic shocks with high Lorentz factors https://pagepressjournals.org/index.php/asd/article/view/710 Jet-plasmas emanating from the vicinity of relativistic objects and in gamma-ray bursts have been observed to propagate with Lorentz factors laying in the range between one and several hundreds. On the other hand, the numerical studies of such flows have been focused so far mainly on the lowest possible range of Lorentz factors Γ, specifically, on the regime 1 ≤ Γ ≤ 5. Therefore, relativistic flows with high Γ− factors have poorly studied, as most numerical methods are found to encounter severe numerical difficulties or even become numerically unstable for Γ &gt;&gt; 1. In this paper we present an implicit numerical advection scheme for modeling the propagation of relativistic plasmas with shocks, discuss its consistency with respect to both the internal and total energy formulation in general relativity. Using the total energy formulation, the scheme is found to be viable for modeling moving shocks with moderate Lorentz factors, though with relatively small Courant numbers. In the limit of high Lorentz factors, the internal energy formulation in combination with a fine-tuned artificial viscosity is much more robust and efficient. We confirm our conclusions by performing test calculations and compare the results with analytical solutions of the relativistic shock tube problem. The aim of the present modification is to enhance the robustness of the general relativistic implicit radiative MHD solver: GR-I-RMHD (http://www1.iwr.uni-heidelberg.de/groups/compastro/home/gr-i-mhdsolver) and extend its range of applications into the high Γ− regime. Ahmad A. Hujeirat Sophie Fehlmann ##submission.copyrightStatement## 2012-10-30 2012-10-30 2 1 e1 e1 10.4081/asd.2012.710