Stars

The jellyfish galaxy JO201 (Image ESA/Hubble & NASA, M. Gullieuszik)

An article in publication and an article under peer-review in “The Astrophysical Journal” report various aspects of a study of 6 so-called jellyfish galaxies. A team of researchers used various instruments to examine them and try to understand the processes taking place in the “tentacles” generated by the gas stripped from those galaxies during the passage within a galaxy cluster. In that space, there’s intergalactic plasma that generates a pressure that caused that gas loss in a process called ram pressure stripping. An image of the jellyfish galaxy cataloged as JO201 captured by the Hubble Space Telescope was published by ESA.

The galaxy NGC 7496 as seen by the James Webb Space Telescope (Image NASA, ESA, CSA, and J. Lee (NOIRLab), A. Pagan (STScI))

A special issue of “The Astrophysical Journal Letters” contains a series of articles reporting the first results of the PHANGS–JWST survey. More than one hundred researchers from the Physics at High Angular resolution in Nearby Galaxies (PHANGS) Collaboration used the James Webb Space Telescope to examine the galaxies M74, NGC 7496, IC 5332, NGC 1365, and NGC 1433. In particular, the Mid-Infrared Instrument (MIRI) made it possible to observe structures within those galaxies in previously unseen detail. The information gathered is valuable for reconstructing star formation processes and the influence they have on the gas surrounding protostars and newborn stars.

The results of some reconstructions of J1135's shape obtained starting from the detections conducted with the ALMA radio telescope in different electromagnetic frequencies

An article published in “The Astrophysical Journal” reports the characterization of the galaxy HATLASJ113526.2-01460, or simply J1135, which we see as it was about two billion years after the Big Bang. So far, the problem was actually being able to resolve their characteristics and now a team led by Professor Andrea Lapi used observations conducted with the ALMA radio telescope to obtain this result. ALMA’s power and sensitivity made it possible to detect even the very weak radio and submillimeter emissions, which might be the only ones that reach us from J1135 due to the considerable presence of interstellar dust within it. These observations help to better understand the formation and evolution of galaxies in the young universe.

A comparison between the systems of Wolf 1069, Proxima Centauri, and TRAPPIST-1

An article published in the journal “Astronomy & Astrophysics” reports the identification of the exoplanet Wolf 1069 b, which has a mass close to the Earth’s and orbits within its star system’s habitable zone. A team of researchers led by Diana Kossakowski of the Max Planck Institute for Astronomy used the CARMENES spectrographs mounted on the 3.5-metre telescope of the Calar Alto Observatory, Spain, to identify traces of Wolf 1069 b using the radial velocity method. This exoplanet is tidally locked with its star, which poses a problem for habitability, but its star doesn’t have powerful flares. These characteristics make Wolf 1069 b an interesting object of study.

The galaxy LEDA 2046648 together with many stars and especially galaxies seen by the James Webb Space Telescope

An image captured by the James Webb Space Telescope portrays the galaxy LEDA 2046648 immersed in a vast group of other more or less distant galaxies. Many spiral galaxies are recognizable and this is to be expected as they’re the most common type. The NIRCam instrument captured many details of LEDA 2046648 despite being over a billion light-years away from Earth, but Webb’s performance is no longer astonishing. The observation that generated this image is among those used to calibrate the NIRISS instrument, which was out of service for a couple of weeks in the second half of January 2023 but has now resumed transmitting the collected data normally.