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Light from an explosion in the early universe illuminated a black hole which astronomers believe could broaden their understanding of the formation of celestial objects.
Three billion years ago, a gamma-ray burst (known as GRB 950830) exploded in the universe. In 1995, astronomers observed the event, essentially scanning “over time” with the high-energy BATSE (Burst And Transient Source Experiment) astrophysical experiment at the Compton Gamma-Ray Observatory, which was launched in 1991 on the space shuttle Atlantis. Now, astronomers have used the light from the ancient explosion to detect a intermediate mass black hole (IMBH), which are elusive and difficult to spot.
The light from the gamma-ray burst allowed the team to use a phenomenon called a gravitational lens to find an IMBH. This finding confirms the existence of IMBHs because they are so difficult to detect that some scientists wonder if they are even real or not. This work also sheds light on how different types of black holes can form and how supermassive black holes (SMBH) could get so huge.
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Intermediate mass black holes are exactly what they look like: celestial average weights. The objects are quite massive: bigger than stellar black holes (SBH) but not as massive as SMBH, perhaps clocked between 100 and 100,000 times the mass of our sun.
However, these medium-sized black holes are particularly difficult to detect “because they are smaller and less active than supermassive black holes; they do not have readily available fuel sources, nor such a strong gravitational pull to attract. stars and other cosmic materials that would produce telltale x-rays shine, ” according to NASA.
“If a black hole is not an accretion material, it is quite difficult to detect, because by name and nature they are black,” said James Paynter, an astrophysicist at the University of Melbourne in Australia who led this research, at Space.com. “Only the effects of their gravity can betray the existence of a quiet black hole.”
But, while IMBHs might not be easily spotted by bright X-ray emissions like a supermassive black hole would, scientists in this new study were able to use the gravitational lens to do the trick. Gravitational lensing is a phenomenon that occurs when an object (like a black hole) acts like a lens, distorting light from a distant light source (like a cosmic explosion). This distortion signals to astronomers that there must be a massive object in the way.
To go further and determine what type of object is at the origin of this lens, the team had to determine its mass. Because the object’s mass is within the range of an IMBH, they decided that was the most likely possibility. They were also able to eliminate suitors like globular clusters for not being dense enough and halos of dark matter for not being compact enough to cause a gravitational lens.
By discovering IMBH using this technique, it “tells us something about how often they [IMBH] are, “Rachel Webster, astronomer at the University of Melbourne and co-author of this study, told Space.com.” If they were very, very rare, it would be very unlikely that we would see even a single case of a gravitational lens. It’s all about statistics and probabilities. “
This IMBH detection could also reveal information about their larger cousins, SMBH. “It is important to discover these objects to fill the observation gap between stellar black holes (SBH) and SMBH,” Paynter said. “Currently, we don’t know how SMBH is able to grow to such huge masses in the universe age. There just isn’t enough for them to grow, nor enough to grow. time.”
The clue to the SMBH puzzle may lie in IMBHs, scientists hope. “If a seed population of IMBH exists, it begins to fill this gap. The origin of IMBHs is another matter… they can be formed from the fusion / collapse of massive stars, pure hydrogen in it. ‘early universe, or they may be older, primordial black holes formed during the very early phases of the universe, ”Paynter added.
While this work is a step forward not only in proving the existence of IMBH, but also in exploring how different types of black holes develop and exist in the cosmos, there is still much to explore and learn about this. IMBH.
“We don’t know now if this IMBH travels the cosmos on its own, or if it is linked to a galaxy or a star cluster. So even though we are able to estimate the prevalence of these objects in the universe, we cannot identify them in a specific location or “habitat”, ”Paynter said.
This work was described in a study published today (March 29) in the journal Nature Astronomy.
Email Chelsea Gohd at [email protected] or follow her on Twitter @chelsea_gohd. Follow us on Twitter @Spacedotcom and on Facebook.
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