Hubble Ultra Deep Field | NASA, ESA, and F. Summers
John R. Weaver
Postdoctoral Research Associate
University of Massachusetts Amherst
Department of Astronomy
Biography
I am a Postdoc based at the University of Massachusetts Amherst in Kate Whitaker’s Group. I received my PhD in 2022 from the Cosmic Dawn Center advised by Sune Toft, and before that my Masters degree in 2018 from the University of St Andrews advised by Vivienne Wild. My research focuses on the stellar mass assembly of galaxiesand star-formation cessation in the early universe through direct observation with telescopes from both space and the ground. I am a core member of several collaborations including the Cosmic Dawn Survey (DAWN), Cosmic Evolution Survey (COSMOS), UNCOVER, as well as the Euclid Consortium.
I have held internship or visiting positions at the California Institute of Technology, the University of Hawaii, the Max-Planck Institute for Astronomy, Leiden 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.
- Galaxy Evolution
- The Early Universe
- Star-formation Cessation
- Statistical Methods
PhD in Astrophysics, 2022
University of Copenhagen
MPhys in Physics with Astrophysics, 2018
University of St Andrews
Research
Beasts in the Bubbles
An approved Cycle 1 JWST program to investigate five remarkanly luminous galaxies at z~9
COSMOS2020
A near-infrared selected catalog of 1.7 million galaxies with precise photometric redshifts
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
MPhys Thesis | We use SDSS-MaNGA integral field spectroscopy to investigate a sample of rare post-starbust galaxies
Galaxy Stellar Mass Assembly History Over 13 Billion Years
We construct and model the Stellar Mass and Mass Density Functions from the COSMOS2020 catalog
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
Can machine learning help identify stars in galaxy catalogs?
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
Robust derivation of Dn4000 and H-delta indices using Principal Component Analysis
Searching for Distant Galaxies with Hubble
We use Hubble Grism Spectroscopy from 3D-HST to identify 29 candidates at z>6
The Farmer
Reproducible and robust profile-fitting photometry powered by The Tractor
The Most Massive Galaxies in the Early Universe
Using the COSMOS2020 catalog to identify the most massive galaxies at 3<z<6
Variable Accretion Disks
Using variability to determine the dust content and test models of the intrinsic spectral index of quasar variations
BUFFALO Survey
Exploring six massive galaxy clusters to investigate dark matter, galaxy evolution, and the first galaxies
COSMOS-Web
A 200 hour JWST Cycle 1 Treasury program with NIRCam and MIRI to map the distant universe
The Cosmic Evolution Survey
The widest multi-wavelength galaxy survey with deep near-infrared coverage and ancillary observations
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 & Upcoming Talks
30 Talks & 8 Posters since 2015
Recent Publications
Total Refereed/Submitted: 38
As First Author: 5
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.
AAVSO’s Stellar Spectroscopy Database
AVSpec is the first spectral database of the American Association of Variable Star Observers.
Astronomy on Tap! Copenhagen
Astronomy on Tap – Copenhagen is a monthly event held at Huset, organised by astronomers in Copenhagen.
Observatory Stewardship
Crisp evening air. Clear skies. Maybe a telescope. Nothing refreshes me more than a night under the stars.
Popular Science Articles
I’ve had articles published in a number of online platforms, including Astrobites.
Public Lectures
An (incomplete) collection of lectures that I’ve given, organized by topic.
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
- john.weaver.astro@gmail.com
- +1 (860)204-1344
- University of Massachusetts Amherst LGRT-517J, Amherst, 01002