The new NASA mini satellite looks at the Milky Way halo

WASHINGTON: A small NASA satellite has been deployed from the International Space Station (ISS) to help scientists search for the missing matter of the universe by studying the X-rays of the "halo" of hot gases surrounding our galaxy.

Astronomers keep being brief when they study "normal" matter, the material that makes up galaxies, stars, and planets.

To search for this missing case, a NASA-sponsored CubeSat mission called HaloSat was deployed from the ISS on July 13th.

The Cosmic Microwave Background (CMB) is the oldest light in the universe, the radiation of when he was 400,000 years old.

Calculations based on CMB observations indicate that the universe contains 5% protons of normal matter, neutrons and other subatomic particles, 25% dark matter – a substance that remains unknown – and 70% of the material. dark energy, negative pressure accelerating the expansion of the universe.

As the universe expanded and cooled, normal matter melted into gases, dust, planets, stars, and galaxies. However, when astronomers count the estimated mbades of these objects, they only represent about half of what cosmologists say should be present.

"We should have everything we had today when the universe was 400,000 years old," said Philip Kaaret, principal investigator at the University of Iowa (UI ) in the United States, who directs the mission.

Researchers believe that the missing material may be in hot gas located either in the space between galaxies or in galactic halos, extended components surrounding individual galaxies.

HaloSat will study gas in the halo of the Milky Way which is around 2 million degrees Celsius. At such high temperatures, oxygen throws most of its eight electrons and produces the X-rays that HaloSat will measure.

Other X-ray telescopes, such as NASTRON's Neutron star Interior Composition Explorer and the Chandra X-ray observatory, study individual sources by observing small spots of the sky.

HaloSat will look at the entire sky, 100 square degrees at a time, which will help determine whether the diffused galactic halo has the shape of a fried egg or a sphere.

"If you think of the galactic halo in the fried egg model, it will have a different luminosity distribution when you look at it from the Earth rather than when you look at wider angles," said Keith Jahoda , astrophysicist. at NASA's Goddard Space Flight Center in the United States.

"If it's in a quasi-spherical shape, compared to the dimensions of the galaxy, then we expect it to be closer to the same brightness in all directions" said Jahoda.

The shape of the halo will determine its mbad, which will help scientists to understand if the missing matter of the universe is in galactic halos or elsewhere. HaloSat will collect most of its data for 45 minutes on the night half of its 90-minute orbit around the Earth.

On the day side, the satellite recharges using its solar panels and transmits the data to NASA's Wallops flight facility in Virginia, which relays the data to the Mission Operations Control Center. at Blue Canyon Technologies in Colorado.

HaloSat measures approximately 10x20x30 centimeters and weighs approximately 12 kilograms.