A new technique for studying some of the brightest objects in the universe has thrown a curve ball into scientists’ understanding of the relationship between energetic monster black holes and suppressed star formation.
quasars They are the ultra-bright cores of galaxies that contain extremely active supermassive black holes. The intense radiation of the quasar arises from huge amounts of hot gas forming an accretion disk around the mau black hole.
Use of the Atacama Large Millimeter/Meter Matrix in Chile (Alma)the researchers targeted the 3C 273 quasar. 2.4 billion light-years away from a land3C 273 is the closest quasar to Milky Way And the first quasar ever identified. However, the quasar’s light glow makes it difficult to observe the rest of its host galaxy, especially at the radio wavelengths used by ALMA.
Seeing the bright and dim features in the same camera shot requires a feature known as High Dynamic Range. A typical digital camera has a dynamic imaging range in the thousands, compared to only the low hundreds for ALMA, which means it’s hard for ALMA to pick out faded details tuned in against brighter features.
So the research team, led by Shinya Komoji of Kogakuen University in Japan, used a new technique they call “self-calibration.” The trick is to reduce the glare from the quasar by using 3C 273 itself to correct for fluctuations in Earth’s atmosphere which could affect ALMA detection of sub-millimeter radio waves.
This method increases contrast. ALMA 3C monitored 273 at frequencies of 93, 233, and 343 GHz, and the self-calibration technology allowed dynamic imaging ranges of 85,000, 39,000 and 2,500, respectively – the highest dynamic ranges ever achieved by ALMA.
This technology has revealed never-before-seen details about its host galaxy 3C 273, including what scientists describe as an “unknown structure” in its A statement about the discovery (Opens in a new tab). The Komugi team saw a faint band of radio emissions across the host galaxy spanning tens of thousands of light years. This radio emission comes from tens of billions to hundreds of billions of solar masses of hydrogen gas ionized by ultraviolet and X-rays from the quasar.
Astronomers strongly doubt the existence of a relationship between the radiation output from the energetic supermass black holes and suppress star formation in host galaxies. The radiation flowing from the accretion disk acts as a negative reaction, heating the molecular hydrogen gas so that it can no longer form stars.
However, there appears to be a lot of cold molecular hydrogen gas remaining in the 3C 273 . host galaxyStar formation continues. So, either the relationship between feedback from the quasar and the cessation of star formation is not as concrete as scientists think, or we may have collided 3C 273 and our galaxy in a short time frame before the effects of the feedback became apparent.
The Komugi team is now observing other quasars in a similar way to gain a broader understanding of these processes.
Komoji said in a book statement (Opens in a new tab).
The research was published online in April in Astrophysical Journal (Opens in a new tab).
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