Thank u so much!! 😁
February 1, 2026 at 11:20 PM
Thank u so much!! 😁
This project wouldn’t have been possible without this incredible team, featuring @rpnaidu.bsky.social @jorryt.bsky.social, and Anna de Graaff! 🙌
February 1, 2026 at 1:04 AM
This project wouldn’t have been possible without this incredible team, featuring @rpnaidu.bsky.social @jorryt.bsky.social, and Anna de Graaff! 🙌
We also infer a BH* duty cycle of ~1% and a BH* lifetime of ~10 Myrs - they are a short-lived, and yet ubiquitous phenomenon. They may be a key phase in the origin story of possibly every massive BH!
February 1, 2026 at 1:04 AM
We also infer a BH* duty cycle of ~1% and a BH* lifetime of ~10 Myrs - they are a short-lived, and yet ubiquitous phenomenon. They may be a key phase in the origin story of possibly every massive BH!
V-shaped LRD selections are preferentially sensitive to high BH*/LRD fractions. So the population of BH*s may be more widespread than what we currently know. Hidden BH*s in e.g. broad-line AGN??
February 1, 2026 at 1:04 AM
V-shaped LRD selections are preferentially sensitive to high BH*/LRD fractions. So the population of BH*s may be more widespread than what we currently know. Hidden BH*s in e.g. broad-line AGN??
With BH*-dominated LRDs on one extreme ⬅️, the other extreme has host-dominated LRDs ➡️, which appear to be some of the most spectacular starbursts at high redshift.
February 1, 2026 at 1:04 AM
With BH*-dominated LRDs on one extreme ⬅️, the other extreme has host-dominated LRDs ➡️, which appear to be some of the most spectacular starbursts at high redshift.
BH*/LRD fractions correlate with easily accessible observables, LRD [OIII] EW and Balmer break strength. This may help accelerate the search for BH*-dominated objects.
February 1, 2026 at 1:04 AM
BH*/LRD fractions correlate with easily accessible observables, LRD [OIII] EW and Balmer break strength. This may help accelerate the search for BH*-dominated objects.
Who dominates the LRD light? In the UV, the BH* contribution is modest relative to the host. But then there is an abrupt transition around (but not exactly at) the Balmer break, redwards of which the BH* begins to dominate the light.
February 1, 2026 at 1:04 AM
Who dominates the LRD light? In the UV, the BH* contribution is modest relative to the host. But then there is an abrupt transition around (but not exactly at) the Balmer break, redwards of which the BH* begins to dominate the light.
LRD hosts lie above the star-forming main sequence, and display rising star-formation histories. Recent starbursts may play a role in the formation of BH*s and/or their entrapment in gas!
February 1, 2026 at 1:04 AM
LRD hosts lie above the star-forming main sequence, and display rising star-formation histories. Recent starbursts may play a role in the formation of BH*s and/or their entrapment in gas!
What about the LRD hosts? They show far stronger emission lines than a control sample, implying highly ionizing, young stellar populations.
February 1, 2026 at 1:04 AM
What about the LRD hosts? They show far stronger emission lines than a control sample, implying highly ionizing, young stellar populations.
All the features (in more detail in the paper) lead us to conclude that BH*s are indeed the central engines of LRDs!
February 1, 2026 at 1:04 AM
All the features (in more detail in the paper) lead us to conclude that BH*s are indeed the central engines of LRDs!
When we look at prominent LRDs like The Cliff and MoM-BH*-1 (~“pure” BH*), they bear remarkable similarities to the (LRD - host) stack. And A2744-45924 shows several emission features (e.g., Fe II-UV) that are also apparent in the stack.
February 1, 2026 at 1:04 AM
When we look at prominent LRDs like The Cliff and MoM-BH*-1 (~“pure” BH*), they bear remarkable similarities to the (LRD - host) stack. And A2744-45924 shows several emission features (e.g., Fe II-UV) that are also apparent in the stack.
A single blackbody with Teff ~4000 K fits the rest-optical well. The inferred radius ~1300 au is 2 dex larger than the largest known stars, but comparable to local broad-line regions.
February 1, 2026 at 1:04 AM
A single blackbody with Teff ~4000 K fits the rest-optical well. The inferred radius ~1300 au is 2 dex larger than the largest known stars, but comparable to local broad-line regions.
The stack has a strong Balmer break ~6.50 that far exceeds the strongest breaks seen in quiescent galaxies, as well as EW(Hα) ~850Å and Balmer decrement ~16 that are far more extreme than local AGN!
February 1, 2026 at 1:04 AM
The stack has a strong Balmer break ~6.50 that far exceeds the strongest breaks seen in quiescent galaxies, as well as EW(Hα) ~850Å and Balmer decrement ~16 that are far more extreme than local AGN!
The (LRD - host) central engine stack exhibits a constellation of features that are the hallmark signatures of BH*s!
February 1, 2026 at 1:04 AM
The (LRD - host) central engine stack exhibits a constellation of features that are the hallmark signatures of BH*s!
We present a novel, empirical approach to isolate the central engines of LRDs, by assuming that the [OIII] luminosity arises purely from the host galaxy. By subtracting the host, we uncover what’s remaining. LRD - Host Galaxy = ??
February 1, 2026 at 1:04 AM
We present a novel, empirical approach to isolate the central engines of LRDs, by assuming that the [OIII] luminosity arises purely from the host galaxy. By subtracting the host, we uncover what’s remaining. LRD - Host Galaxy = ??
I'm an undergrad student at MIT, working in astronomy
January 31, 2026 at 10:38 PM
I'm an undergrad student at MIT, working in astronomy