{
  "abstract": "The galaxy--electron cross-power spectrum $P_{ge}(k)$ measures the small-scale distribution of gas around galaxies, the quantity reshaped by feedback. We measure $P_{ge}$ from the kinetic Sunyaev--Zel'dovich (kSZ) signal of the photometric DESI Legacy Imaging Surveys luminous red galaxies, cross-correlating a velocity-weighted galaxy momentum template with the CMB temperature from ACT DR6 and, for the first time, SPT-3G. The absolute normalization of the cross-spectrum is fixed by a surrogate-field Monte Carlo that propagates the survey mask, lightcone evolution, and photometric-redshift weights, converting the measured pseudo-spectrum into $P_{ge}(k)$ in physical units. We detect $P_{ge}$ at $11.7σ$ with ACT and $8.4σ$ with SPT-3G, and at $12.3σ$ combining SPT-3G with the ACT northern cap, which it does not overlap. The two surveys have independent optics, beams, filtering and noise and share about two thirds of the SPT-3G galaxies; their amplitudes agree channel by channel, the largest difference being $0.7σ$. All $26$ null tests on the adopted night maps are consistent with zero signal, among them the six ACT frequency differences, the three SPT-3G frequency differences, and the four ACT cap differences of the main selection. Turning the amplitude into a gas fraction requires the host halo masses of the sample, which the cross-spectrum does not itself measure; taking them from its measured number density and from a published CMB-lensing calibration of the same galaxies, the gas within the virial radius is $25$--$33\\%$ of the cosmic baryon budget of the halo.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.17676",
  "author_total": 1,
  "authors": [
    {
      "name": "Selim C. Hotinli"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3890sw5pjgtd1.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.17676",
  "fulltext_url": null,
  "id": "3890sw5pjgtd1",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.17676",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.CO"
    ],
    [
      "openalex",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W7213501290",
  "pdf_url": "https://arxiv.org/pdf/2609.17676",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-15",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/3890sw5pjgtd1.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:22:19Z",
      "native_id": "2609.17676",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.17676"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    }
  ],
  "title": "The galaxy-electron cross-spectrum with ACT, SPT-3G and DESILS LRGs",
  "title_text": "The galaxy-electron cross-spectrum with ACT, SPT-3G and DESILS LRGs",
  "type": "preprint",
  "updated_at": "2026-10-30T12:22:19Z",
  "url": "https://research.draconitic.com/paper/3890sw5pjgtd1",
  "venue": "arXiv",
  "versions": []
}