A groundbreaking celestial observation has unveiled the most ancient pulsating quasar yet detected, with its emitted light commencing a journey exceeding 13 billion years to grace our observation instruments.
This discovery holds significant potential in deciphering the developmental trajectories of exceptionally colossal black holes that materialized with surprising rapidity in the nascent stages of the cosmos.
Remarkably, this venerable quasar, identified as J0439+1634, exhibits a flattened configuration in its accretion disk, a swirling vortex of matter drawn into its immense gravitational pull, indicative of an advanced state of maturity for its epoch.
“This discovery furnishes unequivocal evidence that the fundamental feeding mechanisms and structural configurations observed in more proximate regions of the universe were already operative at exceedingly early temporal junctures, notwithstanding vastly divergent cosmic environments,” states Anna-Christina Eilers, a distinguished observational astrophysicist affiliated with MIT.
“Such a phenomenon had remained entirely unobserved until this point.”
Quasars represent incandescent active galactic nuclei, deriving their prodigious energy from the accretion of matter by supermassive black holes (SMBHs).
Among the most luminous and energetic entities within the observable universe, quasars radiate with an intensity that dwarfs the combined brilliance of entire galaxies populated by trillions of stars.
In closer cosmic proximity, quasars are known to exhibit variability in their luminosity, attributed to the irregular influx of matter into their central black holes.
“The observed luminosity fluctuations originate from variations in the rate at which gas is channeled into the black hole,” elucidates MIT astronomer Gene Leung.
“Consequently, the pattern of a quasar’s flickering provides insights into the architecture of its accretion disk and the nature of the material being consumed.”
However, the detection of such temporal variations in the light emanating from the early cosmos presents formidable challenges.
In their recent investigative endeavor, an international consortium of astronomers, spearheaded by researchers from MIT, has successfully documented the earliest instance of this particular celestial phenomenon.
The scientific team observed this quasar seemingly ‘winking’ at us across an immense expanse of spacetime; its emitted light originated from a period when the universe was merely 850 million years old, during the epoch of vigorous star formation known as the cosmic dawn.
“While numerous quasars have been identified within the cosmic dawn period, this marks the inaugural instance where we have observed such luminosity variability,” confirms Leung.
The identification and characterization of this flickering signal, originating from the most remote observable regions of the universe, posed an extraordinary scientific undertaking.
As the universe undergoes expansion, the light traversing vast intergalactic distances is progressively elongated into longer, redder wavelengths, a phenomenon scientifically termed redshift.
A relatable analogy can be drawn to the Doppler effect experienced with sound, where the pitch of an approaching ambulance siren appears higher, subsequently dropping in frequency as it recedes.
Furthermore, due to the intrinsic interconnectedness of space and time, the dilation of the cosmic fabric consequently impacts temporal observations.
From an observational perspective billions of light-years distant on Earth, a luminous fluctuation that transpires over a period of weeks can be perceived as extending over several months.
To ascertain this subtle signal, the astronomical team leveraged multi-spectral data acquired from terrestrial and orbital observatories, including NASA’s Near-Earth Object Wide-field Infrared Survey (NEOWISE), which meticulously compiled a temporal record of the entire nocturnal celestial sphere in infrared wavelengths between 2010 and 2024.
“We observed the quasar exhibiting random luminosity variations over the 14-year observational span, akin to the unpredictable dance of a candle flame,” recounts Leung.
By meticulously tracking its flux across a spectrum of wavelengths, encompassing infrared and X-ray emissions, the astronomers have estimated that this ancient quasar possesses a mass exceeding 600 million solar masses.
In contrast, our local supermassive black hole, Sagittarius A*, situated at the galactic center of the Milky Way, is comparatively diminutive, with an estimated mass of approximately 4 million solar masses.
J0439+1634 is also characterized by an astonishing luminosity, radiating with the combined brilliance of 12 trillion suns.
The detailed analysis of its radiative flux, which provided insights into the temperature and proximity of infalling material to its central black hole, further enabled the astronomers to delineate the structure of its accretion disk.
Intriguingly, their findings indicated a flattened and relatively ordered accretion disk, a configuration that diverges from the prevailing theoretical models postulating immature, chaotically configured ‘puffy’ disks in early SMBHs that had not yet achieved structural stability.
Consequently, quasars in more localized cosmic regions are associated with smaller, more organized accretion disks and coronae, indicative of a more evolved state.
“I surmise that this observation suggests that the protracted and highly dynamic growth phases, which are anticipated to be a universal characteristic of all black hole development, occur at an exceptionally early stage, predating their manifestation as these intensely luminous quasars,” opines Eilers.
This research also introduces novel methodologies for quantifying the mass of some of the most ancient quasars and for constraining the requisite size of initial black hole seeds to facilitate the formation of SMBHs boasting billions of solar masses by the time the universe reached approximately 10 percent of its present age.
The research team now aspires to identify even more nascent quasars to gain a more profound understanding of their evolutionary processes and their impact on galactic development.
Fortuitously, the groundwork, both terrestrial and extraterrestrial, has been laid by this study to enable their detection using next-generation observational facilities, including the recently commissioned Vera C. Rubin Observatory situated in Chile and the Nancy Grace Roman Space Telescope, scheduled for deployment in August.
The future landscape of quasar investigation during the cosmic dawn era appears exceptionally promising, both literally and figuratively, even as the light under scrutiny commenced its immense voyage over 13 billion years ago.
The findings of this investigation have been formally published in the esteemed journal Nature Astronomy.
