Astronomers at Christ University in Bangalore, India, have unintentionally discovered a new ring galaxy with the identifier DES J024008.08-551047.5 that may be a unique type of polar ring galaxy by examining the data from the Dark Energy Camera Legacy Survey (DECaLS). The discovery was detailed in a publication posted on the pre-print service arXiv on August 29.
Polar rings and S0-like galaxies make up the so-called polar ring galaxies (PRGs), which have existed apart for billions of years. These outer polar rings, which are made up of gas and stars, are typically roughly perpendicular to the main axis of the center host galaxy.
Even though there have been more than 400 PRG candidates found thus far, only a small number of them have been verified as genuine polar ring galaxies by further spectroscopic investigations.
Another PRG candidate has now been found by an astronomy team under the direction of Akhil Krishna. DES J024008.08-551047.5 (also known as DJ0240) was discovered by visual inspections of optical imaging data from DECaLS.
The researchers stated in their report, “We found the galaxy DJ0240 as a potential PRG candidate with a ring component almost perpendicular to the host galaxy.”
According to the findings, DJ0240 has a ring that is nearly perpendicular to the host galaxy. The host’s position angle is approximately 10 degrees, while the ring’s position angle is approximately 80 degrees, indicating that the two components are almost orthogonal to one another. It is estimated that the galaxy is 1.8 billion light years away.
The ring is three times more extended than the host galaxy, which is made up of a bulge and a disk, according to the team’s analysis of the photos. Furthermore, as is frequently seen in other known PRGs, the ring turned out to be bluer than the host. The existence of bluer ring components in PRGs, according to the paper’s authors, denotes a higher amount of continuing star formation activity in these structures.
The discovery by the researchers that DJ0240’s ring has a comparatively low Sersic index supports the PRG categorization of this galaxy. The observed effective radii of the galaxy’s constituent parts are comparable to those of other PRGs, they added.
In summarizing their findings, the astronomers ruled out the idea that DJ0240 is a lenticular host galaxy and concluded that DJ0240 is most likely a PRG. To reach firm conclusions, though, more research is necessary.
“We propose that the ringed galaxy DJ0240 is a very promising candidate for PRG catalog inclusion. To confirm that it is a PRG, however, more research is required. In particular, spectroscopic measurements to examine the kinematic characteristics of the host galaxy and the polar structure are needed, the researchers stated.