DOUBLE-NUCLEI GALAXIES (Syllabus: GS Paper 1 - Geography)

THEIASHUB
Get an Instant Call Back from Our Expert Mentors Now!
+91

Context: Researchers have developed a new algorithm which has led to the discovery of thousands of double-nuclei galaxies. 

  • Out of these 159 were confirmed to have pairs of accreting supermassive black holes or active galactic nuclei (AGN) as they are usually called.

Key Points

  • Supermassive black holes (SMBHs) have masses of a million to several billion times the mass of the sun. 
  • Accreting SMBH or AGN gives out enormous amounts of radiation over the entire electromagnetic spectrum. Detecting this radiation is one of the only ways of observing SMBHs in distant galaxies. 
  • So detecting AGN pairs is one of the best ways of tracing the mergers of massive black holes. However, it is extremely rare to find galaxies that have double-nuclei and dual AGN.
  • In fact, detection of dual AGN is often only by accident, and before this study less than 50 were known. 
  • With time, such AGN pairs finally result in two supermassive black holes spinning around each other and giving out nano-Hz gravitational waves.  The final merger of the SMBHs will give out a burst of gravitational waves.
  • Many of these double nuclei galaxies are at separations similar to the separation of the Milky Way and Andromeda galaxies. 
  • Their existence shows us how merging galaxies appear to change with time and how their SMBHs will appear before finally merging to form more massive black holes. 
  • Thus, studying a large sample of double nuclei galaxies can help predict how the Milky Way and Andromeda will appear as they merge in the future. This study also shows that galactic collisions can signal “the beginning of the end” for the individual AGN as they merge to form a more massive SMBH.
  • The investigators also found that the merging galaxies have a tendency to look red - indicating the presence of old stars and the decreased formation of new stars. 
  • Since star formation is the lifeblood of galaxies, red galaxies represent the old, evolved population of galaxies. Thus the study reveals how AGN can extinguish the star formation in galaxies leading to the formation of red and “dead” elliptical galaxies.


UPSC QEP 2026 Batch 5 - English
UPSC QEP 2026 Batch 5 - English
Buy now View Details
Submit Your Details to Learn More
I agree to give my consent to receive updates through SMS/Email & WhatsApp*.

NEEV GS + CSAT Foundation 2026/27
NEEV GS + CSAT Foundation 2026/27
Buy now View Details



Join theIAShub’s Mains Answer Writing Program

Refine your answer writing skills and elevate your UPSC preparation with personalized support and expert feedback.

Fill out the form to get started with the program or any other enquiries !

I agree to give my consent to receive updates through SMS/Email & WhatsApp*.

Best IAS Coaching In Delhi, UPSC Online & Offline Classes by IAShub

Are you dreaming of becoming an IAS officer? Then, IAShub can be your best guide. It is one of the Best IAS Coaching in Delhi. Many students who want to clear the UPSC exam join IAShub for learning. The institute gives both online and offline classes. Their teachers are experienced and helpful. They easily explain every topic. Students also get notes, tests, and tips to do well in the exam.

UPSC Online Classes by IAShub

IAShub is in Delhi and is trusted by many UPSC students. It offers coaching for every part of the UPSC exam – Prelims, Mains, and Interview. The classes are simple and easy to understand. The teachers are experts and guide students in the right way. IAShub is also known for its helpful notes, test series, and answer-writing practice. IAShub is the best coaching in Delhi and also gives UPSC Online Classes. This helps students from any place in India to learn. The online classes are live and also recorded. So, students can watch them anytime. These classes cover the full UPSC syllabus.

Key Offerings Provided by IAShub

Here are some important services provided by IAShub:

  • UPSC Prelims: IAShub teaches for Prelims with a focus on basics. It also gives daily current affairs and monthly magazines.
  • Classroom Courses: IAShub has classroom learning for students in Delhi. The environment is good and peaceful for study.
  • Live Classes: Students who live far can join live UPSC online classes. These classes are just like real classes.
  • QEP for Mains: The Quality Enrichment Program (QEP) is special for Mains preparation. It helps students write better and faster.
  • Answer Writing: Regular answer writing practice is given. Teachers also check answers and give tips to improve.
  • Free Resource: IAShub gives free notes by toppers and helpful Main Booster material.
  • Test Series: Test series are available for every subject. These help students know their weak points and improve.
  • Interview Guidance Session: IAShub also gives interview practice sessions with experts. These help students feel confident.

UPSC Exam Overview

The UPSC Civil Services Exam has three parts:

  • Prelims: It has two papers: General Studies and CSAT.
  • Mains: It has nine papers, including essays and optional subjects.
  • Interview: It tests the personality and confidence of the student.

This exam is tough, but with the right guidance, it becomes easy to manage. Students must study smart and stay regular.

How IAShub Helps in the UPSC Journey

IAShub supports students from the beginning to the end. It gives the right books, tests, and notes. The classes are easy to follow, and the teachers are always ready to help. Students get personal doubt sessions too. The test series and answer checking help students learn where they need to do better. Also, free study materials save time and money.
IAShub also guides students during the final stage – the interview. Experts take mock interviews and give useful tips. This full support makes IAShub one of the best IAS coaching in Delhi.

Best IAS Coaching In Delhi FAQs

Yes, IAShub offers live and recorded online classes. Students can attend from any part of India.

Classes are available in both English and Hindi, so students can choose the language they are comfortable with.

The classroom centre is located in Delhi. Students can visit and join offline batches there.

IAShub gives interview guidance sessions to help students prepare for the final round of UPSC.