Absorber Catalogs & Tools
qsoabsfind
I developed an automated absorber detection pipeline, qsoabsfind, which uses a matched-kernel convolution technique and adaptive signal-to-noise criteria.
The pipeline is designed for high-performance analysis and can run in parallel on thousands of quasars simultaneously, significantly reducing the absorber search time.
- Latest release: v1.0.5
- Features: multi-ion support (Mg II and C IV), robust absorber selection, equivalent width measurements and error estimations.
Mg II / Fe II Absorber Catalog
Using a preliminary version of qsoabsfind (developed during my PhD), I processed all quasars from SDSS DR16 to build the largest Mg II / Fe II catalog to date, containing ~160,000 systems.
This catalog is widely used for CGM–absorber cross-correlation studies and large-scale structure analysis.
C IV Absorber Catalogs
As part of DESI, I developed the first large-scale C IV absorber catalog based on DESI Year 1 quasar spectra.
- C IV Absorber Catalog (DESI DR1): DESI Data Access
- On GitHub: Github Link
This catalog contains over 33,000 CIV systems, enabling statistical measurements of absorber incidence, equivalent width distributions, and cosmic mass density evolution.
Future Work: A DR2 C IV absorber catalog will be released in future — stay tuned, as I will share the link here once available.
Redshift Fitter for Large Surveys
In my recent work Anand et al. 2024, I developed a computationally efficient galaxy archetype-based redshift estimation and spectral classification method for the Dark Energy Spectroscopic Instrument (DESI).
This approach builds upon and extends the redrock pipeline.
Highlights:
- Refits spectra with physical galaxy archetypes + additional terms to absorb data-reduction defects.
- Improves redshift success rates and reduces catastrophic failures by 10–30% for galaxy targets.
- Addresses limitations of classic PCA models (e.g., unphysical modeling, overfitting).
- Generic method that can be extended to other large surveys like WEAVE, WAVES, and PFS