SPEARS 0.1.1

SPEARS : SPARCL Pipeline for Emission-Absorption Line Retrieval and Spectroscopy

SPEARS - Sparcl Pipeline for Emission-Absorption Line Retrieval and Spectroscopy

This library aims to provide users with a quick, and easily scalable pipeline for spectroscopic analysis of spectra from the DESI-EDR accessed through the SPARCL API at NOIRLAB. Provides a list of spectral lines present in a given spectrum, along with other information outlined in spectro_analyze header. Specific usage of each function can be found under Features.

Features

Main Functionality

• spectro_analyze(limit, save_as_fits=False): Returns a list of QTables (or .fits file if specified) with the following headers:

  • ‘Ion’ (str): The ion type present

  • ‘Ion Line Wavelength’ (float64, angstrom): The wavelength of the present spectral line

  • ‘Spectral Flux at Line’ (float64, 1 / (erg17 cm2 s Angstrom)): The model-spectral flux at the given spectral line wavelength

  • ‘Observed Deviation’ (float64, angstrom): The distance from the observed spectral line and the actual line

  • ‘Normalized Deviation’ (float64, dimensionless): The observed deviation divided by the spectral resolution at that given wavelength

  • meta={‘id’}: id of spectrum, identical to dict key

Sub-modules

• fetch_sparcl_ids(limit): Fetches the first n SPARCL ids, based on the limit provided.

• sparcl_ids_to_spectra(sparcl_ids): Takes SPARCL ids and returns a list of Spectrum1D objects with each spectra’s flux, redshifted-accounted wavelength, and SPARCL id.

• normalize_spectra(model_spectra): Takes an array of Spectrum1D object(s) and returns the continuum normalized spectra for each (continuum derived by median-filter smoothing original spectrum).

• norm_spectra_to_lines(normalized_spectra, save_as_fits=False): Takes an array of normalized spectra, and returns the present spectral lines (and other info specified in spectro_analyze) in each in a list of QTables, or .fits file if specified.

Requirements

As listed in setup.py:

• specutils

• numpy

• astropy

• json

• warnings

• scipy

• sparcl.client

• importlib

• pytest

Installation

$ [sudo] pip install SPEARS

Usage

Retrieving spectral analysis info from the first 5 spectra in the database:

from SPEARS import SPEARS

sparcl_ids = SPEARS.fetch_sparcl_ids(limit=5)

info = SPEARS.spectro_analyze(sparcl_ids)

Documentation

Full documentation will be later uploaded to my GitHub.

License

See LICENSE.txt file.

Acknowledgments

• Full accreditation can be found on my GitHub.

• Thanks to NOIRLAB for supplying their vast spectral data for free through SPARCL API.

Contact

Email: [e-mail]