Astrônomos identified 77 quasars hidden by cosmic dust. The discovery expands knowledge about a rare phase in the growth of supermassive black holes. The objects, located in distant galaxies, were hidden for billions of years.
Quasars are extremely bright sources powered by matter falling into central black holes. Dense dust blocked its detection at visible wavelengths. Pesquisadores used infrared observations to reveal the population. The study, led by Matthew Stepney, of Centro from Excelência into Astrofísica and Tecnologias Relacionadas into Chile, was published on arXiv.
NASA’s SPHEREx enabled detection of reddish objects
NASA’s SPHEREx mission provided the crucial infrared data for the work. The team analyzed spectrophotometric measurements and identified the 77 strongly reddened quasars, known as HRQs. Esses objects more than double the previously known number of this class.
Quasars existed when the universe was between 1.6 billion and 4.3 billion years old. Sete of them were detected at redshifts above 3. Isso corresponds to the first 2.1 billion years of cosmic history. The sample makes it possible to study the growth of black holes in older periods.
- HRQs present light strongly altered by intervening dust.
- Eles occupy an intermediate position between galaxies obscured by hot dust and blue quasars.
- The infrared emission was weaker than expected after corrections.
- Sete objects mark the first examples of this class in the early universe.
- Three-quarter Cerca displays extra ultraviolet light.
Características indicate explosion phase in black holes
The researchers compared the new quasars to galaxies obscured by hot dust, called Hot DOGs, and to blue quasars. The HRQs showed less hot dust than predicted. Essa combination suggests a transient moment of high activity.
The black hole becomes so active that it expels gas and dust from the central regions. The authors describe this as an “explosion” phase. The feedback removes obscuring material and allows some of the radiation to escape. The observation of extra ultraviolet light reinforces the idea of escape around the edge of the dust cocoon.
Star formation in the host galaxy may also contribute to the observed brightness. Scientists highlight that the phenomenon represents a short but intense stage in the evolution of these systems.
Comparação with other types of cosmic objects
HRQs differ from Hot DOGs by the amount of hot dust. Eles also contrast with more exposed blue quasars. Após adjusted for the effects of dust, the new objects turned out to be among the brightest ever observed.
Essa luminosity combined with weaker infrared signals points to depleted dust reservoirs. The study strengthens evidence that reddish quasars capture a moment of cleansing of the central regions.
Discovery’s Impacto for Galactic Evolution Models
The sample extends observations of the growth of black holes to more remote times. Ela fills gaps in populations that remained hidden. The SPHEREx data continues to be analyzed and should yield more similar findings.
Pesquisadores plan follow-up observations to confirm physical properties. The work contributes to understanding how supermassive black holes influence the development of their host galaxies.
Detalhes quasar sample technicians
The team used infrared-based selection techniques to filter candidates. High redshift confirms large cosmological distances. Measurements indicate that dust predominantly affects light at certain wavelengths.
The seven quasars at redshifts above 3 represent a pioneering finding. Eles existed in a still young universe. The discovery doubles the known catalog and paves the way for more robust statistical studies.
