MAUNA: Multiphase Analysis of (U)LIRG Nuclear Activity

Tracing Gas, Fueling, and Feedback in Merging Galaxies

Galaxies are made of stars, gas, and black holes, and the interplay between these components determines how a galaxy grows over time. Stars and black holes can change the chemical content of the gas reservoir and/or eject it entirely from the galaxy through winds — an outcome particularly prevalent in interacting galaxy systems that can shut down future generations of star formation. MAUNA leverages new Keck and JWST integral-field spectroscopic observations to study the hot ionized and warm molecular gas phases in a representative sample of galaxy mergers, building a holistic picture of gas dynamics from the dusty nuclear cores out to the circumgalactic medium.

MAUNA Team

Vivian U (PI)
Caltech/IPAC
Justin Kader
Postdoc, Caltech/IPAC
Marina Bianchin
Postdoc, IAC
Raymond Remigio
Grad Student, UC Irvine
Paul Lynam
Staff Astronomer, Lick Observatory
Jorge Moreno
Faculty, Pomona College
Aaron Barth
Faculty, UC Irvine
Anne Medling
Faculty, University of Toledo
Loreto Barcos Muñoz
Associate Scientist, NRAO / NAASC
Gabriela Canalizo
Faculty, UC Riverside
Jeff Rich
Staff Astronomer, Carnegie Observatories
Phil Hopkins
Faculty, Caltech

A Holistic View of Gas Fueling and Feedback

MAUNA uses new Keck and JWST integral-field spectroscopic observations to trace how gas moves through the galactic ecosystem in a representative sample of merging galaxies, enabling a detailed, multiphase understanding of how mergers regulate their own star formation.

Multiphase Gas Across the Merger

Interacting galaxy systems are especially prone to ejecting their gas reservoirs through winds, quenching future star formation. MAUNA studies the hot ionized and warm molecular gas phases together for the same sample of galaxy mergers, measuring outflowing gas masses and energetics and comparing them against predictions from the latest feedback models across the full temperature–density regime — from the dusty nuclear cores out to the circumgalactic medium.

Broader Impacts: Training the Next Generation of Observers

MAUNA also supports the Observational Astronomy Workshop at Lick Observatory, expanding graduate student participation and introducing a new science communication module to enrich the education and professional development of a diverse range of students.

Science Result Highlights

Publication List

  1. Kader, J.A., U, V., Barcos-Muñoz, L., Bianchin, M., Song, Y., Linden, S.T., Canalizo, G., Aravindan, A., Privon, G.C., Díaz-Santos, T., Hayward, C., Malkan, M.A., et al. 2026, "A precessing jet from an active galactic nucleus drives gas outflow from a disk galaxy", Science, 391 (DOI)
  2. Bennert, V.N., Winkel, N., Treu, T., Ding, X., U, V., Remigio, R.P., Barth, A.J., Malkan, M.A., Villafaña, L., Allen, S., Johnson, E., Contreras, S., & Kim, M. 2026, "The Host Galaxies of Active Galactic Nuclei with Direct Black Hole Mass Measurements", ApJ, 1000 (DOI)
  3. Gao, T., U, V., Auge, C.W., Song, Y., Linden, S.T., Iwasawa, K., Peca, A., Privon, G.C., Sanders, D.B., Torres-Albà, N., Barcos-Muñoz, L., Agostino, J., & Medling, A.M. 2025, "Nuclear Spectral Energy Distributions of Luminous Infrared Galaxies", ApJ, 988 (DOI)
  4. Remigio, R.P., U, V., Barth, A.J., Winkel, N., Bennert, V.N., Treu, T., Malkan, M.A., Contreras, S., Williams, P.R., Runco, J.N., & Hunt, L. 2025, "Spatially Resolved [O III] Emission Line Kinematics of Reverberation-mapped Active Galactic Nuclei with the Keck Cosmic Web Imager", ApJ, 992 (DOI)
  5. Kader, J.A., U, V., Rich, J.A., Bianchin, M., Linden, S.T., Medling, A.M., Diaz-Santos, T., Privon, G.C., McGurk, R., Armus, L., Barcos-Muñoz, L., Canalizo, G., Charmandaris, V., et al. 2025, "Shockingly Effective: Cluster Winds as Engines of Feedback in Starburst Galaxy VV 114", ApJ, 988 (DOI)
  6. Nagarajan-Swenson, J., Privon, G.C., Evans, A.S., Barcos-Muñoz, L., Ricci, C., Medling, A.M., U, V., Saravia, A., Green, K.N., Johnstone, M., & Meza, G.A. 2025, "The Relationship Between Eddington Ratio and Column Density in U/LIRG AGN", RNAAS, 9 (DOI)

Additional papers from the collaboration are in preparation and will be listed here upon submission.

Contact Us

Interested in learning more about MAUNA or collaborating with us? Get in touch!
Vivian U can be reached at vivianu [at] ipac [dot] caltech [dot] edu.

This work is supported by NSF Award AST-2536603.