A Quasar Spectra Scanning Tool

Description

This program allows you to scan in velocity any quasar spectrum and with any transitions, marking fit regions and preparing a preliminary fort.13 to start fitting with VPFIT. As of 4.0.0, QSCAN is a React frontend talking to a Flask backend (previously a Dash app) -- see docs/architecture.md and CLAUDE.md for the full picture.

Installation

git clone https://gitlab.com/astroquasar/programs/qscan.git
cd qscan
uv venv
uv pip install -e ".[dev]" --python .venv/bin/python
cd frontend && npm install && npm run build

Cloning over SSH

The GitLab project is public, so git clone https://gitlab.com/astroquasar/programs/qscan.git (as above) needs no authentication at all. If you'd rather clone over SSH (git@gitlab.com:astroquasar/programs/qscan.git) -- e.g. because you also plan to push -- that always requires a working SSH key on your GitLab account, regardless of the project's visibility:

ssh-keygen -t ed25519 -f ~/.ssh/id_ed25519_gitlab
cat ~/.ssh/id_ed25519_gitlab.pub

Paste the printed public key at gitlab.com/-/user_settings/ssh_keys. If that key isn't your default (~/.ssh/id_ed25519/id_rsa), add it to ~/.ssh/config so plain ssh/git commands pick it up automatically:

Host gitlab.com
    HostName gitlab.com
    User git
    IdentityFile ~/.ssh/id_ed25519_gitlab

Verify with ssh -T git@gitlab.com -- it should greet you by username. Pushing (rather than just cloning) additionally requires a project role of at least Developer, set under Project -> Manage -> Members.

Built on Python (NumPy, SciPy, Astropy, Flask) and a Vite/React/TypeScript frontend (Plotly.js, TanStack Query).

Usage

qscan <spectrum> [--zabs Z] [--dv KM_S] [--no-browser]

This loads the spectrum, opens a browser tab, and starts scanning. See Getting Started for the full walkthrough, or qscan --help for all options.

License

(The MIT License)

Copyright (c) 2016-2020, Vincent Dumont. All rights reserved.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.