Pune researchers find massive, grand-design spiral galaxy existing since universe's infancy
Pune (PTI): Two researchers from an astrophysics institute in Pune have discovered one of the most distant spiral galaxies ever observed - a massive, well-formed system that existed when the universe was just 1.5 billion years old.
The finding adds to growing evidence that the early universe was more evolved than previously assumed, they said.
Named 'Alaknanda' after a Himalayan river, the grand-design spiral galaxy challenges existing theories on how early complex galactic structures formed, the researchers said.
"Finding such a well-formed spiral galaxy at this early epoch is quite unexpected. It shows that sophisticated structures were being built much earlier than we thought possible," one of the researchers said.
Despite being present when the universe was only 10 per cent of its current age, Alaknanda appears strikingly similar to the Milky Way. The findings have been published in the European journal 'Astronomy & Astrophysics'.
Using NASA's James Webb Space Telescope (JWST), researchers Rashi Jain and Yogesh Wadadekar from the Pune-based National Centre for Radio Astrophysics (NCRA-TIFR) identified the galaxy.
"Alaknanda lies at a redshift of about 4, meaning its light has travelled more than 12 billion years to reach Earth," Jain said.
"We are seeing this galaxy as it appeared just 1.5 billion years after the Big Bang. Finding such a well-formed spiral galaxy at this early epoch is quite unexpected. It shows that sophisticated structures were being built much earlier than we thought possible," she said.
Using JWST's infrared sensitivity and resolution, the team found that Alaknanda contains roughly "10 billion times the mass of the sun in stars" and is forming new stars at about 63 solar masses per year, nearly 20 to 30 times the Milky Way's current rate, the researchers said in a release.
Before JWST, astronomers believed early galaxies were chaotic and clumpy, with stable spiral structures emerging only after several billion years, they said.
Dominant models suggested that early galaxies were too "hot" and turbulent to form ordered disks capable of sustaining spiral arms, the release said.
"Alaknanda tells a different story," Wadadekar said. "This galaxy had to assemble 10 billion solar masses of stars and build a large disk with spiral arms in just a few hundred million years. That's incredibly rapid by cosmic standards," he said.
The discovery adds to growing JWST evidence that the early universe was more evolved than previously assumed. "While other disk galaxies have been spotted at similar distances, Alaknanda is among the clearest examples of a spiral galaxy with well-defined arms at such a high redshift," the release said.
Jain said the team chose the name Alaknanda - one of the two main headstreams of the river Ganga - because of its connection to the Milky Way.
"Just as the Alaknanda is the sister river of the Mandakini, which is the Hindi name for our own Milky Way, we thought it fitting to name this distant spiral galaxy after the Alaknanda river," she said.
Although Alaknanda's photometric redshift is well-established, follow-up observations with JWST's NIRSpec instrument or the Atacama Large Millimeter/submillimeter Array (ALMA) are needed to measure its disk rotation, the researchers said.
"These measurements will reveal whether the galaxy's disk is 'cold' and orderly or 'hot' and turbulent, helping scientists understand how its spiral arms formed," they added.
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Grok obscene AI content: X submits response, IT Ministry examining it, say sources
New Delhi (PTI): The IT Ministry is examining the response and submissions made by X following a government directive to crack down on misuse of artificial intelligence chatbot Grok by users for the creation of sexualised and obscene images of women and minors, sources said.
X had been given extended time until Wednesday, 5 PM to submit a detailed Action Taken Report to the ministry, after a stern warning was issued to the Elon Musk-led social media platform over indecent and sexually-explicit content being generated through misuse of AI-based services like 'Grok' and other tools.
Sources told PTI that X has submitted their response, and it is under examination.
The details of X's submission were, however, not immediately known.
On Sunday, X's 'Safety' handle said it takes action against illegal content on its platform, including Child Sexual Abuse Material (CSAM), by removing it, permanently suspending accounts, and working with local governments and law enforcement as necessary.
"Anyone using or prompting Grok to make illegal content will suffer the same consequences as if they upload illegal content," X had said, reiterating the stance taken by Musk on illegal content.
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On January 2, the IT Ministry pulled up X and directed it to immediately remove all vulgar, obscene and unlawful content, especially generated by Grok (X's built-in artificial intelligence interface) or face action under the law.
In the directive on Friday, the ministry asked the US-based social media firm to submit a detailed action taken report (ATR) within 72 hours, spelling out specific technical and organisational measures adopted or proposed in relation to the Grok application; the role and oversight exercised by the Chief Compliance Officer; actions taken against offending content, users and accounts; as well as mechanisms to ensure compliance with the mandatory reporting requirement under Indian laws.
The IT Ministry, in the ultimatum issued, noted that Grok AI, developed by X and integrated on the platform, is being misused by users to create fake accounts to host, generate, publish or share obscene images or videos of women in a derogatory or vulgar manner.
"Importantly, this is not limited to creation of fake accounts but also targets women who host or publish their images or videos, through prompts, image manipulation and synthetic outputs," the ministry said, asserting that such conduct reflects a serious failure of platform-level safeguards and enforcement mechanisms, and amounts to gross misuse of artificial intelligence (AI) technologies in violation of stipulated laws.
The government made it clear to X that compliance with the IT Act and rules is not optional, and that the statutory exemptions under section 79 of the IT Act (which deals with safe harbour and immunity from liability for online intermediaries) are conditional upon strict observance of due diligence obligations.
"Accordingly, you are advised to strictly desist from the hosting, displaying, uploading, publication, transmission, storage, sharing of any content on your platform that is obscene, pornographic, vulgar, indecent, sexually explicit, paedophilic, or otherwise prohibited under any law...," the ministry said.
The government warned X in clear terms that any failure to observe due diligence obligations shall result in the loss of the exemption from liability under section 79 of the IT Act, and that the platform will also be liable for consequential action under other laws, including the IT Act and Bharatiya Nyaya Sanhita.
It asked X to enforce user terms of service and AI usage restrictions, including ensuring strong deterrent measures such as suspension, termination and other enforcement actions against violating users and accounts.
X has also been asked to remove or disable access "without delay" to all content already generated or disseminated in violation of applicable laws, in strict compliance with the timelines prescribed under the IT Rules, 2021, without, as such, vitiating the evidence.
Besides India, the platform has drawn flak in the UK and Malaysia too. Ofcom, the UK's independent communications regulator, in a recent social media post, said: "We are aware of serious concerns raised about a feature on Grok on X that produces undressed images of people and sexualised images of children".
"We have made urgent contact with X and xAI to understand what steps they have taken to comply with their legal duties to protect users in the UK. Based on their response, we will undertake a swift assessment to determine whether there are potential compliance issues that warrant investigation," Ofcom said.
