John R. Weaver

John R. Weaver

PhD Fellow in Astrophysics

Cosmic Dawn Center

Niels Bohr Institute

University of Copenhagen

Biography

I am a PhD student based at the Cosmic Dawn Center advised by Sune Toft, with Peter Capak (fmr. Caltech/IPAC), Henry McCracken (IAP), Bahram Mobasher (UCR), and Dave Sanders (IfA/Hawaii). I received my Masters degree in 2018 from the University of St Andrews advised by Vivienne Wild. My research focuses on the assembly and evolution of galaxies across the history of the Universe, through direct observation with telescopes from both space and the ground.

I have held internship or visiting positions at the California Institute of Technology, the University of Hawaii, the Max-Planck Institute for AstronomyLeiden Observatory, and the Maria Mitchell Observatory. I also led the creation of the spectroscopy database AVSpec for the American Association of Variable Star Observers as a Mayall Fellow.

Beyond academia, I am a frequent contributor to popular science publications including the paper digest Astrobites, and have been a long-time volunteer at public observatories.

Download my CV.

Interests
  • Galaxy Evolution
  • The Early Universe
  • Star-formation Cessation
  • Statistical Methods
Education
  • PhD in Astrophysics, 2021

    University of Copenhagen (expected)

  • MPhys in Physics with Astrophysics, 2018

    University of St Andrews

Research

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Distinguishing Quiescent and Dusty Star-forming Galaxies

Distinguishing Quiescent and Dusty Star-forming Galaxies

We employ t-distributed Stochastic Neighborhood Embedding (t-SNE) to tackle this outstanding problem in galaxy evolution

Exploring the Origins of Galaxy Bimodality at z<0.1

Exploring the Origins of Galaxy Bimodality at z<0.1

We use SDSS-MaNGA integral field spectroscopy to investigate a sample of rare post-starbust galaxies

History and Destiny of a Major Merger Remnant

History and Destiny of a Major Merger Remnant

We use ESO’s VLT telescope to disect NGC 7252 with spatially resolved spectroscopy

Improving star-galaxy separation with neural networks

Improving star-galaxy separation with neural networks

Can machine learning help identify stars in galaxy catalogs?

Investigating Star-forming Complexes in a Nearby Dwarf Irregular Galaxy

Investigating Star-forming Complexes in a Nearby Dwarf Irregular Galaxy

We use detailed multi-wavelength Hubble imaging to learn about the history and fate of a peculiar galaxy

PyGAPPY, Gappy Principal Component Analysis with Python

PyGAPPY, Gappy Principal Component Analysis with Python

Robust derivation of Dn4000 and H-delta indices using Principal Component Analysis

Searching for Distant Galaxies with Hubble

Searching for Distant Galaxies with Hubble

We use Hubble Grism Spectroscopy from 3D-HST to identify 29 candidates at z>6

The Most Massive Galaxies in the Early Universe

The Most Massive Galaxies in the Early Universe

Using the COSMOS2020 catalog to identify the most massive galaxies at 3<z<6

Ultra-luminous Galaxies 500 Million years after the Big Bang

Ultra-luminous Galaxies 500 Million years after the Big Bang

An approved Cycle 1 JWST program to investigate five galaxies and their role in reionizing our Universe

Variable Accretion Disks

Variable Accretion Disks

Using variability to determine the dust content and test models of the intrinsic spectral index of quasar variations

BUFFALO Survey

BUFFALO Survey

Exploring six massive galaxy clusters to investigate dark matter, galaxy evolution, and the first galaxies

Euclid Mission

Euclid Mission

An medium-class probe supported by the European Space Agency (ESA)

The Cosmic Dawn Survey

The Cosmic Dawn Survey

An ultra-wide, deep survey of the distant universe

The Cosmic Evolution Survey

The Cosmic Evolution Survey

The widest multi-wavelength galaxy survey with deep near-infrared coverage and ancillary observations

The Hawaii 2-0 Survey

The Hawaii 2-0 Survey

Providing ugrizy photometry over 20deg2 of Euclid Deep Fields

Press

ESO’s VLT Observes a Cosmic Car Crash

Headlines based on Weaver et al. 2018

Appears on: ESO | Sky at Night Magazine | SCI NEWS

Recent Publications

Co-authored: 4
As first author: 1

(2021). Beasts in the Bubbles: Characterizing ultra-luminous galaxies at Cosmic Dawn. JWST Proposal. Cycle 1.

Cite

(2021). Galaxy Protoclusters as Drivers of Cosmic Reionization. JWST Proposal. Cycle 1.

Cite

(2021). Joint Survey Processing I: Compact oddballs in the COSMOS field--low-luminosity Quasars at z> 6?. arXiv preprint arXiv:2103.09836.

Cite

Outreach & Citizen Science

​I began my career in astronomy as an assistant to a planetarium lecturer. Giving back to the community is a part of who I am.

Astronomy on Tap! Copenhagen

Astronomy on Tap! Copenhagen

Astronomy on Tap – Copenhagen is a monthly event held at Huset, organised by astronomers in Copenhagen.

Observatory Stewardship

Observatory Stewardship

Crisp evening air. Clear skies. Maybe a telescope. Nothing refreshes me more than a night under the stars.

Popular Science Articles

Popular Science Articles

I’ve had articles published in a number of online platforms, including Astrobites.

Public Lectures

Public Lectures

An (incomplete) collection of lectures that I’ve given, organized by topic.

Univ. of St Andrews Astronomical Society

Univ. of St Andrews Astronomical Society

One of the largest student-led astronomy societies world-wide.

Astro-
photography

A collection of images taken at either
16" SCT @ St Andrews, UK
2m NOT @ La Palma, ES

Contact