About

Priyamvada Natarajan is a Professor of Astronomy and of Astrophysics at Yale University. She is associated with the Yale Center for Astronomy and Astrophysics, and her office is located at Kline Tower 613. Her research focuses on astrophysics and astronomy, contributing to the understanding of the universe through her academic and scientific work. As a faculty member at Yale, she is involved in advancing knowledge in her field and engaging in scholarly activities related to astronomy and astrophysics.

Research topics

• Artificial Intelligence
• Computer Science
• Physics
• Astronomy
• Nuclear physics
• Computational physics
• Quantum mechanics
• Astrophysics
• Data science

Selected publications

• Constraining the Nature of Dark Matter from Tidal Radii of Cluster Galaxy Subhalos

  The Astrophysical Journal · 2026-01-16 · 1 citations

  preprintOpen accessSenior author

  Abstract Gravitational lensing by galaxy clusters provides a powerful probe of the spatial distribution of dark matter and its microphysical properties. Strong and weak lensing constraints on the density profiles of subhalos and their truncation radii offer key diagnostics for distinguishing between collisionless cold dark matter (CDM) and self-interacting dark matter (SIDM). Notably, in the strongly collisional SIDM regime, subhalo core collapse and enhanced mass loss from ram-pressure stripping predict steeper central density slopes and more compact truncation radii—features that are directly testable with current lensing data. We analyze subhalo truncation in eight lensing clusters (A2218, 383, 963, 209, 2390, and MACS J0416.1, J1206.2, J1149.6) that span the redshift range <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mfenced close="〉" open="〈"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>z</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">spec</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:mfenced> <mml:mo>≃</mml:mo> <mml:mn>0.17</mml:mn> </mml:math> –0.54 with virial masses M 200 ≃ 0.41–2.2 × 10 15 M ⊙ to constrain SIDM versus CDM. Our results indicate that the outer spatial extents of subhalos are statistically consistent with CDM, corroborated by redshift- and mass-matched analogs from the IllustrisTNG simulations. We conclude that the tidal radii of cluster galaxy subhalos serve as an important and complementary diagnostic of the nature of dark matter in these violent, dense environments.

  PublisherDOI

• Table Data and Figures for "Evidence for evolving Dark Energy from a new cosmic probe"

  Zenodo (CERN European Organization for Nuclear Research) · 2026-05-07

  datasetOpen access

  Table_7.csv: Full version of AGN data Table 7: Summary of AGN properties and inferred distance moduli for the plotted sample. spectral_fitting_figures.zip: Figures of SDSS spectral fitting results for the plotted sample. light_curve_fits.zip: Figures of SDSS spectral fitting results for the plotted sample.

  PublisherDOI

• MESA-QUEST: Work directory for "Tracing the Formation of Direct Collapse Black Hole Seeds via Quasi-stars"

  Zenodo (CERN European Organization for Nuclear Research) · 2026-01-01

  datasetOpen access

  This is the MESA work directory for the article "Tracing the Formation of Direct Collapse Black Hole Seeds via Quasi-stars". We include the inlist and run_star_extras files required to run them. The version of MESA used for this work is r24.08.1, though newer releases should work as well.

  PublisherDOI

• New Cold Dark Matter Crisis Revealed by Multiscale Cluster Lensing

  The Astrophysical Journal Letters · 2026-04-08 · 1 citations

  articleOpen access1st authorCorresponding

  Abstract The properties of substructure in galaxy clusters, exquisitely probed by gravitational lensing, offer a stringent test of dark matter (DM) models. Combining strong- and weak-lensing data for massive clusters, we map their total mass—dominated by DM—over the dynamic range needed to confront small-scale predictions for collisionless cold DM (CDM). Using state-of-the-art lens models, we extract four key subhalo properties: the mass function, projected radial distribution, internal density profile, and tidal truncation radius. We find that the subhalo mass functions and truncation radii are consistent with CDM expectations. In contrast, the inner density profiles and radial distributions of subhalos are strongly discrepant with CDM. The incidence of galaxy–galaxy strong lensing from subhalo cores exceeds CDM predictions by nearly an order of magnitude, requiring inner density slopes as steep as γ ≳ 2.5 within r ≲ 0.01 R 200 consistent with core-collapsed self-interacting DM (SIDM), while the same subhalos behave as collisionless in their outskirts. Additionally, the observed radial distribution of subhalos hosting bright cluster member galaxies, explicitly modeled in the lens reconstructions, remains incompatible with CDM. Taken together, these small-scale stress tests reveal an intriguing paradox and challenge the DM microphysics of purely collisionless CDM, motivating hybrid scenarios—such as a dual-component model with both CDM and SIDM or entirely new classes of DM theories.

  PublisherDOI

• The first GLIMPSE of the faint galaxy population at Cosmic Dawn with <i>JWST</i> : The evolution of the ultraviolet luminosity function across <i>z</i> ∼ 9−15

  Monthly Notices of the Royal Astronomical Society · 2026-01-06

  articleOpen access

  ABSTRACT Using ultra-deep James Webb Space Telescope (JWST)/NIRCam imaging from the GLIMPSE survey, enhanced by gravitational lensing from the Abell S1063 cluster, we investigate the faintest galaxies ever observed at redshifts $z\sim 9{\text{-}}15$. We identify 105 galaxy candidates spanning absolute ultraviolet (UV) magnitudes $M_{\mathrm{UV}}$$\sim -18$ to $-13$, about 3 mag fainter, on average, than prior JWST studies. We place strong constraints on the ultra-faint end of the UV luminosity function (UVLF), finding minimal evolution in the faint-end slope, from $\alpha =-2.01\pm 0.20$ at $z=9$ to $\alpha =-2.10\pm 0.19$ at $z=13$, in contrast to the rapid evolution observed at $z\sim 0{\text{-}}9$. Integrating the UVLF down to $M_{\mathrm{UV}}$$=-16$, we find the cosmic star formation rate density, $\rho _{\rm SFR}$, evolves as $\propto (1+z)^{-2.94^{+0.06}_{-0.10}}$, over $z=9{\text{-}}13$, which is significantly shallower than most theoretical predictions. Extending the integration limit to $M_{\mathrm{UV}}$$=-13$ reveals galaxies fainter than $M_{\mathrm{UV}}$$=-16$ contribute over 50 per cent of the total cosmic star formation rate density at $z\sim 12$. This excess may indicate enhanced star formation efficiency during the earliest phases of galaxy formation. Alternatively, it could arise from bursty star formation histories; minimal dust attenuation; or an evolving initial mass function. However, existing models incorporating these effects fail to fully reproduce the observed redshift evolution of $\rho _{\rm SFR}$. We note that low-redshift contamination and cosmic variance may affect our results, as the limited survey volume may not be representative of the broader galaxy population. Similar observations and spectroscopic confirmation are required to validate these findings.

  PublisherDOI

• A Kiloparsec-scale Stellar Cavity in the Center of A402-BCG May Be Caused by Dynamic Interactions with an Ultramassive Black Hole

  The Astrophysical Journal Letters · 2026-04-23

  articleOpen access

  Abstract We present new observations from JWST that reveal a striking kiloparsec-wide cavity in the stellar distribution of the central galaxy in the cluster A402. Supporting data from the Hubble Space Telescope (HST) allow us to rule out extinction due to dust as an explanation, and instead, suggest that this is a localized depression in the stellar density field corresponding to ∼2 × 10 9 M ⊙ in missing stars within a volume of 0.5 kpc 3 . On larger scales, both the JWST and HST data show evidence for a 2.2 kpc flattened core in the stellar distribution (on which the smaller-scale cavity is superimposed), which implies the presence of a central ultramassive black hole with M BH ∼ 5 × 10 10 M ⊙ . We report evidence for a mid-IR-bright point source at one edge of the cavity, suggesting that this black hole is actively accreting. MUSE spectroscopy reveals that this source is a low-ionization nuclear emission-line region active galactic nucleus (AGN) and that there is a second candidate AGN on the opposite side of the cavity with a relative velocity of 370 km s −1 —if real, this implies the presence of a kiloparsec-separation dual AGN with a total binary mass of 6 ± 2 × 10 10 M ⊙ , which would make this the most massive binary black hole system discovered to date. We propose that this unique stellar cavity is the result of a short-lived dynamical interaction between at least one supermassive black hole and the background stellar density field, caused either by three-body scattering during binary hardening or the induction of a dipole instability in the stellar density field.

  PublisherDOI

• MESA-QUEST: Work directory for "Evolutionary Tracks and Spectral Properties of Quasi-stars and Their Correlation with Little Red Dots"

  Open MIND · 2026-01-01

  dataset

  This is the MESA work directory for the article "Evolutionary Tracks and Spectral Properties of Quasi-stars and Their Correlation with Little Red Dots". We include history and profile data for each model used in the paper, as well as the inlist and run_star_extras files required to run them. The version of MESA used for this work is r25.12.1.

  DOI

• Table Data and Figures for "Evidence for evolving Dark Energy from a new cosmic probe"

  Zenodo (CERN European Organization for Nuclear Research) · 2026-05-07

  datasetOpen access

  Table_7.csv: Full version of AGN data Table 7: Summary of AGN properties and inferred distance moduli for the plotted sample. spectral_fitting_figures.zip: Figures of SDSS spectral fitting results for the plotted sample. light_curve_fits.zip: Figures of SDSS spectral fitting results for the plotted sample.

  PublisherDOI

• Bridging Scales in Black Hole Accretion and Feedback: Subgrid Prescription from First Principles

  The Astrophysical Journal Letters · 2026-05-07 · 1 citations

  articleOpen access

  Abstract Understanding how supermassive black holes (BHs) couple to their host galaxies across a vast spatial and temporal dynamic range remains a central challenge in galaxy evolution. Using the multizone framework—designed to capture a bidirectional inflow–outflow from the event horizon to the Bondi scale—we present a suite of long-duration GRMHD simulations spanning BH spins ∣ a * ∣ = 0–0.9 and Bondi radii R B / r g = 4 × 10 2 –2 × 10 6 . From these simulations we derive spin-dependent subgrid prescriptions from first principles, applicable to hot accretion flows with low Eddington ratios ( f Edd ≲ 10 −3 ), for adoption in cosmological simulations and semianalytic models. We provide compact analytic fits for the time-averaged accretion rate <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mi>M</mml:mi> <mml:mo>̇</mml:mo> </mml:mover> <mml:mo stretchy="false">(</mml:mo> <mml:msub> <mml:mi>R</mml:mi> <mml:mi mathvariant="normal">B</mml:mi> </mml:msub> <mml:mo>,</mml:mo> <mml:msub> <mml:mi>a</mml:mi> <mml:mo>*</mml:mo> </mml:msub> <mml:mo stretchy="false">)</mml:mo> </mml:math> and feedback power <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mover accent="true"> <mml:mi>E</mml:mi> <mml:mo>̇</mml:mo> </mml:mover> <mml:mi>fb</mml:mi> </mml:msub> <mml:mo stretchy="false">(</mml:mo> <mml:msub> <mml:mi>R</mml:mi> <mml:mi mathvariant="normal">B</mml:mi> </mml:msub> <mml:mo>,</mml:mo> <mml:msub> <mml:mi>a</mml:mi> <mml:mo>*</mml:mo> </mml:msub> <mml:mo stretchy="false">)</mml:mo> </mml:math> with respect to the Bondi rate <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mover accent="true"> <mml:mi>M</mml:mi> <mml:mo>̇</mml:mo> </mml:mover> <mml:mi mathvariant="normal">B</mml:mi> </mml:msub> </mml:math> , which are largely insensitive to the initial gas configuration and magnetic field strength. To capture intrinsic time variability, we also quantify the full distributions of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>̇</mml:mo> </mml:mrow> </mml:mover> </mml:math> and feedback efficiency η , both well described by lognormal statistics, with widths that increase toward larger R B . We further measure self-consistent spin evolution in the hot accretion mode, finding that the spin-up parameter varies as s ( a * ) ≃ −3.7 a * , which implies a very long spin-down timescale t s ≃ 12(10 −3 / f Edd ) Gyr. Thus, BH spins are effectively frozen during phases of quiescent accretion. Compared to conventional small-domain GRMHD calculations, our simulations, which reach dynamical equilibrium across horizon to galaxy scales, yield systematically different long-term accretion, feedback, and spin properties, cautioning against direct extrapolation from small-scale GRMHD simulations when constructing galactic-scale subgrid models.

  PublisherDOI

• Tracking the Assembly of Supermassive Black Holes: A Comparison of Diverse Models across Cosmic Time

  The Astrophysical Journal · 2026-02-03 · 2 citations

  articleOpen access

  Abstract Galaxies grow alongside central supermassive black holes (SMBHs) through fueling and feedback. However, the origins of this coevolution remain unclear and vary across modeling frameworks. Using semianalytic models (SAMs), we trace SMBH mass assembly across M BH ∼ 10 6−10 M ⊙ . We find significant discrepancies between observations and physics-based models of the local black hole mass function (BHMF), likely from differences in the stellar mass function and scaling relations used to infer the BHMF. Most physics-based models agree at z ∼ 1–4 and broadly match the JWST broad-line active galactic nucleus (AGN) BHMFs at z = 4–5. These models also reproduce the observed bolometric AGN luminosity evolution, except the SAM Dark Sage , which predicts an excess. Interestingly, this pronounced “knee” in the bolometric AGN luminosity function predicted by Dark Sage around L bol ∼ 10 46 erg s −1 is consistent with the inferred abundance and luminosity of “little red dots” at z = 5–6, under the assumption that they are powered entirely by AGN activity. In contrast to other models, Dark Sage deploys multiple growth channels for SMBHs that include mergers, hot-mode accretion, merger-driven cold-accretion, and secular-instability-driven accretion. We analyze the black hole mass buildup and accretion histories in Dark Sage , which, unlike other models, also allows for super-Eddington accretion, and we find that, on average, SMBHs primarily grow through secular disk instabilities and merger-driven cold gas accretion modes. We also find that black hole mergers contribute the majority of the growth of ∼60% of the total mass budget only for the most massive SMBHs by z = 0.

  PublisherDOI

Recent grants

• Collaborative Research: The multi-scale physics of massive black hole formation, fueling, and feedback

  NSF · $429k · 2013–2017

• Cosmography with Cluster Strong Lensing

  NSF · $368k · 2010–2015

Frequent coauthors

• Angelo Ricarte

  Woodwell Climate Research Center

  130 shared

• Jean‐Paul Kneib

  116 shared

• Marceau Limousin

  83 shared

• Mathilde Jauzac

  77 shared

• Johan Richard

  74 shared

• Chiara M. F. Mingarelli

  University of Connecticut

  69 shared

• Ramesh Narayan

  67 shared

• Eric Jullo

  Château Gombert

  63 shared