About

Pieter van Dokkum is the Sol Goldman Family Professor of Astronomy and Professor of Physics at Yale University. He is affiliated with the Yale Center for Astronomy and Astrophysics, located at 260 Whitney Ave, New Haven, CT. His work involves research in astronomy and astrophysics, contributing to Yale's academic community in these fields.

Research topics

• Physics
• Astrophysics
• Astronomy
• Computer Science
• Materials science
• Algorithm

Selected publications

• A population of red candidate massive galaxies ~600 Myr after the Big Bang

  Nature · 2023 · 524 citations

  • Physics
  • Astrophysics
  • Astronomy
  DOI

• Tidal Distortions in NGC1052-DF2 and NGC1052-DF4: Independent Evidence for a Lack of Dark Matter

  The Astrophysical Journal · 2022 · 32 citations

  • Physics
  • Astrophysics
  • Astronomy

  Abstract Two ultra-diffuse galaxies in the same group, NGC1052-DF2 and NGC1052-DF4, have been found to have little or no dark matter and to host unusually luminous globular cluster populations. Such low-mass diffuse objects in a group environment are easily disrupted and are expected to show evidence of tidal distortions. In this work, we present deep new imaging of the NGC1052 group, obtained with the Dragonfly Telephoto Array, to test this hypothesis. We find that both galaxies show strong position-angle twists and are significantly more elongated at their outskirts than in their interiors. The group’s central massive elliptical NGC1052 is the most likely source of these tidal disturbances. The observed distortions imply that the galaxies have a low total mass or are very close to NGC1052. Considering constraints on the galaxies’ relative distances, we infer that the dark matter halo masses of these galaxies cannot be much greater than their stellar masses. Calculating pericenters from the distortions, we find that the galaxies are on highly elliptical orbits, with a ratio of pericenter to present-day radius R peri / R 0 ∼ 0.1 if the galaxies are dark matter–free and R peri / R 0 ∼ 0.01 if they have a normal dark halo. Our findings provide strong evidence, independent of kinematic constraints, that both galaxies are dark matter–deficient. Furthermore, the similarity of the tidal features in NGC1052-DF2 and NGC1052-DF4 strongly suggests that they arose at comparable distances from NGC1052. In Appendix A, we describe sbcontrast , a robust method for determining the surface brightness limits of images.

  PublisherDOI

• Fast, Slow, Early, Late: Quenching Massive Galaxies at z ∼ 0.8

  The Astrophysical Journal · 2022 · 159 citations

  • Physics
  • Astrophysics
  • Astronomy

  Abstract We investigate the stellar populations for a sample of 161 massive, mainly quiescent galaxies at 〈 z obs 〉 = 0.8 with deep Keck/DEIMOS rest-frame optical spectroscopy (HALO7D survey). With the fully Bayesian framework Prospector , we simultaneously fit the spectroscopic and photometric data with an advanced physical model (including nonparametric star formation histories, emission lines, variable dust attenuation law, and dust and active galactic nucleus emission), together with an uncertainty and outlier model. We show that both spectroscopy and photometry are needed to break the dust–age–metallicity degeneracy. We find a large diversity of star formation histories: although the most massive ( M ⋆ &gt; 2 × 10 11 M ⊙ ) galaxies formed the earliest (formation redshift of z f ≈ 5–10 with a short star formation timescale of τ SF ≲ 1 Gyr), lower-mass galaxies have a wide range of formation redshifts, leading to only a weak trend of z f with M ⋆ . Interestingly, several low-mass galaxies have formation redshifts of z f ≈ 5–8. Star-forming galaxies evolve about the star-forming main sequence, crossing the ridgeline several times in their past. Quiescent galaxies show a wide range and continuous distribution of quenching timescales ( τ quench ≈ 0–5 Gyr) with a median of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo stretchy="false">〈</mml:mo> <mml:msub> <mml:mrow> <mml:mi>τ</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>quench</mml:mi> </mml:mrow> </mml:msub> <mml:mo stretchy="false">〉</mml:mo> <mml:mo>=</mml:mo> <mml:msubsup> <mml:mrow> <mml:mn>1.0</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.9</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.8</mml:mn> </mml:mrow> </mml:msubsup> <mml:mspace width="0.50em"/> <mml:mi>Gyr</mml:mi> </mml:math> and of quenching epochs of z quench ≈ 0.8–5.0 ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo stretchy="false">〈</mml:mo> <mml:msub> <mml:mrow> <mml:mi>z</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>quench</mml:mi> </mml:mrow> </mml:msub> <mml:mo stretchy="false">〉</mml:mo> <mml:mo>=</mml:mo> <mml:msubsup> <mml:mrow> <mml:mn>1.3</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.4</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.7</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> ). This large diversity of quenching timescales and epochs points toward a combination of internal and external quenching mechanisms. In our sample, rejuvenation and “late bloomers” are uncommon. In summary, our analysis supports the “grow-and-quench” framework and is consistent with a wide and continuously populated diversity of quenching timescales.

  DOI

• Two Remarkably Luminous Galaxy Candidates at z ≈ 10–12 Revealed by JWST

  The Astrophysical Journal Letters · 2022 · 421 citations

  • Computer Science
  • Physics
  • Materials science

  Abstract The first few 100 Myr at z &gt; 10 mark the last major uncharted epoch in the history of the universe, where only a single galaxy (GN-z11 at z ≈ 11) is currently spectroscopically confirmed. Here we present a search for luminous z &gt; 10 galaxies with JWST/NIRCam photometry spanning ≈1–5 μ m and covering 49 arcmin 2 from the public JWST Early Release Science programs (CEERS and GLASS). Our most secure candidates are two M UV ≈ −21 systems: GLASS-z12 and GLASS-z10. These galaxies display abrupt ≳1.8 mag breaks in their spectral energy distributions (SEDs), consistent with complete absorption of flux bluewards of Ly α that is redshifted to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>z</mml:mi> <mml:mo>=</mml:mo> <mml:msubsup> <mml:mrow> <mml:mn>12.4</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.3</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.1</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>z</mml:mi> <mml:mo>=</mml:mo> <mml:msubsup> <mml:mrow> <mml:mn>10.4</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.5</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.4</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> . Lower redshift interlopers such as quiescent galaxies with strong Balmer breaks would be comfortably detected at &gt;5 σ in multiple bands where instead we find no flux. From SED modeling we infer that these galaxies have already built up ∼10 9 solar masses in stars over the ≲300–400 Myr after the Big Bang. The brightness of these sources enable morphological constraints. Tantalizingly, GLASS-z10 shows a clearly extended exponential light profile, potentially consistent with a disk galaxy of r 50 ≈ 0.7 kpc. These sources, if confirmed, join GN-z11 in defying number density forecasts for luminous galaxies based on Schechter UV luminosity functions, which require a survey area &gt;10× larger than we have studied here to find such luminous sources at such high redshifts. They extend evidence from lower redshifts for little or no evolution in the bright end of the UV luminosity function into the cosmic dawn epoch, with implications for just how early these galaxies began forming. This, in turn, suggests that future deep JWST observations may identify relatively bright galaxies to much earlier epochs than might have been anticipated.

  DOI

Recent grants

• The NEWFIRM Medium-Band Survey: Accurate Redshifts for 80,000 K-Selected Galaxies

  NSF · $441k · 2008–2012

• The Dragonfly Project: Imaging the outer limits of nearby galaxies

  NSF · $480k · 2013–2016

• CAREER: The Formation Epoch of Massive Galaxies

  NSF · $674k · 2005–2010

• The Low Surface Brightness Sky with the 48-Lens Dragonfly Telephoto Array

  NSF · $578k · 2016–2020

Frequent coauthors

• Marijn Franx

  427 shared

• Ivo Labbé

  Swinburne University of Technology

  275 shared

• Gabriel Brammer

  University of Copenhagen

  269 shared

• Katherine E. Whitaker

  University of Massachusetts Amherst

  215 shared

• G. D. Illingworth

  University of California, Santa Cruz

  196 shared

• Erica J. Nelson

  180 shared

• Pascal A. Oesch

  University of Geneva

  162 shared

• Mariska Kriek

  155 shared

Similar researchers at Yale University

• Mark Gersteinh-217
• Liangbing Huh-172
• Akiko Iwasakih-145
• Alan Kazdinh-142
• Douglas L. Rothmanh-125