From SKA: “International team completes large survey of gas in nearby galaxies”

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An international team of investigators led by Dr. Claudia Cicone (INAF – Astronomical Observatory of Brera), Dr. Matt Bothwell (University of Cambridge) and with the SKA Organisation Project Scientist Dr. Jeff Wagg as principal investigator have found the spectra of the carbon monoxide emission line in a sample of small but nearby galaxies and found that the most massive galaxies form stars and are rich in metals.

The 12m APEX ESO telescope, located on the plateau of Chajnantor in Chile, at 5000m altitude.

The team, comprising investigators from Italy, the UK, Germany, Chile and China have completed a large survey of molecular gas in nearby galaxies using the 12m APEX telescope in Chile. The APEX Low-redshift Legacy Survey of MOlecular Gas (ALLSMOG, PI: Dr. Jeff Wagg) has observed the Carbon Monoxide (CO) molecule in a sample of 97 galaxies in the local Universe. The ALLSMOG data provide important information on the cold molecular gas content of these galaxies which have been well characterised in terms of their star-formation rates, gas-phase metallicities and atomic HI gas masses.

ALLSMOG is an ESO observing program conceived by Dr. Jeff Wagg to study the molecular gas through the carbon monoxide emission line with the telescope Atacama Pathfinder Experiment (Apex), a collaboration between the Max Planck Institute for Radio Astronomy (MPIfR), the Onsala Space Observatory (Oso) and ESO, which is located on the plain of Chajnantor at 5000 meters above sea level, in the Chilean Andes.

The article The final release date of ALLSMOG: a survey of CO in typical local low-M star-forming galaxies published today in the journal Astronomy & Astrophysics includes observations of 97 galaxies, 88 of whom studied with Apex (for more than 300 hours of observation from summer 2013 to winter 2015/2016) and 9 with the telescope of the Institute of millimetric radio astronomy (Iram) to Pico Veleta, Spain (between 2014 and 2015).

IRAM 30m Radio telescope, on Pico Veleta in the Spanish Sierra Nevada

The survey is the first major campaign ALLSMOG systematic observation of carbon monoxide extragalactic made with Apex telescope.

“The ALLSMOG survey is the first large systematic extragalactic survey of CO ever conducted with the APEX telescope”, says Claudia Cicone, a Marie Skłodowska-Curie fellow at INAF- Osservatorio Astronomico di Brera. “Our research 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.”

“For all the galaxies in our sample we have additional information on their physical properties from optical observations and on their atomic gas content (HI) from radio observations of the HI21cm line published in previous studies and by other teams. We have created a real identikit of these galaxies which allows us to study the relations between the molecular gas and their other physical properties.”

“In the near future, multi-wavelength galaxy studies like this will be greatly enhanced by data from the SKA telescope and its precursors such as ASKAP and MeerKAT”, says Dr. Jeff Wagg.

SKA/ASKAP radio telescope at the Murchison Radio-astronomy Observatory (MRO) in Mid West region of Western Australia

SKA Meerkat telescope, 90 km outside the small Northern Cape town of Carnarvon, SA

“While the SKA precursors are expected to detect more than half a million galaxies in HI line emission, these sample sizes have the potential to increase by nearly an order of magnitude when the SKA1-mid telescope comes online.”

SKA1-mid is the dish array telescope to be built in South Africa that will be operating in the 350Mhz -14Ghz frequency range, complementary to the low-frequency telescope (so-called SKA1-low) to be built in Australia. Although SKA1-mid and the SKA precursors do not have the frequency coverage needed to measure the molecular gas in nearby galaxies, they will be able to detect the atomic gas through the 21cm atomic HI line transition.

“Quantifying the total gas content (atomic and molecular) of significant samples of galaxies out to large distances remains one of the crucial elements needed for a full understanding of galaxy formation”, concludes Dr. Jeff Wagg.

See the full article here .

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About SKA

The Square Kilometre Array will be the world’s largest and most sensitive radio telescope. The total collecting area will be approximately one square kilometre giving 50 times the sensitivity, and 10 000 times the survey speed, of the best current-day telescopes. The SKA will be built in Southern Africa and in Australia. Thousands of receptors will extend to distances of 3 000 km from the central regions. The SKA will address fundamental unanswered questions about our Universe including how the first stars and galaxies formed after the Big Bang, how dark energy is accelerating the expansion of the Universe, the role of magnetism in the cosmos, the nature of gravity, and the search for life beyond Earth. Construction of phase one of the SKA is scheduled to start in 2016. The SKA Organisation, with its headquarters at Jodrell Bank Observatory, near Manchester, UK, was established in December 2011 as a not-for-profit company in order to formalise relationships between the international partners and centralise the leadership of the project.

The Square Kilometre Array (SKA) project is an international effort to build the world’s largest radio telescope, led by SKA Organisation. The SKA will conduct transformational science to improve our understanding of the Universe and the laws of fundamental physics, monitoring the sky in unprecedented detail and mapping it hundreds of times faster than any current facility.

Already supported by 10 member countries – Australia, Canada, China, India, Italy, New Zealand, South Africa, Sweden, The Netherlands and the United Kingdom – SKA Organisation has brought together some of the world’s finest scientists, engineers and policy makers and more than 100 companies and research institutions across 20 countries in the design and development of the telescope. Construction of the SKA is set to start in 2018, with early science observations in 2020.