An international team of astronomers has conducted a comprehensive new survey of the Milky Way, revealing with unprecedented sensitivity and detail previously unseen signatures that indicate how stars form and die, complex processes that have plagued researchers for centuries. attracted to.
The results were published in a series of papers in ‘Astronomy and Astrophysics’ by the team, which includes scientists from the Indian Institute of Science (IISc) and the Indian Institute of Space Science and Technology (IIST).
Data for the survey, which spanned a large part of the Milky Way, was collected using two powerful radio telescopes: the Carl G. Jansky Very Large Array (VLA) at the National Radio Astronomy Observatory, USA, and the Effelsberg 100-M Radio The telescope is operated by the Max Planck Institute for Radio Astronomy Germany, as part of the GLOSTAR (Global View on Star Formation in the Milky Way) project.
Nirupam Roy, assistant professor in the Department of Physics and Rohit Dokara, his former graduate student from IISc, as well as Jagdeep D Pandian, associate professor in the Department of Earth and Space Sciences at IIST, are among the Indian scientists who are part of the study. The GLOSTAR project, Bengaluru-based IISc said in a statement on Friday.
Dokara, now a PhD student at MPIFR, is the first author on a paper that reports the detection of new supernova remnant (SNR) structures born from the explosive death of massive stars in our galaxy.
According to the statement, previous surveys have found only a third of the expected number of SNRs in the Milky Way (which is about 1000).
The GLOSTAR team has now discovered 80 new SNR candidates in the VLA data alone, which are expected to identify more than the combined Effelsberg and VLA data.
They were able to confirm the presence of 77 previously discovered SNR candidates and reclassify some that had been misidentified.
This is impressive, given that the northern telescopes used by GLOSTAR are able to see only half of the inner regions of the Milky Way, it said.
“This is an important step forward in solving this long-standing mystery of missing supernova remnants,” Dokara said.
The researchers were also able to detect other traces of star formation.
One of them, for example, is the radio emission from methanol molecules in ‘Cygnus X’, a large star-forming complex nearby.
These are typically emitted from massive stars in the early stages of formation.
The team was also able to detect dense pockets of ionized hydrogen, another indication of the presence of massive young stars.
Young stars are usually surrounded by thick clouds of dust and gas.
“Since visible light is absorbed in this dense cloud around stars, most optical telescopes don’t reveal much.
People look for radio emissions instead,” explained Roy, who has previously worked in both NRAO and MPIFR.
“Since the GloStar survey detects a wide range of radio emissions such as from methanol molecules to ionized hydrogen, it has been able to probe the formation of massive stars, which are in relatively late stages, that provide a complete picture of the star. It is important to achieve formation in the Milky Way,” said Pandian, who has previously worked in the MPIFR as well.
The Effelsberg Radio Telescope is a large dish spanning 100 meters in diameter, capable of detecting massive structures, while the VLA is a collection of small antennas that work together as an interferometer to capture details at high resolution .
Data collected from both telescopes helped the researchers paint a more comprehensive picture of the various astrophysical objects in the field.
“This clearly demonstrates that the Effelsberg telescope is still very important after 50 years of operation,” said MPIFR’s Andreas Brunthler, project leader and first author of the survey’s observation paper.
MPIFR director, Karl Menten, who started GLOSTAR, said: “It’s great to see beautiful science as a result of our two favorite radio telescopes joining forces.”
Both Pandian and Roy currently maintain a Max Planck-India Partner Group with Maintain to continue closer collaboration and, in particular, to expand the scope of the GloStar project.
Other members of the research team include scientists from MPIFR and NRAO and collaborators from institutions in the UK, South Africa, Mexico, France and Australia.
With observations and analysis, more results are expected to be published over time, it was said.
Source : EastMojo