Copertina

Salvato in:
Dettagli Bibliografici
Autori principali: Pérez-González, Pablo G., Barro, Guillermo, Carniani, Stefano, D'Eugenio, Francesco, Rieke, George H., Tripodi, Roberta, Bunker, Andrew J., Ji, Xihan, Marques-Chaves, Rui, Schaerer, Daniel, Venturi, Giacomo, Arévalo-González, Flor, Arribas, Santiago, Rinaldi, Pierluigi, Del Pino, Bruno Rodríguez, Witstok, Joris, Bhatawdekar, Rachana, Boogaard, Leindert A., Charlot, Stephane, Chevallard, Jacopo, Costantin, Luca, Curti, Mirko, Curtis-Lake, Emma, Daddi, Emanuele, Davis, Kelcey, Dickinson, Mark, Donnan, Callum T., Donnan, Fergus R., Dunlop, James S., Eisenstein, Daniel J., Ferguson, Henry C., Aranda, Román Fernández, Finkelstein, Steven L., Fujimoto, Seiji, Gandolfi, Giovanni, Giavalisco, Mauro, Grogin, Norman A., Hamed, Mahmoud, Hirschmann, Michaela, Kartaltepe, Jeyhan S., Kocevski, Dale D., Koekemoer, Anton M., Leung, Gene C. K., Lofaro, Cristina M., Lucas, Ray A., McLeod, Derek J., Melinder, Jens, Östlin, Goran, Papovich, Casey, Pentericci, Laura, Pérez-Díaz, Borja, Rieke, Marcia, Scholtz, Jan, Somerville, Rachel S., Stanton, Thomas M., Stevenson, Struan D., Shivaei, Irene, Tacchella, Sandro, Trump, Jonathan R., Übler, Hannah, Wang, Xin, Williams, Christina C., Willmer, Christopher N. A., Yung, L. Y. Aaron, Zhu, Yongda
Natura: Preprint
Pubblicazione: 2026
Soggetti:
Astrophysics of Galaxies
Accesso online:https://arxiv.org/abs/2602.20247
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
Sommario:
  • We compile JWST/NIRSpec prism and MIRI data for 249 Little Red Dots (LRDs) at 2.3<z<9.3, forming a representative spectroscopic subset of NIRCam-selected LRDs. We derive a median stacked spectrum covering rest-frame 0.09-1.2 $μ$m, with MIRI photometry extending the spectral energy distribution to 4 $μ$m. Four additional stacks for subsamples defined by optical-to-UV luminosity ratios show that LRDs form a heterogeneous population spanning diverse continuum slopes and line properties. Assuming LRDs host super-massive black holes (BHs) surrounded by dense gas clouds, and stars accompany this core, we infer masses of $M_{BH}\sim10^{6.0-6.5}$ M$_\odot$ and $M_\bigstar\sim10^{8.3}$ M$_\odot$, corresponding to BH-to-stellar mass ratios of 1-2%. The stacks show ubiquitous UV and optical FeII emission, indicating a direct view of the broad-line region and high (but sub-Eddington) accretion ($λ_{Edd}=0.6\pm0.2$). We find a significant stellar contribution in the far-UV, reaching $\sim80$% in the bluest systems. Possible Wolf-Rayet features (HeII$λ$4687, nitrogen lines) are identified, tracing a young (3-7 Myr) compact starburst event. We also detect strong Balmer breaks and atypical Balmer, Paschen, [OIII], and optical and near-infrared HeI line ratios, and an absorption at $\sim4550$ Angstrom (probably linked to FeII), all consistent with radiative-transfer effects in high-density gas with warm temperatures (4000-7000 K). We find a diversity of LRD flavors modulated by the luminosity ratio between between a short ($\lesssim20$ Myr) and intense phase of BH activity, the most extreme stage lasting $\sim3-7$ Myr, characterized by near-Eddington-limit radiation, and a nuclear and compact starburst dominated by massive stars (even super-massive, $\mathrm{M}_\mathrm{SMS}\sim10^{5}$ M$_\odot$), all embedded in dense gas with modest dust content producing a variety of optical depths.

Documenti analoghi