hiss, a new tool for H i stacking: application to NIBLES spectra

J Healy , S-L Blyth , E Elson , W. Van driel (1, 2) , Z Butcher , S Schneider , M Lehnert , R Minchin

1 GEPI - Galaxies, Etoiles, Physique, Instrumentation
2 USN - Unité Scientifique de la Station de Nançay

H I stacking has proven to be a highly effective tool to statistically analyse average H I properties for samples of galaxies which may or may not be directly detected. With the plethora of H I data expected from the various upcoming H I surveys with the SKA Precursor and Pathfinder telescopes, it will be helpful to standardize the way in which stacking analyses are conducted. In this work we present a new PYTHON-based package, HISS, designed to stack H I (emission and absorption) spectra in a consistent and reliable manner. As an example, we use HISS to study the H I content in various galaxy sub-samples from the NIBLES survey of SDSS galaxies which were selected to represent their entire range in total stellar mass without a prior colour selection. This allowed us to compare the galaxy colour to average H I content in both detected and non-detected galaxies. Our sample, with a stellar mass range of 10 8 < M (M) < 10 12 , has enabled us to probe the H I-to-stellar mass gas fraction relationship more than half an order of magnitude lower than in previous stacking studies.

Mots clés: methods; data analysis -methods; statistical -galaxies; evolution -galaxies; general -radio lines; galaxies

Domaines: Astrophysique [astro-ph]

J Healy, S-L Blyth, E Elson, W. Van driel, Z Butcher, et al.. hiss, a new tool for H i stacking: application to NIBLES spectra. Monthly Notices of the Royal Astronomical Society, 2019, 487 (4), pp.4901-4938. ⟨10.1093/mnras/stz1555⟩. ⟨hal-03103887⟩