The astronomical distance over which the sign was picked up is up to now the farthest. That is additionally the primary confirmed detection of sturdy lensing of 21 cm emission from a galaxy.
The findings have been revealed within the Month-to-month Notices of the Royal Astronomical Society.
Utilizing GMRT information, Arnab Chakraborty, a postdoctoral researcher on the Division of Physics and Trottier Area Institute of McGill College and Nirupam Roy, Affiliate Professor, Division of Physics, IISc have detected a radio sign from atomic hydrogen in a distant galaxy at redshift z=1.29.
“Because of the immense distance from the galaxy, the 21 cm emission line had redshifted to 48 cm by the point the sign travelled from the supply to the telescope,” stated Chakraborty.
The sign detected by the crew was emitted from this galaxy when the universe was solely 4.9 billion years previous; in different phrases, the look-back time for this supply is 8.8 billion years.
This detection was made potential by a phenomenon referred to as gravitational lensing, during which the sunshine emitted by the supply is bent as a result of presence of one other large physique, akin to an early sort elliptical galaxy, between the goal galaxy and the observer, successfully ensuing within the “magnification” of the sign.
“On this particular case, the magnification of the sign was a couple of issue of 30, permitting us to see via the excessive redshift universe,” defined Roy.
The crew additionally noticed that the atomic hydrogen mass of this specific galaxy is sort of twice as excessive as its stellar mass.
These outcomes reveal the feasibility of observing atomic gasoline from galaxies at cosmological distances in comparable lensed techniques with a modest quantity of observing time. It additionally opens up thrilling new potentialities for probing the cosmic evolution of impartial gasoline with current and upcoming low-frequency radio telescopes within the close to future.
Yashwant Gupta, Heart Director at NCRA, stated, “Detecting impartial hydrogen in emission from the distant Universe is extraordinarily difficult and has been one of many key science objectives of GMRT. We’re joyful to this new path breaking end result with the GMRT, and hope that the identical could be confirmed and improved upon sooner or later.”
The Big Metrewave Radio Telescope was constructed and is operated by NCRA-TIFR. The analysis was funded by McGill and IISc.