GA-NIFS: sRMS, a new method for disentangling resolved and unresolved emission in integral field spectroscopy. Application to distant quasars

@misc{perna2026ganifs,
  title = {{GA-NIFS: sRMS, a new method for disentangling resolved and unresolved emission in integral field spectroscopy. Application to distant quasars}},
  author = {Michele Perna and Santiago Arribas and Carlota Prieto-Jiménez and Isabella Lamperti and Lorenzo Ulivi and Hannah Übler and Giovanni Cresci and Bruno Rodríguez Del Pino and Torsten Böker and Andrew J. Bunker and Stéphane Charlot and Roberto Maiolino and Chris J. Willott and Ivan Delvecchio and Elena Bertola and Madeline A. Marshall and Eleonora Parlanti and Pablo G. Pérez-González and Giacomo Venturi and Sandra Zamora and Filippo Mannucci and Quirino D'Amato and Alessandra De Rosa and Ismael García-Bernete and Alessandro Marconi and Miguel Pereira-Santaella and Fabio Rigamonti and Martina Scialpi and Paola Severgnini and Cristian Vignali and Maria Vittoria Zanchettin},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2609.37625},
  eprint = {2609.37625},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.37625},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - GA-NIFS: sRMS, a new method for disentangling resolved and unresolved emission in integral field spectroscopy. Application to distant quasars
AU  - Michele Perna
AU  - Santiago Arribas
AU  - Carlota Prieto-Jiménez
AU  - Isabella Lamperti
AU  - Lorenzo Ulivi
AU  - Hannah Übler
AU  - Giovanni Cresci
AU  - Bruno Rodríguez Del Pino
AU  - Torsten Böker
AU  - Andrew J. Bunker
AU  - Stéphane Charlot
AU  - Roberto Maiolino
AU  - Chris J. Willott
AU  - Ivan Delvecchio
AU  - Elena Bertola
AU  - Madeline A. Marshall
AU  - Eleonora Parlanti
AU  - Pablo G. Pérez-González
AU  - Giacomo Venturi
AU  - Sandra Zamora
AU  - Filippo Mannucci
AU  - Quirino D'Amato
AU  - Alessandra De Rosa
AU  - Ismael García-Bernete
AU  - Alessandro Marconi
AU  - Miguel Pereira-Santaella
AU  - Fabio Rigamonti
AU  - Martina Scialpi
AU  - Paola Severgnini
AU  - Cristian Vignali
AU  - Maria Vittoria Zanchettin
PY  - 2026
DA  - 2026/10/10
PB  - arXiv
DO  - 10.48550/arxiv.2609.37625
UR  - https://arxiv.org/abs/2609.37625
AB  - The interpretation of AGN emission-line profiles in type1 AGN is often complicated by the dominance of bright, spatially unresolved nuclear continuum and broad-line region (BLR) emission over narrower and blended components from the narrow-line region (NLR) and the host galaxy. This remains challenging even with integral-field spectroscopy (IFS), as the relevant spatial variations can occur on scales smaller than the angular resolution, particularly in the compact host of distant AGN. We introduce the spatial root-mean-square (sRMS) technique, a new approach to analyse single-epoch IFS that uses the spatial variance of spectra extracted from partially overlapping apertures to isolate off-nuclear emission of high-z BL-AGN, and investigate whether the resulting kinematic information can improve the decomposition of their integrated spectra. We construct sRMS spectra from ensembles of overlapping apertures centred on the unresolved nucleus. Emission that is spatially invariant on the scales probed by the apertures is consequently suppressed, whereas spatially varying emission is retained. We apply the procedure to JWST/NIRSpec data of two z~6.5 QSOs. We model the resulting sRMS spectra with multiple Gaussian components to determine the kinematics of the spatially varying emission, and use these kinematic constraints to model the integrated spectra. The sRMS technique identifies spatially varying narrow-line emission on scales up to ~5x smaller than the NIRSpec PSF and provides robust constraints on the kinematics of individual kinematic components. Imposing these kinematic constraints on the integrated-spectrum fit reduces significantly the degeneracy of multi-component decompositions. Simulations further demonstrate the potential of the method to detect spatially offset BLR emission from close dual BL-AGN, down to projected separations of ~200 pc at z~6.5 for a BLR flux ratio of ~10.
ER  -