A team of researchers, led by Claudia Cicone from Brera Astronomical Observatory of the National Institute for Astrophysics (INAF), in the context of the Apex Low-redshift Legacy Survey for MOlecular Gas (ALLSMOG) observing programme, has observed a sample of small nearby galaxies.

The analysis carried out by the team (made up of researchers from various institutes including ETH, University of Cambridge, SKA and ESO) focused on the detection of the spectra of the carbon monoxide emission line and found that the more the galaxies are massive, star-forming and rich in metals, the brighter the carbon monoxide emission line.

ALLSMOG is an observing programme of the European Southern Observatory (ESO), an international astronomical organization of 16 countries, conceived by Jeff Wagg (SKA Organisation).

The project aims to study molecular gas through the carbon monoxide emission line using the Atacama Pathfinder Experiment (Apex)telescope, in collaboration with the Max Planck Institute for Radio Astronomy (MPIfR), the Onsala Space Observatory (OSO) and ESO.

The article published in Astronomy & Astrophysics, entitled “The final data release of ALLSMOG: a survey of CO in typical local low-M star-forming galaxies”, contains observations of 97 galaxies, 88 of which studied in more than 300 hours of APE observations and 9 with the radio telescope of the Institute for Radio Astronomy in the Millimetre Range (IRAM) in Spain.

Claudia Cicone, fellow of the AstroFIt2 project (a programme that promotes incoming mobility, co-funded by INAF and the European Programme Horizon 2020) explained the results achieved with this study: “The paper describes in detail the sample selection, the observations, data reduction and analysis methods, in essence, we provide all the technical information needed to evaluate the quality of millimetre observations and to allow it to be used by the scientific community. Along with the spectra of the carbon monoxide emission line obtained wit APEX and IRAM, we provide all additional information available on these galaxies, that is, their optical images, the physical properties obtained from optical data, such as star formation rates, stellar masses, redshift or distance, gas-phase metallicities. For all the galaxies in our sample we have additional information on their atomic gas content (HI) from radio observations published in previous studies (by other teams). We have therefore created a real multi-band ‘identikit’ of these galaxies which allows us to study the relations between the molecular gas and their other physical properties”.

The study conducted by the Italian researcher provides new data on the correlations between carbon monoxide luminosity and star formation rate, and between carbon monoxide luminosity and stellar mass also in a sample of ‘normal’ galaxies, less massive than the samples previously examined. The data obtained reveal that all the star-forming galaxies in the local Universe obey similar scaling relations between molecular gas and the physical properties of the galaxies examined.

“Our study – concluded the researcher – has an enormous legacy value because the entire scientific community can exploit our data. We really hope our efforts will stimulate new ideas and results”.

Source: ResearchItaly