Priscilla Holguin Luna

Profile picture of Priscilla Holguin Luna



I am interested in the multiphase gas (intracluster and circumgalactic) and stellar populations in the outskirts of galaxy clusters. My current research at NMSU with Dr. Joe Burchett involves studying this elusive region using different methods:

  • quasar absorption line spectroscopy
  • spectroscopic stellar population modeling
  • large volume cosmological simulations

Quasar absorption line spectroscopy

This method of observation involves using a quasar as a background light source to study diffuse gas, detected via absorption, between the observer and the quasar. My work is in the UV, using data from the Cosmic Origins Spectrograph aboard the Hubble Space Telescope. I analyze quasar spectra to identify absorption associated with galaxy clusters in the foreground of the QSO. The two projects I’m currently working on that make use this method are a statistical analysis of H I and O VI absorbers in ~30 cluster-quasar papers (paper submittal expected late 2023), and a cycle 31 HST program (PID 17478) focused on probing the nearby Fornax cluster with 8 quasars (paper expected late 2024 or early 2025).

Spectroscopic stellar population modeling

I have been analyzing stellar population parameters (age, metallicity, SFH) of cluster member galaxies in the eROSITA Final Equatorial Depth Survey (eFEDS) in context of the host cluster’s X-ray properties. We are leveraging archival spectra of cluster members from surveys like SDSS and GAMA, as well as proprietary SDSS-V data for the spectroscopic follow-up of the eFEDS field. Our sample extends to ~5 R200 to include blue, star-forming galaxies in the outskirts of clusters, and we are deriving SFR, metallicity, and age through spectral fitting with pPXF to analyze stellar populations in context of host cluster X-ray properties like luminosity, temperature, and radii. This work is ongoing, and we expect to submit a paper in mid – late 2024.

Large volume cosmological simulations

Disentangling the relative contributions of different quenching mechanisms is difficult to do in the cluster environment. One such mechanism that might contribute to quenching is the outer accretion shock, as neutral gas that encounters it is shock-heated by the high entropy gas. I am tracking satellites around 12 galaxy clusters in the TNG100 simulation that encounter this shock front to examine what happens to the gas in their halo, the circumgalactic medium (CGM). We theorize the shock front can work in tandem with other quenching mechanisms to cease star formation through things like directly stripping or disturbing gas in the CGM, or compressing gas and triggering black hole feedback or a burst of star formation. I am currently in the advanced stages of this analysis and we expect to submit a paper in early 2024.


Meetings Attended

  • A Journey Through Galactic Environments: from the halo assembly bias to the satellite quenching, 2023 – poster
  • SDSS–V Collaboration Meeting, 2023
  • Wide Field Spectroscopy vs. Galaxy Formation Theory workshop, 2023
  • What Matter(s) Around Galaxies, 2022 – talk
  • Galaxy Clusters 2022: Challenging our Cosmological Perspectives (STScI Spring Symposium), 2022 – talk
  • Galaxy Cluster Formation II workshop, 2021 – poster
  • 240th AAS Meeting, talk
  • 233rd AAS Meeting, poster – Chambliss Astronomy Achievement Student Award Recipient