Examinando por Autor "Bunker, Andrew J."

Mostrando 1 - 3 de 3

Acceso Abierto
A fast-rotator post-starburst galaxy quenched by supermassive black-hole feedback at z = 3
(Springer Nature, 2024-09-16) D’Eugenio, Francesco; Pérez-González, Pablo G., E. M.; Maiolino, Roberto; Scholtz, Jan; Perna, Michele; Circosta, Chiara; Übler, Hannah; Arribas, Santiago; Böker, Torsten; Bunker, Andrew J.; Carniani, Stefano; Charlot, Stephane; Chevallard, Jacopo; Cresci, Giovanni; Curtis-Lake, Emma; Jones, Gareth C.; Kumari, Nimisha; Lamperti, Isabella; Looser, Tobias J.; Parlanti, Eleonora; Rix, Hans Walter; Robertson, Brant; Rodriguez Del Pino, Bruno; Tacchella, Sandro; Venturi, Giacomo; Willott, Chris J.; European Research Council (ERC); Ministerio de Ciencia e Innovación (MICINN); Comunidad De Madrid; Agencia Estatal de Investigación (España); Istituto Nazionale di Astrofisica (INAF); Arizona State University (ASU); State University of Santa Cruz (UESC); National Science Foundation (NSF)
The most massive galaxies in the Universe stopped forming stars due to the time-integrated feedback from central supermassive black holes (SMBHs). However, the exact quenching mechanism is not yet understood, because local massive galaxies were quenched billions of years ago. Here we present JWST/NIRSpec integral-field spectroscopy observations of GS-10578, a massive, quiescent galaxy at redshift z = 3.064 ± 0.002. From its spectrum, we measure a stellar mass M⋆ = 1.6 ± 0.2 × 1011 M⊙ and a dynamical mass Mdyn = 2.0 ± 0.5 × 1011 M⊙. Half of its stellar mass formed at z = 3.7–4.6, and the system is now quiescent, with a current star-formation rate of less than 19 M⊙ yr−1. We detect ionized- and neutral-gas outflows traced by [O iii] emission and Na i absorption, with mass outflow rates 0.14–2.9 and 30–100 M⊙ yr−1, respectively. Outflow velocities reach vout ≈ 1,000 km s−1, comparable to the galaxy escape velocity. GS-10578 hosts an active galactic nucleus, evidence that these outflows are due to SMBH feedback. The neutral outflow rate is higher than the star-formation rate. Hence, this is direct evidence for ejective SMBH feedback, with a mass loading capable of interrupting star formation by rapidly removing its fuel. Stellar kinematics show ordered rotation, with spin parameter λRe=0.62±0.07, meaning GS-10578 is rotation-supported. This study presents direct evidence for ejective active galactic nucleus feedback in a massive, recently quenched galaxy, thus helping to clarify how SMBHs quench their hosts. The high value of λRe implies that quenching can occur without destroying the stellar disk.
Restringido
Accelerated quenching and chemical enhancement of massive galaxies in a z ≈ 4 gas-rich halo
(Nature Astronomy, 2025-07-21) Pérez-González, Pablo G.; D'Eugenio, Francesco; Rodriguez Del Pino, Bruno; Perna, Michele; Übler, Hannah; Maiolino, Roberto; Arribas, Santiago; Cresci, Giovanni; Lamperti, Isabella; Bunker, Andrew J.; Carniani, Stefano; Willott, Chris J.; Böker, Torsten; Parlanti, Eleonora; Scholtz, Jan; Venturi, Giacomo; Barro, Guillermo; Costantin, Luca; Martin-Navarro, Ignacio; Dunlop, James S.; Magee, Daniel; Ministerio de Ciencia e Innovación (MICINN); Agencia Estatal de Investigación (España); European Commission; Science and Technology Facilities Council (STFC); European Research Council (ERC); Istituto Nazionale di Astrofisica (INAF); Fundación La Caixa
Stars in galaxies form when baryons radiatively cool down and fall into gravitational wells whose mass is dominated by dark matter. Eventually, star formation quenches as gas is depleted and/or perturbed by feedback processes, no longer being able to collapse and condense. We report the first spatially resolved spectroscopic observations, using the JWST/NIRSpec IFU, of a massive, completely quiescent galaxy (Jekyll) and its neighborhood at $z=3.714$, when the Universe age was 10% of today's. Jekyll resides in a massive dark matter halo (with mass M$_\mathrm{DM}>10^{12}$ M$_\odot$) and forms a galaxy pair with Hyde, which shows very intense dust-enshrouded star formation (star formation rate $\sim300$ M$_\odot$yr$^{-1}$). We find large amounts of kinematically perturbed ionized and neutral gas in the circumgalactic medium around the pair. Despite this large gas reservoir, Jekyll, which formed $10^{11}$ M$_\odot$ in stars and chemically enriched early (first billion years of the Universe) and quickly (200-300 Myr), has remained quiescent for over 500 Myr. The properties of the gas found around the two galaxies are consistent with intense, AGN-induced photoionization, or intense shocks. However, with the current data no obscured or unobscured AGN is detected in the central galaxy (Jekyll) nor in the very active and dust rich star-forming galaxy (Hyde).
Acceso Abierto
Molecular gas stratification and disturbed kinematics in the Seyfert galaxy MCG-05-23-16 revealed by JWST and ALMA
(EDP Sciences, 2025-01-15) Esparza Arredondo, D., S.; Ramos Almeida, Cristina; Audibert, A.; Pereira Santaella, Miguel; García Bernete, I.; García-Burillo, Santiago, S.; Shimizu, T.; Davies, R.; Hermosa Muñoz, Laura; Alonso-Herrero, Almudena; Combes, Francoise; Speranza, G.; Zhang, Lulu; Campbell, Stephanie; Bellocchi, Enrica; Bunker, Andrew J.; Díaz Santos, T.; García Lorenzo, B.; González Martín, O.; Hicks, Erin K. S.; Labiano, Alvaro; Levenson, Nancy A.; Ricci, C.; Rosario, D.; Hönig, Sebastian; Packham, Christopher, C.; Stalevski, Marko; Fuller, L.; Izumi, T.; López Rodríguez, Enrique, E.; Rigopoulou, Dimitra; Rouan, D.; Ward, Martin; European Research Council (ERC); Comunidad de Madrid; Agencia Estatal de Investigación (España); Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT); Space Telescope Science Institute (US); Hellenic Foundation for Research and Innovation; Agencia Nacional de Investigación y Desarrollo (Chile)
Understanding the processes that drive the morphology and kinematics of molecular gas in galaxies is crucial for comprehending star formation and, ultimately, galaxy evolution. Using data from the Galactic Activity, Torus and Outflow Survey (GATOS) obtained with the James Webb Space Telescope (JWST) and the archival data from the Atacama Large Millimeter/submillimeter Array (ALMA), we study the behavior of the warm molecular gas at temperatures of hundreds of Kelvin and the cold molecular gas at tens of Kelvin in the galaxy MCG−05−23−16, which hosts an active galactic nucleus (AGN). Hubble Space Telescope (HST) images of this spheroidal galaxy, classified in the optical as S0, show a dust lane resembling a nuclear spiral and a surrounding ring. These features are also detected in CO(2−1) and H2, and their morphologies and kinematics are consistent with rotation plus local inward gas motions along the kinematic minor axis in the presence of a nuclear bar. The H2 transitions 0-0 S(3), 0-0 S(4), and 0-0 S(5), which trace warmer and more excited gas, show more disrupted kinematics than 0-0 S(1) and 0-0 S(2), including clumps of high velocity dispersion (of up to ∼160 km s−1), in regions devoid of CO(2−1). The kinematics of one of these clumps, located ∼350 pc westward of the nucleus, are consistent with outflowing gas, possibly driven by localized star formation traced by polycyclic aromatic hydrocarbon emission at 11.3 μm. Overall, we observe a stratification of the molecular gas, with the colder gas located in the nuclear spiral, ring, and connecting arms, and most of the warmer gas with a higher velocity dispersion filling the inter-arm space. The compact jet, approximately 200 pc in size, detected with Very Large Array (VLA) observations, does not appear to significantly affect the distribution and kinematics of the molecular gas, possibly due to its limited intersection with the molecular gas disk.